Clinico-pathology and prognosis of endometrial cancer in patients previously treated for breast cancer, with or without tamoxifen: a comparative study in 363 patients.

Objective: To compare the clinic-pathologic variables and the prognosis of endometrial cancer in patients with and without previous breast cancer, with and without Tamoxifen.

Methods: We analyzed patients treated for an endometrial carcinoma from 1994 to 2004: patients without breast cancer (group 1), patients with a previous breast cancer without tamoxifen (group 2) and patients treated for breast cancer with tamoxifen (group 3). Survival rates were calculated according to Kaplan-Meier method and compared using a Log rank test, multivariate analysis was performed with a Cox regression model.

Results: 363 patients were analyzed. 80 patients had a previous history of breast cancer (43 received tamoxifen). Although it was not statistically significant, more carcinosarcomas were observed in patients in group 3 than patients in groups 1 and 2 (11.7% versus 4.2% and 5.4% respectively, p = 0.17).) Median follow-up was 87 months [2-185]. 5-year overall survival rate was respectively in groups 1, 2 and 3: 82%, 73.2%, and 61% (p = 0.0006). 5-year local relapse-free survival rate was respectively: 95.9%, 93.1% and 82.5% (p = 0.02). In multivariate analysis, factors affecting overall survival rate were: age ≥65 ans (HR 3.62, p < 0.0001), FIGO stage (HR 3.33 p < 0.0001 for locally advanced stage versus early stage, HR 8.87 p = 0.03 for distant extension versus early stage), and group 3 (HR 2.83 p < 0.001 versus group 1).

Conclusion: Patients with endometrial cancer previously treated for breast cancer show a worse prognostic, particularly if they reveived tamoxifen.