Citations

e15030 Background: Deficiencies in the DNA mismatch repair (dMMR) system cause errors during DNA replication, which in turn give rise to microsatellite instability (MSI-H). MSI-H in mCRC is rare and its prognostic and predictive impact on outcome is unclear. This cohort study aims to investigate the prognostic and predictive value of MSI-H in metastatic CRC prior to the immune therapy era. Methods: 75 MSI-H mCRC patients (pts) and 75 matched (age, gender, disease sidedness, metachronous) MSS mCRC pts were identified from 1268 mCRC who had MSI/MMR test results at Mayo Clinic Rochester between 1/1992 and 7/2016. A retrospective review was conducted by using data from electronic medical records (EMR). Statistical analyses utilized Kaplan-Meier method, Log-rank test, and Cox proportional hazards models. Results: In the MSI-H group, there were 39 male (52%) and 36 female (48%) pts. Median age at metastatic disease diagnosis was 54.7 years. 35 patients presented with stage IV CRC. Primary tumors location: 38 right side, 11 transverse colon, 15 left side, 11 rectum. The MSS group was well matched (3 mismatches for gender and 1 mismatch for metachronous metastatic disease). Median overall survivals (OS) were 28.1 and 37.4 months for MSI-H and MSS pts, respectively ( p= 0.098). 98.7% MSS pts and 94.7% MSI-H pts had Fluoropyrimidine-based chemotherapy for metastatic disease and there was no median OS difference between these two groups (37.4 vs. 32.3 months p= 0.91). 43 MSI-H and 39 MSS pts had metastasectomy including ablation ( p= 0.51) with longer median OS (82.0 and 69.9 months, p= 0.90) compared to pts without metastasectomy (13.9 and 19.7 months, p= 0.15). Age < 65, metastasectomy, asymptomatic metastatic lesions, BRAF wild type, and multiple metastasectomy were associated with better survival in univariate analysis. Only metastasectomy remained statistically significant in multivariate analysis ( p< 0.0001). Conclusions: MSI-H mCRC do not appear to have improved prognosis compared with MSS cancers, in fact, there is a trend toward inferior outcome. In both groups, metastasectomy including multiple metastasectomy should be considered to optimize OS.

3556 Background: To define and update survival rates and relapse patterns in patients (pts) with isolated advanced abdominal nodal metastasis secondary to colorectal cancer (CRC), treated with curative intent using aggressive trimodality therapy. Methods: Fifty-seven pts with isolated advanced abdominal lymph node metastasis (retroperitoneal and mesenteric) secondary to colorectal cancer received trimodality therapy defined as chemotherapy delivered in conjunction with external beam radiotherapy (EBRT) followed by lymphadenectomy and intraoperative radiotherapy (IORT). Infusional 5-FU was the most common radiosensitizer used (66%, 38 pts). The median dose of EBRT was 50 Gy & the median dose of intraoperative radiotherapy was 12.5 Gy. End points included distant metastasis, toxicities, local failure within EBRT field, recurrence within the intraoperative radiotherapy field, and survival. Results: 49% of pts were male, median age 50.5 yrs. All patients had ECOG ≤ 1. 27 pts had primary right sided colon cancer, 16 left sided colon cancer and 14 rectal primaries. Median time from initial CRC diagnosis to development of abdominal lymph node metastatic disease was 24 months (95% CI, 23.5-45.1 months). 84% (48 pts) had paraaortic nodal metastases, 12% (7 pts) had mesenteric nodal metastases, and 3% (2 pts) had both. With a median follow up of 89.4 months, the median overall survival and 5-year estimated survival rate were 53.2 months (95% CI, 46.4-78.8 months) and 42%, respectively. Median progression free survival was 19.3 months (95% CI, 15.6-32.8 months). 21 (37%) pts never developed distant disease. Outcome was not affected by disease sidedness, rectal primary, or mutational profile. Treatment was well tolerated without any grade 3/4 toxicities. Conclusions: The use of trimodality therapy including EBRT with radiosensitizing chemotherapy, lymphadenectomy and IORT produces sustainable long-term survival in selected metastatic CRC pts presenting with isolated retroperitoneal/mesenteric nodal relapse.

