Ureteral Injury.

CASE SUMMARY: A 70-year-old man underwent laparoscopic low anterior resection for a rectal adenocarcinoma after neoadjuvant chemoradiotherapy. Postoperatively, the patient had high drain volume output, with 800 mL of clear serous fluid being drained on the second postoperative day. Drain creatinine returned as 300 mmol/L, with a corresponding serum creatinine of 100 mmol/L. CT scan of the abdomen and pelvis confirmed a left ureteric injury with an associated urinoma. After urology consultation, the patient underwent a left ureteric reimplantation emergently.

Safe discharge for patients admitted for lower gastrointestinal bleeding (LGITB): derivation and validation of a novel scoring system.

AIM: Bleeding from the lower gastrointestinal tract (LGITB) is a common clinical presentation. Recent guidelines have recommended for incorporation of clinical risk assessment tools in the management for LGITB. We derived and validated a novel clinical scoring system to predict safe discharge after LGITB admission, and compared it to other published scoring systems in current literature. METHODS: A retrospective cohort of 798 patients with LGITB from August 2018 to March 2021 was included in the derivation cohort. Multivariate binary logistic regression was performed to identify significant clinical variables predictive of safe discharge. A clinical scoring system was developed based on the results, and validated on a prospective cohort of 312 consecutive patients with LGITB from April 2021 to March 2022. The performance of the novel scoring system was compared to other LGITB clinical risk assessment scores via area under the receiver operating characteristics curve (AUROC) analysis. RESULTS: Variables predictive of safe discharge included the following; absence of previous LGITB admission, absence of ischemic heart disease, absence of blood on digital rectal examination, absence of dizziness or syncope at presentation and the systolic blood pressure and haemoglobin levels at presentation. The novel score had an AUROC of 0.907. A cut-off point of 4 provided a sensitivity of 41.9%, specificity of 97.5%, positive predictive value of 96.4% and negative predictive value of 51.5% for prediction of safe discharge. The score performs comparably to the Oakland score. CONCLUSION: The novel LGITB clinical risk score has good predictive performance for safe discharge in patients admitted for LGITB.

The Role and Effect of Multimodal Prehabilitation Before Major Abdominal Surgery: A Systemic Review and Meta-Analysis.

BACKGROUND: For patients undergoing abdominal surgery, multimodal prehabilitation, including nutrition and exercise interventions, aims to optimize their preoperative physical and physiological capacity. This meta-analysis aims to explore the impact of multimodal prehabilitation on surgical and functional outcomes of abdominal surgery. METHODS: Medline, Embase and CENTRAL were searched for articles about multimodal prehabilitation in major abdominal surgery. Primary outcomes were postoperative complications with a Clavien-Dindo score ≥3, and functional outcomes, measured by the 6-Minute Walking Test (6MWT). Secondary outcome measures included the quality-of-life measures. Pooled risk ratio (RR) and 95% confidence interval (CI) were estimated, with DerSimonian and Laird random effects used to account for heterogeneity. RESULTS: Twenty-five studies were included, analysing 4,210 patients across 13 trials and 12 observational studies. Patients undergoing prehabilitation had significantly fewer overall complications (RR = 0.879, 95% CI 0.781-0.989, p = 0.034). There were no significant differences in the rates of wound infection, anastomotic leak and duration of hospitalization. The 6MWT improved preoperatively in patients undergoing prehabilitation (SMD = 33.174, 95% CI 12.674-53.673, p = 0.005), but there were no significant differences in the 6MWT at 4 weeks (SMD = 30.342, 95% CI - 2.707-63.391, p = 0.066) and 8 weeks (SMD = 24.563, 95% CI - 6.77-55.900, p = 0.104) postoperatively. CONCLUSIONS: As preoperative patient optimization shifts towards an interdisciplinary approach, evidence from this meta-analysis shows that multimodal prehabilitation improves the preoperative functional capacity and reduces postoperative complication rates, suggesting its potential in effectively optimizing the abdominal surgery patient. However, there is a large degree of heterogenicity between the prehabilitation interventions between included articles; hence results should be interpreted with caution.

Systematic review and meta-analysis of the use of serum procalcitonin levels to predict intra-abdominal infections after colorectal surgery.

