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Background: The identification of tumor deposits (TD) currently plays a limited role in staging for colorectal cancer (CRC) aside from N1c lymph node designation. The objective of this study was to determine the prognostic impact, beyond American Joint Committee on Cancer N1c designation, of TDs among patients with primary CRC., Methods: Patients who had resected stage I-III primary CRC diagnosed between 2010 and 2019 were identified from the National Cancer Institute's Surveillance, Epidemiology, and End Results database. Cancer-specific survival (CSS) stratified by TD status and lymph node (N) status was calculated using the Kaplan-Meier method and multivariable Cox proportional hazards regression analyses., Results: In total, 147,783 patients with primary CRC were identified. TDs were present in 15,444 patients (10.5%). The presence of TDs was significantly associated with adverse tumor characteristics, including advanced pathologic stage, nodal status, and metastasis status. The presence of TDs was associated with worse CSS (hazard ratio [HR], 3.12; 95% confidence interval [CI], 3.02-3.22), as it was for each given N category (e.g., N2a and TD-negative [HR, 2.50; 95% CI, 2.37-2.64] vs. N2a and TD-positive [HR, 3.75; 95% CI, 3.49-4.03]). The presence of multiple TDs was also associated with decreased CSS for each given N category compared with a single TD (e.g. N2a with one TD [HR, 3.09; 95% CI, 2.65-3.61] vs. N2a with two or more TDs [HR, 4.32; 95% CI, 3.87-4.82])., Conclusions: TDs were identified as an independent predictor of a worse outcome in patients with CRC. The presence of TDs confers distinctly different CSS and provides important prognostic information among patients with CRC and warrants further investigation as a unique variable in future iterations of CRC staging., (© 2024 American Cancer Society.)

Introduction: Inadequate treatment of enlarged lateral lymph nodes (LLNs) in rectal cancer patients is associated with an increased lateral local recurrence (LLR) risk, despite neoadjuvant treatment and total mesorectal excision (TME) surgery. There is a promising role for LLN dissection (LLND) to lower this risk, but this challenging procedure requires appropriate training. This study protocol describes a prospective evaluation of oncological outcomes after standardised treatment based on multidisciplinary training, thereby aiming for a 50% reduction in LLR rate., Methods and Analysis: A prospective registration study will be opened in hospitals in which the involved multidisciplinary team members (radiologists, radiation oncologists, surgeons and pathologists) have received dedicated training to enhance knowledge and awareness of LLNs and in which standardised treatment including LLND has been implemented. Patients with rectal cancer and at least one enlarged LLN (short-axis ≥7.0 mm), or intermediate LLN (short-axis 5.0-6.9 mm) with at least one malignant feature on primary MRI, evaluated by a trained radiologist, are eligible. Patients will undergo neoadjuvant treatment by trained radiation oncologists, followed by TME surgery in combination with a minimally invasive, nerve-sparing LLND performed by trained surgeons. LLND specimens are evaluated by trained pathologists or grossing assistants. The primary outcome is LLR rate 3 years postoperatively. Secondary outcomes are morbidity, disease-free survival, overall survival and quality of life. To demonstrate a significant reduction in LLR rate from 13% (based on historical control data) to 6% after optimised treatment, 200 patients with enlarged LLNs are required., Ethics and Dissemination: The medical ethics board of the Vrije Universiteit Medical Centre (VUMC), the Netherlands, approved the study on 23 November 2022 (reference: 2021.0524). Participating centres must obtain local approval and participants are required to provide written informed consent. Results obtained from this study will be communicated via peer-reviewed medical journals and presentations at conferences., Trail Registration Number: NCT04486131, 24 July 2020, https://clinicaltrials.gov/ct2/show/NCT04486131., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Rectal MRI provides a detailed depiction of pelvic anatomy; specifically, the relationship of the tumor to key anatomic structures, including the mesorectal fascia, anterior peritoneal reflection, and sphincter complex. However, anatomic inconsistencies, pitfalls, and confusion exist, which can have a strong impact on interpretation and treatment. These areas of confusion include the definition of the rectum itself, specifically differentiation of the rectum from the anal canal and the sigmoid colon, and delineation of the high versus low rectum. Other areas of confusion include the relative locations of the mesorectal fascia and peritoneum and their significance in staging and treatment, the difference between the mesorectal fascia and circumferential resection margin, involvement of the sphincter complex, and evaluation of lateral pelvic lymph nodes. The impact of these anatomic inconsistencies and sources of confusion is significant, given the importance of MRI in depicting the anatomic relationship of the tumor to critical pelvic structures, to triage surgical resection and neoadjuvant chemoradiotherapy with the goal of minimizing local recurrence. Evolving treatment paradigms also place MRI central in management of rectal cancer. © RSNA, 2024.

The pathogenesis of duodenal tumors in the inherited tumor syndromes familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP) is poorly understood. This study aimed to identify genes that are significantly mutated in these tumors and to explore the effects of these mutations. Whole exome and whole transcriptome sequencing identified recurrent somatic coding variants of phosphatidylinositol N-acetylglucosaminyltransferase subunit A (PIGA) in 19/70 (27%) FAP and MAP duodenal adenomas, and further confirmed the established driver roles for APC and KRAS. PIGA catalyzes the first step in glycosylphosphatidylinositol (GPI) anchor biosynthesis. Flow cytometry of PIGA-mutant adenoma-derived and CRISPR-edited duodenal organoids confirmed loss of GPI anchors in duodenal epithelial cells and transcriptional profiling of duodenal adenomas revealed transcriptional signatures associated with loss of PIGA., Implications: PIGA somatic mutation in duodenal tumors from patients with FAP and MAP and loss of membrane GPI-anchors may present new opportunities for understanding and intervention in duodenal tumorigenesis., (©2024 The Authors; Published by the American Association for Cancer Research.)

Purpose: Appendiceal adenocarcinoma (AA) remains an orphan disease with limited treatment options for patients unable to undergo surgical resection. Evidence supporting the efficacy of combined VEGF and PD-1 inhibition in other tumor types provided a compelling rationale for investigating this combination in AA, where immune checkpoint inhibitors have not been explored previously., Experimental Design: We conducted a prospective, single-arm phase II study evaluating efficacy and safety of atezolizumab in conjunction with bevacizumab (Atezo+Bev) in advanced, unresectable AA., Results: Patients treated with the Atezo+Bev combination had 100% disease control rate (1 partial response, 15 stable disease) with progression-free survival (PFS) of 18.3 months and overall survival not-yet-reached with median duration of follow-up of 40 months. These survival intervals were significantly longer relative to a clinically and molecularly matched synthetic control cohort treated with cytotoxic chemotherapy designed for colorectal cancer (PFS of 4.4 months, P = 0.041)., Conclusions: In light of recent data demonstrating a lack of efficacy of 5-fluorouracil-based chemotherapy, Atezo+Bev is a promising treatment option for patients with low-grade unresectable AA; further study is warranted., Significance: AA remains an orphan disease with limited systemic therapy options for patients who are not candidates for surgical resection. These data suggest activity from combined VEGF and PD-L1 inhibition that warrants further study., (© 2024 The Authors; Published by the American Association for Cancer Research.)

Background & Aims: Lynch syndrome (LS) carriers develop mismatch repair-deficient neoplasia with high neoantigen (neoAg) rates. No detailed information on targetable neoAgs from LS precancers exists, which is crucial for vaccine development and immune-interception strategies. We report a focused somatic mutation and frameshift-neoAg landscape of microsatellite loci from colorectal polyps without malignant potential (PWOMP), precancers, and early-stage cancers in LS carriers., Methods: We generated paired whole-exome and transcriptomic sequencing data from 8 colorectal PWOMP, 41 precancers, 8 advanced precancers, and 12 early-stage cancers of 43 LS carriers. A computational pipeline was developed to predict, rank, and prioritize the top 100 detected mutated neoAgs that were validated in vitro using ELISpot and tetramer assays., Results: Mutation calling revealed >10 mut/Mb in 83% of cancers, 63% of advanced precancers, and 20% of precancers. Cancers displayed an average of 616 MHC-I neoAgs/sample, 294 in advanced precancers, and 107 in precancers. No neoAgs were detected in PWOMP. A total of 65% of our top 100 predicted neoAgs were immunogenic in vitro, and were present in 92% of cancers, 50% of advanced precancers, and 29% of precancers. We observed increased levels of naïve CD8 + and memory CD4 + T cells in mismatch repair-deficient cancers and precancers via transcriptomics analysis., Conclusions: Shared frameshift-neoAgs are generated within unstable microsatellite loci at initial stages of LS carcinogenesis and can induce T-cell responses, generating opportunities for vaccine development, targeting LS precancers and early-stage cancers., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Appendiceal adenocarcinoma (AA) is unique from other gastrointestinal malignancies in that it almost exclusively metastasizes to the peritoneal cavity. However, few studies have investigated the molecular interaction of the peritoneal microenvironment and AA. Here, we use a multi-omics approach with orthotopic and flank-implanted patient-derived xenografts (PDX) to study the effect of the peritoneal microenvironment on AA. AA tumors implanted in the peritoneal microenvironment tended to grow faster and displayed greater nuclear expression of Ki-67 relative to the same tumors implanted in the flank. Comparing the tumor-specific transcriptome (excluding stromal transcription), the peritoneal microenvironment relatively upregulated genes related to proliferation, including MKI67 and EXO1. Peritoneal tumors were also enriched for proliferative gene sets, including E2F and Myc Targets. Proteomic studies found a 2.5-fold increased ratio of active-to-inactive phosphoforms of the YAP oncoprotein in peritoneal tumors, indicating downregulation of Hippo signaling., Implications: The peritoneal microenvironment promotes growth of appendiceal tumors and expression of proliferative pathways in PDXs., (©2024 American Association for Cancer Research.)

