Short-Term Hormone Use May Increase Breast Cancer Risk For Decades

During the San Antonio Breast Cancer Symposium today, researchers highlighted a concerning risk associated with the use of certain hormone pills: greater odds of developing breast cancer. The research dates all the way back to 2002 when a study revealed that taking combination hormone pills featuring both estrogen and progestin as a way to deal with menopause symptoms may have tragic consequences.

The link between certain exogenous hormones (the kind taken as pills, patches, creams, or injections rather than the kind produced by the body itself) and the increased risk of developing cancer, experiencing a heart attack, and more is a known one, though many questions remain. Numerous studies over past decades have found that taking estrogen and progestin hormones may increase the risk of developing breast cancer.

This research has prompted many doctors to advise against taking exogenous hormones as a way to alleviate menopause symptoms or restore energy lost due to testosterone levels that naturally drop with age. Despite that, many people remain unaware of the studies and may seek out such hormone treatments, putting themselves at risk of developing a more severe condition.

The major federal study from 2002, which was recently discussed at the aforementioned symposium, highlights another concern: elevated breast cancer risk may remain for decades. The study involved around 16,000 older women who were given either placebo pills or combination hormone pills containing estrogen and progestin.

The study ultimately came to an end in 2002 because of the concerning levels of breast cancer and heart conditions that developed in women taking the hormones. The women stopped taking the pills, but their health was still monitored over the next approximately two decades.

Based on the number of cases of breast cancer that appeared in the study participants during those years, researchers have found that the women who took hormone pills had a 29-percent greater chance of developing cancer. On the other hand, the study found that women who took only estrogen had a 23-percent lower chance of developing breast cancer over the same 19-year duration.

Estrogen is not typically prescribed on its own because it increases the risk of developing uterine cancer. Some older women who have entered menopause, however, have undergone hysterectomies that remove the uterus, making that potential risk a non-issue.

Many questions remain over whether getting these exogenous hormones from a method other than pills carries the same risk (or benefits). Ultimately, some women still may choose to use hormones to alleviate particularly severe menopause symptoms, though they're encouraged to do so for a short period of time and to get regular breast cancer screenings.