PURPOSE: There has been much recent interest in the use of procalcitonin (PCT) as a marker of intra-abdominal infection (IAI) following colorectal surgery. However, the literature remains divided on the value of PCT in this setting. This meta-analysis aims to evaluate the value of PCT in predicting IAI after colorectal surgery. METHODS: Systemic literature search was performed using MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Database of Systematic Reviews to identify studies evaluating the diagnostic accuracy of PCT as a predictor for detecting IAI on postoperative days (POD) 3 to 5 following colorectal surgery. A meta-analysis was performed using random effect model and pooled predictive parameters as well as cut-off values for POD 3 to 5 were derived. RESULTS: Eight studies consisting 1629 patients were included. The pooled prevalence of IAI was 5.7% on POD 3, 9.7% on POD 4, and 6.3% on POD 5. The pooled AUC for POD 3 to 5 were 0.83 (95% CI 0.78-0.88), 0.79 (95% CI 0.64-0.93), and 0.94 (95% CI 0.91-0.97), respectively. The derived PCT cut-off values were 1.45 ng/ml on POD 3, 1.28 ng/ml on POD 4, and 1.26 ng/ml on POD 5. PCT had the highest diagnostic capability on POD 5 with diagnostic odds ratio of 32.9 (95% CI 15.01-69.88), sensitivity of 0.78 (95% CI 0.65-0.89), and specificity of 0.88 (95% CI 0.85-0.90). CONCLUSIONS: PCT is a useful diagnostic predictor of IAI after colorectal surgery. It has the greatest diagnostic accuracy on POD 5 and can help guide safe discharge of patients after colorectal surgery.

A Novel Derivation Predicting Survival After Primary Tumor Resection in Stage IV Colorectal Cancer: Validation of a Prognostic Scoring Model and an Online Calculator to Provide Individualized Survival Estimation.

BACKGROUND: A prognostic scoring model has been devised previously to predict survival following primary tumor resection in patients with metastatic colorectal cancer and unresectable metastases. This has yet to be validated. OBJECTIVE: The main objectives of this study are to validate the proposed prognostic scoring model and create an interactive online calculator to estimate an individual's survival after primary tumor resection. DESIGN: Clinical data and survival outcomes of patients were extracted from a prospectively maintained database. Patients were categorized into good, moderate, or poor survivor groups based on the previously proposed scoring algorithm. Discrimination was assessed and recalibration was performed, with the recalibrated model implemented as an interactive Web application to provide individualized survival probability. SETTINGS: This study was conducted at a tertiary referral center. PATIENTS: The study included 324 consecutive patients with metastatic colorectal carcinoma and unresectable metastases who underwent primary tumor resection between January 2008 and December 2013. MAIN OUTCOME MEASURES: The primary outcome measured was overall survival. RESULTS: Three hundred twenty-four patients were included in the study. Median survival in the good, moderate, and poor prognostic groups was 56.8, 25.7, and 19.9 months (log rank test, p = 0.003). The κ statistic was 0.638 and RD was 0.101. Significant differences in survival were found between the moderate and good prognostic groups (HR, 2.79; 95% CI, 1.51-5.15; p = 0.001) and between poor and good prognostic groups (HR, 4.12; 95% CI, 1.98-8.55; p < 0.001). The model was implemented as an interactive online calculator to provide individualized survival estimation after primary tumor resection (http://bit.ly/Stage4PrognosticScore). LIMITATIONS: Selection bias and single-center data preclude the generalizability of the proposed model. Information regarding the severity or likelihood of developing symptoms from the primary tumor were also not accounted for in the prognostic scoring model proposed. CONCLUSIONS: The prognostic scoring model provides good prognostic stratification of survival after primary tumor resection and may be a useful tool to predict survival after primary tumor resection. See Video Abstract at http://links.lww.com/DCR/A330.

Evaluating the surgical trainee ergonomic experience during minimally invasive abdominal surgery (ESTEEMA study).

Minimally invasive abdominal surgery (MAS) can exert a physical cost. Surgical trainees spend years assisting minimally-invasive surgeries, increasing the risk of workplace injury. This prospective questionnaire-based cohort study was conducted amongst general surgery residents in Singapore. Residents assisting major MAS surgery were invited to complete anonymous online survey forms after surgery. The Phase 1 survey assessed physical discomfort scores and risk factors. Intraoperative measures to improve ergonomics were administered and evaluated in Phase 2. During Phase 1 (October 2021 to April 2022), physical discomfort was reported in at least one body part in 82.6% (n = 38) of respondents. Over a third of respondents reported severe discomfort in at least one body part (n = 17, 37.0%). Extremes of height, training seniority, longer surgical duration and operative complexity were significant risk factors for greater physical discomfort. In Phase 2 (October 2022 to February 2023), the overall rate of physical symptoms and severe discomfort improved to 81.3% (n = 52) and 34.4% (n = 22) respectively. The ergonomic measure most found useful was having separate television monitors for the primary surgeon and assistants, followed by intraoperative feedback on television monitor angle or position. Close to 20% of survey respondents felt that surgeon education was likely to improve physical discomfort.

