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Recent evidence suggests that Fusobacterium nucleatum (Fn) is associated with the development and progression of colorectal cancer. We aimed to delineate the clinical implications of Fn in metastatic colon cancer. We performed quantitative polymerase chain reaction (qPCR) using DNA samples from synchronous metastatic colon cancer patients with either formalin-fixed paraffin-embedded (FFPE) archival primary site tumor samples or fresh colon tissues. Progression-free survival (PFS)1 and PFS2 were defined as PFS of first- and second-line palliative settings. qPCR for Fn was successfully performed using 112 samples (FFPE, n = 61; fresh tissue, n = 51). Forty-one and 68 patients had right-sided and left-sided colon cancer, respectively. Patients with Fn enriched right-sided colon cancers had shorter PFS1 (9.7 vs. 11.2 months) than the other subgroups (HR 3.54, 95% confidence interval [CI] 1.05–11.99; P = 0.04). Fn positive right-sided colon was also associated with shorter PFS2 (3.7 vs. 6.7 months; HR 2.34, 95% CI 0.69–7.91; P = 0.04). In the univariate analysis, PFS1 was affected by differentiation and Fn positive right-sided colon cancer. The multivariate analysis showed that differentiation (HR 2.68, 95% CI 1.40–5.14, P = 0.01) and Fn positive right-sided colon (HR 0.40, 95% CI 0.18–0.88, P = 0.02) were associated with PFS1. Fn enrichment in right sided colon was not associated with overall survival (OS). Fn enrichment has significantly worse prognosis in terms of PFS1 and PFS2 in patients with right-sided metastatic colon cancers.

Although the safety and feasibility of conventional laparoscopic surgery (CLS) for appendiceal mucocele (AM) has been reported, studies on single-incision laparoscopic surgery (SILS) for AM have not been reported. Here, we aimed to compare the perioperative and short-term outcomes between SILS and CLS for AM and to evaluate the oncological safety of SILS. We retrospectively analyzed the medical records of patients, diagnosed based on computed tomography findings, who underwent laparoscopic surgery for AM between 2010 and 2018 at one institution. We excluded patients strongly suspected of having malignant lesions and those with preoperative appendiceal perforation. Patients were divided into two groups—CLS and SILS. Pathological outcomes and long-term results were investigated. The median follow-up period was 43.7 (range: 12.3–118.5) months. Ultimately, 116 patients (CLS = 68, SILS = 48) were enrolled. Patient demographic characteristics did not differ between the groups. The preoperative mucocele diameter was greater in the CLS than in the SILS group (3.2 ± 2.9 cm vs. 2.3 ± 1.4 cm, P = 0.029). More extensive surgery (right hemicolectomies and ileocecectomies) was performed in the CLS than in the SILS group (P = 0.014). Intraoperative perforation developed in only one patient per group. For appendectomies and cecectomies, the CLS group exhibited a longer operation time than the SILS group (63.3 ± 24.5 min vs. 52.4 ± 17.3 min, P = 0.014); the same was noted for length of postoperative hospital stay (2.9 ± 1.8 days vs. 1.7 ± 0.6 days, P

Background and objectives This study aimed to investigate the clinical course and prognostic factors after isolated local recurrence (iLR) and to identify the predictive factors for R0 resection of locally recurrent rectal cancer (LRRC). Methods We retrospectively reviewed the medical records of 76 patients with iLR who had undergone radical surgery for a primary tumor from 2003 to 2015. Results The iLR rate was 2.5%. From 76 patients, 39 patients underwent R0 resection for iLR. Multivariate analysis revealed that initial open surgery, neoadjuvant chemoradiation, and p/ypT ≥ 3 were poor prognostic factors after iLR as regard to the variables related to the primary tumor; and symptom presence at the time of iLR diagnosis, higher fixity, and no chemotherapy after iLR were associated with shorter overall survival after iLR, and R0 resection of LRRC was the only favorable prognostic factor for progression-free survival after iLR as regard to the variables related to LRRC. Higher tumor level, negative pathologic circumferential margin of the primary tumor, and low fixity of LRRC were favorable factors in achieving R0 resection of LRRC. Conclusions Early detection of iLR before symptom development, use of chemotherapy after iLR and R0 resection of LRRC should be considered to improve survival outcomes after iLR.

BACKGROUND Comparable to circumferential resection margin in rectal cancer, radial margin is a potential prognostic factor in colon cancer that has just begun to be studied. No previous studies have investigated the influence of radial margin in the context of complete mesocolic excision. OBJECTIVE This study aimed to examine the impact of radial margin on oncologic outcomes after complete mesocolic excision for colon cancer. DESIGN We retrospectively reviewed patients with stage I to III colon cancer who underwent curative resection from October 2010 to March 2013. SETTINGS This study was conducted using the prospective colorectal cancer registry of Severance hospital. PATIENTS A total of 834 consecutive patients who underwent complete mesocolic excision for colon adenocarcinoma were included. INTERVENTIONS We assigned patients into 3 groups according to radial margin distance: group A, radial margin ≥2.0 mm; group B, 1.0 ≤ radial margin < 2.0 mm; group C, radial margin

Although studies of robotic rectal cancer surgery have demonstrated the effects of learning on operation time, comparisons have failed to demonstrate differences in clinicopathological outcomes between unadjusted learning phases. This study aimed to investigate the learning curve of robotic rectal cancer surgery for clinicopathological outcomes and compare surgical outcomes between adjusted learning phases. Study design We enrolled 506 consecutive patients with rectal adenocarcinoma who underwent robotic resection by a single surgeon between 2007 and 2018. Risk-adjusted cumulative sum (RA-CUSUM) for surgical failure was used to analyze the learning curve. Surgical failure was defined as the occurrence of any of the following: conversion to open surgery, severe complications (Clavien–Dindo grade ≥ 3a), insufficient number of harvested lymph nodes (LNs), or R1 resection. Comparisons between learning phases analyzed by RA-CUSUM were performed before and after propensity score matching. In RA-CUSUM analysis, the learning curve was divided into two learning phases: phase 1 (1st–177th cases, n = 177) and phase 2 (178th–506th cases, n = 329). Before matching, patients in phase 2 had deeper tumor invasion and higher rates of positive LNs on pretreatment images and preoperative chemoradiotherapy. After matching, phase 1 (n = 150) and phase 2 (n = 150) patients exhibited similar clinical characteristics. Phase 2 patients had lower rates of surgical failure overall and these components: conversion to open surgery, severe complications, and insufficient harvested LNs. For robotic rectal cancer surgery, surgical outcomes improved after the 177th case. Further studies by other robotic surgeons are required to validate our results.