BACKGROUND: Excessive perioperative fluid administration likely increases postoperative cardiovascular, infectious, and GI complications. Early administration of diuretics after elective surgery facilitates rapid mobilization of excess fluid, potentially leading to decreased bowel edema, more rapid return of bowel function, and reduced length of hospital stay. OBJECTIVE: This study aimed to evaluate the benefit of early diuresis after elective colon and rectal surgery in the setting of an enhanced recovery after surgery practice. DESIGN: This was a prospective study. SETTINGS: The study was conducted at a quaternary referral center. PATIENTS: A randomized, open-label, parallel-group trial was conducted in patients undergoing elective colon and rectal surgery at a single quaternary referral center. INTERVENTION: The primary intervention was administration of intravenous furosemide plus enhanced recovery after surgery on postoperative day 1 and 2 versus enhanced recovery after surgery alone. MAIN OUTCOME MEASURES: The primary outcome was length of hospital stay. Secondary outcomes included 30-day readmission rate, time to stool output during hospitalization after surgery, and incidence of various complications within the first 48 hours of hospital stay. RESULTS: In total, 123 patients were randomly assigned to receive either furosemide plus enhanced recovery after surgery (n = 62) or enhanced recovery after surgery alone (n = 61). Groups were evenly matched at baseline. At interim analysis, length of hospital stay was not superior in the intervention group (80.6 vs 99.6 hours, p = 0.564). No significant difference was identified in the rates of nasogastric tube replacement (1.6% vs 9.7%, p = 0.125). Time to return of bowel function was significantly longer in the intervention group (45.4 vs 48.8 hours, p = 0.048). The decision was made to end the study early because the conditional power of the study favored futility. LIMITATIONS: This was a single-center study. CONCLUSIONS: Early administration of furosemide does not significantly reduce the length of hospital stay after elective colon and rectal surgery in the setting of enhanced recovery after surgery practice. See Video Abstract at http://links.lww.com/DCR/A714.

Objective: To determine the disease-free survival (DFS) and recurrence after the treatment of patients with rectal cancer with open (OPEN) or laparoscopic (LAP) resection. Background: This randomized clinical trial (ACOSOG [Alliance] Z6051), performed between 2008 and 2013, compared LAP and OPEN resection of stage II/III rectal cancer, within 12 cm of the anal verge (T1-3, N0-2, M0) in patients who received neoadjuvant chemoradiotherapy. The rectum and mesorectum were resected using open instruments for rectal dissection (included hybrid hand-assisted laparoscopic) or with laparoscopic instruments under pneumoperitoneum. The 2-year DFS and recurrence were secondary endpoints of Z6051. Methods: The DFS and recurrence were not powered, and are being assessed for superiority. Recurrence was determined at 3, 6, 9, 12, and every 6 months thereafter, using carcinoembryonic antigen, physical examination, computed tomography, and colonoscopy. In all, 486 patients were randomized to LAP (243) or OPEN (243), with 462 eligible for analysis (LAP = 240 and OPEN = 222). Median follow-up is 47.9 months. Results: The 2-year DFS was LAP 79.5% (95% confidence interval [CI] 74.4–84.9) and OPEN 83.2% (95% CI 78.3–88.3). Local and regional recurrence was 4.6% LAP and 4.5% OPEN. Distant recurrence was 14.6% LAP and 16.7% OPEN. Disease-free survival was impacted by unsuccessful resection (hazard ratio [HR] 1.87, 95% CI 1.21–2.91): composite of incomplete specimen (HR 1.65, 95% CI 0.85–3.18); positive circumferential resection margins (HR 2.31, 95% CI 1.40–3.79); positive distal margin (HR 2.53, 95% CI 1.30–3.77). Conclusion: Laparoscopic assisted resection of rectal cancer was not found to be significantly different to OPEN resection of rectal cancer based on the outcomes of DFS and recurrence.