Importance: Serum tumor markers carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and cancer antigen 125 (CA125) have been useful in the management of gastrointestinal and gynecological cancers; however, there is limited information regarding their utility in patients with appendiceal adenocarcinoma., Objective: To assess the association of serum tumor markers (CEA, CA19-9, and CA125) with clinical outcomes and pathologic and molecular features in patients with appendiceal adenocarcinoma., Design, Setting, and Participants: This is a retrospective cohort study at a single tertiary care comprehensive cancer center. The median (IQR) follow-up time was 52 (21-101) months. Software was used to query the MD Anderson internal patient database to identify patients with a diagnosis of appendiceal adenocarcinoma and at least 1 tumor marker measured at MD Anderson between March 2016 and May 2023. Data were analyzed from January to December 2023., Main Outcomes and Measures: Association of serum tumor markers with survival in patients with appendiceal adenocarcinoma. Cox proportional hazards regression analyses were also performed to assess associations between clinical factors (serum tumor marker levels, demographics, and patient and disease characteristics) and patient outcomes (overall survival)., Results: A total of 1338 patients with appendiceal adenocarcinoma were included, with a median (range) age at diagnosis of 56.5 (22.3-89.6) years. The majority of the patients had metastatic disease (1080 patients [80.7%]). CEA was elevated in 742 of the patients tested (56%), while CA19-9 and CA125 were elevated in 381 patients (34%) and 312 patients (27%), respectively. Individually, elevation of CEA, CA19-9, or CA125 were associated with worse 5-year survival; elevated vs normal was 81% vs 95% for CEA (hazard ratio [HR], 4.0; 95% CI, 2.9-5.6), 84% vs 92% for CA19-9 (HR, 2.2; 95% CI, 1.4-3.4), and 69% vs 93% for CA125 (HR, 4.6; 95% CI, 2.7-7.8) (P < .001 for all). Quantitative evaluation of tumor markers was associated with outcomes. Patients with highly elevated (top 10th percentile) CEA, CA19-9, or CA125 had markedly worse survival, with 5-year survival rates of 59% for CEA (HR, 9.8; 95% CI, 5.3-18.0), 64% for CA19-9 (HR, 6.0; 95% CI, 3.0-11.7), and 57% for CA125 (HR, 7.6; 95% CI, 3.5-16.5) (P < .001 for all). Although metastatic tumors had higher levels of all tumor markers, when restricting survival analysis to 1080 patients with metastatic disease, elevated CEA, CA19-9, or CA125 were all still associated worse survival (HR for CEA, 3.4; 95% CI, 2.5-4.8; P < .001; HR for CA19-9, 1.8; 95% CI, 1.2-2.7; P = .002; and HR for CA125, 3.9; 95% CI, 2.4-6.4; P < .001). Interestingly, tumor grade was not associated with CEA or CA19-9 level, while CA-125 was slightly higher in high-grade tumors relative to low-grade tumors (mean value, 18.3 vs 15.0; difference, 3.3; 95% CI, 0.9-3.7; P < .001). Multivariable analysis identified an incremental increase in the risk of death with an increase in the number of elevated tumor markers, with an 11-fold increased risk of death in patients with all 3 tumor markers elevated relative to those with none elevated. Somatic mutations in KRAS and GNAS were associated with significantly higher levels of CEA and CA19-9., Conclusions and Relevance: In this retrospective study of serum tumor markers in patients with appendiceal adenocarcinoma, CEA, CA19-9, and CA125 were associated with overall survival in appendiceal adenocarcinoma. Given their value, all 3 biomarkers should be included in the initial workup of patients with a diagnosis of appendiceal adenocarcinoma.

Introduction: Many patients with mucinous appendiceal adenocarcinoma experience peritoneal recurrence despite complete cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Prior work has demonstrated that repeat CRS/HIPEC can prolong survival in select patients. We sought to validate these findings using outcomes from a high-volume center., Patients and Methods: Patients with mucinous appendiceal adenocarcinoma who underwent CRS/HIPEC at MD Anderson Cancer Center between 2004 and 2021 were stratified by whether they underwent CRS/HIPEC for recurrent disease or as part of initial treatment. Only patients who underwent complete CRS/HIPEC were included. Initial and recurrent groups were compared., Results: Of 437 CRS/HIPECs performed for mucinous appendiceal adenocarcinoma, 50 (11.4%) were for recurrent disease. Patients who underwent CRS/HIPEC for recurrent disease were more often treated with an oxaliplatin or cisplatin perfusion (35%/44% recurrent vs. 4%/1% initial, p < 0.001), had a longer operative time (median 629 min recurrent vs. 511 min initial, p = 0.002), and had a lower median length of stay (10 days repeat vs. 13 days initial, p < 0.001). Thirty-day complication and 90-day mortality rates did not differ between groups. Both cohorts enjoyed comparable recurrence free survival (p = 0.82). Compared with patients with recurrence treated with systemic chemotherapy alone, this select cohort of patients undergoing repeat CRS/HIPEC enjoyed better overall survival (p < 0.001)., Conclusions: In appropriately selected patients with recurrent appendiceal mucinous adenocarcinoma, CRS/HIPEC can provide survival benefit equivalent to primary CRS/HIPEC and that may be superior to that conferred by systemic therapy alone in select patients. These patients should receive care at a high-volume center in the context of a multidisciplinary team., (© 2023. The Author(s).)

BACKGROUND Invasive cervical tumors are often seen in clinical practice. However, there are multiple structures within the pelvis, and invasion of the cervix from another site must be included in the differential diagnosis. In such cases, a multidisciplinary approach is needed to define the organ of tumor origin. Ensuring proper staging and histologic analysis are critical for optimal management. CASE REPORT We present a case of a 68-year-old woman who presented to her gynecologist with painless post-menopausal vaginal bleeding. She was diagnosed with a locally aggressive cervical adenocarcinoma, which was histologically confirmed by an in-office biopsy. She was referred to the gynecologic oncology service at a tertiary care hospital for definitive management, where a thorough clinical workup was performed. Physical exam revealed that the mass had invaded the anterior rectal wall. Through a multidisciplinary approach and a repeat biopsy, she was correctly diagnosed with an invasive rectal adenocarcinoma. She was treated with neoadjuvant chemoradiotherapy and underwent curative surgery. Had she been incorrectly treated as having a primary cervical adenocarcinoma, there would have been no role for surgery. The change in the organ of primary drastically altered the patient's management and outcome. She is currently undergoing surveillance with cross-sectional imaging. CONCLUSIONS Cervical masses originating from non-gynecologic organs can be difficult to differentiate on physical exam and histologic analysis. When a mass involves the rectum, an invasive primary rectal adenocarcinoma must be included in the differential. This will have a significant impact on patient management and ultimately on patient survival.

Objective: Frozen-section evaluation of the pancreatic margin is challenging. We aimed to determine interobserver variability among gastrointestinal pathologists for the assessment of frozen sections of pancreatic margins with marked chronic pancreatitis and to determine the challenging histological features in discrepant cases., Methods: We identified 45 patients who underwent pancreas resection for pancreatic ductal adenocarcinoma and showed marked chronic pancreatitis at pancreatic margin. Deidentified first levels of frozen-sections of the pancreatic margins from all cases were independently reviewed by 5 experienced gastrointestinal pathologists for the presence of carcinoma and/or high-grade dysplasia., Results: Interobserver agreement among pathologists was calculated as kappa coefficients ([Formula: see text]). A consensus diagnosis for discordant cases was obtained after group review and discussion. Interobserver agreement for adenocarcinoma diagnosis was 87%, and there was "substantial agreement" (Fleiss [Formula: see text]=0.78, P <0.01) and "almost perfect agreement" (Brennan-Prediger [Formula: see text]=0.86, P <0.01). Using the final diagnosis based on frozen and permanent sections as the gold standard and the concordant read of at least 3 of 5 pathologists for comparison, the diagnosis of adenocarcinoma was made in frozen-sections of pancreas margins, with accuracy 98%, sensitivity 83%, specificity 100%, negative predictive value 97%, positive predictive value 100%, false negative rate 9%, and false positive rate 0%., Conclusions: We showed excellent interobserver agreement among gastrointestinal pathologists for diagnosis of adenocarcinoma on frozen sections of pancreatic margins with marked chronic pancreatitis. Missed adenocarcinoma at the margin was mainly caused by freezing or cautery artifacts or by overlooking a tiny focus of perineural invasion in a background of marked chronic pancreatitis. The evaluation of deeper levels led to perfect agreement., (© 2023 by the Association of Clinical Scientists, Inc.)