Purpose Upfront systemic chemotherapy with target agents has been recommended for patients with stage IV colon cancer. Some with partial response are considered for curative resection. There is high risk of developing postoperative complications following upfront systemic chemotherapy. We aimed to evaluate short-term perioperative outcomes of curative surgery after upfront chemotherapy in comparison with upfront surgery in patients with metastatic colon cancer. Methods Between January 2010 and October 2015, 146 patients (80 in the surgery first group, 66 in the upfront chemotherapy group) who underwent surgical resection before or after systemic chemotherapy for metastatic colon cancer were included in the present study. All decisions for treatment were made through a multidisciplinary team. Postoperative clinical outcomes and complications were analyzed to compare the groups. Results There was no difference between the 2 groups in terms of postoperative clinical outcomes. Overall complication rates were not different between the groups (surgery first group: 46.3% vs. upfront chemotherapy group: 60.6%; P = 0.084). When classified according to the Clavien-Dindo method, there was no difference between the 2 groups in terms of major complications (grade 3 or more) (surgery first group: 18.9% vs. upfront chemotherapy group: 27.5%; P = 0.374). Conclusion There was no significant increase in major postoperative complications in metastatic colon cancer patients who received upfront chemotherapy followed by curative surgery. Careful patient selection and treatment planning are important.

Purpose Tailgut cysts are rare congenital or developmental lesions that arise from vestiges of the embryological hindgut. They are usually present in the presacral space. We report our single-center experience with managing tailgut cysts. Methods We conducted a retrospective analysis of 24 patients with tailgut cyst treated surgically at the Colorectal Surgery Department of Severance Hospital, Yonsei University, Seoul, South Korea, between 2007–2018. Results This study included 24 patients (18 females) with a median age of 51.5 years (range, 21–68 years). Ten cases were symptomatic and 14 were asymptomatic. Cysts were retrorectal in 21 patients. Cysts were below the coccyx level in 16 patients, opposite the coccyx in 6, and above the coccyx in 2. Cysts were supralevator in 5 patients, had a supra- and infralevator extension in 18 patients, and were infralevator in 1. Ten patients were managed using an anterior laparoscopic approach, 11 using a posterior approach, and 3 using a combined approach. Mean cyst size was 5.5 ± 2.7 cm. Postoperative complications were Clavien-Dindo (CD) classification grade II in 9 patients (37.5%) and CD grade III in 1 (4.2%). The posterior approach group showed the highest rate of complications (P = 0.021). Patients managed using a combined approach showed a larger cyst size (P < 0.001), longer operation times (P < 0.001), and a greater likelihood of tumor level above the coccyx (P = 0.002) compared to other approaches. The tumors of 2 male patients were malignant: 1 was a neuroendocrine tumor treated with radiotherapy, while the other was a closely followed adenocarcinoma. Median follow-up was 12 months (range, 1–66 months) with no recurrence. Conclusion Tailgut cysts are uncommon but can cause perineal or pelvic pain. Complete surgical excision via an appropriate approach according to tumor size, location, and correlation with adjacent pelvic floor muscles is the key treatment.

Total mesorectal excision (TME) is challenging to perform in a deep, narrow pelvis. While previous studies used pelvimetry to assess bony pelvic structures, there is no consensus on exact definition of deep, narrow pelvis. We hypothesized that the shape of pelvic floor muscle may impact the performance of transabdominal pelvic dissection. We aimed to evaluate which parameters of the shape of pelvic floor muscle impact the difficulty of TME and present a predictive reference value for TME difficulty. From January 2015 to December 2015, 85 consecutive patients who had undergone curative resection for middle to lower rectal cancer were retrospectively studied. Pelvimetry was performed using preoperative T2-weighted magnetic resonance imaging. Predictive factor analysis for surgical duration was studied using linear regression. Mann–Whitney U test, comparing surgical duration between two groups classified by predictive factor, was used for the analysis of reference value. Multivariate analysis revealed that body mass index, protective stoma, number of surgeon, and incline angle of pelvic floor muscle (β) were independent predictors of surgical duration. Test statistics of Mann–Whitney U for the difference in surgical duration between groups above and below a β of 54° were maximized. The incline angle of pelvic floor muscle is an independent predictor of surgical duration. In patients with steeper incline of PFM, transabdominal TME is expected to be difficult. This index is novel, but needs to be further validated.

With increasing rates of sphincter preservation because of advances in preoperative chemoradiation, restoration of bowel continuity has become a main goal of rectal cancer treatment. However, in many patients, postoperative bowel dysfunction negatively affects the quality of life.This study aimed to analyze predictors of bowel dysfunction after sphincter-preserving surgery in patients with rectal cancer.This was a cross-sectional study.Assessment of bowel dysfunction was conducted between November 2015 and June 2017 at our institution.A total of 316 patients with rectal cancer who underwent sphincter-preserving surgery between February 2009 and April 2017 and agreed with an interview for assessing bowel dysfunction were included.Bowel dysfunction was assessed with the Memorial Sloan Kettering Cancer Center Bowel Function Instrument and Wexner score. All the assessments were conducted face-to-face by the same interviewer.The median time interval between the restoration of bowel continuity and assessment was 10 months (interquartile range, 3-37), and the median total Memorial Sloan Kettering Cancer Center and Wexner scores were 65 (interquartile range, 58-73) and 6 (interquartile range, 0-11). The time interval was correlated with the Memorial Sloan Kettering Cancer Center scores (rho, 0.279) and Wexner scores (rho, -0.306). In a multivariate analysis, handsewn anastomosis and short time interval (≤1 year) were independently associated with poor bowel function (Memorial Sloan Kettering Cancer Center score ≤65). A short time interval (≤1 year), preoperative chemoradiation, and ileostomy were independently associated with major fecal incontinence (Wexner ≥8).Selection bias may be inherent.Bowel function recovers with time after the restoration of bowel continuity. A short time interval, handsewn anastomosis, preoperative chemoradiation, and ileostomy were significantly associated with poor bowel function or major fecal incontinence. Surgeons should discuss postoperative bowel dysfunction and its predictive factors with the patients. See Video Abstract at http://links.lww.com/DCR/A930.

