Joint Pain and Estrogen Connection

Research on a current hormone treatment for breast cancerhas shed light on what is referred to as menopausal arthritis, acondition caused by lack of the female hormone that inflames thejoints and causes muscle pain. Researchers at Boston UniversityClinical Epidemiology Unit and the University of California, SanFrancisco, have examined the evidence linking aromataseinhibitors, a breast cancer treatment, and estrogen-deprivationjoint pain. The findings were published in the September 2005issue of Arthritis & Rheumatism.

Aromatase inhibitors work by blocking the conversion of androgenprecursors into estrogens, thus lowering estradiol levels in theblood and estrogen levels in peripheral tissues. As effective as thistreatment is in reducing the rates of recurrence in patients with postmenopausalbreast cancers, the joint and musculoskeletal pain itcauses is enough to make some women stop treatment altogether.

In 3 separate trials that studied the hormonal effects of cancertreatments, women who experienced estrogen deprivationreported a higher incidence of joint and muscle pain than thosewho did not. In a National Cancer Institute of Canada study,5187 postmenopausal women, who had completed a 5-yearcourse of tamoxifen therapy for breast cancer, were followed for5 years as they took either the aromatase inhibitor or a placebo.Joint pain was reported in 25% of the women taking the inhibitor,compared with 16% of those taking the placebo.