Breast Cancer practice watch
May 29, 2014
Tamoxifen and Endometrial Neoplasia: Updated Statements from the American College of Obstetricians and Gynecologists
Andrew M. Kaunitz, MD Reviewing The American College of Obstetricians and Gynecologists., Obstet Gynecol 2014 Jun 123:1394
In asymptomatic tamoxifen users, routine endometrial surveillance is not recommended, but baseline assessment to exclude endometrial polyps seems warranted.
The selective estrogen receptor modulator (SERM) tamoxifen is often prescribed as adjuvant therapy for breast cancer in women who are not candidates for aromatase inhibitors. This agent is also approved for prevention of breast cancer in high-risk women and treatment of metastatic breast cancer. Tamoxifen’s efficacy results from its antiestrogenic properties in breast tissue; however, as an estrogen agonist in reproductive tissues, this SERM raises risk for endometrial proliferation, hyperplasia, polyps, adenocarcinoma (in postmenopausal women), and uterine sarcoma, and may also contribute to the growth of endometriosis, adenomyosis, and leiomyoma. Prior guidelines recommended that adjuvant tamoxifen therapy be continued for ≤5 years; however, newly updated guidance from the American Society of Clinical Oncology based on extended efficacy of tamoxifen means that some women will be using this SERM for as long as 10 years.
After reviewing the available evidence, the American College of Obstetricians and Gynecologists’ Committee on Gynecologic Practice recommends that:
Women receiving tamoxifen should be counselled about risks for uterine disease and encouraged to promptly report symptoms such as abnormal vaginal spotting or bleeding, which should be evaluated.
Routine endometrial surveillance (i.e., vaginal ultrasound or endometrial biopsy) is not recommended in asymptomatic women at average risk for endometrial cancer at the time of tamoxifen initiation.
Baseline evaluation (i.e., vaginal ultrasound, sonohysterography, or in-office hysteroscopy) is appropriate to exclude the presence of endometrial polyps before initiating tamoxifen.
If endometrial hyperplasia with atypia arises during tamoxifen use, this agent should be reconsidered. If hysterectomy is performed for endometrial cancer, subsequent restarting of tamoxifen may be considered in consultation with the physician providing breast care.