Intraperitoneal chemotherapy provides a clear survival benefit in stage III ovarian cancer in real-world practice as it did in clinical trials, yet it is still underused, according to a study published online in Journal of Clinical Oncology.
The National Cancer Institute issued an unusual Clinical Announcement in 2006 encouraging the use of combined intraperitoneal/intravenous (IP/IV) chemotherapy in this setting, after clinical trials showed it substantially improved overall survival, compared with IV chemotherapy alone.
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But some clinicians may be reluctant to use the combined approach, believing that other regimens such as dose-dense paclitaxel yield comparable survival with fewer toxicities. Others cite barriers such as increased toxicity with intraperitoneal treatment, the lack of a standardized regimen, the inconvenience because inpatient administration is required, and patient preference for other approaches, said Dr. Alexi Wright of Dana-Farber/Brigham and Women’s Cancer Center, Boston, and her associates.
To assess the uptake of intraperitoneal therapy over time and its use in real-world practice, Dr. Wright and her associates analyzed data from two cohorts treated at six elite comprehensive cancer centers: a cohort of 823 women treated during a 9-year period that spanned before and after the 2006 Clinical Announcement, and a propensity-matched cohort of 498 women treated outside of clinical trials and after 2006. They found that the use of IP/IV increased from 0% to 33% between 2003 and 2006, increased again to nearly 50% between 2007 and 2008, but plateaued after that.
Three-year overall survival was 81% with IP/IV chemotherapy, significantly higher than the 71% survival for IV chemotherapy. The relative risk of death in the IP/IV group compared with the IV group was 0.68. Thus, the magnitude of benefit in this real-world population matches that reported in clinical trials, the investigators said (J Clin Oncol. 2015 Aug 3. doi:10.1200/JCO.2015.61.4776).
Yet only 41% of patients eligible for IP/IV therapy in this study received it. Use of the treatment varied dramatically across the six cancer centers, from 4% to 67% of patients, even though sociodemographic and disease characteristics were relatively uniform. And IP/IV regimens varied widely, with 43% of the women who received it given modified regimens to reduce its toxicity.
The findings show that cancer treatment may be influenced by local culture and by leaders’ endorsement of particular treatments or trial results. Women with ovarian cancer may receive substantially different treatment depending on where they seek care. “Additional interventions may be required to ensure that IP/IV chemotherapy decision-making is more uniform and patient-centered,” Dr. Wright and her associates said.
The National Cancer Institute supported the study. Dr. Wright reported having no financial conflicts. Her associates reported ties to McKesson, Genentech, Boehringer Ingelheim, AstraZeneca, AbbVie, Sanofi, Novartis, ImmunoGen, Endocyte, Gradalis, Amgen, Janssen, Oxigene, Roche, CSL Behring, Medtronic, and Eisai.