Colonic stenting: is the bridge to surgery worth its cost? A cost-effectiveness analysis at a single Asian institution.

Purpose: In patients with acute left-sided colonic obstruction, stenting can convert an emergency operation into a semi-elective procedure. However, its use continues to be debated. We performed a cost-effective analysis using our institution's experiences. Methods: Endoscopic, surgical, and financial details were prospectively collected for patients who presented with acute colonic obstruction and underwent stenting between 2019 and 2022. Outcomes were defined as technical/clinical success and successful surgical resection. The financial cost of stenting was compared with the expected cost without stenting. Results: Forty patients were included, with 29 undergoing definitive resection. The most common pathology was primary colon cancer (27 patients, 93%). Endoscopic stenting had high technical (90%) and clinical (83%) success rates, with low rates of complications such as perforation (2 patients, 7%) and migration (0 patients, 0%). As a bridge to surgery, the median procedure time was 226 minutes and the surgical outcomes also showed a low rate of complications (3 patients, 11%), such as anastomotic leakage (0 patients, 0%), intraabdominal abscesses (2 patients, 7%), and 30-day postoperative mortality (0 patients, 0%). The cumulative costs with colonic stenting were $32,900, while the expected costs with emergency surgery, including stoma reversal, were $40,700 (healthcare cost-savings of $7,800 per person). The difference was mainly due to the avoidance of upfront emergency surgery. The incremental cost-effectiveness ratio was 0.81, favoring colonic stenting over upfront emergency surgery. Conclusion: Colonic stenting as a bridge to surgery is safe and cost-effective for treating left-sided colonic obstruction with high success rates and low complication rates.

Quality of life after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: an Asian perspective.

BACKGROUND: Data on quality of life (QOL) after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) is scarce in the Asian population. This study assesses QOL outcomes after CRS and HIPEC in an Asian cancer center. METHODS: Patients who completed CRS + HIPEC 6-18 months ago (27 patients) were enrolled in the study. QOL was measured via the European Organization for Research and Treatment of Cancer QLQ-C30 questionnaires. The scores were compared with a group of 393 disease-free cancer patients, not on active treatment, who had ECOG scores of either 0 or 1. The 1-sample t test was used to compare differences in QOL scores between the 2 groups. RESULTS: A total of 27 patients were analyzed, of which 22 (81 %) were females. Median age was 51 years (15-59 years). CRS + HIPEC were performed for ovarian cancer in 15 patients (55 %), appendiceal carcinoma in 5 patients (19 %), and colorectal carcinoma in 4 patients (15 %). The median intraoperative peritoneal carcinomatosis index (PCI) score was 15 (2-31) while the completeness of CC score was 0 and 1 in 25 and 2 patients, respectively. The median duration after CRS + HIPEC was 10 months (6-16 months). Global health status and functional and symptom scores were largely similar between patients after CRS + HIPEC and the control group. Cognitive functioning scores and fatigue scores were significantly better in the group after CRS + HIPEC (p = 0.014 and 0.04). CONCLUSIONS: QOL after CRS and HIPEC can be equivalent to that of well-functioning, disease-free cancer patients.

Prognostic significance of invasion depth in oral tongue squamous cell carcinoma.

PURPOSE: Staging for tongue carcinoma does not consider its depth of invasion. We aim to determine the prognostic significance of invasion depth in tongue cancer. MATERIALS AND METHODS: Retrospective review of patients with tongue carcinoma who underwent curative surgery between 2002 and 2005; 67 patients were analyzed. Tumors were divided into 2 groups: group A = invasion depth <4 mm; group B = invasion depth ≥4 mm. Recurrence and survival rates were calculated for each group and compared. RESULTS: The local recurrence rate in group B was significantly higher (10 vs. 29.7%, p = 0.048). Group A patients had a superior 5-year overall survival (68.8 vs. 41.6%, p = 0.012), disease-specific survival (67.1 vs. 41.1%, p = 0.026) and local recurrence-free survival (89.5 vs. 65.4%, p = 0.035). Five-year regional recurrence, locoregional recurrence and distant recurrence-free survival rates were not significantly different between the 2 groups (p = 0.390, p = 0.173 and p = 0.207). The impact of invasion depth on survival was maintained on multivariate analysis (p = 0.031). CONCLUSION: Invasion depth is an important prognostic indicator in tongue cancer.