The Society of Abdominal Radiology's Colorectal and Anal Cancer Disease-Focused Panel (DFP) first published a rectal cancer lexicon paper in 2019. Since that time, the DFP has published revised initial staging and restaging reporting templates, and a new SAR user guide to accompany the rectal MRI synoptic report (primary staging). This lexicon update summarizes interval developments, while conforming to the original lexicon 2019 format. Emphasis is placed on primary staging, treatment response, anatomic terminology, nodal staging, and the utility of specific sequences in the MRI protocol. A discussion of primary tumor staging reviews updates on tumor morphology and its clinical significance, T1 and T3 subclassifications and their clinical implications, T4a and T4b imaging findings/definitions, terminology updates on the use of MRF over CRM, and the conundrum of the external sphincter. A parallel section on treatment response reviews the clinical significance of near-complete response and introduces the lexicon of "regrowth" versus "recurrence". A review of relevant anatomy incorporates updated definitions and expert consensus of anatomic landmarks, including the NCCN's new definition of rectal upper margin and sigmoid take-off. A detailed review of nodal staging is also included, with attention to tumor location relative to the dentate line and locoregional lymph node designation, a new suggested size threshold for lateral lymph nodes and their indications for use, and imaging criteria used to differentiate tumor deposits from lymph nodes. Finally, new treatment terminologies such as organ preservation, TNT, TAMIS and watch-and-wait management are introduced. This 2023 version aims to serve as a concise set of up-to-date recommendations for radiologists, and discusses terminology, classification systems, MRI and clinical staging, and the evolving concepts in diagnosis and treatment of rectal cancer., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Objective: Lynch Syndrome (LS) carriers have a significantly increased risk of developing colorectal cancer (CRC) during their lifetimes. Further stratification of this patient population may help in identifying additional risk factors that predispose to colorectal carcinogenesis. In most LS patients CRC may arise from adenomas, although an alternative non-polypoid carcinogenesis pathway has been proposed for PMS2 carriers. Using data from our institutional LS cohort, our aim was to describe our current colorectal screening outcomes with a focus on the incidence of adenomas in the context of different MMR genotypes and patient demographics such as gender, race, and ethnicity., Design: We collected demographics, genetic, colonoscopy, and pathology results from a total of 163 LS carriers who obtained regular screening care at MD Anderson Cancer Center. Data were extracted from the electronic health records into a REDCap database for analysis. Logistic regressions were performed to measure the association between MMR variants and the likelihood of adenomas, advanced adenomas, and CRC. Then, we analyzed the cumulative incidences of these outcomes for the first 36 months following enrollment using Kaplan-Meier incidence curves, and Cox proportional hazard regressions., Results: On multivariate analysis, age (≥45 years old) was associated with an increased risk of developing adenomas ( P= 0.034). Patients with a prior or active cancer status were less likely to develop adenomas ( P =0.015), despite of the lack of association between surgical history with this outcome ( P =0.868). We found no statistically significant difference in likelihood of adenoma development between MLH1 and MSH2/EPCAM, MSH6, and PMS2 carriers. Moreover, we observed no statistically significant difference in the likelihood of advanced adenomas or CRC for any measured covariates. On Cox proportional hazard, compared to MLH1 carriers, the incidence of adenomas was highest among MSH2/EPCAM carriers during for the first 36-months of follow-up ( P <0.001). We observed a non-statistically significant trend for Hispanics having a higher and earlier cumulative incidence of adenomas compared to non-Hispanics ( P= 0.073). No MMR carrier was more likely to develop advanced adenomas. No difference in the incidence of CRC by MMR gene ( P= 0.198)., Conclusion: Screening recommendations for CRC in LS patients should be based on specific MMR variants and should also be tailored to consider patient demographics., Competing Interests: Dr. Vilar has a consulting or advisory role with Janssen Research and Development, Recursion Pharma, Guardant Health, and Tornado/Cambrian. He has received research support from Janssen Research and Development. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 del Carmen, Reyes-Uribe, Goyco, Evans, Bowen, Kinnison, Sepeda, Weber, Moskowitz, Mork, Thirumurthi, Lynch, Rodriguez-Bigas, Taggart, You and Vilar.)

Introduction: Appendiceal neoplasms have a propensity for peritoneal dissemination. The standard of care for select individuals is CRS/HIPEC. In the current 8 th AJCC Staging system, a finding of only intraperitoneal acellular mucin (M1a) is classified as Stage IVa. There is concern that the current AJCC system may over-stage patients., Methods: This was a single-institution retrospective review of 164 cases of mucinous appendiceal neoplasm. Patients undergoing CRS/HIPEC with M1a disease were compared to patients with peritoneal deposits containing tumor cells (well-differentiated adenocarcinoma; low-grade mucinous carcinoma peritonei-M1b,G1). Overall and recurrence-free survival were assessed., Results: Median age was 51 years, 70% were female, and 75% White. Sixty-four patients had M1a disease and 100 M1b,G1 disease. M1a disease had a lower median PCI score (11 vs. 20, p = .0001) and a higher rate of complete CRS (62% vs. 50%, p = .021). Median follow-up was 7.6 years (IQR 5.6-10.5 years). For M1a disease, there were no recurrences and only one patient died during the study interval. In comparison, for M1b disease, 66/100 (66%) recurred with a 5-year RFS of 40.5% (HR 8.0, 95% CI 4.9-15.1, p < .0001), and 31/100 (31%) died with a 5-year OS of 84.8% (HR 4.5, 95% CI 2.2-9.2, p < .0001)., Conclusions: Acellular mucin (M1a disease) after CRS/HIPEC for appendiceal neoplasm is associated with longer OS and RFS compared to M1b, G1 disease. Current AJCC staging does not accurately reflect the differing outcomes of these two patient populations. The presence of acellular mucin in the peritoneal cavity should not be perceived as a metastatic equivalent., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Objective: Lateral pelvic lymph node (LPLN) metastases are an important cause of preventable local failure in rectal cancer. The aim of this study was to evaluate clinical and oncological outcomes following magnetic resonance imaging (MRI)-directed surgical selection for lateral pelvic lymph node dissection (LPLND) after total neoadjuvant therapy (TNT)., Methods: A retrospective consecutive cohort analysis was performed of rectal cancer patients with enlarged LPLN on pretreatment MRI. Patients were categorized as LPLND or non-LPLND. The main outcomes were lateral local recurrence rate, perioperative and oncological outcomes and factors associated with decision making for LPLND., Results: A total of 158 patients with enlarged pretreatment LPLN and treated with TNT were identified. Median follow-up was 20 months (interquartile range 10-32). After multidisciplinary review, 88 patients (56.0%) underwent LPLND. Mean age was 53 (SD±12) years, and 54 (34.2%) were female. Total operative time (509 vs 429 minutes; P =0.003) was greater in the LPLND group, but median blood loss ( P =0.70) or rates of major morbidity (19.3% vs 17.0%) did not differ. LPLNs were pathologically positive in 34.1%. The 3-year lateral local recurrence rates (3.4% vs 4.6%; P =0.85) did not differ between groups. Patients with LPLNs demonstrating pretreatment heterogeneity and irregular margin (odds ratio, 3.82; 95% confidence interval: 1.65-8.82) or with short-axis ≥5 mm post-TNT (odds ratio 2.69; 95% confidence interval: 1.19-6.08) were more likely to undergo LPLND., Conclusions: For rectal cancer patients with evidence of LPLN metastasis, the appropriate selection of patients for LPLND can be facilitated by a multidisciplinary MRI-directed approach with no significant difference in perioperative or oncologic outcomes., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Knowing the sensitivity and specificity of tissue-specific immunohistochemical markers is crucial for accurate determination of the primary tumor site. PAX8 has been used as a diagnostic marker for carcinomas of the gynecologic tract, kidney, and thyroid gland, and CDX2 has been used as a marker of gastrointestinal carcinoma. Neither is considered a marker for breast carcinoma (BC). However, we have encountered BCs that express PAX8 or CDX2, some of which caused diagnostic confusion. We investigated the immunohistochemical staining frequency of PAX8 and CDX2 in BC. We identified 237 BCs for which PAX8 staining results were reported (102 primary and 135 metastatic BCs); seven primary and four metastatic BCs (4.6%) were positive for PAX8, with various intensities and staining patterns. CDX2 staining results were reported for 271 BCs (78 primary and 193 metastatic); four primary BCs and one metastatic BC (1.8%) were positive for CDX2, ranging from focal and weak to diffuse and strong. We also stained primary invasive BCs with PAX8 and CDX2 using tissue microarrays. None of the 332 PAX8-stained cases was positive, while one of 143 CDX2-stained cases was positive. Four PAX8-positive and three CDX2-positive cases were stained with TRPS1, and all were positive for TRPS1. In addition, we reviewed the literature for PAX8 and CDX2 expression in BCs and found 5.5% PAX8-positive BCs (90/1625) in 17 studies and 0.8% CDX-2 positive BCs (7/909) in 20 studies. PAX8 and CDX2 are infrequently expressed in BC by immunohistochemistry, and in rare cases, the staining can be strong and diffuse. Additional diagnostic markers are necessary and helpful in distinguishing breast from other primary origins., (Published by Elsevier Inc.)

