Phase II study of interval debulking surgery followed by intraperitoneal chemotherapy for advanced ovarian cancer: a Kansai Clinical Oncology Group study (KCOG9812).

Objective: Intraperitoneal chemotherapy (IP) is known to be effective after optimal primary debulking surgery (PDS) for ovarian cancer (OC). Here, we conducted a phase II study to investigate its effectiveness after interval debulking surgery (IDS).

Methods: Thirty-seven patients with FIGO stage IIIB-IV and suboptimal (≥1cm diameter) residual disease after PDS were enrolled. Carboplatin (AUC 4 IV, Day 1) and cisplatin (50mg/m(2) IV, Day 3) were given q21d for 3cycles. After IDS, paclitaxel (175mg/m(2) IV Day 1 or 60mg/m(2) IV Days 1, 8, and 15, since 2000) and cisplatin (75mg/m(2) IP Day 2) were given q21d for 4cycles. The primary endpoint was progression-free survival (PFS), and secondary endpoints were overall survival (OS) and adverse events (CTCAE ver. 2.0). Clinical manifestations at first recurrence and subsequent treatment were also surveyed.

Results: Of the 37 patients, high-grade, serous adenocarcinoma was found in 33. Stages IIIB, IIIC, and IV were found in 2, 24, and 11 patients, respectively. After IDS, 23 patients had no macroscopic residual tumor. No patients had permanent enterostomy, febrile neutropenia, or platelet transfusion. The treatment protocol was completed in 22 patients, and discontinued in 5 due to IP catheter-related complications. Median PFS and OS were 22 and 57months, respectively. Among the 28 patients with recurrence, 10 had no intraperitoneal disease at first recurrence. Among the 8 patients who underwent surgical cytoreduction, 6 had no residual tumor, while 2 had a <1-cm-diameter residual tumor.

Conclusion: IP after IDS for patients with initially suboptimally debulked OC was effective.