BACKGROUND A survival paradox of stage IIB/IIC and IIIA colon cancer has been consistently observed throughout revisions of the TNM system. This study aimed to understand this paradox with clinicopathological and molecular differences. METHODS Clinicopathological characteristics of patients with pathologically confirmed stage IIB/IIC or IIIA colon cancer were retrospectively reviewed from a database. Publicly available molecular data were retrieved, and intrinsic subtypes were identified and subjected to gene sets enrichment analysis (GSEA). RESULTS Among the 159 patients included in the clinicopathological analysis, those at stage IIB/IIC had worse 3-year disease-free and overall survival than those at stage IIIA (59.3% vs 91.7%, P

Although self-expandable metal stents (SEMS) are widely used as a bridge to surgery (BTS) in patients with malignant colorectal cancer obstruction, there has been some debate about their effect on long-term oncological outcomes. Furthermore, data on the safety and feasibility of minimally invasive surgery (MIS) combined with stent placement are scarce. We aimed to determine the long-term oncological outcomes of SEMS as a BTS, and the short-term outcomes of SEMS used with minimally invasive colorectal surgery. Data from patients who were admitted with malignant obstructing colon cancer between January 2006 and December 2015 were retrospectively reviewed; 71 patients underwent direct surgery and 182 patients underwent SEMS placement as a BTS. Long-term and short-term outcomes of the groups were compared. In a subgroup analysis of the BTS group, the short-term outcomes of conventional open surgery and MIS were compared. There were no differences in long-term oncologic outcomes between groups. The primary anastomosis rate was higher in the stent group than in the direct surgery group. In the stent group, postoperative complication rates were lower in the minimally invasive group than in the open surgery group. Time to flatus and time to soft diet resumption were shorter in the minimally invasive group, as was length of hospital stay. Elective surgery after stent insertion does not adversely affect long-term oncologic outcomes. Furthermore, MIS combined with stent insertion for malignant colonic obstruction is safe and feasible.

BackgroundAlthough the current standard preoperative chemoradiotherapy (PCRT) for stage II/III rectal cancer decreases the risk of local recurrence, it does not improve survival and increases the likelihood of preoperative overtreatment, especially in patients without circumferential resection margin (CRM) involvement.MethodsStage II/III rectal cancer without CRM involvement and lateral lymph node metastasis was radiologically defined by preoperative magnetic resonance imaging (MRI). Patients who received PCRT followed by total mesorectal excision (TME) (PCRT group) and upfront surgery (US) with TME (US group) between 2010 and 2016 were analyzed. We derived cohorts of PCRT group versus US group using propensity-score matching for stage, age, and distance from the anal verge. Three-year relapse-free survival rate, disease-free survival (DFS), and overall survival (OS) were compared between the two groups.ResultsA total of 202 patients were analyzed after propensity score matching. There were no differences in baseline characteristics. The median follow-up duration was 62 months (interquartile range, 46–87). There was no difference in the 3-year disease-free survival rate between the PCRT and US groups (83 vs. 88%, respectively; p=0.326). Likewise, there was no significant difference in the 3-year OS (89 vs. 91%, respectively; p=0.466). The 3-year locoregional recurrence rates (3 vs. 2% with US, p=0.667) and distant metastasis rates (16 vs. 11%, p=0.428) were not significantly different between the two groups. Time to completion of curative treatment was significantly shorter in the US group (132 days) than in the PCRT group (225 days) (pConclusionUsing MRI-guided selection for better risk stratification, US without neoadjuvant therapy can be considered in early stage patients with good prognosis. PCRT may not be required for all stage II/III rectal cancer patients, especially for the MRI-proven intermediate-risk group (cT1-2/N1, cT3N0) without CRM involvement and lateral lymph node metastasis. Further prospective studies are warranted.

Background The introduction of complete mesocolic excision (CME) with central vascular ligation (CVL) for right-sided colon cancer has improved the oncologic outcomes. Recently, we have introduced a modified CME (mCME) procedure that keeps the same principles as the originally described CME but with a more tailored approach. Some retrospective studies have reported the favourable oncologic outcomes of laparoscopic mCME for right-sided colon cancer; however, no prospective multicentre study has yet been conducted. Methods This study is a multi-institutional, prospective, single-arm study evaluating the oncologic outcomes of laparoscopic mCME for adenocarcinoma arising from the right side of the colon. A total of 250 patients will be recruited from five tertiary referral centres in South Korea. The primary outcome of this study is 3-year disease-free survival. Secondary outcome measures include 3-year overall survival, incidence of surgical complications, completeness of mCME, and distribution of metastatic lymph nodes. The quality of laparoscopic mCME will be assessed on the basis of photographs of the surgical specimen and the operation field after the completion of lymph node dissection. Discussion This is a prospective multicentre study to evaluate the oncologic outcomes of laparoscopic mCME for right-sided colon cancer. To the best of our knowledge, this will be the first study to prospectively and objectively assess the quality of laparoscopic mCME. The results will provide more evidence about oncologic outcomes with respect to the quality of laparoscopic mCME in right-sided colon cancer. Trial registration ClinicalTrials.gov ID: NCT03992599 (June 20, 2019). The posted information will be updated as needed to reflect protocol amendments and study progress.

Summary: Background/objective: Some locally advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (CRT) prior to total mesorectal excision (TME) show early recurrence with a short disease-free interval. This is unacceptable for patients and their families, necessitating re-evaluation of the treatment process. We aimed to evaluate the risk factors and prognostic impact of early recurrence in patients who received preoperative CRT (pCRT) followed by TME for LARC. Methods: Of 714 patients who underwent curative resection after pCRT for LARC from January 2010 to December 2016, we included 139 who developed recurrence after resection. Patients were divided into an early recurrence group, diagnosed

Although multiple studies have examined anastomotic leakage (AL) after low anterior resection (LAR), their definitions of AL varied, and few have studied late diagnosed AL after surgery. This study aimed to characterize late AL after anal sphincter saving surgery (SSS) for rectal cancer by examining clinical characteristics, risk factors, and management of patients with late AL compared with early AL. Data from January 2005 to December 2014 were collected from a total of 1903 consecutive patients who underwent anal sphincter saving surgery for rectal cancer and were retrospectively reviewed. Late AL was defined as AL diagnosed more than 30 days after surgery. Variables and risk factors associated with early and late diagnosed AL were analyzed by multivariate logistic regression. Overall, early, and late rates of AL were 13.7%, 6.7%, and 7%, respectively. Receiving neoadjuvant chemoradiotherapy (nCRT) was a risk factor for developing late AL, but not early AL (OR, 3.032; 95% CI, 1.947–4.722; p

