Treatment results in patients with stage IV colorectal cancer complicated by intestinal obstruction

Background. Acute large bowel obstruction is one of the most common complications requiring emergency or immediate surgical intervention. This condition is diagnosed in 10–26 % of patients with nonresectable metastases of colorectal cancer. Resection of the primary lesion is an extensive intervention which is often associated with the risk of delaying systemic therapy. Therefore, less invasive surgical strategies – formation of a defunctioning stoma or placement of a self-expandable metallic stent – have come to the forefront.

Aim. To compare early and long-term clinical outcomes of using self-expanding metallic stents (SEMS) and defunctioning stoma formation in patients with stage IV colorectal cancer complicated by intestinal obstruction.

Materials and methods. The retrospective cohort study included 82 patients with a diagnosis of stage IV colorectal cancer and clinically confirmed intestinal obstruction caused by progression of the main disease. The patients were divided into 2 groups: in the 1^st group, SEMS were placed (SEMS group, n = 18); in the 2^nd group, stoma was formed (stoma group, n = 64). Clinical success (elimination of obstruction symptoms during the 1^st day after the surgery), rates of early (under 30 days) and late (after 30 days) postoperative complications, necessity of repeat interventions, and overall survival were assessed.

Results. Clinical success was achieved in 17 (94 %) patients in the SEMS group and 64 (100 %) patients in the stoma group (p = 0.221). The rate of early postoperative complications was 3 (16.7 %) cases in the SEMS group and 9 (14.1 %) cases in the stoma group (p = 0.720). The groups did not significantly differ in the rates of late complications (4 (22.2 %) cases in patients after stenting versus 5 (7.8 %) in patients with stoma (p = 0.101)). The frequency of repeat interventions did not differ between the groups and was 2 (11.1 %) cases in the SEMS group and 6 (9.4 %) in the stoma group (p = 0.810). Analysis of overall survival (OS) included 82 patients, 18 in the SEMS group and 64 in the stoma group. At the end of follow-up period, deaths were reported for 17 (94.4 %) and 52 (81.3 %) patients, respectively; 1 (5.6 %) and 12 (18.7 %) observations, respectively, were censored. Median follow-up was 38.2 months therefore OS was calculated at the maximal horizon of 36 months as to not exceed the median follow-up. At month 36, OS was 7.3 % (95 % confidence interval (CI) 0.5–27.8) in the SEMS group and 16.7 % (95 % CI 7.9–28.3) in the stoma group; differences between the OS curves were not statistically significant (log-rank test; p = 0.069) with a trend towards less favorable OS in the SEMS group. Median OS was 7.4 months in the SEMS group and 18.0 months in the stoma group. Cox’s model showed a marked dynamic toward higher risk of death in the SEMS group compared to the stoma group (hazard ratio 1.71; 95 % CI 0.95–3.07).

Conclusion. Placement of SEMS and defunctioning stoma formation in patients with stage IV colorectal cancer complicated by large bowel obstruction were characterized by similar clinical efficacy and early safety with faster functional recovery and earlier start of systemic therapy in the SEMS group. In the long term at 36-month horizon, a trend toward less favorable OS in the SEMS group without statistically significant differences between the curves and increased relative risk of death in this group were observed. Considering limitations of the study (retrospective design, single center, small number of patients in the SEMS group), the results should be considered hypothesis-forming and requiring further prospective studies.