Colorectal cancer (CRC) remains the third most common cancer in the US with 15% of cases displaying Microsatellite Instability (MSI) secondary to Lynch Syndrome (LS) or somatic hypermethylation of the MLH1 promoter. A cohort of rhesus macaques from our institution developed spontaneous mismatch repair deficient (MMRd) CRC with a notable fraction harboring a pathogenic germline mutation in MLH1 (c.1029C

Introduction: Rectal neuroendocrine carcinomas (rNECs) are poorly characterized and, given their aggressive nature, optimal management is not well-established. We therefore sought to describe clinicopathologic traits, treatment details, and survival patterns for patients with rNECs., Methods: Patients captured in the National Cancer Database (NCDB; 2004-2016) with rNECs managed with observation, chemotherapy, or proctectomy ± chemotherapy were considered for analysis., Results: The inclusion criteria were met by 777 patients. Mean age was 62.4 years, 45% were male, 80% were Caucasian, 40% presented with lymph nodes metastases, and 49% presented with distant metastases. Chemotherapy and surgical resection were administered in 72 and 19% of cases, respectively. Median overall survival (OS) was 0.83 years (1 year, 41%; 3 years, 13%; 5 years, 10%). During the study interval, 659 (85%) patients died, with a median follow-up of 0.79 years. On multivariable analysis, age ≥60 years, male sex, and distant metastases were associated with worse survival; surgical resection and administration of chemotherapy were associated with a reduced risk of death. Among non-metastatic patients treated with surgical resection, administration of chemotherapy was protective, while a positive lymph node ratio (LNR) ≥42% (median value) was associated with an increased risk of death. There was no difference in the number of examined lymph nodes between LNR cohorts., Conclusions: Patients with rNECs experience dismal survival outcomes, including those with non-metastatic disease treated with curative-intent surgical resection. Neoadjuvant therapy can serve as a useful biologic test, and surgical resection should be judiciously employed., (© 2021. Society of Surgical Oncology.)

Background: Patients with T4 colon adenocarcinomas have an increased risk of peritoneal metastases (PM) but the histopathologic risk factors for its development are not well-described., Objective: The purpose of this study was to determine factors associated with PM, time to recurrence, and survival after recurrence among patients with T4 colon cancer., Patients and Methods: Patients with pathologic T4 colon cancer who underwent curative resection from 2005 to 2017 were identified from a prospectively maintained institutional database and classified by recurrence pattern: (a) none - 68.8%; (b) peritoneal only - 7.9%; (c) peritoneal and extraperitoneal - 9.9%; and (d) extraperitoneal only - 13.2%. Associations between PM development and patient, primary tumor, and treatment factors were assessed., Results: Overall, 151 patients were analyzed, with a median follow-up of 66.2 months; 27 patients (18%) developed PM (Groups B and C) and 20 (13%) patients recurred at non-peritoneal sites only (Group D). Median time to developing metastases was shorter for Groups B and C compared with Group D (B and C: 13.7 months; D: 46.7 months; p = 0.022). Tumor deposits (TDs) and nodal stage were associated with PM (p < 0.05), and TDs (p = 0.048) and LVI (p = 0.015) were associated with additional extraperitoneal recurrence. Eleven (41%) patients with PM underwent salvage surgery, and median survival after recurrence was associated with the ability to undergo cytoreduction (risk ratio 0.20, confidence interval 0.06-0.70)., Conclusion: PM risk after resection of T4 colon cancer is independently associated with factors related to lymphatic spread, such as N stage and TDs. Well-selected patients can undergo cytoreduction with long-term survival. These findings support frequent postoperative surveillance and aggressive early intervention, including cytoreduction., (© 2022. Society of Surgical Oncology.)

Context.—: During the past 3 decades, numerous articles in the literature have offered terminology, diagnostic criteria, and consensus recommendations regarding the entity currently referred to by the World Health Organization as sessile serrated lesion. Given the many names and various, variably reproducible diagnostic criteria ascribed to sessile serrated lesion, confusion persists for many pathologists and gastroenterologists regarding the diagnosis. This distinction is important, as sessile serrated lesion can progress to malignancy, unlike its main differential diagnosis, hyperplastic polyp. Research studies have shed light on the characteristic architecture and morphology, immunohistochemical patterns, and molecular alterations of sessile serrated lesion, and multiple consensus meetings around the globe have developed their criteria and nomenclature, often clashing or mixing terms., Objective.—: To provide a narrative review from the entity's early description to our current understanding., Data Sources.—: The existing scientific and clinical literature, published texts, medical society recommendations, and specialty consensus guidelines., Conclusions.—: The current World Health Organization criteria are a distillation of this scientific process, but terminology is still a point of contention worldwide.

Familial adenomatous polyposis (FAP) is a hereditary colorectal cancer syndrome, which results in the development of hundreds of adenomatous polyps carpeting the gastrointestinal tract. NSAIDs have reduced polyp burden in patients with FAP and synthetic rexinoids have demonstrated the ability to modulate cytokine-mediated inflammation and WNT signaling. This study examined the use of the combination of an NSAID (sulindac) and a rexinoid (bexarotene) as a durable approach for reducing FAP colonic polyposis to prevent colorectal cancer development. Whole transcriptomic analysis of colorectal polyps and matched normal mucosa in a cohort of patients with FAP to identify potential targets for prevention in FAP was performed. Drug-dose synergism of sulindac and bexarotene in cell lines and patient-derived organoids was assessed, and the drug combination was tested in two different mouse models. This work explored mRNA as a potential predictive serum biomarker for this combination in FAP. Overall, transcriptomic analysis revealed significant activation of inflammatory and cell proliferation pathways. A synergistic effect of sulindac (300 μmol/L) and bexarotene (40 μmol/L) was observed in FAP colonic organoids with primary targeting of polyp tissue compared with normal mucosa. This combination translated into a significant reduction in polyp development in Apc Min/+ and Apc LoxP/+ -Cdx2 mice. Finally, the reported data suggest miRNA-21 could serve as a predictive serum biomarker for polyposis burden in patients with FAP. These findings support the clinical development of the combination of sulindac and bexarotene as a treatment modality for patients with FAP. PREVENTION RELEVANCE: This study identified a novel chemopreventive regimen combining sulindac and bexarotene to reduce polyposis in patients with FAP using in silico tools, ex vivo , and in vivo models. This investigation provides the essential groundwork for moving this drug combination forward into a clinical trial., (©2021 American Association for Cancer Research.)