Tumor location and KRAS mutational status have emerged as prognostic factors of colorectal cancer. We aimed to define the prognostic impact of primary tumor location and KRAS mutational status among synchronous colorectal liver metastases (CRLM) patients who underwent simultaneous curative-intent surgery (SCIS). We compared the clinicopathologic characteristics and long-term outcomes of 227 patients who underwent SCIS for synchronous CRLM, according to tumor location and KRAS mutational status. We cross-classified tumor location and KRAS mutational status and compared survival outcomes between the four resulting patient groups. Forty-one patients (18.1%) had right-sided (RS) tumors and 186 (81.9%) had left-sided (LS) tumors. One-third of tumors (78/227) harbored KRAS mutations. The KRAS mutant-type (KRAS-mt) was more commonly observed among RS tumors than among LS tumors [21/41 (51.2%) vs. 57/186 (30.6%), p = 0.012]. Median follow-up time was 43.4 months. Patients with RS tumors had shorter survival times than those with LS tumors [median disease-free survival (DFS): RS, 9.9 months vs. LS, 12.1 months, p = 0.003; median overall survival (OS): RS, 49.7 months vs. LS, 88.8 months, p = 0.039]. RS tumors were a negative prognostic factor for DFS [hazard ratio (HR) 1.878, p = 0.001] and OS (HR 1.660, p = 0.060). RS KRAS-mt and LS KRAS wild-type (KRAS-wt) tumors had the worst and best oncological outcomes, respectively. Tumor location has a prognostic impact in patients who underwent SCIS for CRLM, and RS KRAS-mt tumors yielded the worst oncological outcome. These results may allow for more tailored multimodality treatments.

We compared short-term and long-term surgical and oncological outcomes of robotic surgery versus hand-assisted laparoscopic surgery for rectal cancers patients. Study was conducted at the National Cancer Institute and Yonsei Cancer Centre from August 2006 to December 2012. We prospectively reviewed all patients who underwent RS and HALS for upper and middle third rectal cancers. Patients’ demographics, postoperative short-term and long-term outcomes were assessed. Baseline patients’ characteristics were similar in both groups. Average operative time was 321.3 ± 70 min for robotic surgery versus 106.0 ± 37 min for hand-assisted laparoscopic surgery, P < 0.001). Higher number of patients (n = 74, 94.9%) with tumour in the upper rectum was found in hand-assisted laparoscopic group (P < 0.01). Perioperative complications were more common in the robotic surgery group (9 vs. 5 patients). In all stages, 3-year overall survival was 86.9% in the hand-assisted laparoscopic group vs. 89.6% in the robotic group: 80.0% vs. 79.2 for stage I and 82.4% vs. 88.9 for stage II and III. The 3-year DFS was 83.6% in hand-assisted laparoscopic group vs. 83.2%—robotic surgery group considering all stages. Anastomotic leakage, bleeding, number of postoperative complications, overall survival and disease-free survival were similar and not much different between robotic and hand-assisted laparoscopic rectal cancer surgery.

Senescent T cells have been implicated in chronic inflammatory and cardiovascular diseases. In this study, we explored the relationship between senescent T cells and glycemic status in a cohort of 805 participants by investigating the frequency of CD57+ or CD28null senescent T cells in peripheral blood. Participants with normal glucose tolerance (NGT) with follow-up data (N = 149) were included to determine whether hyperglycemia (prediabetes or type 2 diabetes) developed during follow-up (mean 2.3 years). CD8+CD57+ and CD8+CD28null T-cell frequencies were significantly higher in prediabetes and type 2 diabetes compared with NGT. Increased CD57+ or CD28null cells in the CD8+ T-cell subset were independently associated with hyperglycemia. Furthermore, among participants with baseline NGT, the frequency of CD8+CD57+ T cells was an independent predictor of hyperglycemia development. Immunofluorescent analyses confirmed that CD8+CD57+ T-cell infiltration was increased in visceral adipose tissue of patients with prediabetes or type 2 diabetes compared with those with NGT. Our data suggest that increased frequency of senescent CD8+ T cells in the peripheral blood is associated with development of hyperglycemia.

PD-1–based cancer immunotherapy is a successful example of immune checkpoint blockade that provides long-term durable therapeutic effects in patients with cancer across a wide spectrum of cancer types. Accumulating evidence suggests that anti-PD-1 therapy enhances antitumor immunity by reversing the function of exhausted T cells in the tumor environment. However, the responsiveness rate of patients with cancer to anti-PD-1 therapy remains low, providing an urgent need for optimization and improvement. In this study, we designed an anti-PD-1–resistant mouse tumor model and showed that unresponsiveness to anti-PD-1 is associated with a gradual increase in CD8 T-cell exhaustion. We also found that invariant natural killer T cell stimulation by the synthetic ligand α-galactosylceramide (αGC) can enhance the antitumor effect in anti-PD-1–resistant tumors by restoring the effector function of tumor antigen–specific exhausted CD8 T cells. IL2 and IL12 were among the cytokines produced by αGC stimulation critical for reinvigorating exhausted CD8 T cells in tumor-bearing mice and patients with cancer. Furthermore, we observed a synergistic increase in the antitumor effect between αGC-loaded antigen-presenting cells and PD-1 blockade in a therapeutic murine tumor model. Our study suggests NKT cell stimulation as a promising therapeutic strategy for the treatment of patients with anti-PD-1–resistant cancer. Significance: These findings provide mechanistic insights into the application of NKT cell stimulation as a potent adjuvant for immunotherapy against advanced cancer. Cancer Res; 78(18); 5315–26. ©2018 AACR.

Peritoneal carcinomatosis (PC) was previously considered an incurable disease with a poor survival outcome. As our understanding of its biology evolved, the paradigm of the management of PC from colorectal cancer (CRC) has changed, including the combination of macroscopic disease control, cytoreductive surgery (CRS), maximal regional chemotherapy to treat residual microscopic disease, and hyperthermic intraperitoneal chemotherapy (HIPEC). As with many surgical innovations, CRS with HIPEC has evolved faster than data to support it, leaving many skeptics and critics. This review highlights the recent evidence of current practice and outcome of CRS with HIPEC. Furthermore, it also summarizes the ongoing clinical trials and potential future progress of this treatment modality.