Colorectal cancer surgery in Asia during the COVID-19 pandemic: A tale of 3 cities.

PURPOSE: The COVID-19 pandemic has put tremendous strain on healthcare systems. Surgical societies worldwide have advised minimizing non-essential surgeries in order to preserve hospital resources. Given the medical resources and COVID-19 incidence between countries across the world differ, so should colorectal practices. No formal guidelines have emerged from Asia. We wanted to find out what the current practice was in Asian colorectal centres outside China. INTRODUCTION: The COVID-19 pandemic has significantly impacted surgical practice worldwide. At the time of the writing of this paper, there are over 4.2 million cases reported with deaths exceeding 290 000 patients.1 With an abrupt disruption to worldwide supply chains, societal lockdowns and surge of cases into many hospitals, resource allocation was diverted and prioritised for all COVID-19 related services. METHODS: A questionnaire survey of current colorectal practice was carried out involving 3 major colorectal cancer centres, one each from 3 major cities: Singapore, Taichung and Daegu. Components of the survey include infrastructure and manpower, case selection, surgical approach, operating room management and endoscopy practice. RESULTS: All 3 centres continued to provide standard-of-care colorectal cancer surgery despite the COVID-19 pandemic. Two centres deferred surgery for benign colorectal conditions. Minimally Invasive Surgery (MIS) was still the preferred approach when indicated but with protocolized precautions undertaken. Other services such as pelvic exenteration, TATME and pelvic lymph node dissection were still offered if oncologically indicated. Elective diagnostic endoscopy services have also continued in two centres. CONCLUSION: Elective colorectal services continue to take place in the 3 surveyed Asian hospitals with heightened precautions. Provided there is adequate resource, colorectal cancer services should still continue to prevent consequences of neglecting or delaying cancer treatment. Practice should hence be tailored to the local resource of individual centres accordingly.

Moving towards the New International Study Group for Pancreatic Surgery (ISGPS) definitions in pancreaticoduodenectomy: a comparison between the old and new.

BACKGROUND: The International Study Group for Pancreatic Surgery (ISGPS) has proposed several definitions for postoperative pancreatic fistula (POPF), delayed gastric emptying (DGE) and post-pancreatectomy haemorrhage (PPH). We assessed the effects of implementing these definitions on predicting outcomes. METHODS: A database of 77 patients who underwent pancreaticoduodenectomy between January 2005 and December 2009 was analysed. Morbidities were defined and classified using the ISGPS definitions and recalculated based on the definitions adopted by our institution ('Old' definitions) prior to the implementation of ISGPS definitions. Data for the two groups were then compared. RESULTS: The morbidity rate rose to 70.1% from 27.2% when ISGPS rather than Old definitions were used to define morbidities (P < 0.001). Incidences of DGE, POPF and PPH were 20.7%, 39.0% and 10.4%, respectively. Rates of DGE and POPF were significantly higher according to ISGPS definitions than to Old definitions (20.7% vs. 5.2% [P= 0.001] and 39.0% vs. 15.6% [P= 0.004], respectively). According to the ISGPS definitions, all of the 12 additional patients with DGE and 12 of the 18 additional patients with POPF had grade A morbidities. Patients with ISGPS-defined morbidity had a longer intensive care unit (ICU) stay, longer postoperative stay and longer total stay (P= 0.030, P= 0.007 and P= 0.001, respectively). CONCLUSIONS: The morbidity rate more than doubled when ISGPS definitions were applied (an additional 42.9% of patients demonstrated morbidities). The majority of patients with DGE and POPF had grade A morbidities. The ISGPS definitions correlate well with ICU stay, postoperative stay and total length of stay.

A prognostic score predicting survival following emergency surgery in patients with metastatic colorectal cancer.