Hepatic steatosis can lead to liver cancer, cirrhosis, and portal hypertension. There are two main types, non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease. The detection and quantification of hepatic steatosis with lifestyle changes can slow the evolution from NAFLD to steatohepatitis. Currently, the gold standard for the quantification of fat in the liver is biopsy, has some limitations. Hepatic steatosis is frequently detected during cross sectional imaging. Ultrasound (US), Computed Tomography (CT), and Magnetic Resonance Imaging (MRI) provide noninvasive assessment of liver parenchyma and can detect fat infiltration in the liver. However, the non-invasive quantification of hepatic steatosis by imaging has been challenging. Recent MRI techniques show great promise in the detection and quantification of liver fat. The aim of this article is to review the utilization of non-invasive imaging modalities for the detection and quantification of hepatic steatosis, to evaluate their advantages and limitations., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Early diagnosis of hepatic fibrosis (HF) is pivotal for management to cease progression to cirrhosis and hepatocellular carcinoma. HF is the telltale sign of chronic liver disease, and confirmed by liver biopsy, which is an invasive technique and inclined to sampling errors. The morphologic parameters of cirrhosis are assessed on conventional imaging such as on ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI). Newer imaging modalities such as magnetic resonance elastography and US elastography are reliable and accurate. More research studies on novel imaging modalities such as MRI with diffusion weighted imaging, enhancement by hepatobiliary contrast agents, and CT using perfusion are essential for earlier diagnosis, surveillance and accurate management. The purpose of this article is to discuss non-invasive CT, MRI, and US imaging modalities for diagnosis and stratify HF., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Lynch syndrome is the most common cause of hereditary colorectal cancer and is secondary to germline alterations in one of four DNA mismatch repair (MMR) genes. Here we aimed to provide novel insights into the initiation of MMR-deficient (MMRd) colorectal carcinogenesis by characterizing the expression profile of MMRd intestinal stem cells (ISC). A tissue-specific MMRd mouse model (Villin-Cre;Msh2 LoxP/LoxP ) was crossed with a reporter mouse ( Lgr5-EGFP-IRES-creERT2 ) to trace and isolate ISCs (Lgr5+) using flow cytometry. Three different ISC genotypes ( Msh2 -KO, Msh2 -HET, and Msh2 -WT) were isolated and processed for mRNA-seq and mass spectrometry, followed by bioinformatic analyses to identify expression signatures of complete MMRd and haplo-insufficiency. These findings were validated using qRT-PCR, IHC, and whole transcriptomic sequencing in mouse tissues, organoids, and a cohort of human samples, including normal colorectal mucosa, premalignant lesions, and early-stage colorectal cancers from patients with Lynch syndrome and patients with familial adenomatous polyposis (FAP) as controls. Msh2 -KO ISCs clustered together with differentiated intestinal epithelial cells from all genotypes. Gene-set enrichment analysis indicated inhibition of replication, cell-cycle progression, and the Wnt pathway and activation of epithelial signaling and immune reaction. An expression signature derived from MMRd ISCs successfully distinguished MMRd neoplastic lesions of patients with Lynch syndrome from FAP controls. SPP1 was specifically upregulated in MMRd ISCs and colocalized with LGR5 in Lynch syndrome colorectal premalignant lesions and tumors. These results show that expression signatures of MMRd ISC recapitulate the initial steps of Lynch syndrome carcinogenesis and have the potential to unveil novel biomarkers of early cancer initiation. SIGNIFICANCE: The transcriptomic and proteomic profile of MMR-deficient intestinal stem cells displays a unique set of genes with potential roles as biomarkers of cancer initiation and early progression., (©2021 American Association for Cancer Research.)

Objective: Patients with Lynch syndrome (LS) are at markedly increased risk for colorectal cancer. It is being increasingly recognised that the immune system plays an essential role in LS tumour development, thus making an ideal target for cancer prevention. Our objective was to evaluate the safety, assess the activity and discover novel molecular pathways involved in the activity of naproxen as primary and secondary chemoprevention in patients with LS., Design: We conducted a Phase Ib, placebo-controlled, randomised clinical trial of two dose levels of naproxen sodium (440 and 220 mg) administered daily for 6 months to 80 participants with LS, and a co-clinical trial using a genetically engineered mouse model of LS and patient-derived organoids (PDOs)., Results: Overall, the total number of adverse events was not different across treatment arms with excellent tolerance of the intervention. The level of prostaglandin E2 in the colorectal mucosa was significantly decreased after treatment with naproxen when compared with placebo. Naproxen activated different resident immune cell types without any increase in lymphoid cellularity, and changed the expression patterns of the intestinal crypt towards epithelial differentiation and stem cell regulation. Naproxen demonstrated robust chemopreventive activity in a mouse co-clinical trial and gene expression profiles induced by naproxen in humans showed perfect discrimination of mice specimens with LS and PDOs treated with naproxen and control., Conclusions: Naproxen is a promising strategy for immune interception in LS. We have discovered naproxen-induced gene expression profiles for their potential use as predictive biomarkers of drug activity., Trial Registration Number: gov Identifier: NCT02052908., Competing Interests: Competing interests: JS has a consulting role with Janssen Research and Development, and Cancer Prevention Pharmaceuticals. IW has an advisory role with Genentech/Roche, Bayer, Bristol-Myers Squibb, AstraZeneca/Medimmune, Pfizer, HTG Molecular, Asuragen, Merck, GlaxoSmithKline, Guardant Health and MSD, has received speaker fees from Medscape, MSD, Genentech/Roche, Pfizer and received research support from Genentech, Oncoplex, HTG Molecular, DepArray, Merck, Bristol-Myers Squibb, Medimmune, Adaptive, Adaptimmune, EMD Serono, Pfizer, Takeda, Amgen, Karus, Johnson & Johnson, Bayer, Iovance, 4D, Novartis, and Akoya. SL and EV are co-principal investigators in an NIH/NCI U01 award with co-investigators employed by Nouscom, s.r.l. EV has a consulting and advisory role with Janssen Research and Development and Recursion Pharma., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

New treatments are needed to address persistent unmet clinical needs for diffuse large B-cell lymphoma (DLBCL). Overexpression of transferrin receptor 1 (TFR1) is common across cancer and permits cell-surface targeting of specific therapies in preclinical and clinical studies of various solid tumors. Here, we developed novel nanocarrier delivery of chemotherapy via TFR1-mediated endocytosis, assessing this target for the first time in DLBCL. Analysis of published datasets showed novel association of increased TFR1 expression with high-risk DLBCL cases. Carbon-nitride dots (CND) are emerging nanoparticles with excellent in vivo stability and distribution and are adaptable to covalent conjugation with multiple substrates. In vitro , linking doxorubicin (Dox) and transferrin (TF) to CND (CND-Dox-TF, CDT) was 10-100 times more potent than Dox against DLBCL cell lines. Gain- and loss-of-function studies and fluorescent confocal microscopy confirmed dependence of these effects on TFR1-mediated endocytosis. In contrast with previous therapeutics directly linking Dox and TF, cytotoxicity of CDT resulted from nuclear entry by Dox, promoting double-stranded DNA breaks and apoptosis. CDT proved safe to administer in vivo , and when incorporated into standard frontline chemoimmunotherapy in place of Dox, it improved overall survival by controlling patient-derived xenograft tumors with greatly reduced host toxicities. Nanocarrier-mediated Dox delivery to cell-surface TFR1, therefore, warrants optimization as a potential new therapeutic option in DLBCL. SIGNIFICANCE: Targeted nanoparticle delivery of doxorubicin chemotherapy via the TRF1 receptor presents a new opportunity against high-risk DLBCL tumors using potency and precision., (©2020 American Association for Cancer Research.)

Aim: There are limited outcome data for lateral pelvic lymph node dissection (LPLND) following neoadjuvant chemoradiotherapy (nCRT), particularly in the West. Our aim was to evaluate the short-term perioperative and oncological outcomes of robotic LPLND at a single cancer centre., Method: A retrospective analysis of a prospective database of consecutive patients undergoing robotic LPLND for rectal cancer between November 2012 and February 2020 was performed. The main outcomes were short-term perioperative and oncological outcomes. Major morbidity was defined as Clavien-Dindo grade 3 or above., Results: Forty patients underwent robotic LPLND during the study period. The mean age was 54 years (SD ± 15 years) and 13 (31.0%) were female. The median body mass index was 28.6 kg/m 2 (IQR 25.5-32.6 kg/m 2 ). Neoadjuvant CRT was performed in all patients. Resection of the primary rectal cancer and concurrent LPLND occurred in 36 (90.0%) patients, whilst the remaining 4 (10.0%) patients had subsequent LPLND after prior rectal resection. The median operating time was 420 min (IQR 313-540 min), estimated blood loss was 150 ml (IQR 55-200 ml) and length of hospital stay was 4 days (IQR 3-6 days). The major morbidity rate was 10.0% (n = 4). The median lymph node harvest from the LPLND was 6 (IQR 3-9) and 13 (32.5%) patients had one or more positive LPLNs. The median follow-up was 16 months (IQR 5-33 months), with 1 (2.5%) local central recurrence and 7 (17.5%) patients developing distant disease, resulting in 3 (7.5%) deaths., Conclusion: Robotic LPLND for rectal cancer can be performed in Western patients to completely resect extra-mesorectal LPLNs and is associated with acceptable perioperative morbidity., (© 2020 The Association of Coloproctology of Great Britain and Ireland.)

The aim of this study was to compare the outcomes of robotic total mesorectal excision (TME) in obese versus non-obese patients. A total of 533 patients, of whom 161 were obese (30·2 per cent) underwent robotic proctectomy during the study interval. Patient obesity was not associated with adverse short-term clinical outcomes after robotic rectal cancer surgery. Indicated in the obese perhaps?, (© 2020 BJS Society Ltd Published by John Wiley & Sons Ltd.)

