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The aim of this study was to identify risk factors for lymph node positivity in T1 colon cancer and to carry out a surgical quality assurance audit.The sample consisted of consecutive patients treated for early-stage colon lesions in 15 colorectal referral centres between 2011 and 2014. The study investigated 38 factors grouped into four categories: demographic information, preoperative data, indications for surgery and post-operative data. A univariate and multivariate logistic regression analysis was performed to analyze the significance of each factor both in terms of lymph node (LN) harvesting and LN metastases.Out of 507 patients enrolled, 394 patients were considered for analysis. Thirty-five (8.91%) patients had positive LN. Statistically significant differences related to total LN harvesting were found in relation to central vessel ligation and segmental resections. Cumulative distribution demonstrated that the rate of positive LN increased starting at 12 LN harvested and reached a plateau at 25 LN.Some factors associated with an increase in detection of positive LN were identified. However, further studies are needed to identify more sensitive markers and avoid surgical overtreatment. There is a need to raise the minimum LN count and to use the LN count as an indicator of surgical quality.

Introduction: Transverse colon cancer (TCC) is poorly studied, and TCC cases are often excluded from large prospective randomized trials because of their complexity and their potentially high complication rate. The best surgical approach for TCC has yet to be established. The aim of this large retrospective multicenter Italian series is to investigate the advantages and disadvantages of both hemicolectomy and transverse colectomy in order to identify the best surgical approach. Materials and methods: This was a retrospective cohort study of patients with mid-transverse colon cancer treated with a segmental colon resection or an extended hemicolectomy (right or left) between 2006 and 2016 in 28 high-volume (more than 70 procedures/year) Italian referral centers for colorectal surgery. Results: The study included 1529 patients, 388 of whom underwent a segmental resection while 1141 underwent an extended resection. A higher number of complications has been reported in the segmental group than in the extended group (30.1% versus 23.6%; p 0.010). In 42 cases the main complication was the anastomotic leak (4.4% versus 2.2%; p 0.020). Recovery outcomes also showed statistical differences: time to first flatus (p 0.014), time to first mobilization (p 0.040), and overall hospital stay (p < 0.001) were significantly shorter in the extended group. Even if overall survival were similar between the groups (95.1% versus 97%; p 0.384), 3-year disease-free survival worsened after segmental resection (78.1% versus 86.2%; p 0.001). Conclusions: According to our results, an extended right colon resection for TCC seems to be surgically safer and more oncologically valid.

BACKGROUND: There is good evidence that radiotherapy is beneficial in advanced rectal cancer, but its application in Italy has not been investigated. METHODS: We conducted a nationwide survey among members of the Italian Society of Colo-Rectal Surgery (SICCR) on the use of radiation therapy for rectal cancer in the year 2005. Demographic, clinical and pathologic data were retrospectively collected with an online database. Italy was geographically divided into 3 regions: north, center and south which included the islands. Hospitals performing 30 or more surgeries per year were considered high volume. Factors related to radiotherapy delivery were identified with multivariate analysis. RESULTS: Of 108 centers, 44 (41%) responded to the audit. We collected data on 682 rectal cancer patients corresponding to 58% of rectal cancers operated by SICCR members in 2005. Radiotherapy was used in 307/682 (45.0%) patients. Preoperative radiotherapy was used in 236/682 (34.6%), postoperative radiotherapy in 71/682 (10.4%) cases and no radiotherapy in 375 (55.0%) cases. Of the 236 patients who underwent preoperative radiotherapy, only 24 (10.2%) received short-course radiotherapy, while 212 (89.8%) received long-course radiotherapy. Of the 339 stage II-III patients, 159 (47%) did not receive any radiotherapy. Radiotherapy was more frequently used in younger patients (P < 0.0001), in patients undergoing abdominoperineal resection (APR) (P < 0.01) and in the north and center of Italy (P < 0.001). Preoperative radiotherapy was more frequently used in younger patients (P < 0.001), in large volume centers (P < 0.05), in patients undergoing APR (P < 0.005) and in the north-center of Italy (P < 0.05). CONCLUSION: Our study first identified a treatment disparity among different geographic Italian regions. A more systematic audit is needed to confirm these results and plan adequate interventions.