BACKGROUND: Revisional and reconstructive surgery for IPAA is rare given the high success of pouch surgery for chronic ulcerative colitis. Limited data exist on both surgical and functional outcomes in patients with chronic ulcerative colitis who undergo IPAA revision or reconstruction. OBJECTIVE: This study aimed to determine the surgical and functional outcome in patients with chronic ulcerative colitis who undergo IPAA revision or reconstruction. DESIGN: A prospectively collected surgical database was accessed for this study. SETTING: This study was conducted at an IBD referral center. PATIENTS: Patients with chronic ulcerative colitis who underwent IPAA revision or reconstruction were selected. MAIN OUTCOME MEASURES: The primary outcomes measured were 30-day postoperative outcomes and long-term pouch function. RESULTS: Eighty-one patients were identified. Original IPAA was performed for chronic ulcerative colitis (n = 71; 88%) and indeterminate colitis (n = 11; 12.%), and the most common configuration was a J-pouch (n = 69; 86%) with handsewn anastomosis (n = 41;68%). No independent predictors of 30-day postoperative complications following reconstructive/revisional surgery were identified. Pelvic abscesses and Crohn’s disease of the pouch were independently associated with ultimate pouch excision. Median follow-up following revision/reconstruction was 40 months (range, 1–292 months) during which 15 patients (23%) had pouch failure. The 5- and 10-year pouch survival rates following revision were 85 ± 5% and 65 ± 9% by Kaplan-Meier estimation; age <30 years was significantly associated with pouch survival. Long-term function (n = 30; 35%) compared with a matched control cohort of primary IPAA was characterized by significantly increased daytime bowel incontinence (p = 0.0119), liquid stool (p = 0.0062), and medication to thicken stools (p = 0.0452). LIMITATIONS: This was a single-center series, and response rate for functional data was 35%. CONCLUSIONS: In properly selected patients with a failing pouch, originally made for chronic ulcerative colitis or indeterminate colitis, revisional and reconstructive surgery is associated with low complication rates, high pouch salvage, and acceptable long-term pouch function. See Video Abstract at http://links.lww.com/DCR/A640.

Objective: Determine the safety of overlapping surgery in a tertiary care colorectal surgery practice. Summary: Although overlapping surgery is common in academic centers, reports on outcomes of this practice are limited. The primary aim of this study was to investigate the safety of overlapping surgery in a dedicated tertiary care academic colorectal practice by comparing groups of patients who did or did not have their surgery performed in an overlapping fashion. Methods: Retrospective review of 1270 colorectal patients undergoing inpatient colorectal surgery at our institution. Eligible participants were all patients undergoing elective inpatient colorectal surgery by one of the colorectal surgeons at the Mayo Clinic Rochester between January 1, 2012 and December 31, 2015. Patients under the age of 18 or who underwent an emergent procedure were excluded. Data were abstracted using the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) database. Additionally, each subject's chart was reviewed and further abstracted. The safety of overlapping surgery on outcomes was assessed using multiple multivariable models. Results: One thousand two hundred seventy patients were included in the study cohort of whom 50.7% were female and the average age was 55.4 years. Overlapping surgery occurred in 576 patients (45%). There were no significant differences in demographic, surgical indications, procedures, or operative complexity between patients undergoing overlapping surgery and those who did not. Overall adverse events were significantly less likely in patients undergoing overlapping surgery compared with those who did not (18.4% vs 23.6%, P = 0.02). We found that overlapping surgery was associated with significantly less adverse events compared with patients not undergoing overlapping surgery using a model that controlled for the effect of the individual surgeon (OR 0.7, 95% CI 0.6 – 0.96; P = .02) and a multivariable propensity score (OR 0.7, 95% CI 0.5– 0.9; P = 01). Conclusions: Overlapping surgery in a tertiary care colorectal practice is safe and not associated with adverse patient outcomes.

INTRODUCTION: An IPAA is the preferred operative approach for restoration of intestinal continuity in patients with ulcerative colitis and familial adenomatous polyposis. As minimally invasive approaches have become more widely adopted, their use in IPAA has also become increasingly commonplace. Laparoscopy has the same limitations during the proctectomy portion as seen in operations for rectal cancer, including dissection in the mid-to-lower rectum attributed to angles created by bony confines of the deep pelvis and lack of visibility when constructing the anastomosis. Robotic surgery provides improved 3-dimensional and high-definition visualization of the pelvis and multiple degrees of freedom, which greatly enhance performance during the proctectomy and construction of the anastomosis. TECHNIQUE: In the setting of a previous subtotal colectomy, the ileostomy site is taken down and stapled across. A 15-mm balloon trocar is placed in the site to achieve insufflation, and the robotic ports are placed horizontally just above the umbilicus. The lateral mesenteric attachments are mobilized laparoscopically, then the J-pouch is constructed through the ostomy site. The J-pouch is placed back into the abdomen with the anvil in place, and the proctectomy is performed after docking the robot. The rectum is stapled with the robotic stapler and exteriorized from the ileostomy site, and the anastomosis is constructed under direct robotic visualization. RESULTS: In addition to the potential ergonomic advantages, the maneuverability and visualization in the pelvis during the proctectomy and construction of the anastomosis are reported by many surgeons to be improved as compared with laparoscopy, especially in male or obese patients. CONCLUSIONS: A robotic approach during the proctectomy and IPAA offers significant advantages to a laparoscopic approach, expanding our armamentarium of minimally invasive surgical techniques to IPAA.

