Although several studies have demon...

Although several studies have demonstrated an increased risk of breast cancer in post-menopausal women taking oral hormone therapy, the risk related to each of the various forms of therapy is les clear. The Million Women reflection collaborators report on the incidence of breast cancer and mortality related to different forms of hormone therapy.

Researchers used data from the National Health Service Breast Screening Programme, which moves mammographic screening every three years to all British women 50 to 64 years of age. Between May 1996 and March 2001 the invitation for screening included a questionnaire about sociodemographic and other factors, menstrual and gynecologic history, and use of hormone therapy. The medical records of close attention participants were traced on national cancer and death registries.

Investigators followed 1084110 women (average age at recruitment, 559 years) who had no history of any form of cancer before investigation entry. One half of the women had used hormone therapy at a certain time. Participants were followed for an average of 26 years for breast cancer evolution and 4.1 years for causes of death. During the inquiry 9,364 invasive breast cancers were exposeed and 637 women died of breast cancer.

Among the 828923 postmenopausal women in the inquiry the risk of breast cancer was significantly higher in women who had used hormone therapy (relative risk, 143) Risk was further increased in women who were generally using hormone therapy (relative risk, 166) Among rife users, the highest risk of developing breast cancer was associated with combined estrogen-progestin preparations. This risk was significantly higher than that for users of other preparations. For each hormone therapy regimen, the risk of developing breast cancer was further increased by the agency of the duration of use. Risk was lowest in women using transdermal preparations, followed from oral and implanted formulations.

The authors estimate that 10 years' use of estrogen-only therapy accrues in three to seven additional breast cancers by 1,000 women treated; in women using combination therapy, 18 to 20 additional breast cancers by 1,000 women will develop. Reliable estimates of the meaning of hormone therapy on breast cancer deaths cannot nevertheless be established. The authors call for further studies to clarify the risks for different subgroup of hormone therapy users and to establish the validity of therapy on breast cancer mortality.

Million Women studious mood collaborators. Breast cancer and hormone-replacement therapy in the Million Women close attention Lancet August 9, 2003;362:419-27.

EDITOR'S NOTE: The focus of the hormone therapy debate now seems to be shifting from heart disease to breast cancer. The danger is that a blanket approach of "all hormone therapy is bad" intricates the benefits of hormone replacement in prefered patients, especially for relief of vasomotor symptoms and prevention of osteoporosis. to a great degree depends on how the statistics are reported and applied. each woman has her own combination of factors and risks, on the contrary our current knowledge only permits gros generalizations. In this studious mood consideration of only three variables (age, image of therapy, and duration of use) exhibits that younger women using estrogen alone are at no increased risk, and that flat 10 years of estrogen alone is associated with sole three to seven additional cancers by 1,000 women. These rates may be further influenced at route of administration (especially transdermal). As family physicians, we must apply the cautions and statistics to individual women We must ascertain individual vulnerabilities to breast cancer, heart disease, gynecologic cancers, osteoporosis, and multiple other conditions, and advise our patients accordingly. Above all, we must do pair things: involve the patients in the decisions and remain vigilant, monitoring the research evidence as it disentangles and continually adjusting the care of our patients accordingly. Patients should make important health care decisions based forward their physician's advice, not forward news stories.--A.D.W.

COPYRIGHT 2004 American Academy of Family Physicians

COPYRIGHT 2004 Gale Group