An expert consensus panel convened by the Italian Association for Inherited and Familial Gastrointestinal Tumors (Associazione Italiana per lo Studio della Familiarita ed Ereditarieta dei Tumori Gastrointestinali, AIFEG) reviewed the literature and agreed on a number of position statements regarding the definition and management of polyposis coli without an identified pathogenic mutation on the APC or MUTYH genes, defined in the document as NAMP (non-APC/MUTYH polyposis).

BACKGROUND Patient-reported outcomes associated with different bowel reconstruction techniques following anterior resection for rectal cancer are still a matter of debate. OBJECTIVE This study aimed to assess quality of life and bowel function in patients who underwent colonic J-pouch or straight colorectal anastomosis reconstruction after low anterior resection. DESIGN Bowel function and quality of life were assessed within a multicenter randomized trial. Questionnaires were administered before the surgery (baseline) and at 6, 12, and 24 months after surgery. SETTINGS Patients were enrolled by 19 centers. The enrollment started in October 2009 and was stopped in February 2016. The study was registered at www.clinicaltrials.gov (Identifier: NCT01110798). PATIENTS Patients who underwent low anterior resection for primary mid-low rectal cancer and who were randomly assigned in a 1:1 ratio to receive either stapled colonic J-pouch or straight colorectal anastomosis were selected. MAIN OUTCOME MEASURES The primary outcomes measured were quality of life and bowel function. RESULTS Of the 379 patients who were evaluable, 312 (82.3%) completed the baseline, 259 (68.3%) the 6-month, 242 (63.9%) the 12-month, and 199 (52.5%) the 24-month assessment. Bowel functioning and quality of life did not significantly differ between arms for almost all domains. The total bowel function score, the urgency, and the stool fractionation scores significantly worsened after surgery and remained impaired over time in both arms (p < 0.0032), whereas constipation improved after surgery but recovered to baseline levels from 1 year onward (p < 0.0036). All patients showed a significant and continuous improvement in emotional functioning (p < 0.0013) and future perspective (p < 0.0001) from baseline to the end of the study. LIMITATIONS Limitations of the study include missing data, which increased over time; the possibility that some treatments have slightly changed since the study was conducted; and investigators not blind to treatment allocation. CONCLUSION The findings of this study do not support the routine use of colonic J-pouch reconstruction in patients with rectal cancer who undergo a low anterior resection. See Video Abstract at http://links.lww.com/DCR/B328. BOLSA J COLONICA O RECONSTRUCCION COLORRECTAL RECTA DESPUES DE RESECCION ANTERIOR BAJA PARA CANCER RECTAL: IMPACTO EN LA CALIDAD DE VIDA Y LA FUNCION INTESTINAL: UN ESTUDIO ALEATORIZADO PROSPECTIVO MULTICENTRICO: Los resultados informados por el paciente asociados con diferentes tecnicas de reconstruccion intestinal despues de la reseccion anterior para el cancer de recto aun son tema de debate.Evaluar la calidad de vida y la funcion intestinal en pacientes que se sometieron a una bolsa en J colonica o reconstruccion de anastomosis colorrectal recta despues de una reseccion anterior baja.La funcion intestinal y la calidad de vida se evaluaron en un ensayo aleatorizado multicentrico. Los cuestionarios se administraron antes de la cirugia (basal) y a los 6, 12 y 24 meses despues de la cirugia.Los pacientes fueron incluidos en 19 centros. La inscripcion comenzo en Octubre de 2009 y se detuvo en Febrero de 2016. El estudio se registro en www.clinicaltrials.gov (Identificador: NCT01110798).Pacientes que se sometieron a reseccion anterior baja por cancer rectal primario medio-bajo y que fueron aleatorizados en una proporcion de 1: 1 para recibir bolsa J colonica con grapas o anastomosis colorrectal recta.calidad de vida y funcion intestinal.De los 379 pacientes que fueron evaluables, 312 (82.3%) completaron la evaluacion inicial, 259 (68.3%) a los 6 meses, 242 (63.9%) a los 12 meses y 199 (52.5%) a los 24 meses. . El funcionamiento intestinal y la calidad de vida no difirieron significativamente entre los dos grupos en casi todos los dominios. La puntuacion total de la funcion intestinal, la urgencia y las puntuaciones de fraccionamiento de las heces empeoraron significativamente despues de la cirugia y continuaron con el tiempo extra en ambos grupos (p

