Peritoneal metastases of lower gastrointestinal tract origin: a comparative study of patient outcomes following cytoreduction and intraperitoneal chemotherapy.

BACKGROUND: Cytoreductive surgery (CS) combined with intraperitoneal chemotherapy (IPC) is a multimodal approach to the treatment of peritoneal metastases (PM) of lower gastrointestinal origin. This study examines patient outcomes and critically evaluates its patterns of recurrences relative to the site of metastatic origin.
METHODS: Patients treated with CS/IPC from 2000 to 2012 where PM arose from a primary tumour of the appendix, colon and rectum were identified from a prospective database for retrospective evaluation. The primary end points were survival (overall and disease-free), and secondary end points include patterns of recurrence and prognostic factors associated with overall outcomes.
RESULTS: Two hundred and eleven patients were followed up for a median of 23.3 months (range 1-156). Overall median survival was 46.8 months, and the 1-, 3-, 5-year survival rates were 87, 56 and 42 %, respectively. The 5-year survival of patients with appendiceal, colonic and rectal PM was 55, 33 and 20 %, respectively. Tumour origin was the only independent prognostic factor associated with overall survival (p = 0.03). Recurrences were more common in patients of colorectal origin over appendiceal origin (p < 0.001) and were more likely to be of a systemic nature (p = 0.05).
CONCLUSION: CS/IPC provides an option for improved survival in patients with PM of lower gastrointestinal origin and appears to be most promising in patients with disease of appendiceal origin.