ASCO 2016: Adding Intraperitoneal Chemotherapy to Intravenous Chemotherapy Slows Ovarian Cancer Progression


Key Points

  • At 9 months, 42.2% of women who received IV chemotherapy had disease worsening compared to 23.3% of those treated with IP/IV chemotherapy.
  • The median progression­–free survival was similar between the two groups—11.3 months with IV chemotherapy and 12.5 months with the IV/IP regimen. 
  • The median overall survival was longer with IV/IP therapy than with IV therapy alone (59.3 months vs 38.1 months), but the difference was not statistically significant.

For some women with advanced ovarian cancer that was successfully treated surgically, delivering chemotherapy intraperitoneally as well as intravenously appears more effective than intravenous chemotherapy alone. For women who were initially treated with chemotherapy prior to surgery, the initial results from a randomized phase II trial show that 23.3% of women who received chemotherapy by both administration methods had disease progression at 9 months vs 42.2% of those who received intravenous chemotherapy alone.

The study, by Mackay et al, was featured in a press briefing today at the 2016 ASCO Annual Meeting (Abstract LBA5503).

According to the authors, the proportion of women with ovarian cancer who receive neoadjuvant therapy prior to surgery is growing. An estimated 30­% to 40% of all women with epithelial ovarian cancer will receive neoadjuvant chemotherapy in North America and Europe. Women who undergo optimal debulking surgery following this approach may now be candidates for intraperitoneal/intravenous combination chemotherapy.

Intraperitoneal chemotherapy allows the delivery of higher doses of chemotherapy to the tumor, while sparing other parts of the body from side effects. Several prior randomized clinical trials showed that intraperitoneal chemotherapy improved outcomes for certain women with ovarian cancer. However, this is the first randomized study to explore the benefit of intraperitoneal chemotherapy among women who had received neoadjuvant chemotherapy.

“At this early time frame, we already see that women are doing better with [intraperitoneal] chemotherapy, without a significant difference in toxicity,” said lead study author Helen Mackay, MD, Divisional Head of Medical Oncology and Hematology at the Sunnybrook Odette Cancer Centre in Toronto. “However, women should consider the side effects of [intraperitoneal] and [intravenous] chemotherapy, as well as recovery from cancer surgery, when discussing this option with their doctors.”

To see Dr. Mackay discuss this study with The ASCO Post, please click here.

About the Study

This randomized phase II trial, OV21/PETROC, compared the efficacy and side effects of two combination chemotherapy regimens in patients with stage IIB–IV epithelial ovarian cancer. The majority (82%) of women had stage IIIC disease (cancer spread into the intraperitoneal cavity).

In this study, 275 women received neoadjuvant platinum­–based chemotherapy, followed by debulking surgery. Following surgery, 200 were randomly assigned to treatment with intravenous chemotherapy or an intraperitoneal/intravenous regimen.

Key Findings

At 9 months, 42.2% of women who received IV chemotherapy had disease worsening compared to 23.3% of those treated with intraperitoneal/intravenous chemotherapy. The median progression­–free survival was similar between the two groups—11.3 months with intavenous chemotherapy and 12.5 months with the intravenous/intraperitoneal regimen. The median overall survival was longer with intravenous/intraperitoneal therapy than with intravenous therapy alone (59.3 vs 38.1 months), but the difference was not statistically significant.

“Although this randomized phase II trial was not statistically powered to evaluate survival, our results offer information on how to incorporate [intraperitoneal] chemotherapy when women receive neoadjuvant chemotherapy followed by debulking surgery,” said Dr. Mackay. “The findings also offer supportive and additional information to the previous published adjuvant randomized trials that showed an improvement in overall survival when [intraperitoneal] chemotherapy was given following initial optimal debulking surgery.”

The rate of severe side effects was slightly lower among women who receive intraperitoneal/intravenous chemotherapy (16% vs 23%), but this difference was not statistically significant.

Next Steps

Prior research has suggested that some molecular subtypes of ovarian cancer are more sensitive to chemotherapy than others. The researchers plan to assess tissue samples collected during this study to see if certain biologic characteristics were associated with improved outcomes with intraperitoneal vs intravenous chemotherapy. “If we can identify the long-term survivors, we hope this will help us better predict who truly benefits from this approach,” concluded Dr. Mackay.

The study received funding support from the Canadian Cancer Society Research Institute (CCSRI), Cancer Research, UK (CR UK), and NIH/NCI (US).

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.