BackgroundMetabolic reprogramming towards aerobic glycolysis in cancer supports unrestricted cell proliferation, survival and chemoresistance. The molecular bases of these processes are still undefined. Recent reports suggest crucial roles for microRNAs. Here, we provide new evidence of the implication of miR-27a in modulating colorectal cancer (CRC) metabolism and chemoresistance.MethodsA survey of miR-27a expression profile in TCGA-COAD dataset revealed that miR-27a-overexpressing CRCs are enriched in gene signatures of mitochondrial dysfunction, deregulated oxidative phosphorylation, mTOR activation and reduced chemosensitivity. The same pathways were analysed in cell lines in which we modified miR-27a levels. The response to chemotherapy was investigated in an independent cohort and cell lines.ResultsmiR-27a upregulation in vitro associated with impaired oxidative phosphorylation, overall mitochondrial activities and slight influence on glycolysis. miR-27a hampered AMPK, enhanced mTOR signalling and acted in concert with oncogenes and tumour cell metabolic regulators to force an aerobic glycolytic metabolism supporting biomass production, unrestricted growth and chemoresistance. This latter association was confirmed in our cohort of patients and cell lines.ConclusionsWe disclose an unprecedented role for miR-27a as a master regulator of cancer metabolism reprogramming that impinges on CRC response to chemotherapy, underscoring its theragnostic properties.

Background: The standard approach for locally advanced rectal cancer (LARC) is neoadjuvant chemoradiotherapy (nCRT) followed by total mesorectal excision (TME). After nCRT 20% of patients achieve a clinical complete response (pCR) and could be treated with a non-operative management (NOM). Methods: The panel of the Italian Association of Medical Oncology (AIOM) Guidelines on rectal cancer applied the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach addressing the following question: Should NOM vs. TME be used for patients with rectal cancer with clinical complete response after nCRT? Five outcomes were identified: disease-free survival (DFS), mortality, local recurrence, colostomy rate, and functional outcomes. Results: Nine studies were included in the analysis. A higher risk of disease recurrence was observed in the NOM group compared to the TME group (RR = 1.69, 95% CI 1.08, 2.64) on the other hand, we observed a slightly positive but not significant effect on mortality of NOM (RR = 0.82, 95% CI 0.46, 1.45). Patients in the NOM group were more likely to experience local recurrence (RR = 5.37, 95% CI 2.56, 11.27) and patients in the TME group were more likely to have a permanent colostomy (RR = 0.15, 95% CI 0.08, 0.29). Only one study evaluated functional outcomes. The overall certainty of evidence was rated as very low. Conclusions: NOM was found to correlate with a higher risk of local recurrence which did not translate in worse OS and a lower colostomy rate. Due to the paucity of evidences, no recommendations are possible. NOM remains an experimental treatment; thus, patients managed with NOM should be enrolled in clinical trials with a dedicated follow-up schedule.

Background Local excision might represent an alternative to total mesorectal excision for patients with locally advanced rectal cancer who achieve a major or complete clinical response after neoadjuvant chemoradiotherapy. Methods Between August 2005 and July 2011, 63 patients with mid-low rectal adenocarcinoma who had a major/complete clinical response after neoadjuvant chemoradiotherapy were enrolled in a multicenter prospective phase 2 trial and underwent transanal full thickness local excision. The main endpoint of this study was to evaluate the 5- and 10-year overall, relapse-free, local, and distant relapse-free survival, which were calculated by applying the Kaplan–Meier method. The rate of patients with rectum preserved and without stoma were also calculated. Results Of 63 patients, 38 (60%) were male and 25 (40%) were female, with a median (range) age of 64 (25–82) years. At baseline, the following clinical stages were found: cT2, n = 21 (33.3%); cT3, n = 42 (66.6%), 39 (61.9%) patients were cN+. At a median (range) follow-up of 108 (32–166) months, the estimated cumulative 5- and 10-year overall survival, relapse-free survival, local recurrence-free survival, and distant recurrence-free survival were 87% (95% CI 76–93) and 79% (95% CI 66–87), 89% (95% CI 78–94) and 82% (95% CI 66–91), both 91% (95% CI 81–96), and 90% (95% CI 80–95) and 86% (95% CI 73–93), respectively. Overall, 49 (77.8%) patients had their rectum preserved, and 54 (84.1%) were stoma-free. Conclusion In highly selected patients, the local excision approach after neoadjuvant chemoradiotherapy is associated with excellent long-term outcomes, high rates of rectum preservation and absence of permanent stoma.