Increased expression of coinhibitory molecules such as PD-1 and Tim-3 on NK cells has been demonstrated in advanced cancer patients who harbor MHC class I–deficient tumors. However, even in preclinical models, the antitumor effects of checkpoint blockade on NK cells have not been clearly elucidated. Here, we show that anti–PD-1/anti–Tim-3 treatment suppressed tumor progression in mice bearing MHC class I–deficient tumors, and the suppression was further enhanced by recombinant IL21 (rIL21) treatments through an NK-cell–dependent mechanism. We also show that the intratumoral delivery of rIL21 attracted NK cells to the tumor site in a CXCR3-dependent fashion. A combination of IL21 and checkpoint blockade facilitated the effector function of exhausted NK cells in cancer patients. Given the effects of the checkpoint blockade and rIL21 combination on NK cells infiltrating into MHC class I–deficient tumors, we suggest that the efficacy of checkpoint blockade can be enhanced through the administration of IL21 for advanced cancer patients with MHC class I–low/deficient tumors. Cancer Immunol Res; 6(6); 685–95. ©2018 AACR.

Introduction There was no report for comparing long-term survival group with short-term survival group in patients who underwent liver resection for colorectal cancer with liver metastasis. Here, we compared the difference between the short-term and long-term survivors and analyzed the factors that influence the prognosis. Methods From January 2016 to December 2018, liver resections were performed for 478 patients of liver metastasis at the Yonsei University Severance Hospital. Except 111 patients due to lack of data, total 367 patients were analyzed retrospectively. Patients were divided into two groups: those who survived less than 24 months (short-term survival group, n = 87) and those who survived more than 24 months (long-term survival group, n = 280). Results In the short-term survival group, there were more patients with tumor size of 2 cm or more than the long-term survival group (p = 0.017). And the short-term survival group had more patients with margin positive than the long-term survival group (p < 0.05). The long-term survival group had more patients with single lesion than the short-term survival group (p = 0.028). In cox regression analysis, tumor size, tumor number, and resection margin were the prognostic factors effect survival. Conclusions For long-term survival of patients with liver metastasis of colorectal cancer, when deciding whether to undergo liver resection, whether a tumor smaller than 2 cm or a single lesion or curative resection is possible should be considered.

During cancer immunoediting, loss of major histocompatibility complex class I (MHC-I) in neoplasm contributes to the evasion of tumours from host immune system. Recent studies have demonstrated that most natural killer (NK) cells that are found in advanced cancers are defective, releasing the malignant MHC-I-deficient tumours from NK-cell-dependent immune control. Here, we show that a natural killer T (NKT)-cell-ligand-loaded tumour-antigen expressing antigen-presenting cell (APC)-based vaccine effectively eradicates these advanced tumours. During this process, we find that the co-expression of Tim-3 and PD-1 marks functionally exhausted NK cells in advanced tumours and that MHC-I downregulation in tumours is closely associated with the induction of NK-cell exhaustion in both tumour-bearing mice and cancer patients. Furthermore, the recovery of NK-cell function by IL-21 is critical for the anti-tumour effects of the vaccine against advanced tumours. These results reveal the process involved in the induction of NK-cell dysfunction in advanced cancers and provide a guidance for the development of strategies for cancer immunotherapy., Loss of major histocompatibility complex MHC-I expression contributes to cancer immune evasion. Here, the authors show that, in both mice and humans, MHC-I downregulation is associated with the induction of NK-cell exhaustion and that IL-21 restores NK-cell function and inhibits tumours progression.

Background Trans-anal endoscopic operation (TEO) has developed to facilitate proper tumor location and ensure excision safely. Methods We reviewed 92 patients enrolled in our database between 2006 and 2014 who were diagnosed with early rectal tumors and who underwent conventional trans-anal excision (TAE) or TEO. Clinical data were collected prospectively to compare safety and feasibility between two techniques. Results Ninety-two patients underwent trans-anal local excision for lower rectal tumors. TEO and TAE were performed in 48 and 44 patients, respectively. Age, sex, and comorbidities were similar. There was no significant difference in tumor diameter (1.6 ± 1.68 cm vs. 1.17 ± 1.17, respectively). Tumor height, however, was higher in the TEO (7.46 ± 3 cm) than the TAE group (3.84 ± 1.88 cm, p, Highlights • TEO is treatment modality of choice in addressing lower rectal lesions. • Evolving of TEO technique facilitate higher standard of academic teaching. • TEO has few drawbacks; first, long term learning curve; second, technique is demanding (through single port + narrow space). • TEO has promising results in the field of surgical oncology with equivalent results to conventional surgery.

Purpose Previous studies have demonstrated the prognostic impact of the prognostic nutritional index (PNI), a proposed indicator of immunonutritional statuses of surgical patients, on patients with various gastrointestinal cancers. Although the prognostic impact of the PNI on patients with colorectal cancer has been well established, its value has not been studied in patients treated with preoperative chemoradiation (pCRT). This study aimed to evaluate the prognostic impact of PNI on patients receiving pCRT for locally advanced rectal cancer (LARC). Methods Patients with LARC who underwent curative pCRT followed by surgical resection were enrolled. The PNI was measured in all patients before and after pCRT, and the difference in values was calculated as the PNI difference (dPNI). Patients were classified according to dPNI (10). Clinicopathologic parameters and long-term oncologic outcomes were assessed according to dPNI classification. Results No significant intergroup differences were observed in clinicopathologic parameters such as age, histologic grade, tumor location, tumor-node-metastasis stage, and postoperative complications. Approximately 53% of the patients had a mild dPNI (10). Univariate and multivariate analyses identified the dPNI as an independent prognostic factor for disease-free status (P < 0.01; hazard ratio [HR], 2.792; 95% confidence interval [CI], 1.577–4.942) and for cancer-specific survival (P = 0.012; HR, 2.469; 95%CI, 1.225–4.978). Conclusion The dPNI is predictive of long-term outcomes in pCRT-treated patients with LARC. Further prospective studies should investigate whether immune-nutritional status correction during pCRT would improve oncologic outcomes.

Background Despite acceptable oncologic outcomes of sphincter preserving surgeries for low rectal cancer, bowel dysfunction occurs. This study aimed to compare the oncologic and functional bowel outcomes between ultralow anterior resection (ULAR) and intersphincteric resection (ISR) for low rectal cancer. Methods One hundred sixty-four patients who underwent ULAR with or without ISR for low rectal cancer between December 2010 and May 2018 were included. The Wexner and Memorial Sloan Kettering Cancer Center (MSKCC) scores were used to evaluate the bowel function of patients. Overall survival (OS) and disease-free survival (DFS) were compared between patients. Results The ISR group had higher incidence of major fecal incontinence than the ULAR group (75.9% vs 49.3%; P = .016). The median Wexner score decreased from 12 to 9 (P = .062) at 1-year follow-up. However, the frequency and urgency/soilage subscales of MSKCC score improved significantly in the ULAR group. ISR and follow-up interval less than 1-year significantly increased the major incontinence risk. The OS in the ULAR and ISR groups was 91.4% and 91.7%. Whereas the DFS in both groups was 79% and 79.2%, respectively. Conclusion ULAR and ISR are comparable in oncologic outcomes. Severe bowel dysfunctions and major incontinence were noted in ISR group. Careful selection of patients is mandatory.

