Malignant bowel obstruction: effectiveness and safety of systemic chemotherapy.

Objectives: Although systemic chemotherapy is often administered to patients with malignant bowel obstruction (MBO), its benefit remains unknown. This study assessed the outcomes of patients who received systemic chemotherapy as part of MBO treatment.

Methods: For this retrospective cohort study, data were extracted from records of patients hospitalised due to MBO in a tertiary cancer centre from 2008 to 2020. Eligible patients were not candidates for surgery and received systemic chemotherapy targeting the underlying malignancy causing MBO. Primary objective was to assess patient outcomes after chemotherapy; secondary objectives were rates of intestinal function recovery, hospital discharge and grade ≥3 toxicities. The primary endpoint was overall survival (OS).

Results: A total of 167 patients were included: median age was 55 (18-81) years, 91% had an Eastern Cooperative Oncology Group (ECOG) performance status ≥2, 75.5% had gastrointestinal tumours and 70% were treatment-naive. The median OS after chemotherapy was 4.4 weeks (95% CI 3.4 to 5.5) in the overall population. No OS difference was observed according to treatment line (p=0.24) or primary tumour (p=0.13). Intestinal function recovery occurred in 87 patients (52%), out of whom 21 (24.1%) had a reobstruction. Hospital discharge was possible in 74 patients (44.3%). Grade≥3 adverse events occurred in 26.9% of the patients, and a total of 12 deaths (7%) attributed to toxicities were observed after chemotherapy.

Conclusions: MBO was associated with a dismal prognosis in this mostly treatment-naive population. The administration of chemotherapy yielded a significant risk of toxicities, whereas it did not appear to provide any relevant survival benefit in this scenario.