Chemotherapy-associated pneumoperitoneum in cancer patients: a scoping review.

Background: The presence of air in the peritoneal cavity (pneumoperitoneum) is often secondary to perforated viscus. Emergent operative intervention is typically warranted in non-cancer patients. Cancer patients present a unique challenge as they have an increased risk of pneumoperitoneum due to local tumour invasion, radiation therapy, and frequent endoscopic procedures. There is a paucity of literature on the management of patients undergoing chemotherapy who present with pneumoperitoneum. The authors conducted a scoping review to identify and synthesize preliminary evidence on the presentation, management, and outcomes of this patient population. Materials and methods: A scoping review of cases of pneumoperitoneum in cancer patients from 1990 to 2022 was conducted using the Arksey and O'Malley five-stage approach. Inclusion criteria were a known diagnosis of cancer, chemotherapy within 6 months of presentation, and imaging confirmation of pneumoperitoneum. The authors' exclusion criteria were cancer diagnosis at the time of presentation, perforation secondary to local cancer invasion, and last chemotherapy session greater than 6 months prior to presentation. Results: Thirty-four cases (8 paediatric, 26 adults) were identified. The median time from the last chemotherapy treatment to presentation with pneumoperitoneum was 14 days. Twenty-one patients were managed operatively, and 13 were managed non-operatively. The most common source of perforation was multiple sites along the bowel. Thirty-day mortality was 33.3% for the operative cohort and 23.1% for the non-operative group. Conclusions: Pneumoperitoneum in cancer patients remains a highly morbid condition with a mortality rate of approximately 30%, regardless of the treatment approach. Non-operative management should be pursued whenever possible.