Background: Multicystic peritoneal mesothelioma (MPM) and well-differentiated papillary peritoneal mesothelioma (WDPPM) are exceedingly uncommon lesions with uncertain malignant potential and no uniform treatment strategy. The aim of the current study was to review our experience with cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) in these clinical settings.
Methods: Four women with MPM and eight with WDPPM underwent 13 procedures of cytoreduction and close-abdomen HIPEC with cis-platin and doxorubicin. Seven patients had recurrent disease after previous debulking (one operation in five patients, two in one, four in one). Potential clinicopathological prognostic factors were assessed.
Results: Optimal cytoreduction (residual tumor nodules <or=2.5 mm) was performed in 12 of 13 procedures. Median follow-up was 27 months (range 6-94). One grade 4 postoperative complication (NCI/CTCAE v.3.0) and no operative mortalities occurred. One patient underwent the procedure twice due to locoregional MPM recurrence. Transition of typical WDPPM to malignant biphasic mesothelioma was documented in one patient who died of disease progression following incomplete cytoreduction and HIPEC. Following multimodality treatment, 5-year overall and progression-free survival were 90.0% (standard error = 9.0) and 79.7% (11.9), respectively. Progression-free survival following previous debulking surgery (median 24 months; range 2-87) was statistically worse (P = .0156). Incomplete cytoreduction and poor performance status correlated to both reduced overall and progression-free survival after cytoreduction and HIPEC.
Conclusions: MPM and WDPPM are borderline tumors capable of transformation into potentially lethal processes. Definitive tumor eradication by means of cytoreduction and HIPEC seems more effective than debulking surgery in preventing disease recurrence or transition to aggressive malignancies.