NEW YORK (Reuters Health) – Cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (HIPEC) together provide long term survival for patients with pseudomyxoma peritonei of appendiceal origin, a retrospective study indicates.
“Cytoreductive surgery and HIPEC/EPIC (early postoperative intraperitoneal chemotherapy) should be recommended for all patients with peritoneal dissemination of gastrointestinal malignancies, in particular, for appendiceal mucinous neoplasms,” lead author Dr. Terence C. Chua from University of New South Wales, Sydney, Australia told Reuters Health by email.
He added, “This treatment has been shown to be effective in achieving long term disease control in the abdomen for both low grade and high grade variants of appendiceal pseudomyxoma.”
An editorialist commenting on the study, online May 21 in the Journal of Clinical Oncology, is unconvinced, however: “Given the significant morbidity associated with cytoreductive surgery and HIPEC, one has to wonder whether an alternative approach might be prudent.”
Dr. Chua and colleagues reviewed registry data on 2,298 patients treated with cytoreductive surgery for appendiceal pseudomyxoma peritonei, including 2,054 (89%) who received HIPEC intraoperatively (mitomycin C and oxaliplatin). At seven of the 16 hospitals that contributed data, patients also received early postoperative intraperitoneal therapy with fluorouracil.
The researchers reported that 1,904 patients (83%) had “optimal” cytoreduction and 1,165 patients (51%) had complete cytoreduction.
Postoperative mortality was low (2%), but 24% of patients had major operative complications. Major complications were more common among patients with a history of surgery in more than five abdominal regions, at least two prior operations, and a peritoneal cancer index (PCI) more than 20 (on a scale of 1 to 39).
During a median follow-up of 36 months (range, 1 to 220 months), median survival was 196 months (16.3 years), and median progression-free survival was 98 months (8.2 years).
Overall survival rates were 80% at three years, 74% at five years, 63% at 10 years, and 59% at 15 years.
Prior chemotherapy treatment, peritoneal mucinous carcinomatosis histopathologic subtype, less complete debulking surgery, and major postoperative complications independently predicted poorer progression-free and overall survival.
Higher peritoneal cancer index and not using HIPEC were additional predictors of poor progression-free survival, whereas older age additionally predicted poor overall survival.
“Patients with peritoneal spread of cancer should be referred to a high volume tertiary referral center with specialized expertise in cytoreductive surgery and HIPEC/EPIC for evaluation,” Dr. Chua said in his email.
“A randomized trial to confirm the results would provide level 1 evidence,” Dr. Chua explained, “but from our clinical experience and clinic interactions with patients, these retrospective and large cohort series results have made a randomized trial almost impossible to conduct due to the disparate survival outcomes, and there will likely be no patients who would commit towards such a trial especially for appendiceal pseudomyxoma.”
But Dr. Eric K. Nakakura from University of California, San Francisco writes in an editorial, “There are data to suggest that similar outcomes can be obtained by the selective use of extensive debulking surgery with emphasis on preserving function and managing symptoms without routine intraperitoneal chemotherapy.”
“As with many challenging issues in oncology,” Dr. Nakakura concludes, “there remain more questions than answers with respect to the treatment of patients with pseudomyxoma peritonei.”
J Clin Oncol 2012.