BACKGROUND: Survival of patients with metastatic colorectal cancer (mCRC) varies. We aim to develop a prognostic score for mCRC after emergency surgery to guide treatment decisions. METHODS: Newly diagnosed mCRC patients who presented with primary tumor-related complications and underwent emergency surgery between January 1999 and December 2013 were included. Univariate and multivariate Cox regression analyses were performed to identify covariates significantly associated with the time to death following surgery. A survival score was derived using the Cox regression equation. RESULTS: The study cohort comprised 248 patients. Median patient age was 66 ± 13 years. Primary tumor was located in the left colon and rectum in 211 patients (85.1%) while 37 patients (14.9%) had primaries in the right colon. Liver, lung, and peritoneal metastases occurred in 161 patients (64.9%), 59 patients (23.8%), and 96 patients (38.7%), respectively. Majority of patients presented with either obstruction (174 patients, 70.1%) or perforation (52 patients, 21%). On multivariate analysis, age of 60 years or older (p = 0.007), carcinoembryonic antigen levels greater than 45 ng/ml (p = 0.022), presence of liver metastases (p = 0.024), and peritoneal carcinomatosis (p < 0.001) were found to be significantly associated with overall survival. A simplified score was derived with good survivors (score 0-2), moderate survivors (score 3-4), and poor survivors (score 5 and above) experiencing median survival of 7, 14, and 23 months, respectively (p < 0.001). CONCLUSION: The management of mCRC presenting with an emergency is challenging. A prognostic score that estimates survival after emergency surgery may aid clinical decision-making.

Randomized control trial comparing an Alvarado Score-based management algorithm and current best practice in the evaluation of suspected appendicitis.

BACKGROUND: An objective algorithm for the management of suspected appendicitis guided by the Alvarado Score had previously been proposed. This algorithm was expected to reduce computed tomography (CT) utilization without compromising the negative appendectomy rate. This study attempts to validate the proposed algorithm in a randomized control trial. METHODS: A randomized control trial comparing the management of suspected acute appendicitis using the proposed algorithm compared to current best practice, with the rate of CT utilization as the primary outcome of interest. Secondary outcomes included the percentage of missed diagnosis, negative appendectomies, length of stay in days, and overall cost of stay in dollars. RESULTS: One hundred sixty patients were randomized. Characteristics such as age, ethnic group, American Society of Anesthesiologist score, white cell count, and symptom duration were similar between the two groups. The overall CT utilization rate of the intervention arm and the usual care arm were similar (93.7% vs 92.5%, p = 0.999). There were no differences in terms of negative appendectomy rate, length of stay, and cost of stay between the intervention arm as compared to the usual care arm (p = 0.926, p = 0.705, and p = 0.886, respectively). Among patients evaluated with CT, 75% (112 out of 149) revealed diagnoses for the presenting symptoms. CONCLUSION: The proposed AS-based management algorithm did not reduce the CT utilization rate. Outcomes such as missed diagnoses, negative appendectomy rates, length of stay, and cost of stay were also largely similar. CT utilization was prevalent as 93% of the study cohort was evaluated by CT scan. TRIAL REGISTRATION: The study has been registered at ClinicalTrials.gov (NCT03324165, Registered October 27 2017).

Prediction of overall survival following colorectal cancer surgery in elderly patients.

BACKGROUND: With advanced age and chronic illness, the life expectancy of a patient with colorectal cancer (CRC) becomes less dependent on the malignant disease and more on their pre-morbid condition. Justifying major surgery for these elderly patients can be challenging. An accurate tool demonstrating post-operative survival probability would be useful for surgeons and their patients. AIM: To integrate clinically significant prognostic factors relevant to elective colorectal surgery in the elderly into a validated pre-operative scoring system. METHODS: In this retrospective cohort study, patients aged 70 and above who underwent surgery for CRC at Singapore General Hospital between 1 January 2005 and 31 December 2012 were identified from a prospectively maintained database. Patients with evidence of metastatic disease, and those who underwent emergency surgery or had surgery for benign colorectal conditions were excluded from the analysis. The primary outcome was overall 3-year overall survival (OS) following surgery. A multivariate model predicting survival was derived and validated against an equivalent external surgical cohort from Kyungpook National University Chilgok Hospital, South Korea. Statistical analyses were performed using Stata/MP Version 15.1. RESULTS: A total of 1267 patients were identified for analysis. The median post-operative length of stay was 8 [interquartile range (IQR) 6-12] d and median follow-up duration was 47 (IQR 19-75) mo. Median OS was 78 (IQR 65-85) mo. Following multivariate analysis, the factors significant for predicting overall mortality were serum albumin < 35 g/dL, serum carcinoembryonic antigen ≥ 20 µg/L, T stage 3 or 4, moderate tumor cell differentiation or worse, mucinous histology, rectal tumors, and pre-existing chronic obstructive lung disease. Advanced age alone was not found to be significant. The Korean cohort consisted of 910 patients. The Singapore cohort exhibited a poorer OS, likely due to a higher proportion of advanced cancers. Despite the clinicopathologic differences, there was successful validation of the model following recalibration. An interactive online calculator was designed to facilitate post-operative survival prediction, available at http://bit.ly/sgh_crc. The main limitation of the study was selection bias, as patients who had undergone surgery would have tended to be physiologically fitter. CONCLUSION: This novel scoring system generates an individualized survival probability following colorectal resection and can assist in the decision-making process. Validation with an external population strengthens the generalizability of this model.