Background: Appendiceal adenocarcinoma (AA) is an orphan disease with unique clinical attributes but often treated as colorectal cancer (CRC). Understanding key molecular differences between AA and CRC is critical., Methods: We performed retrospective analyses of AA patients (N = 266) with tumour and/or blood next-generation sequencing (NGS) (2013-2018) with in-depth clinicopathological annotation. Overall survival (OS) was examined. For comparison, CRC cohorts annotated for sidedness, consensus molecular subtypes (CMS) and mutations (N = 3283) were used., Results: Blood-NGS identified less RAS/GNAS mutations compared to tissue-NGS (4.2% vs. 60.9%, P < 0.0001) and showed poor concordance with tissue for well-/moderately differentiated tumours. RAS (56.2%), GNAS (28.1%) and TP53 (26.9%) were most frequent mutations. Well/moderately differentiated tumours harboured more RAS (69.2%/64.0% vs. 40.5%) and GNAS (48.7%/32.0% vs. 10.1%) while moderate/poorly differentiated tumours had more TP53 (26.0%/27.8% vs. 7.7%) mutations. Appendiceal adenocarcinoma (compared to CRC) harboured significantly fewer APC (9.1% vs. 55.4%) and TP53 (26.9% vs. 67.5%) and more GNAS mutations (28.1% vs. 2.0%) (P < 0.0001). Appendiceal adenocarcinoma mutation profile did not resemble either right-sided CRC or any of the four CMS in CRC. High grade, but no mutation, was independently predictive of survival., Conclusion: Integrated clinico-molecular profiling of AA identified key molecular drivers distinct from CRC. Appendiceal adenocarcinoma has a predominantly grade-driven biology that trumps mutations.

Background: The role of neoadjuvant short-course radiation therapy (SCRT) in treating rectal adenocarcinoma is a topic of ongoing debate. Growing interest in total neoadjuvant therapy has spurred discussion on the optimal sequence of preoperative SCRT and chemotherapy., Patients and Methods: All patients receiving SCRT (5 Gy × 5 fractions) were identified. Details about preoperative treatments, radiation toxicities, and postoperative complications were collected. Patients were divided into 2 groups: those who underwent surgery within 14 days of completing SCRT and those with a longer delay. Outcomes compared included extent of pathologic response, margin-negative resection rate, acute radiation toxicities, and postoperative complications., Results: Fifty-seven patients with locally advanced or metastatic rectal cancer received SCRT between 2008 and 2018. Thirty-nine of 57 patients underwent definitive pelvic surgery with total mesorectal excision. There were no significant differences in tumor downstaging, radial margin status, or percent tumor viability between patients with immediate surgery versus delayed surgery. The delay group had higher rates of nodal downstaging (64.7% vs. 18.2%; P = .003). There were no differences in total or grade 3+ gastrointestinal radiation toxicity, postoperative complications, reoperation, readmission, and mortality between the 2 groups., Conclusions: Though not yet common in the United States, SCRT has compared favorably with long course chemoradiation in multiple trials. Moreover, it is associated with greater efficiency and less disruption to chemotherapy. Our data show similar response and toxicity outcomes between the immediate and delay groups, suggesting SCRT is well-tolerated regardless of treatment sequence. Recently completed prospective trials may reveal the optimal preoperative treatment sequence., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: Acellular intra-abdominal mucin is associated with a favourable prognosis in pseudomyxoma peritonei. There are no current guidelines on how many blocks are needed to classify the mucin as acellular with confidence., Methods: Specimens from cytoreductive surgery for mucinous appendiceal neoplasia, in which acellular mucin was found on initial histopathological examination, were prospectively identified. Additional tissue blocks were then taken to include either all residual visible intra-abdominal mucin or a maximum of 30 blocks. We also sent a questionnaire to pathologists in other centres., Results: Twelve patients were identified. In two cases, neoplastic epithelial cells were found on taking additional blocks. The questionnaire results suggested considerable variation in block-taking practice., Conclusion: Taking additional tissue identified neoplastic cells in 2 of 12 cases. We recommend that sampling additional material should be considered when only acellular mucin is found on initial histology. Further work to determine the optimum sampling protocol is indicated., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Germline mutations in the tumor suppressor Adenomatous Polyposis Coli ( APC ) define Familial Adenomatous Polyposis (FAP), the genetic predisposition to developing adenomatous polyps. Recent sequencing of FAP adenomas have challenged established dogma that APC mutations alone represent the adenoma mutational landscape because recurrent somatic mutations in non-WNT pathway genes were also discovered. In particular, one of these novel genes, CNOT3 , presented E20K and E70K mutations that are predicted to be deleterious in silico . We utilized zebrafish embryos to determine if these mutations affect CNOT3 function and perform novel biology in an APC-dependent pathway in vivo . Human CNOT3 ( hCNOT3 ) and E20K mRNA injection rescued zebrafish cnot3a knockdown lordosis phenotype while E70K did not. In the FAP apc mcr zebrafish model, we show that ctbp1 , but not retinoic acid, regulates cnot3a expression. Injection of hCNOT3 and E20K , but not E70K , to homozygous apc mcr zebrafish initiated gut differentiation while cnot3a knockdown in wildtype embryos led to decreased intestinal development and differentiation. Finally, targeted sequencing of 37 additional FAP adenomas revealed CNOT3 mutations in 20% of these samples. Overall, our work supports a mechanism where CTBP1 regulates CNOT3 and that overall CNOT3 perturbation could work in concert with germline APC mutations in advancing adenomas to a more transformed state prior to progression to adenocarcinoma., Competing Interests: CONFLICTS OF INTEREST EV reports a consulting role for Janssen Research and Development.

Background: Gene expression-based profiling of colorectal cancer (CRC) can be used to identify four molecularly homogeneous consensus molecular subtype (CMS) groups with unique biologic features. However, its applicability to colorectal premalignant lesions remains unknown., Patients and Methods: We assembled the largest transcriptomic premalignancy dataset by integrating different public and proprietary cohorts of adenomatous and serrated polyps from sporadic (N = 311) and hereditary (N = 78) patient populations and carried out a comprehensive analysis of carcinogenesis pathways using the CMS random forest (RF) classifier., Results: Overall, transcriptomic subtyping of sporadic and hereditary polyps revealed CMS2 and CMS1 subgroups as the predominant molecular subtypes in premalignancy. Pathway enrichment analysis showed that adenomatous polyps from sporadic or hereditary cases (including Lynch syndrome) displayed a CMS2-like phenotype with WNT and MYC activation, whereas hyperplastic and serrated polyps with CMS1-like phenotype harbored prominent immune activation. Rare adenomas with CMS4-like phenotype showed significant enrichment for stromal signatures along with transforming growth factor-β activation. There was a strong association of CMS1-like polyps with serrated pathology, right-sided anatomic location and BRAF mutations., Conclusions: Based on our observations made in premalignancy, we propose a model of pathway activation associated with CMS classification in colorectal carcinogenesis. Specifically, while adenomatous polyps are largely CMS2, most hyperplastic and serrated polyps are CMS1 and may transition into other CMS groups during evolution into carcinomas. Our findings shed light on the transcriptional landscape of premalignant colonic polyps and may help guide the development of future biomarkers or preventive treatments for CRC.

Importance: Colorectal carcinomas in patients with Lynch syndrome (LS) arise in a background of mismatch repair (MMR) deficiency, display a unique immune profile with upregulation of immune checkpoints, and response to immunotherapy. However, there is still a gap in understanding the pathogenesis of MMR-deficient colorectal premalignant lesions, which is essential for the development of novel preventive strategies for LS., Objective: To characterize the immune profile of premalignant lesions from a cohort of patients with LS., Design, Setting, and Participants: Whole-genome transcriptomic analysis using next-generation sequencing was performed in colorectal polyps and carcinomas of patients with LS. As comparator and model of MMR-proficient colorectal carcinogenesis, we used samples from patients with familial adenomatous polyposis (FAP). In addition, a total of 47 colorectal carcinomas (6 hypermutants and 41 nonhypermutants) were obtained from The Cancer Genome Atlas (TCGA) for comparisons. Samples were obtained from the University of Texas MD Anderson Cancer Center and "Regina Elena" National Cancer Institute, Rome, Italy. All diagnoses were confirmed by genetic testing. Polyps were collected at the time of endoscopic surveillance and tumors were collected at the time of surgical resection. The data were analyzed from October 2016 to November 2017., Main Outcomes and Measures: Assessment of the immune profile, mutational signature, mutational and neoantigen rate, and pathway enrichment analysis of neoantigens in LS premalignant lesions and their comparison with FAP premalignant lesions, LS carcinoma, and sporadic colorectal cancers from TCGA., Results: The analysis was performed in a total of 28 polyps (26 tubular adenomas and 2 hyperplastic polyps) and 3 early-stage LS colorectal tumors from 24 patients (15 [62%] female; mean [SD] age, 48.12 [15.38] years) diagnosed with FAP (n = 10) and LS (n = 14). Overall, LS polyps presented with low mutational and neoantigen rates but displayed a striking immune activation profile characterized by CD4 T cells, proinflammatory (tumor necrosis factor, interleukin 12) and checkpoint molecules (LAG3 [lymphocyte activation gene 3] and PD-L1 [programmed cell death 1 ligand 1]). This immune profile was independent of mutational rate, neoantigen formation, and MMR status. In addition, we identified a small subset of LS polyps with high mutational and neoantigen rates that were comparable to hypermutant tumors and displayed additional checkpoint (CTLA4 [cytotoxic T-lymphocyte-associated protein 4]) and neoantigens involved in DNA damage response (ATM and BRCA1 signaling)., Conclusions and Relevance: These findings challenge the canonical model, based on the observations made in carcinomas, that emphasizes a dependency of immune activation on the acquisition of high levels of mutations and neoantigens, thus opening the door to the implementation of immune checkpoint inhibitors and vaccines for cancer prevention in LS.

