Short-term outcomes and prognosis of palliative surgery for malignant bowel obstruction caused by peritoneal metastasis of colorectal cancer

Abstract

Objective: To explore the short-term efficacy and prognosis of palliative surgical treatment for malignant bowel obstruction (MBO) caused by peritoneal metastasis of colorectal cancer (mCRC). Methods: A retrospective cohort study was conducted. The inclusion criteria for patients were as follows: (1) primary colorectal cancer; (2) massive peritoneal metastasis; (3)obstructive site located below Treitz ligament by imaging; (4) obstruction refractory to conservative treatment; (5) estimated rese survival time more than 2 months; (6) patients and their families had strong willingness for operation; (7) surgical treatment included stoma/bypass and debulking surgery. In accordance with the above criteria, clinicopathological data of 46 patients undergoing palliative surgery at Peking University Gastrointestinal Cancer Center, Unit III from January 2016 to October 2018 were retrospectively collected. Postoperative symptomatic relief rate, morbidity of complication within 30 days, complication classification (Clavien-Dindo classification), mortality and survival after operation were analyzed. Kaplan-Meier method was used to evaluate survival and Cox regression analysis was used to identify prognostic factors. Results: Among 46 patients, 30 were male and 16 were female with median age of 63 (19-87) years; 23 patients received stoma/bypass surgery (stoma/bypass group), and 23 cases received tumor debulking surgery (debulking group). The overall symptom relief rate was 76.1% (35/46), while symptom relief rate in the debulking group was 91.3% (21/23), which was significantly higher than 60.9% (14/23) in the stoma/bypass group (χ(2)=4.301, P=0.038). Postoperative complications occurred in 25 patients. The complication rate was 52.2% (12/23) in the debulking group and 56.5% (13/23) in the stoma/bypass group, without statistically significant difference (χ(2)=0.088, P=0.767). Morbidity of complication beyond grade III was 8.7% (2/23) and 13.0% (3/23) in the debulking group and stoma/bypass group respectively, without statistically significant difference (χ(2)=0.224, P=0.636). Four patients died within 30 days after operation, 2 (8.7%) in each group. Twenty-four patients underwent 1-8 cycles of chemotherapy ± targeting therapy (regimens: CapeOX ± Bevacizumab, FOLFOX/FOLFIRI ± Bevacizumab/Cetuximab), including 10 cases in the stoma/bypass group and 14 cases in the debulking group. Two patients of debulking group received postoperative radiotherapy and chemotherapy (50.6 Gy/22 f, with concurrent oral capecitabine). Till the last follow up of April 2019, 34 patients died (34/46, 73.9%) with a median overall survival time of 6.4 months, and the 6-month and 1-year survival rate was 54.5% and 29.2% respectively. The median survival time in the debulking group was significantly longer than that in the stoma/bypass group (11.5 months vs. 5.2 months, χ(2)=5.117, P=0.024). The median survival time of the 35 patients with symptomatic relief after operation was significant longer than that of 11 patients without relief (7.1 months vs 5.1 months, χ(2)=3.844, P=0.050). Multivariate analysis showed stoma/bypass surgery (HR=2.917, 95%CI:1.357-6.269, P=0.006) and greater omental metastasis (HR=4.060, 95%CI:1.419-11.617, P=0.009) were independent risk factors associated with prognosis of patients with MBO caused by peritoneal mCRC. Conclusions: For patients of MBO caused by peritoneal mCRC, tumor debulking surgery may achieve higher symptom relief rate and prolong survival. Greater omental metastasis indicates poor prognosis.