The effects of tamoxifen therapy on the endometrium

From January 1992 to December 1998, 219 women (aged between 30 and 81 yrs; average 55 years) affected by breast cancer were treated. These women in addition to the usual adjuvant therapy, were treated with TAM 20 mg/day, for a period between 24 and 72 months (average 40). In this group there were 84 postmenopausal and 31 premenopausal women. In 8 fertile patients ovarian activity was suppressed with GnRh analogue therapy and one patient underwent attinic castration. Before performing TAM therapy, a hysteroscopic exam was done and patients were followed-up with an annual check-up. None had any endometrial side-effects after the first check-up. After two years, 31 women (26.9%) complained of endometrial alterations (hyperplasia, polyps and endometrial cancer). One women only after 6 years of follow-up, had metrorrhagia; an endometrial adenocarcinoma was found. We would like to point out the necessity of monitoring these patients with an annual check-up (transvaginal sonography and/or hysteroscopy).

Tamoxifen-Endometrial cancer; Breast cancer; Female genital tract; Hyperplasia

[1] Early Breast Cancer Trialist Collaborative Group: "Effect of adjuvant TAM and cytotoxic therapy on mortality in early breast cancer: an overview of 61 randomized trials among 28, 896 women". N. Engl. J. Med., 1988, 319, 1681.

[2] Ugwumadu A.H., Carmichaeles P. L., Neven P.: "Tamoxifen and the female genital tract". Internat. J. of Gynecological Cancer, 1998, 8(1), 6.

[3] Fisher B., Costantino J. P., Wickerham D. L. et al.: "Tamoxifen for prevention of breast cancer: report of the National Surgical Adjuvant Breast and Bowel Project P-1 study". J. of the Nat. Cancer Institute, Sept. 16, 1998, Vol. 90, n. 18.

[4] Vergote I., Neven P., Vanderick G. et al.: "Tamoxifen and the uterus". European J. of Cancer, 1998, 34(Suppl. 4), S1-S3.

[5] Ryden S., Femo M., Moller T.: "Long term effects of adjuvant tamoxifen and/or radiotherapy". Acta Oneal., 1992, 31, 271.

[6] Andersson M., Storm H. H., Moundsen H. T.: "Incidence of new primary after adjuvant tamoxifen therapy and radiotherapy for early breast cancer". J. Natl. Cancer Inst., 1991, 83, 1013.

[7] Fischer B., Costantino J. P., Redmond C. K. et al.: "Endometrial cancer in tamoxifen treated breast cancer patients. Findings from the National Surgical and Bowel Project (NSABP B-14)". J. Natl. Cancer Inst.,1994, 86, 527.

[8] Pomander T., Cedermark B. et al.: "Adjuvant tamoxifen in early breast cancer: occurrance of new primary cancers". Lancet, 1989, 2, 117.

[9] Stearns V., Gelmann E. P.: "Does tamoxifen cause cancer in humans?". Journal of Clin. Oneal., 1998, 16(2), 779.

[10] Fleischer A. C., Cullinan J. A. et al.: "Conventional and color doppler transvaginal sonography of pelvic masses: a comparison of relative histologic specificities". J. Ultrasound Med., 1993, 12, 705.

[11] Nasri M. N., Shepherd J. H. et al.: "The role of vaginal scanin measurement of endometrial thickness in postmenopausal women". Br. J. Obstet. Gyhaecol., 1991, 98, 470.

[12] Atlante M., Botti C. et al.: "Ruolo dell'isteroscopia nel follow-up di pazienti mastectomizzate sottoposte a terapia adiuvante con TAM". Minerva Ginecol., 1995, 47, 251.

[13] Creasman W. T.: "Endometrial cancer: incidence, prognostic factors, diagnosis and treatment". Seminars in Oncology, 1997, 24(1), 140.

[14] Fornander T., Rutqvist L. E.: "Adjuvant tamoxifen and second cancers". Lancet, 1989, 1, 616.

[15] Jordan V.,C raig: "Tamoxifen the herald of a new era of preventive therapeutcs". J. of the Nat. Cancer Institute, 1997, 89(11), 747.

[16] MacGregor J., Jordan V. Craig: "Basic guide to the mechanisms of antiestrogen action". Pharmacological Reviews 1998, 50, 2, 151.

[17] Robert W.,M organ M. D.: "Risk of endometrial cancer after tamoxifen treatment". Oncology, 1997, 11(2) suppl. 1, 25.

[18] Waxman J., James N.: "New endocrine therapies for cancer". In: Ponder B. A. J., Waring M. J. ed: "The Science of Cancer Treatment". Dordrecht, Kluwer Academic Publisher, 43, 1990.

[19] Wilking N., Isaksson E., Von Schoultz E.: "Tamoxifen and secondary tumors". Drug Safety, 1997, 16(2), 104.