Researchers have observed for several years that people who have a history of using oral contraceptives are less likely to develop ovarian cancer. A team from Roswell Park Comprehensive Cancer Center and the University at Buffalo analyzed those connections more deeply, reporting that the protective benefit of oral contraceptives is most pronounced with the most aggressive and fatal subtypes of ovarian cancer. These findings were presented by Mongiovi et al at the American Association for Cancer Research (AACR) Annual Meeting (Abstract 641).
The research team, led by Kirsten Moysich, PhD, MS, Distinguished Professor of Oncology in the Departments of Cancer Prevention and Control and Immunology at Roswell Park, evaluated data from the Ovarian Cancer Association Consortium to determine whether any associations existed between prediagnostic use of oral contraceptives and incidence of highly fatal ovarian cancer. They looked at pooled data from 20 case-control studies involving 579 patients who died within 12 months of being diagnosed with ovarian cancer, matched to a control group of 2,279 patients who did not have ovarian cancer.
After adjusting for potential confounding factors including age, parity, or whether the patients had given birth, the results show that any history of using oral contraceptives was associated with a 46% reduction in the odds of death within 12 months of diagnosis (odds ratio [OR] = 0.54, 95% confidence interval [CI] = 0.43–0.68).
“The longer the history of oral contraceptive use, the greater the protection we observed in terms of reduced chance of dying from aggressive ovarian cancer,” added first study author Jennifer Mongiovi, a PhD student working with Dr. Moysich at Roswell Park, and a cancer epidemiology fellow in the Department of Epidemiology and Environmental Health at the University at Buffalo. “For every 5 years of use, we observed 32% lower odds of highly fatal disease, compared to 13% for all ovarian cancer as previously reported by other researchers. This association also varies by histological subtype, and was found most protective for highly fatal endometrioid ovarian cancers.” Among those who used oral contraceptives for over 10 years, a 66% reduction in the odds of death within 12-months was observed (OR = 0.34, 95% CI = 0.23–0.49), while there was no significant benefit from use of oral contraceptives for 1 year or less (OR = 0.83, 95% CI = 0.60–1.14).
“Our results provide strong evidence that this is an area worthy of further study, so that we can better understand the mechanisms behind this association and identify specific groups of people who may benefit most from this chemopreventive strategy,” concluded Dr. Moysich.
Disclosure: The study authors’ full disclosures can be found at abstractsonline.com.
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