Background: Mucinous appendiceal neoplasms can contain radiopaque calcifications. Whether appendiceal radiographic calcifications indicate the presence of an appendiceal epithelial neoplasm is unknown. This study aimed to determine whether appendiceal calcifications detected by computed tomography (CT) correlate with the presence of appendiceal epithelial neoplasms., Methods: From prospective appendiceal and pathology databases, 332 cases of appendiceal neoplasm and 136 cases of control appendectomy were identified, respectively. Only cases with preoperative CT scans available for review were included in the study. Images were reviewed by two abdominal radiologists. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated, and the kappa statistic was used to determine agreement between the radiologists' interpretations., Results: Interobserver agreement between the radiologists was substantial, with a kappa of 0.74. Appendiceal mural calcifications were identified on CT scans in 106 appendiceal neoplasm cases (32%) and in 1 control case (1%) (P = 0.0001). In the appendiceal neoplasm subgroup, the presence of radiographic calcifications was associated with mucinous histology (35% vs 17%; P = 0.006; odds ratio [OR], 0.38; 95% confidence interval [CI], 0.18-0.78) and with well-differentiated histologic grade (40% vs 24%; P = 0.002; OR, 0.47; 95% CI, 0.29-0.76). The findings showed a sensitivity of 31.9% (95% CI, 26.9-37.2%), a specificity of 99.3% (95% CI, 96-100%), a PPV of 99.1% (95% CI, 94.9-100%), and an NPV of 37.4% (95% CI, 32.4-42.6%)., Conclusion: This case-control study showed that appendiceal mural calcifications detected on CT are associated with underlying appendiceal epithelial neoplasms and that the identification of incidental mural appendiceal calcifications may have an impact on decisions regarding surgical intervention.

Purpose: The majority of genomic alterations causing intratumoral heterogeneity (ITH) in colorectal cancer are thought to arise during early stages of carcinogenesis as a burst but only after truncal mutations in APC have expanded a single founder clone. We have investigated if the initial source of ITH is consequent to multiple independent lineages derived from different crypts harboring distinct truncal APC and driver KRAS mutations, thus challenging the prevailing monoclonal monocryptal model. Experimental Design: High-depth next-generation sequencing and SNP arrays were performed in whole-lesion extracts of 37 familial adenomatous polyposis colorectal adenomas. Also, ultrasensitive genotyping of hotspot mutations of APC and KRAS was performed using nanofluidic PCRs in matched bulk biopsies ( n = 59) and crypts ( n = 591) from 18 adenomas and seven carcinomas and adjacent normal tissues. Results: Multiple co-occurring truncal APC and driver KRAS alterations were uncovered in whole-lesion extracts from adenomas and subsequently confirmed to belong to multiple clones. Ultrasensitive genotyping of bulk biopsies and crypts revealed novel undetected APC mutations that were prominent among carcinomas, whereas abundant wild-type APC crypts were detected in adenomas. KRAS mutational heterogeneity within crypts was evident in both adenomas and carcinomas with a higher degree of concordance between biopsy and crypt genotyping in carcinomas. Nonrandom heterogeneity among crypts was also observed. Conclusions: The striking degree of nonrandom intercrypt heterogeneity in truncal and driver gene mutations observed in adenomas and carcinomas is consistent with a polycryptal model derived from multiple independent initiation linages as the source of early ITH in colorectal carcinogenesis. Clin Cancer Res; 23(19); 5936-47. ©2017 AACR ., (©2017 American Association for Cancer Research.)

Lynch syndrome (LS) is a genetic condition secondary to germline alterations in the DNA mismatch repair (MMR) genes with 30% of changes being variants of uncertain significance (VUS). Our aim was to perform an in silico reclassification of VUS from a large single institutional cohort that will help prioritizing functional validation. A total of 54 VUS were detected with 33 (61%) novel variants. We integrated family history, pathology, and genetic information along with supporting evidence from eight different in silico tools at the RNA and protein level. Our assessment allowed us to reclassify 54% (29/54) of the VUS as probably damaging, 13% (7/54) as possibly damaging, and 28% (15/54) as probably neutral. There are more than 1,000 VUS reported in MMR genes and our approach facilitates the prioritization of further functional efforts to assess the pathogenicity to those classified as probably damaging. Cancer Prev Res; 10(10); 580-7. ©2017 AACR ., (©2017 American Association for Cancer Research.)

Aim: To investigate the importance of a three-tiered histologic grade on outcomes for patients with mucinous appendiceal adenocarcinoma (MAA)., Methods: Two hundred and sixty-five patients with MAA undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy were identified from a prospective database from 2004 through 2014. All pathology was reviewed by our gastrointestinal subspecialty pathologists and histological grade was classified as well-differentiated, moderately differentiated, and poorly differentiated. Survival analysis was performed using Cox proportional hazards regression., Results: There were 201 (75.8%) well-, 45 (16.9%) moderately- and 19 (7.2%) poorly-differentiated tumors. Histological grade significantly stratified the 5-year overall survival (OS), 94%, 71% and 30% respectively ( P < 0.001) as well as the 5-year disease-free survival (DFS) 66%, 21% and 0%, respectively ( P < 0.001). Independent predictors of DFS included tumor grade (HR = 1.78, 95%CI: 1.21-2.63, P = 0.008), lymph node involvement (HR = 0.33, 95%CI: 0.11-0.98, P < 0.02), previous surgical score (HR = 1.31, 95%CI: 1.1-1.65, P = 0.03) and peritoneal carcinomatosis index (PCI) (HR = 1.05, 95%CI: 1.02-1.08, P = 0.002). Independent predictors of OS include tumor grade (HR = 2.79, 95%CI: 1.26-6.21, P = 0.01), PCI (HR = 1.10, 95%CI: 1.03-1.16, P = 0.002), and complete cytoreduction (HR = 0.32, 95%CI: 0.11-0.92, P = 0.03). Tumor grade and PCI were the only independent predictors of both DFS and OS. Furthermore, histological grade and lymphovascular invasion stratified the risk of lymph node metastasis into a low (6%) and high (40%) risk groups., Conclusion: Our data demonstrates that moderately differentiated MAA have a clinical behavior and outcome that is distinct from well- and poorly-differentiated MAA. The three-tier grade classification provides improved prognostic stratification and should be incorporated into patient selection and treatment algorithms., Competing Interests: Conflict-of-interest statement: Dr. Taggart has received a small educational grant from Bristol-Meyers Squibb. The other authors have no disclosures.

Purpose: Determination of microsatellite instability (MSI) by PCR is the gold standard; however, IHC of mismatch repair (MMR) proteins is frequently performed instead. The reliability of these methods on postneoadjuvant therapy specimens is unknown. We examined the effect of neoadjuvant therapy on MSI results by PCR and IHC. Experimental design: A total of 239 colorectal cancers resected after neoadjuvant therapy were assessed for MSI with PCR and IHC. PCR and IHC results for matched paired pre- and posttreatment specimens were compared. In parallel, 2 isogenic cell lines conditioned for MMR functioning and 2 different patient-derived xenografts (PDXs) were exposed to chemotherapy, radiation, or both. We also examined whether establishment of PDXs induced MSI changes in 5 tumors. IHC and MSI were tested after treatment to assess for changes. Results: We identified paired pre- and posttreatment specimens for 37 patients: 2 with PCR only, 34 with IHC only, and 1 with both. All 3 patients with PCR had microsatellite stable pre- and posttreatment specimens. Of the 35 patients with IHC, 30 had intact MMR proteins in pre- and posttreatment specimens, 1 had equivocal MLH1 staining in the pretreatment and loss in the posttreatment specimen, and 4 had intact pretreatment MSH6 but variable posttreatment staining. In the experimental setting, no changes in MSI status were detected after treatment or tumor implantation in animals. Conclusions: Our findings show that the expression of MMR proteins, commonly MSH6, can change after neoadjuvant therapy and confirm PCR as the gold-standard test for MSI after neoadjuvant therapy. Clin Cancer Res; 23(17); 5246-54. ©2017 AACR ., (©2017 American Association for Cancer Research.)