Background and purpose: The role of the immune system in tumor response to chemo-radiotherapy (CRT) is an emerging issue. This work aimed at identifying predictive and prognostic immunogenetic variants in LARC patients after preoperative (po)-CRT and surgery. Materials and methods: A set of 192 polymorphisms in 34 candidate genes involved in the regulation of the immune response signalling network, was selected and analyzed in 370 LARC patients treated with po-CRT and surgery, split into a Test Set (n = 233) and a Validation Set (n = 137). Immunogenetic markers were selected based on a concordant significant effect on 2-year relapse-free survival (2-yrRFS) (bootstrapped P < 0.05) in both patients Sets. The effect of the selected immunogenetic variants on 5-year metastases-free (5yrMFS), 5-year disease-free (5yrDFS), and 10-year overall (10yrOS) survival was tested in the entire Set of 370 patients. Results: Two immunogenetic IL17F (IL17F-rs641701 and IL17F-rs9463772) markers predictive of 2yrRFS, 5yrDFS, 5yrMFS, and 10yrOS were identified. The combination of tumor regression grade (TRG) and patients genotype for IL17F-rs641701 and IL17F-rs9463772 allowed the identification of subgroups of patients with differential prognosis in term of both 5yrDFS (HR 11.29, P-value

Colorectal cancer (CRC) is the fourth cause of death from cancer worldwide mainly due to the high incidence of drug-resistance. During a screen for new actionable targets in drug-resistant tumours we recently identified p65BTK–a novel oncogenic isoform of Bruton's tyrosine kinase. Studying three different cohorts of patients here we show that p65BTK expression correlates with histotype and cancer progression. Using drug-resistant TP53-null colon cancer cells as a model we demonstrated that p65BTK silencing or chemical inhibition overcame the 5-fluorouracil resistance of CRC cell lines and patient-derived organoids and significantly reduced the growth of xenografted tumours. Mechanistically, we show that blocking p65BTK in drug-resistant cells abolished a 5-FU-elicited TGFB1 protective response and triggered E2F-dependent apoptosis. Taken together, our data demonstrated that targeting p65BTK restores the apoptotic response to chemotherapy of drug-resistant CRCs and gives a proof-of-concept for suggesting the use of BTK inhibitors in combination with 5-FU as a novel therapeutic approach in CRC patients. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Background and purpose: Capecitabine-based radiochemotherapy (cbRCT) is standard for preoperative long-course radiochemotherapy of locally advanced rectal cancer. This prospective, parallel-group, randomised controlled trial investigated two intensification regimens. cT4 lesions were excluded. Primary objective: pathological outcome (TRG 1-2) among arms.Materials and methods: Low-located cT2N0-2M0, cT3N0-2M0 (up to 12 cm from anal verge) presentations were treated with cbRCT randomly intensified by either radiotherapy boost (Xelac arm) or multidrug concomitant chemotherapy (Xelox arm). Xelac: concomitant boost to bulky site (45 Gy/1.8 Gy/die, 5 sessions/week to the pelvis, + 10 Gy at 1 Gy twice/week to the bulky) plus concurrent capecitabine (1650 mg/mq/die). Xelox: 45 Gy to the pelvis + 5.4 Gy/1.8 Gy/die, 5 sessions/week to the bulky site + concurrent capecitabine (1300 mg/mq/die) and oxaliplatin (130 mg/mq on days 1,19,38). Surgery was planned 7-9 weeks after radiochemotherapy.Results: From June 2005 to September 2013, 534 patients were analysed: 280 in Xelac, 254 in Xelox arm. Xelox arm presented higher G >= 3 haematologic (p = 0.01) and neurologic toxicity (p < 0.001). Overall, 98.5% patients received curative surgery. The tumour regression grade distribution did not differ between arms (p = 0.102). TRG 1+2 rate significantly differed: Xelac arm 61.7% vs. Xelox 52.3% (p = 0.039). Pathological complete response (ypT0N0) rates were 24.4 and 23.8%, respectively (p non-significant). Median follow-up: 5.62 years. Five-year disease-free survival rate were 74.7% (Xelac) and 73.8% (Xelox), respectively (p = 0.444). Five-year overall survival rate were 80.4% (Xelac) and 85.5% (Xelox), respectively (p = 0.155).Conclusion: Xelac arm significantly obtained higher TRG1-2 rates. No differences were found about clinical outcome. Because of efficacy on TRG, inferior toxicity and good compliance, Xelac schedules or similar radiotherapy dose intensification schemes could be considered as reference treatments for cT3 lesions. (C) 2018 Published by Elsevier B.V.

