Background: A treatment option for patients with peritoneal mucinous carcinomatosis (PMCA) from an appendiceal neoplasm is cytoreductive surgery and perioperative intraperitoneal chemotherapy. Also, these patients are recommended for systemic chemotherapy using an oxaliplatin and 5-fluorouracil (FOLFOX) regimen. A major question concerns the proper timing (neoadjuvant vs. adjuvant) of the systemic chemotherapy.
Methods: In January of 2005 a prospective study was initiated to routinely treat patients with peritoneal dissemination of a mucinous adenocarcinoma of the appendix with neoadjuvant chemotherapy using FOLFOX. All patients had a clinical, CT, intraoperative, and histopathological assessment of chemotherapy effects. The study was closed in July of 2009.
Results: Thirty-four consecutive patients were available for evaluation. In the clinical evaluation and CT evaluation, 24 (71%) and 22 (65%), respectively, had stable disease on chemotherapy. By intraoperative examination 17 (50%) patients were observed to have progressed. By histopathology seven had a partial response and three patients a complete response (29%).
Conclusions: In these carcinomatosis patients clinical and CT assessment of response to neoadjuvant chemotherapy seldom provided useful data over this short time period. Intraoperative findings indicated progression in 50% of patients. By histopathology, 29% of patients had a response.