The role of intraperitoneal (IP) chemotherapy in the treatment of advanced ovarian cancer has been debated for a long time. According to a new study presented at the 2016 ASCO Annual Meeting, a combination of IP and intravenous (IV) chemotherapy appears more effective than IV chemotherapy alone in women with optimally resected advanced ovarian cancer following neoadjuvant chemotherapy, reducing the progressive disease rate at 9 months by 18.9%.¹

These results were achieved with IP carboplatin instead of the more toxic cisplatin in combination with paclitaxel. Previous, fully published, randomized studies have evaluated IP cisplatin-based chemotherapy regimens.

Our results offer clinicians information on how to incorporate IP treatment for women undergoing neoadjuvant chemotherapy followed by definitive surgery.

— Helen J. MacKay, MD

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“It has been shown that IP chemotherapy reduces the risk of death in select patients following upfront optimal cytoreductive surgery. Now, approximately 40% of women with ovarian cancer are treated with neoadjuvant chemotherapy. We wanted to determine if patients who received neoadjuvant chemotherapy benefit from IP chemotherapy,” said presenting author Helen J. MacKay, MD, of Sunnybrook Odette Cancer Centre, Toronto, Ontario, Canada.

Study Details

The OV21/PETROC trial was a randomized phase II trial that enrolled patients with primary stage IIB–IV (at diagnosis) ovarian cancer treated with neoadjuvant platinum-based chemotherapy who underwent optimal surgery (no residual disease or minimal residual disease). A total of 275 patients were originally randomized in a 1:1:1 ratio to three arms: carboplatin/paclitaxel given IV, cisplatin/paclitaxel given IP, or carboplatin/paclitaxel given IP.

At a preplanned interim analysis, the IP cisplatin/paclitaxel arm was discontinued at the recommendation of the independent data safety monitoring committee based on lack of efficacy and tolerability. The study continued as a two-arm comparison of IP/IV, and patients continued on IP carboplatin/paclitaxel vs IV carboplatin/paclitaxel (100 patients in each arm).

“To date, tolerability of IP cisplatin-based regimens has been one barrier to the uptake of IP chemotherapy,” noted Dr. MacKay.

Study Results

The primary endpoint was the rate of progressive disease at 9 months, which was 42.2% for the IV chemotherapy arm (per protocol), representing a significant 18.9% reduction (P = .03 stratified).

Median overall survival was 38.1 months for patients treated with IV chemotherapy vs 59.3 months for the IP arm, which did not reach statistical significance. “The study was not powered to predict a difference in overall survival, but the median overall survival in the IV arm of this trial is similar to that in other neoadjuvant studies in advanced ovarian cancer,” Dr. MacKay told listeners.

It is important to note that no significant differences in quality of life were observed between the two treatment arms.

“We have to take these data in the context of other IP studies, which showed a benefit for IP chemotherapy in the front-line setting. Our results offer clinicians information on how to incorporate IP treatment for women undergoing neoadjuvant chemotherapy followed by definitive surgery,” Dr. MacKay concluded. She added that correlative studies will be conducted on tissue samples collected in this study “going forward.” ■

Disclosure: Dr. MacKay reported no potential conflicts of interest.

Reference

1. MacKay H, Gallagher CJ, Parulekar WR, et al: OV21/PETROC: A randomized Gynecologic Cancer Intergroup (GCIG) phase II study of intraperitoneal versus intravenous chemotherapy following neoadjuvant chemotherapy and optimal debulking surgery in epithelial ovarian cancer. 2016 ASCO Annual Meeting. Abstract LBA5503. Presented June 5, 2016.