Background Colorectal cancer (CRC) screening can effectively reduce disease-related mortality by detecting CRC at earlier stages. We have previously demonstrated that the presence of SDC2 methylation in stool DNA is significantly associated with the occurrence of CRC regardless of clinical stage. The aim of this study was to evaluate the clinical performance of stool DNA-based SDC2 methylation test for CRC. Methods Aberrant SDC2 methylation in stool-derived DNA was measured by linear target enrichment (LTE)-quantitative methylation-specific real-time PCR (qMSP). Duplicate reactions of meSDC2 LTE-qMSP test were performed for stool samples obtained from CRC patients representing all stages (0–IV) and asymptomatic individuals who were subsequently underwent colonoscopy examination. To determine the diagnostic value of test in CRC and control groups, sensitivity and specificity were evaluated by receiver operating characteristic curve analysis. Results Of 585 subjects who could be evaluated, 245 had CRC, 44 had various sizes of adenomatous polyps, and 245 had negative colonoscopy results. Stool DNA-based meSDC2 LTE-qMSP showed an overall sensitivity of 90.2% with AUC of 0.902 in detecting CRC (0–IV) not associated with tumor stage, location, sex, or age (P > 0.05), with a specificity of 90.2%. Sensitivity for detecting early stages (0-II) was 89.1% (114/128). This test also detected 66.7% (2/3) and 24.4% (10/41) of advanced and non-advanced adenomas, respectively. Conclusions Results of this study validated the capability of stool DNA based-SDC2 methylation test by LTE-qMSP for early detection of CRC patient with high specificity. Trial registration ClinicalTrials.gov, NCT03146520, Registered 10 May 2017, Retrospectively registered; however, control arm was prospectively registered.

Aim: To investigate the level of vessel ligation in splenic flexure cancer (SFC) in term of oncology outcome and overall survival.

Classic colon cancer surgery refers to a wide resection of the tumor-bearing segment and the lymphatics draining along the named artery. The concept of TME has been applied to colon cancer and complete mesocolic excision (CME) in conjuction with central vascular ligation (CVL) has been introduced as the surgical treatment for colon cancer. Here, we discuss appropriate CME procedure with regard to the oncologic backgrounds, essential components, applied anatomy, laparoscopic technique, short-term, and oncologic outcomes. The introduction of CME has improved oncologic outcomes greatly in patients with colon cancer. The improved outcomes with CME can be attributed to underlying sound oncologic principles such as dissection through the proper plane of mesocolic excision, central vascular ligation, and sufficient length of proximal and distal margins. Thereby, CME technique can achieve en bloc removal of the diseased lesion with the increased amount of the colonic mesentery even though the length of for both bowel and mesentery resection remains a matter of debate. CME is a technically demanding operation thus, comprehensive understanding of the applied vascular anatomy is essential for successful CME. Favorable outcomes of open CME have been replicated with a laparoscopic approach. In future perspective, incorporating a structured education program on minimally invasive (laparoscopy or robot) CME would be beneficial.

The treatment strategy and benefit of extended lymph node dissection among patients with preoperatively diagnosed paraaortic lymph node metastasis (PALNM) in colon cancer remains highly controversial. In the current study, we analyzed the oncologic outcomes of patients who underwent extraregional lymph node dissection for colon cancer with isolated PALNM. From March 2000 to December 2009, the study group included 1082 patients who underwent curative surgery for colonic adenocarcinoma with pathological lymph node metastasis. Of 1082 patients who underwent curative surgery for colonic carcinoma, 953 (88.1 %) patients underwent regional lymphadenectomy, and 129 (11.9 %) patients underwent paraaortic lymph node dissection. Pathologic examination revealed N1 stage disease in 738 (68.2 %), N2 in 295 (27.3 %), and PALNM in 49 (4.5 %). Five-year overall survival (OS) and disease-free survival (DFS) rate were significantly better in the regional LNM group than in the PALNM group (OS 75.1 vs. 33.9 %, p

Purpose The number of international visiting scholars has been on the increase in Korea and we aim to investigate the program's current situation. Methods This cross-sectional study is based on an online survey questionnaire responded by international visiting scholars in surgical departments of 8 Korean hospitals between 2014 and 2018 about their experiences and satisfaction with the visiting scholar program. Results A total of 1,496 international scholars from 80 countries visited various surgical departments in 8 Korean hospitals between 2014 and 2018. The numbers have been on the increase over the years. Out of 355 visiting scholars in 2018, 71 replied to the online survey, of whom 52 were male and 19 female, and mostly in their 30s and 40s. Information about the program was accessed mostly through friends or colleagues (42.3%) and international conferences (36.6%). The commonest funding source was private (35.2%) and more than half stayed for less than 3 months. The visiting scholar's main roles were mostly observation or participation in surgery and clinical research. All but 1 were satisfied with the program (98.6%) and would recommend it to friends and colleagues, although the language barrier was identified as an inconvenience. Those aged 20-39 years with governmental or institutional funding were associated with stays of more than 1 year. Conclusion The number of international visiting scholars at surgical departments in Korean hospitals has been on the increase with high satisfaction levels. Improvements need to be made on funding sources and lengthening visiting period to maximize the benefits of the program.

Purpose Previous studies have reported conflicting results regarding the prognostic value of tumor sidedness in colon cancer. We investigated the oncologic impact of tumor location and examined whether recurrence patterns were related to tumor sidedness in colon cancer patients. Methods We identified stage I-III colon adenocarcinoma patients from a prospective colorectal cancer registry at Severance Hospital, Seoul, Korea, who underwent complete mesocolic excision between 2005 and 2012. Adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for predictors of cancer-specific survival (CSS), recurrence-free survival (RFS), and cumulative recurrence at specific anatomic sites were examined using Cox proportional hazard regression analysis. Results Overall, 1,912 patients, 1,077 (56.3%) with left-sided colon cancer (LCC), and 835 (43.7%) with right-sided colon cancer (RCC), at a median follow-up of 59 months, were eligible and included in the study. In univariate analysis, similar 5-year CSS and RFS were observed for LCC and RCC in the total patient population, and when stratified by stage for stage I and II patients. For stage III patients, an adjusted Cox regression analysis indicated that RCC patients had a higher risk of cancer-specific mortality (HR, 1.75; 95% CI, 1.07-2.86; P = 0.024) and recurrence (HR, 1.78; 95% CI, 1.22-2.60; P = 0.003). Furthermore, RCC was an independent predictor of peritoneal recurrence (HR, 1.86; 95% CI, 1.05-3.29; P = 0.031) in stage III patients. Conclusion RCC correlated with worse CSS and RFS than LCC. In stage III patients, RCC correlated with increased risk of peritoneal recurrence. The reasons for these differences remain to be investigated.