Background: No data is available on the molecular background of the extra-nodal extension (ENE) of lymph node metastasis (LN) in colorectal cancer (CRC). Methods: A series of 22 ENE-positive CRCs was considered and three samples per case were selected (the primary CRC, an ENE-negative and an ENE-positive metastatic LN). Samples (n=66) were analysed by immunohistochemistry for PD-L1, CD4, CD8, CD68 and CD80. Fifteen out of twenty-two cases were further profiled through a hotspot multigene mutational custom panel, including 164 hotspot regions of AKT1, APC, BRAF, CTNNB1, KIT, KRAS, NRAS, PDGFRA, PIK3CA, PTEN and TP53 genes. Results: A significantly higher percentage of CD4-, CD8- and CD68-positive cells was observed at the invasive front of both CRCs and in ENE in contrast with what observed at the core of both CRCs and their matched nodal metastases. ENE was also characterized by a significantly higher number of CD80-positive cells. No significant difference was observed in PD-L1 distribution among the different specimens. Fourteen out of 15 CRCs (93%) showed at least a driver mutation. The most frequently mutated gene was TP53 (n=8 tumors), followed by APC (n=6), BRAF (n=4), KRAS, NRAS and PIK3CA (n=2). In 11 out of 15 CRCs (73%) the mutational profiling of the primary tumor was consistent with what obtained from the two matched LNs. Conclusions: A heterogeneous intratumor immune-microenvironment has been observed in ENE-positive CRCs, which are characterized by an increased leukocytic infiltration at the ENE invasive front. © 2018 The Author(s).

Preoperative chemoradiotherapy is widely used to improve local control of disease, sphincter preservation and to improve survival in patients with locally advanced rectal cancer. Patients enrolled in the present study underwent preoperative chemoradiotherapy, followed by surgical excision. Response to chemoradiotherapy was evaluated according to Mandard’s Tumor Regression Grade (TRG). TRG 3, 4 and 5 were considered as partial or no response while TRG 1 and 2 as complete response. From pretherapeutic biopsies of 84 locally advanced rectal carcinomas available for the analysis, only 42 of them showed 70% cancer cellularity at least. By determining gene expression profiles, responders and non-responders showed significantly different expression levels for 19 genes (P < 0.001). We fitted a logistic model selected with a stepwise procedure optimizing the Akaike Information Criterion (AIC) and then validated by means of leave one out cross validation (LOOCV, accuracy D 95%). Four genes were retained in the achieved model: ZNF160, XRCC3, HFM1 and ASXL2. Real time PCR confirmed that XRCC3 is overexpressed in responders group and HFM1 and ASXL2 showed a positive trend. In vitro test on colon cancer resistant/susceptible to chemoradioterapy cells, finally prove that XRCC3 deregulation is extensively involved in the chemoresistance mechanisms. Protein-protein interactions (PPI) analysis involving the predictive classifier revealed a network of 45 interacting nodes (proteins) with TRAF6 gene playing a keystone role in the network. The present study confirmed the possibility that gene expression profiling combined with integrative computational biology is useful to predict complete responses to preoperative chemoradiotherapy in patients with advanced rectal cancer.

