Effectiveness and safety of chemotherapy for patients with malignant gastrointestinal obstruction: A Japanese population-based cohort study.

Background: The impacts of chemotherapy on patients with malignant gastrointestinal obstructions remain unclear, and multicenter evidence is lacking.

Aim: To evaluate the effectiveness and safety of chemotherapy in patients with unresectable malignant gastrointestinal obstructions.

Methods: We conducted a multicenter retrospective cohort study that compared the chemotherapy group who received any chemotherapeutics after interventions, including palliative surgery or self-expandable metal stent placement, for unresectable malignant gastrointestinal obstruction the best supportive care (BSC) group between 2014 and 2019 in nine hospitals. The primary outcome was overall survival, and the secondary outcomes were patency duration and adverse events, including gastrointestinal perforation and gastrointestinal bleeding.

Results: In total, 470 patients in the chemotherapy group and 652 patients in the BSC group were analyzed. During the follow-up period of 54.1 mo, the median overall survival durations were 19.3 mo in the chemotherapy group and 5.4 mo in the BSC group (log-rank test, < 0.01). The median patency durations were 9.7 mo [95% confidence interval (CI): 7.7-11.5 mo] in the chemotherapy group and 2.5 mo (95%CI: 2.0-2.9 mo) in the BSC group (log-rank test, < 0.01). The perforation rate was 1.3% (6/470) in the chemotherapy group and 0.9% (6/652) in the BSC group ( = 0.567). The gastrointestinal bleeding rate was 1.5% (7/470) in the chemotherapy group and 0.5% (3/652) in the BSC group ( = 0.105).

Conclusion: Chemotherapy after interventions for unresectable malignant gastrointestinal obstruction was associated with increased overall survival and patency duration.