Pill use associated with better ovarian cancer outcomes

Volume 5, Issue 1, 2016


Research findings may drive new therapeutic targets for patients with ovarian cancer.

Photograph of Aminah Jatoi, M.D.

Aminah Jatoi, M.D.

Photograph of Ellen L. Goode, Ph.D.

Ellen L. Goode, Ph.D.

Patients who develop ovarian cancer seem to have better outcomes if they have a history of using oral contraceptives.

"Multiple studies from a variety of sources have indicated that oral contraceptives are associated with a reduced risk of ovarian cancer, one of the most deadly cancers in women," said Aminah Jatoi, M.D., an oncologist with the Mayo Clinic Cancer Center. "However, few studies have explored the connection between the pill and outcomes in patients who ultimately develop the disease."

Mayo Clinic Cancer Center researchers set out to explore that possible connection, and subsequently published a new study about ovarian cancer and use of the birth control pill in the October 2015 issue of the journal BMC Cancer.

In the study, co-authors Dr. Jatoi and Ellen L. Goode, Ph.D., an epidemiologist with the Mayo Clinic Cancer Center, examined the outcomes of patients with ovarian cancer who were seen at Mayo Clinic from 2000 through 2013.

Each patient was given a risk factor questionnaire about prior oral contraceptive use. Of the 1,398 patients who completed the questionnaire, 827 responded that they had previously taken birth control pills.

The researchers performed two types of statistical analyses on clinical data extracted from the patients' electronic health records.

One analysis found that patients who had been on the pill had improved progression-free survival (the length of time patients lived with the disease without it worsening) and improved survival (the length of time patients with the disease lived), compared with those who had not been on the pill.

A second type of statistical analysis provided less consistent findings, indicating a statistically significant association between oral contraceptive use and progression-free survival but not overall survival. The researchers think that one possible explanation for the latter finding is that older patients who passed away may have died from noncancer causes, although other factors may have come into play.

Although it's still not clear how oral contraceptives improve outcomes for ovarian cancer patients, Dr. Jatoi said there are various hypotheses.

For example, by halting ovulation, oral contraceptives protect against the repeated monthly changes that occur on the surface of the ovary. Contraceptives may reduce the risk of DNA mutations and thereby result in a less aggressive form of ovarian cancer at a later date.

The study findings underscore the need for research into the mechanisms driving a more favorable prognosis for women who used the pill, Dr. Jatoi said. Such knowledge may one day provide researchers with new therapeutic targets to create better outcomes for patients diagnosed with ovarian cancer.

"Without question, further studies are needed in this area," Dr. Jatoi said, "but our study might provide a sense of hope for patients who are struggling with ovarian cancer."