Systemic inflammatory response, as measured by C-reactive protein (CRP), is associated with prognosis in various types of human malignancies. However, to the best of our knowledge, the clinical significance of CRP in patients with locally advanced rectal cancer that undergo preoperative chemoradiation has not been investigated in detail. This retrospective study validates CRP as a potential predictive marker for survival outcomes in rectal cancer patients. In this study, we enrolled 125 patients that received total mesorectal excision after preoperative chemoradiation for rectal cancer between January 2003 and December 2010. We investigated the association between preoperative CRP and clinicopathological characteristics and assessed the prognostic value of CRP. The median follow-up was 41 months. Elevated CRP showed significant correlation with high histological grade (P = 0.009) and cancer recurrence (P = 0.027). The 5-year disease-free survival and cancer-specific survival were significantly lower in the elevated CRP group (P = 0.001). Moreover, CRP was the strongest predictive factor for cancer-specific survival in multivariate analysis (P = 0.001). In the subgroup analysis, elevated CRP was a significant prognostic factor in patients with node-positive disease (P = 0.025) and was associated with poorer tumor regression (TRG4–5; P = 0.011). The results of our study suggest that preoperative CRP level shows prognostic significance in rectal cancer patients that have undergone chemoradiation. Therefore, preoperative CRP may help clinicians to identify patients that need additional therapy to reduce systemic failure.

We measured systemic changes in the immune response in 92 patients receiving preoperative chemoradiation therapy (CRT) and subsequent surgery for rectal cancer. The peripheral blood was sampled five times from the onset of CRT until surgery. Lymphocytes decreased continuously during CRT but increased after CRT. The increased lymphocyte population was predominantly CD8+ T lymphocytes, which accounted for a significantly larger proportion in patients without residual lymph node metastasis than in those with residual lymph node metastasis. Neutrophils and monocytes decreased during the initial two weeks of CRT but were maintained or increased afterwards. Neutrophil and monocyte counts were significantly lower in patients with a pCR (pathologic complete response) than in those without a pCR two weeks after CRT began but not at the initiation of CRT. All cytokines showed dramatic changes one month after the termination of CRT. Cytokines related to the antitumour immune response increased, and those related to tumour progression decreased. The predictive value of cytokines was not clear. In short, we observed that immune components in peripheral blood are affected by CRT and show dynamic changes over time. We identified biomarker candidates to predict the pathologic response in the future.

Background Colorectal cancer (CRC) screening is the most efficient strategy to reduce disease-related mortality. Frequent aberrant DNA methylation is known to occur in selected genes and early during CRC development, which has emerged as a new epigenetic biomarker for early detection of CRC. Previously, we reported that we identified that CpG sites of SDC2 were aberrantly methylated in tumor tissues of most CRC patients through comprehensive methylation analysis and demonstrated a high potential of quantification of SDC2 methylation in blood for early detection of colorectal cancer. In this study, we aim to investigate the feasibility of quantifying SDC2 methylation in stool DNA for the early detection of CRC. The objective of this study was to confirm a high frequency of SDC2 methylation in tumor tissues at various stages of CRC and investigate the feasibility of a quantitative test for SDC2 methylation in fecal DNA by highly sensitive and accurate real-time PCR for early detection of CRC. Methods Bisulfite-pyrosequencing assay was performed to measure the SDC2 methylation status in tissue samples. For methylation analysis in stool DNA, a highly sensitive and accurate method was applied which implements consecutive two rounds of PCR consisting of unidirectional linear target enrichment (LTE) of SDC2 and quantitative methylation-specific real time PCR (qMSP) for SDC2, named as meSDC2 LTE-qMSP assay. Its limit of detection was 0.1% methylation (corresponding to ~ 6 copies in total ~ 6200 genome copies). Results Positive SDC2 methylation was observed in 100% of primary tumors, 90.6% of adenomatous polyps, 94.1% of hyperplastic polyps, and 0% of normal tissues. SDC2 methylation level also significantly (P

Background Ulcerative colitis (UC) harbours a high risk of UC-associated colorectal cancer (UCCC), which is important cause of morbidity and mortality in patients with inflammatory bowel disease. Overall Survival (OS) of patients with UCCC has not been addressed well in the literature. Thus, we compared oncologic outcome of UCCC and sporadic colorectal cancer (SCC) using propensity score matching analysis. Methods Propensity score matching was performed for 36 patients, a 1:1 matching method stratified into 18 in UCCC and 18 patients in SCC. Matched variables were sex, age, body mass index, tumour stage, histology, preoperative carcinoembryonic antigen (CEA) level, and adjuvant treatment status. Patients with SCC or UCCC were retrospectively retrieved from our database from March 2000 to December 2015. All patients had undergone either oncological segmental resection or total proctocolectomy. Results The majority of cancers were found in the sigmoid colon. Total proctocolectomy was performed only in the UCCC group; however, half of the UCCC group underwent a standard operation. Five cases of postoperative complication occurred within six months in the UCCC group compared to one case in the SCC group. There was no significant difference in recurrence rate (p = 0.361) or OS (p = 0.896) between the arms. Conclusion UCCC showed more postoperative complications than SCC, and equivalent oncology outcome, however the difference was not statistically significant. This study represents an experience of a single institution, thus further randomized studies are required to confirm our.