Surgery is the only curative treatment in patients with locally recurrent rectal cancer (LRRC). The aim of this study was to evaluate the outcome and the prognostic factors of tumour-free resection margin (R0) and overall survival (OS) in LRRC. METHODS: Consecutive LRRC patients observed between 1987 and 2005 in three Italian university hospitals were evaluated. Survival curves were estimated using the Kaplan-Meier method and compared with the log-rank test. In order to identify factors associated with both R0 resection and OS, a logistic regression analysis was performed in patients who underwent surgery with curative intent. RESULTS: Out of 150 patients with LRRC, 107 underwent surgery, but since 7 were found to have unresectable disease only 100 underwent surgical resection. Of them, 51 underwent radical and 49 extended resection. Sixty of the 107 patients underwent multimodality treatment. In 61 patients, R0 resection was achieved. Median OS after surgery was 43.4 months. In patients, who had surgery with curative intent, independent variables associated with R0 resection were: surgery for the primary tumour performed in other hospitals (p = 0.042) extended resection (p = 0.025) and use of positron emission tomography (PET) as a staging modality (p = 0.03). Independent variables associated with OS were: post-operative radiotherapy (p = 0.004), stage of the primary tumour (p = 0.004), R0 resection (p = 0.00001), and use of PET (0.02). CONCLUSIONS: Resection for LRRC results in improved survival. Other than the well-known prognostic factors R0 resection and OS, PET scan has an independent impact both on OS and R0 resection. It should therefore be included in routine clinical practice when staging LRRC.

Currently there is no reliable technique for predicting clinical or pathologic complete tumor response after radiochemotherapy (RCT) in patients with rectal cancer. We applied reverse phase protein microarray (RPMA) technology to find a signal pathway that may predict the response to preoperative treatment.Fifteen rectal cancer samples were collected during preoperative RCT. Seven patients had a good response to preoperative therapy (Mandard grade I-II) and 8 patients had a poor response (Mandard grade III-V). Using laser capture microdissection (LCM) and RPMA analysis, we measured the phosphorylation level of nearly 80 end points and analyzed the signaling pathways.We identified 4 signaling proteins whose phosphorylation levels were significantly different (P.05) between the good vs. poor responders; CHK2 and β-catenin were more highly phosphorylated in poor responders, whereas PDK1 and glycogen synthase kinase (GSK)-3α/β had lower phosphorylation levels in poor responders. Interestingly GSK-3α/β, β-catenin, and PDK1 are all present in the phosphatidylinositol-3-kinase (PI3K)-AKT signaling pathway.Based on our results, we hypothesize that the activating state of the PI3K-AKT pathway can stratify patients who could benefit most from neoadjuvant treatment. Moreover, identification of theranostic targets has the potential to pinpoint new therapeutic strategies for the nonresponsive population.

The aim of the study was the identification of a pharmacogenetic profile predictive of the tumor regression grade (TRG), considered as tumor response parameter, after neo-adjuvant treatment in rectal cancer patients. A total of 238 rectal cancer patients treated in a neo-adjuvant setting by a fluoropyrimidines-based chemo-radiotherapy (RT) were genotyped for 25 genetic polymorphisms in 16 genes relevant for treatment-associated pathways. Two polymorphisms were associated with TRG in a multivariate analysis: hOGG1-1245C>G, which can affect radiosensitivity and MTHFR-677C>T, which is involved in fluoropyrimidines action. Patients bearing at least one variant allele had a lower chance to get TRG T, which is responsible for the multi-drug resistance (odds ratio (OR)=1.96, 95% confidence interval (CI) 0.98-3.95, P=0.057). Exploratory classification and regression tree (CART) analysis highlighted high-order gene-gene and gene-environment interactions and a genetic signature associated with differential response, with hOGG1-1245C>G as the most predictive factor. Other significant variables were: ABCB1-3435C>T, MTHFR-677C>T, ERCC1-8092C>A, ABCC2-1249G>A, XRCC1-28152G>A, XRCC3-4541A>G and patients gender. On the basis of CART results, patients were categorized into three groups according to tumor response probability: intermediate and high profiles had a higher probability to get TRG G and MTHFR-677C>T polymorphisms in the tumor response of rectal cancer patients treated with chemo-RT in neo-adjuvant setting, and shows the relevance of gene-gene and gene-environment interactions for complex phenotypes as tumor response. The Pharmacogenomics Journal (2011) 11, 214-226; doi:10.1038/tpj.2010.25; published online 6 April 2010