Background: Moderately and poorly differentiated adenocarcinoma of the appendix represents an aggressive histological variant with a high risk of recurrence and death., Methods: Overall, 178 patients with moderately and poorly differentiated appendiceal adenocarcinoma were identified from a prospective database. Clinical, pathologic, and treatment factors were analyzed for outcomes., Results: Diagnostic laparoscopy (DL) identified radiographic occult peritoneal metastasis in 25 (42%) patients. These patients had a significantly lower peritoneal carcinomatosis index (PCI) and improved overall survival (OS) compared with those with radiographic disease. Twenty-seven (41%) patients were excluded from cytoreductive surgery (CRS) because of findings on DL, while 116 (65%) patients underwent CRS and hyperthermic intraperitoneal chemotherapy (HIPEC), with a median disease-free survival (DFS) of 23 months. Mucinous histology (hazard ratio [HR] 0.52, p = 0.04) and PCI (HR 1.054, p = 0.02) were independent predictors of DFS. The median OS following CRS and HIPEC was 48 months. Mucinous histology (HR 0.352, p = 0.018), signet ring cells (HR 3.34, p = 0.02), positive peritoneal cytology (HR 0.081, p = 0.04), and PCI (HR 1.076, p = 0.004) were independently associated with OS. Eight-five (73.3%) patients received neoadjuvant chemotherapy, and 40 (47.1%) patients achieved a radiographic response; 36 (42.3%) had stable disease, while 9 (10.6%) had progressive disease. Stable or responsive disease was associated with improved median OS of 44 months, compared with 21 months for those with progressive disease (p = 0.011)., Conclusions: In selected patients, long-term survival can be obtained. Mucinous histology, absence of signet ring cells, negative peritoneal cytology, PCI ≤ 20, and response/stable disease after neoadjuvant chemotherapy are important selection criteria for CRS and HIPEC.

Traditional germline sequencing and deletion/duplication analysis does not detect Lynch syndrome-causing mutations in all individuals whose colorectal or endometrial tumors demonstrate mismatch repair (MMR) deficiency. Unique inversions and other rearrangements of the MMR genes have been reported in families with Lynch syndrome. In 2014, a recurrent inversion of MSH2 exons 1-7 was identified in five families suspected to have Lynch syndrome. We aimed to describe our clinical experience in identifying families with this specific inversion. Four probands whose Lynch syndrome-associated tumors demonstrated absence of MSH2/MSH6 staining and who had negative MMR germline testing were evaluated for the MSH2 inversion of exons 1-7, offered during initial genetic workup or upon routine clinical follow-up. All four probands tested positive for the MSH2 inversion. Proband cancer diagnoses included colon and endometrial adenocarcinoma and sebaceous adenoma. A variety of Lynch syndrome-associated cancers were reported in the family histories, although only one family met Amsterdam II criteria. Thirteen at-risk relatives underwent predictive testing. MSH2 inversion of exons 1-7 was found in four probands previously suspected to have Lynch syndrome based on family history and tumor testing. This testing should be offered routinely to patients with tumors demonstrating loss of MSH2/MSH6 staining.

Constitutional mismatch repair deficiency syndrome (CMMRD) is a rare autosomal recessive predisposition to colorectal polyposis and other malignancies, often childhood-onset, that is caused by biallelic inheritance of mutations in the same mismatch repair gene. Here, we describe a patient with a clinical diagnosis of CMMRD based on colorectal polyposis and young-onset endometrial cancer who was identified to have two alterations in trans in PMS2: one known pathogenic mutation (c.1831insA; p.Ile611Asnfs*2) and one novel variant of uncertain significance (c.505C>G; p.Arg169Glu), a missense alteration. We describe the clinical and molecular features in the patient harboring this novel alteration c.505C>G, who meets clinical criteria for CMMRD and exhibits molecular evidence supporting a diagnosis of CMMRD. Although experimental validation is needed to confirm its pathogenicity, PMS2 c.505C>G likely has functional consequences that contributes to our patient's phenotype based on the patient's clinical presentation, tumor studies, and bioinformatics analysis., Competing Interests: The authors disclose no potential conflicts of interest.

The molecular basis of the adenoma-to-carcinoma transition has been deduced using comparative analysis of genetic alterations observed through the sequential steps of intestinal carcinogenesis. However, comprehensive genomic analyses of adenomas and at-risk mucosa are still lacking. Therefore, our aim was to characterize the genomic landscape of colonic at-risk mucosa and adenomas. We analyzed the mutation profile and copy number changes of 25 adenomas and adjacent mucosa from 12 familial adenomatous polyposis patients using whole-exome sequencing and validated allelic imbalances (AI) in 37 adenomas using SNP arrays. We assessed for evidence of clonality and performed estimations on the proportions of driver and passenger mutations using a systems biology approach. Adenomas had lower mutational rates than did colorectal cancers and showed recurrent alterations in known cancer driver genes (APC, KRAS, FBXW7, TCF7L2) and AIs in chromosomes 5, 7, and 13. Moreover, 80% of adenomas had somatic alterations in WNT pathway genes. Adenomas displayed evidence of multiclonality similar to stage I carcinomas. Strong correlations between mutational rate and patient age were observed in at-risk mucosa and adenomas. Our data indicate that at least 23% of somatic mutations are present in at-risk mucosa prior to adenoma initiation. The genomic profiles of at-risk mucosa and adenomas illustrate the evolution from normal tissue to carcinoma via greater resolution of molecular changes at the inflection point of premalignant lesions. Furthermore, substantial genomic variation exists in at-risk mucosa before adenoma formation, and deregulation of the WNT pathway is required to foster carcinogenesis. Cancer Prev Res; 9(6); 417-27. ©2016 AACR., (©2016 American Association for Cancer Research.)

Primary sinonasal tumors with neuroendocrine differentiation (STNDs) are uncommon, with overlapping histology. According to the amount of neuroendocrine component, they can be subcategorized into esthesioneuroblastoma, high-grade sinonasal neuroendocrine carcinoma/small cell carcinoma, and sinonasal undifferentiated carcinoma. Achaete-scute homolog 1 (ASH1) is a master gene for neuroendocrine differentiation and is expressed in fetal and adult neuroendocrine tissues. Expression of ASH1 protein may be a useful marker for cancers with neuroendocrine features. The aim of this study was to compare and assess the value of ASH1 protein expression/levels in STND. We reviewed the morphological features and performed immunohistochemical analyses for ASH1 in 30 samples of surgically resected cancers with neuroendocrine differentiation from our institution. Achaete-scute homolog 1 was found to be expressed in STND, indicating that it is instrumental in the development of a subset of neurons and neuroendocrine cells and plays a key role in regulating neuroendocrine differentiation in tumor cells. Achaete-scute homolog 1 levels were associated with the degree of STND tumor differentiation (high-grade tumors show increased expression of this protein), correlating well with studies indicating that expression of ASH1 appears to be restricted to immature cells., (Published by Elsevier Inc.)

Context: The prognosis of appendiceal goblet cell carcinoid tumors (GCTs) is believed to be intermediate between appendiceal adenocarcinomas and conventional carcinoid tumors. However, GCTs can have mixed morphologic patterns, with variable amount of adenocarcinoma., Objective: To evaluate the behavior of GCTs and related entities with variable components of adenocarcinoma., Design: We classified 74 cases of appendiceal tumors into 3 groups: group 1, GCTs or GCTs with less than 25% adenocarcinoma; group 2, GCTs with 25% to 50% adenocarcinoma; group 3, GCTs with more than 50% adenocarcinoma; and a comparison group of 68 adenocarcinomas without a GCT component (group 4). Well-differentiated mucinous adenocarcinomas were excluded. Clinicopathologic features and follow-up were obtained from computerized medical records and the US Social Security Death Index., Results: Of the 142 tumors studied, 23 tumors (16%) were classified as group 1; 27 (19%) as group 2; 24 (17%) as group 3; and 68 (48%) as group 4. Staging and survival differed significantly among these groups. Among 140 patients (99%) with available staging data, stages II, III, and IV were present in 87%, 4%, and 4% of patients in group 1 patients; 67%, 7%, and 22% of patients in group 2; 29%, 4%, and 67% of patients in group 3; and 19%, 6%, and 75% of patients in group 4, respectively (P = .01). Mean (SD) overall survival was 83.8 (34.6), 60.6 (30.3), 45.6 (39.7), and 33.6 (27.6) months for groups 1, 2, 3, and 4, respectively (P = .01). By multivariate analysis, only stage and tumor category were independent predictors of overall survival., Conclusion: Our data highlight the importance of subclassifying the proportion of adenocarcinoma in appendiceal tumors with GCT morphology because that finding reflects disease stage and affects survival.