Extraovarian peritoneal serous papillary carcinoma: a phase II trial of cisplatin and cyclophosphamide with comparison to a cohort with papillary serous ovarian carcinoma-a Gynecologic Oncology Group Study.

Objectives: The goals of this study were first, to assess the clinical effectiveness of cisplatin and cyclophosphamide in a phase II study involving a well-defined group of women with extraovarian peritoneal serous papillary carcinoma (EPSPC); and second, to compare these results with those of a group of patients with papillary serous ovarian carcinoma (PSOC) who received identical therapy.

Methods: After primary surgery, patients were treated with cisplatin 75 mg/m(2) and cyclophosphamide 750 mg/m(2) every 21 days for six cycles. Patient demographics, tumor characteristics, clinical and surgical response to treatment, progression-free survival, and overall survival were evaluated. These patients were then compared with patients with PSOC who received identical treatment on a separate protocol.

Results: Women with a diagnosis of tended to be older that those with EPSPC PSOC (median age: 65.8 years vs 60.3 years, P = 0.04). The estimated probability of clinical response (complete and partial) to the treatment regimen for EPSPC was 65% (95% confidence interval [CI]: 41-85%) compared with 59% (95% CI: 47-71%) for women with PSOC. Surgical complete responses were similar (20% vs 19%) in the two patient groups. Additionally, the death rates did not significantly differ between the two groups (hazard ratio: 1.25, 95% CI: 0.834-1.88).

Conclusion: Women with EPSPC and PSOC exhibit a similar probability of response to cisplatin and cyclophosphamide and a similar overall survival. Based on these findings and the fact that results of ovarian cancer trials are frequently extrapolated to patients with EPSPC, it is reasonable to include EPSPC patients in future large-scale treatment trials involving patients with advanced ovarian cancer.