Rectal Cancer Surveillance-Recurrence Patterns and Survival Outcomes from a Cohort Followed up Beyond 10 Years.

AIM: The intensity and duration of surveillance for rectal cancer after surgical resection remain contentious. We evaluated the pattern of recurrences in a rectal cancer cohort followed up beyond 10 years. METHODS: An analysis was performed on a retrospective database of 326 patients with rectal cancer who underwent curative surgical resection from 1999 to 2007. The above study duration was chosen to ensure at least 10 years of follow-up. Data on patient demographics, peri-operative details, and follow-up outcomes were extracted from the database. The pattern of recurrences and investigative modality that detected recurrences was identified. Patients were followed up until either year 2016 or the day of their demise. RESULTS: Two hundred seventeen patients (66.6%) were male and 109 patients (33.3%) female. Median age was 64 years old. Close to a third of the patients received adjuvant therapy (34%). Among the 326 patients studied, 29.8% of (97/326) patients developed recurrence. 7.7% (25/326) had loco-regional recurrence while 22.1% (72/326) had distant metastasis. Median time to recurrence was 16 months (4-83) and 18 months (3-81), respectively. Computed tomography scan was the best modality to detect both loco-regional and distant recurrences (48% in loco-regional and 41.7% in distant metastasis). The most common site of distant metastasis is the lung (34.7%). The salvage rate for loco-regional and distant recurrences was 52 and 12.5%, respectively. CONCLUSION: The predominant pattern of recurrence in rectal cancer is distant disease. Surveillance regimes may need to be altered to increase early detection of distant metastases.

Evaluation of Long-Term Outcomes of Microsatellite Instability Status in an Asian Cohort of Sporadic Colorectal Cancers.

PURPOSE: Microsatellite instability in colorectal cancer (CRC) and its long-term outcomes remains poorly studied in Asians. We investigate the prognostic significance of microsatellite instability in an Asian population and assess its clinical impact in patients who undergo adjuvant chemotherapy. METHODS: Six hundred fifty-four consecutive CRC patients who underwent surgical resection between January 2010 and December 2012 were recruited. Survival was estimated using the Kaplan-Meier approach. Univariate Cox proportional hazard models were used to estimate the hazard ratios for variables associated with survival. A subgroup analyses was performed for stage III patients who underwent chemotherapy to evaluate the prognostic significance of microsatellite instability in this group. RESULTS: Five hundred ninety-one (90.4%) patients were microsatellite stable (MSS) while 63 (9.6%) were microsatellite instable (MSI). Three years recurrence-free survival (RFS) and disease-specific survival (DSS) were 83.7 versus 73.7% (p = 0.295) and 87.1 versus 91.2% (p = 0.307) in MSS and MSI tumors, respectively. Among stage III patients who received adjuvant therapy, MSI status was found to be an adverse prognostic factor for RFS (HR 2.74 (95% CI 1.43-5.26), p = 0.002). This remained significant on multivariate analysis (HR 2.38 (95% CI 1.15-4.93), p = 0.018). Adjuvant chemotherapy was associated with survival benefit for patients with MSS tumors (HR 0.35, 95% CI 0.17-0.69, p = 0.002) but not MSI tumors (HR 0.67, 95% CI 0.08-8.15, p = 0.750). CONCLUSIONS: MSI status is not a prognostic indicator in the general CRC population but appears to be an adverse prognostic indicator for RFS in stage III CRC patients who received adjuvant chemotherapy.