The mounting controversy concerning the true benefits Study: History of Hormone Replacement Therapy Does Not Worsen Breast Cancer Prognosis (dateline December 7, 2002) | Breast Health News | Imaginis - The Women's Health & Wellness Resource Network

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Study: History of Hormone Replacement Therapy Does Not Worsen Breast Cancer Prognosis (dateline December 7, 2002)

The mounting controversy concerning the true benefits and risks of hormone replacement therapy (HRT) continues with the release of a new study that finds that HRT users have less aggressive, more treatable breast cancer diagnoses than women who never took HRT. This finding contradicts some previous studies that have found that HRT increases breast density, thereby making it more difficult to detect breast cancer with mammography. Again, experts urge women to discuss the advantages and disadvantage of using HRT with their physicians and come to an informed decision based on their individual medical situation.

Hormone replacement therapy (HRT) is synthetic estrogen and progesterone (called progestin), designed to "replace" a woman’s depleting hormone levels as she reaches menopause. Decreased levels of estrogen may cause hot flashes, vaginal dryness, sleep disturbances, or other bothersome side effects. HRT has been found to be highly effective at treating menopausal symptoms. Several recent studies have found that HRT may increase the risk of breast cancer, especially when taken for a prolonged period (over five years).

To investigate the prognosis of breast cancer among women who have used HRT, Julie Cheek, MD of the General Medical Center in Akron, Ohio and her colleagues from Oregon Health and Sciences University analyzed data from 292 post-menopausal women who had been diagnosed with breast cancer. The researchers determined whether the women had used HRT and then analyzed the size and stage of their breast cancers.

Dr. Cheek and her colleagues found that women who had used HRT tended to have smaller, less aggressive cancers that were less likely to involve the axillary (armpit) lymph nodes compared to those cancers detected in non-HRT users. More diagnoses of ductal carcinoma in situ (DCIS), a very early stage of breast cancer with a close to 100% survival rate, were detected among the women who had used HRT. Overall, women who had used HRT were more likely to survive breast cancer than non-HRT users.

The study did not replicate findings of some previous studies that suggested that prior HRT use led to a worse breast cancer prognosis. However, experts cite possible limitations to this latest study, including the fact that the study was retrospective: it analyzed events that had already taken place instead of randomly assigning some women to take HRT and others to take a placebo (an inactive pill) and then prospectively following the women to see if they developed breast cancer.

Thus, the studies leaves critical questions unanswered, including whether or not the women who had used HRT in the past tended to be healthier and more proactive about their health, thus improving their chances of surviving breast cancer. Nevertheless, the study suggests that the women who have used HRT in the past need not panic about developing breast cancer in the future.

The benefits and risk of HRT have been heatedly debated in recent years as studies have emerged contradicting the once-believed advantages of HRT. While no research denies the benefits of HRT in relieving menopausal symptoms, studies have been challenging prior data that suggested HRT could help prevent heart disease and the bone-thinning disease, osteoporosis. Emerging studies have also found that long-term use of HRT (over five years) may increase the risk of breast cancer. The uncertainty of contradictory findings has caused confusion in the medical community and alarm among many women taking or considering HRT.

To further complicate matters, a large government study designed to learn the true benefits and risks of HRT was recently stopped before completion because of the observed health problems among women who had been assigned to take combination HRT (estrogen plus progesterone). The findings that led to the halt of the combined estrogen/progesterone arm of the study consisted of an increased risk of invasive breast cancer and increased risks of coronary artery disease, stroke, and pulmonary embolism (blood clots in the lungs).

In the latest study on HRT that found favorable prognoses among past HRT users, the women developed breast cancer an average of 16 years after taking HRT. The average age of a breast cancer diagnosis in the study was 66.

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