UNLABELLED Tumour microsatellite instability (MSI) is useful in identifying patients with hereditary non-polyposis colorectal cancer (HNPCC) with defective DNA mismatch repair (MMR) genes. A reference Bethesda panel has limitations resulting from the inclusion of dinucleotide markers, which are less sensitive and specific for detection of tumours with MMR deficiencies. We developed a multiplex PCR assay with additional four mononucleotide markers and one dinucleotide marker (NR-21, NR-24, BAT-40, TGF-BetaR and D18S58) for a rapid and proper classification of MSI-H, MSI-L and MSS colorectal cancers. Two tetranucleotide markers were added to identify sample mix-ups and/or contamination. RESULTS all the 44 cases test cases were in agreement with previous classification except for three cases: one case MSI-H-Bethesda unstable only for dinucleotides markers shifted to MSI-L category and two cases MSI-L-Bethesda unstable for mononucleotide markers shifted to MSI-H category. Immunohistochemistry analysis revealed that these two MSI-H cases did not expressed hMLH1 and they were found to be methylated at the MLH1 promoter, while the first one that shifted to MSI-L showed MMR protein expression. CONCLUSION a complete panel of ten markers including four dinucleotide and six mononucleotide microsatellites allows accurate evaluation of tumor MSI status.

Aim Rectal cancer staging represents a crucial step to select the best treatment for this tumour. Particularly after neo-adjuvant chemoradiotherapy (CRT), it may influence the surgical procedure (e.g. radical resection vs. local excision). The aim of this study was to determine the best lymph node size cut-off at computed tomography (CT) to predict nodal metastasis in rectal cancer patients with and without preoperative CRT. Methods A consecutive series of patients operated on for primary mid–low rectal adenocarcinoma, all staged with pelvic CT scan, were subdivided as follows: those who underwent surgery alone treatment without CRT (Group A) and those who underwent preoperative CRT (Group B). All CT scans were re-viewed by a single radiologist and, based on the lymph node size, findings were compared with pathologic lymph node status (pN). At each lymph node size cut-off value, the following were calculated: accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). The best cut-off value was defined as having an accuracy ≥70% with the highest NPV. Results The study population consisted of 162 patients: Group A ( n = 52) and Group B ( n = 110). Patients classified as pN-positive ( n = 45) had a higher number of and larger sized lymph nodes by CT scan than patients classified as pN-negative ( n = 117). The cut-off values with an accuracy ≥70% ranged between 7 and 11 mm in Group A and between 9 and 14 mm in Group B. The cut-off with the best NPV was 7 mm for Group A and 10 mm for Group B. Conclusions Acknowledging the limitations of the dimensional criterion, lymph node size cut-off values found in our study may be useful for planning rectal cancer treatment using CT scan.

OBJECTIVE: The objective of the present study was to evaluate whether germline methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms as well as polymorphisms in the thymidylate synthase gene promoter, namely the variable number tandem repeat polymorphism (TS VNTR) and the intrarepeat G to C single nucleotide polymorphism (TS SNP), are predictive markers of tumor regression in rectal cancer patients following preoperative chemoradiotherapy. BASIC METHODS: Blood samples from 125 patients with primary adenocarcinoma of the mid-low rectum who received 5-fluorouracil-based chemotherapy and external beam radiotherapy (median dose 48.4 Gy), 125 patients (women n=45, men n=80; median age 60 years, range 31-79 years) were genotyped. Response to preoperative treatment was evaluated employing the Tumor Regression Grade criteria. On the basis of the pathologic response, patients were classified as responders (TRG 1-2, n=48) and non-responders (TRG 3-5, n=74). Three patients were excluded because of insufficient data. MAIN RESULTS: Among the polymorphic variants examined, the MTHFR 677T-1298A haplotype was, upon univariate analysis, the only variable found associated with tumor regression (P=0.004). Moreover, at multivariate analysis, the MTHFR 677T-1298A haplotype was an independent predictor of tumor regression. Patients not carrying the MTHFR 677T-1298A haplotype (odds ratio 0.29, 95% confidence interval 0.13-0.64, P=0.002) displayed a higher response rate than patients with the MTHFR 677T-1298A haplotype. CONCLUSIONS: Unlike TS VNTR and SNP polymorphisms, MTHFR 677T-1298A haplotype in genomic DNA has the potential to be a predictive marker of tumor response in rectal cancer patients submitted to preoperative chemoradiotherapy.