Outcomes following diagnostic laparoscopy in patients with peritoneal carcinomatosis deemed ineligible for cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) due to disease burden

Introduction: While cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) can improve overall survival (OS) for patients with peritoneal carcinomatosis from appendiceal or colorectal cancer, some patients are ineligible for CRS/HIPEC due to disease burden. This paper characterizes outcomes for patients who are evaluated by diagnostic laparoscopy (DL) and deemed ineligible for CRS/HIPEC. Methods: Medical records were retrospectively reviewed for patients who underwent DL and deemed ineligible for CRS/HIPEC (1/1/2009–1/1/2024). Date of death was confirmed using public obituaries. Treatment course/causes of death are summarized by descriptive statistics and OS by Kaplan-Meier analysis. Results: 124 patients were included. Median Peritoneal Cancer Index (PCI) score was 25. Median follow-up was 1.14 and median OS 1.29 years. 58 (46.8 %) died of their malignancy, 42 (33.9 %) died of unknown cause, and 24 (19.4 %) were alive at last follow-up. The most common causes of death were bowel obstruction (29, 23.4 %), multifactorial/failure to thrive (21, 16.9 %), and malignant ascites (15, 12.1 %). Patients who underwent some form of additional therapy after DL (1.43 versus 0.48 years, p < 0.001) or who enrolled in a clinical trial (1.91 versus 1.21 years, p = 0.030) had prolonged OS. Conclusions: OS for patients with peritoneal carcinomatosis from appendiceal or colorectal cancer who are deemed ineligible for CRS/HIPEC after DL is 1.29 years without significant variation by primary pathology, PCI, peritoneal cytology, or presence of hematogenous metastases. Patients who get some form of additional therapy following their DL have prolonged OS. The most common causes of death are bowel obstruction, failure to thrive, and malignant ascites.