Abstract Background Deficiencies in the DNA mismatch repair system cause errors during DNA replication, which in turn give rise to microsatellite instability (MSI). The impact of MSI on survival in metastatic colorectal cancer (mCRC) is unclear. This cohort study aims to investigate the prognostic and predictive value of MSI in mCRC prior to the immune therapy era. Materials and Methods A total of 75 MSI-high (MSI-H) mCRC patients (pts) and 75 matched (age, gender, disease sidedness, metachronous/synchronous) microsatellite-stable (MSS) mCRC pts were identified from 1,268 mCRC pts who had MSI/mismatch repair test results at Mayo Clinic Rochester between January 1992 and July 2016. A retrospective review was conducted by using data from electronic medical records. Statistical analyses utilized the Kaplan-Meier method, log-rank test, and Cox proportional hazards models. Results The MSS group was well matched to the MSI-H group based on age, gender, location, and chronicity of metastatic disease. MSI-H mCRC pts had earlier disease recurrence (median time from initial diagnosis to metastatic disease diagnosis, MSI-H group 12.9 vs. MSS group 20.9 months, p = .034). Median overall survival (OS) was 28.1 and 37.4 months for MSI-H and MSS pts, respectively (p = .99). In total, 94.7% of MSI-H pts and 98.7% of MSS pts had fluoropyrimidine-based chemotherapy for metastatic disease, and there was no difference in OS between these two groups (32.3 vs. 37.4 months, p = .91). Forty-three MSI-H and thirty-nine MSS pts had metastasectomy and/or ablation of metastases (p = .51) with longer median OS compared with pts without metastasectomy (MSI-H: 82.0 vs. 13.9, p &lt; .001; MSS: 69.9 vs. 19.7, p &lt; .001). Age &lt;65 years, BRAF wild type, and metastasectomy were associated with better OS in univariate analysis. Only metastasectomy remained statistically significant in multivariate analysis (p &lt; .001). Conclusion In mCRC, patients with MSI-H tumors have similar, but numerically shorter, median overall survival compared with those with MSS tumors. In both groups, metastasectomy and ablation of metastatic disease should be considered to optimize OS. Implications for Practice This study clearly demonstrated the survival benefits that aggressive metastasectomy provides in selected microsatellite instability-high metastatic colorectal cancer patients. This could be meaningful practice-changing information that has been long awaited.

Abstract Background The prognostic value of pathological lymph node status following neoadjuvant radiotherapy (ypN) remains unclear. This study was designed to determine whether ypN status predicted overall survival. Methods Patients with locally advanced rectal adenocarcinoma who underwent neoadjuvant long-course radiation between 2005 and 2014 were identified from the National Cancer Data Base, and divided into ypN0, ypN1 and ypN2 groups. The primary outcome was overall survival. Univariable and multivariable analyses were used to determine factors associated with overall survival. Results Of 12 271 patients, 3713 (30·3 per cent) were found to have residual nodal positivity. A majority of patients with ypN1 (1663 of 2562) and ypN2 (878 of 1151) disease had suspected lymph node-positive disease before neoadjuvant therapy, compared with 3959 of 8558 with ypN0 tumours (P &lt; 0·001). Moreover, ypN1 and ypN2 were significantly associated with ypT3–4 disease (65·7 and 83·0 per cent respectively versus 39·4 per cent for ypN0; P &lt; 0·001). In unadjusted analyses, survival differed significantly between ypN groups (P &lt; 0·001). Five-year survival rates were 81·6, 71·3 and 55·0 per cent for patients with ypN0, ypN1 and ypN2 disease respectively. After adjustment for confounding variables, ypN1 and ypN2 remained independently associated with overall survival: hazard ratio (HR) 1·61 (95 per cent c.i. 1·46 to 1·77) and 2·63 (2·34 to 2·95) respectively (P &lt; 0·001). Overall survival was significantly longer in patients with ypN1–2 combined with ypT0–2 status than among those with ypT3–4 tumours even with ypN0 status (P = 0·031). Clinical nodal status before neoadjuvant therapy was not significantly associated with overall survival (HR 1·05, 0·97 to 1·13; P = 0·259). Conclusion Both ypT and ypN status is of prognostic significance following neoadjuvant therapy for rectal cancer.