Tamoxifen does not shorten survival in endometrial cancer

In a study of breast cancer patients who later developed endometrial cancer, a history of tamoxifen use was not linked to worse survival. However, such use seemed to shorten the diagnostic interval between the two malignancies.

Women with breast cancer also have an increased risk of endometrial cancer, researchers note in the July issue of Obstetrics and Gynecology. While tamoxifen is effective in preventing breast cancer and disease recurrence, its effect on prognosis when endometrial cancer occurs is unclear.To investigate, Dr. Karen H. Lu and colleagues, from M. D. Anderson Cancer Center in Houston, analyzed data from 89 women who developed endometrial cancer after surviving breast cancer. Forty-six of the patients had a history of tamoxifen use.Clinically and pathologically, tamoxifen users were similar to nonusers, the investigators found. Moreover, there was no significant difference in overall or endometrial cancer-specific survival between the groups. However, the interval from breast cancer to endometrial cancer diagnosis averaged 77.2 months in tamoxifen users, whereas the interval in nonusers was 121.3 months (p = 0.01), the researchers state. “Larger prospective studies are needed to determine whether tamoxifen use affects overall survival,” the authors note. “Molecular studies are needed to determine the specific effects of tamoxifen on the endometrium.” (Source: Obstet Gynecol 2004: Reuters Health: Oncolink: July 2004)