PreventDisease.com - Hormones Reduce Cancer Risk



		Hormones Reduce Cancer Risk WASHINGTON (AP) - Hormone replacement therapy after a diagnosis of breast cancer does not increase the risk of recurrence of the disease and may even lower chances that the cancer will return, according to a new study. The therapy, in which post-menopausal women take pills to replace female hormones that diminish with age, generally has been avoided by women with breast cancer because it was known that estrogen was linked to the growth of some tumors. But Dr. Ellen O'Meara, a University of Washington cancer researcher, said her new study in the Journal of the National Cancer Institute suggests that breast cancer patients should not fear hormone replacement therapy, or HRT. ``The data are reassuring for women who take HRT after a breast cancer diagnosis,'' O'Meara said Tuesday. ``HRT need not be ruled out automatically.'' However, O'Meara and a University of Washington co-author, Dr. Noel Weiss, said their study should not be considered the final answer. ``This is not a definitive study,'' Weiss said. ``It is possible that a larger study will show a proven risk reduction, but it is premature now to show an actual benefit from HRT in this patient population.'' Weiss said the numbers in the University of Washington study are too small to give final statistical evidence of the effects of HRT on breast cancer patients. Hormone replacement therapy is used by women to relieve post-menopausal symptoms, such as flushing and hot flashes. It also lowers the risk of heart disease and osteoporosis, the brittle bone disease, after menopause. Some studies have suggested, however, that using HRT for five years or longer can produce a slight increase in the risk of breast cancer. O'Meara said so much uncertainty remains about long-term effects of HRT that opting for it is a highly individual consideration, and there currently is no universal recommendation for the therapy. The new study, O'Meara said, is an attempt to find answers about effects of HRT for a limited population: women who already have breast cancer. In the study, O'Meara, Weiss and their co-authors at the Group Health Cooperative of Puget Sound analyzed data from a group of 2,755 women who had been diagnosed with invasive breast cancer. Within this group were 174 women who began using hormone replacement therapy after the cancer diagnosis. Each of the HRT users was matched by age, disease and year of diagnosis with four randomly selected nonusers. The researchers then compared the long-term outcomes of the two groups. The study found the rate of breast cancer recurrence for the HRT users was 17 per 1,000 person-years, while for nonusers the rate was 30 per 1,000 person-years. A person-year is one year of human life. Death from breast cancer was 5 per 1,000 person-years for HRT users and 15 per 1,000 person-years for nonusers, the study found. The study found some data that suggested HRT might increase the risk of cancer in the previously unaffected breast. Researchers said the risk of developing tumors in the unaffected breast was 12 per 1,000 person-years for the HRT users and eight per 1,000 person-years for nonusers. O'Meara said the numbers of HRT users who developed cancer in the opposing breast were too small for strong statistical conclusions. ``That could be just a chance finding,'' she said. However, the authors noted that the finding about cancer in the other breast ``reinforces the need for caution in assessing the overall impact of HRT after breast cancer.'' An editorial in the journal also advised caution in interpreting the results. ``These results must be considered preliminary,'' the editorial said. Two large studies investigating questions about HRT and breast cancer are under way in Sweden and in Britain. In another study in the Journal, 15 researchers analyzed data from five 1993 studies that sought a possible linkage between breast cancer and two manmade chemicals, polychlorinated biphenyls (PCBs) and DDE, a byproduct of the insecticide DDT. The original studies tested the suggestion that the chemicals could have had a role in an increased incidence of breast cancer in the northeastern United States. No strong link was found. In the new study, researchers combined the five sets of data to see if the added statistical power would give a different result. There was no change. ``Combined evidence does not support an association of breast cancer risk with ... concentrations of PCBs or DDE,'' the authors concluded. ``Exposure to these compounds, as measured in adult women, is unlikely to explain the high rates of breast cancer experienced in the northeastern United States.'' On the Net: Journal of the National Cancer Institute: http://jnci.oupjournals.org/ Reference Source 102 For more information on how to prevent other diseases, use PreventDisease.com's "Quick Prevention Resources".