Inguinal hernia is a common disease treated with diverse methods. Nowadays, laparoscopic totally extraperitoneal approach is gaining its validity and shows favorable outcomes. However, single-incision laparoscopic surgery is also widening its applicable fields as a new technique. This study aimed to find whether single-incision laparoscopic total extraperitoneal inguinal hernia repair (SILTEP) is applicable compared to conventional laparoscopic total extraperitoneal hernia repair (CLTEP).We retrospectively reviewed 120 cases of SILTEP and 60 cases of CLTEP in Yonsei University Severance Hospital from January 2012 to December 2013. Each group was compared with patients' characteristics, operative details, and postoperative complications.There were no statistical difference in patient age, sex, body mass index, American Society of Anesthesiologists score, hernia type, or location between SILTEP and CLTEP. In operative details, operation time (61.77 ± 16.48 minutes versus 77.83 ± 35.15 minutes, P = .001) was shorter in SILTEP. Postoperative complication rate has shown no statistical difference in SILTEP compared to CLTEP (n = 20, 16.7% versus n = 16, 26.7%, P = .114).SILTEP is feasible and provides comparable postoperative outcomes compared to CLTEP. Although SILTEP has its own challenges for mastering the procedure, with some experiences, it is possible to operate as well as CLTEP.

Anastomotic leakage (AL) after stapled anastomosis in rectal cancer surgery is a major concern. Various types of intraoperative anastomotic air leakage tests (ALTs) have been proposed to reduce AL. This study aimed to evaluate the impact of intraoperative colonoscopy (IOC) as an intraoperative ALT in low anterior resection for rectal cancer. A total of 1266 patients were retrospectively reviewed. Among them, 215 patients who underwent IOC as an ALT in rectal cancer surgery were identified. IOC was performed after anastomosis to visualize the anastomosis line and to perform an ALT by insufflating the neorectum. Propensity score matching was used to match this group at a 1:1 ratio with 215 patients who underwent ALT with a 250-mL bulb irrigation syringe. Anastomotic defects that were found intraoperatively were resolved either by means of primary repair of the anastomotic defect, if possible, or by performing a preventive diverting ileostomy. The patient characteristics, pathologic outcomes, and operation details showed no significant difference between the two groups. Comparison of the AL rate showed a significant difference between the groups (IOC group without intraoperative leaks vs. non-IOC group without intraoperative leaks 4.3 vs. 11.7%, P = 0.007). The incidence of preventive diverting ileostomy because of a positive ALT was significantly higher in the IOC group than in the non-IOC group (10 vs. 2 cases, P = 0.036). IOC can be a valuable method for the assessment of stapled anastomosis and has the additional benefit of directly visualizing the anastomosis line.

PURPOSE We aim to report outcomes and learning curve of transanal endoscopic operation (TEO) for rectal tumors, using standard laparoscopic instruments under a magnifying laparoscopic monitor view. MATERIALS AND METHODS From January 2012 to July 2014, local excision was performed using a TEO system in 46 consecutive patients with rectal tumors. Patient and tumor characteristics and perioperative outcomes were prospectively assessed. RESULTS The median patient age was 56 years for 15 women and 31 men. The mean tumor size was 1.8 cm, and the mean distance from the anal verge was 7.8 cm. The mean operative time was 85 minutes, and the mean postoperative hospital stay was 4.5 days. The postoperative pathologic diagnosis was adenocarcinoma for 17 patients (37%), adenoma for 4 patients (9%), carcinoid tumor for 23 patients (50%), and leiomyoma and lipoma for the 2 remaining patients (2%). A positive resection margin was documented for 4 patients (9%). No mortality was associated with the procedure although postoperative bleeding, leakage, perianal fistula, fecal incontinence, and voiding difficulty developed in 8 patients. According to the cumulative sum (CUSUM) analysis, the operation time and hospital stay significantly decreased after 17 case experiences. CONCLUSIONS TEO is a feasible and safe treatment option for local excision of rectal tumors. TEO has the advantage of being a precise surgical procedure with a stable and magnifying endoscopic view. However, TEO requires a learning period and a careful selection of patients through proper indications and preoperative diagnostics.

Background and objectives: Advanced rectal cancers require local and systemic control. Chemo radiotherapy (CRT) is adequate to achieve adequate local control. Systemic control, however, is a dominant obstacle remained in debates. We compared oncology outcome in both arms in patients with advanced rectal cancers in order to identify high-risk group of distant metastasis. Methods: Data for 723 patients for advanced rectal cancer from 2005 to 2013 retrieved retrospectively. Patients were classified to CRT (n=364) or no CRT (n=359) arms. Results: CRT group showed greater local control and achieved pT stage 0, 1, or 2 in 43.7% vs. 28.4% in no CRT (p

Preoperative chemoradiotherapy (CRT) is the standard of care for patients with stage II and III rectal cancer. This strategy leads to pathologic complete response (pCR) in a significant number of patients. Factors predictive of pCR are currently being extensively investigated. The aim of this study was to analyze clinical factors that might be predictive of pCR. This study was a retrospective analysis of rectal cancer patients from January 2004 through December 2012. A total of 332 stage II and III patients with middle and low rectal cancer (≤10 cm) who received CRT and underwent curative total mesorectal excision were eligible. The median radiation dose was 50.4 Gy, and 72.6% of patients received infusional 5-fluorouracil with leucovorin, whereas 19.6% of patients received TS-1 with irinotecan, and 7.8% of patients received xeloda only. Pathologic complete response was confirmed by using pathologic specimens and analyzed based on predictive clinical factors. Among the 332 patients, 27.4% (n = 91) achieved pCR. Age, sex, body mass index, clinical T and N stages, tumor differentiation, the chemotherapy agent for CRT, and the time interval between CRT and surgery did not differ between the pCR and non-pCR groups. Carcinoembryogenic antigen (CEA) levels before CRT were 4.61 ± 7.38 ng/mL in the pCR group and 10.49 ± 23.83 ng/mL in the non-pCR group (P = 0.035). Post-CRT CEA levels were 1.4 ± 1.07 ng/mL in the pCR group and 2.16 ± 2.8 ng/mL in the non-pCR group (P = 0.014), and the proportion of middle rectal cancer patients was higher in pCR group (54.9%, P = 0.028). The results from multivariate logistic regression analysis indicated that higher tumor location (odds ratio 2.151; P = 0.003) and low post-CRT CEA level (odds ratio 0.789; P = 0.04) were independent predictive factors for pCR. Tumor location and post-CRT CEA level were predictive factors in pCR for rectal cancer patients. Therefore, these factors may be important determinants in achieving pCR, and may also be used to predict oncologic outcomes.

A minimum of 12 harvested lymph nodes (hLNs) are recommended in colorectal cancer. However, a paucity of hLNs is frequently presented after preoperative chemoradiation (pCRT) in rectal cancer and the significance of this is still uncertain. The aim of this study is to analyze the impact of hLNs on long-term oncologic outcomes. A total of 302 patients with locally advanced rectal cancer who underwent pCRT and curative resection between 1989 and 2009 were reviewed. Patients were categorized into 2 groups according to the number of hLNs