Prognostic impact of the history of breast cancer and of hormone therapy in uterine carcinosarcoma.

OBJECTIVE: Recent studies reveal an association between hormone therapy for breast cancer (BC), such as tamoxifen (TAM) and toremifene (TOR), and uterine carcinosarcoma (UCS). The aim of this study was to investigate the characteristics and prognosis of patients with UCS after BC and hormone therapy.

METHODS: Between January 1997 and December 2007, we treated 51 patients with UCS. The medical records of these patients were reviewed, and factors that influenced their survival were retrospectively analyzed using univariate and multivariate analyses.

RESULTS: Ten (19.6%) of the 51 patients had a history of BC; 6 (11.8%) had received hormone therapy with TAM or TOR. The characteristics of the patients with UCS were similar regardless of whether they had a history of BC or hormone therapy. On univariate analysis, age greater than 56 years, elevated serum lactate dehydrogenase levels, residual tumors, FIGO (International Federation of Gynecology and Obstetrics) stage higher than stage IIIa, and non-endometrioid carcinomatous components were identified as prognostic factors. On multivariate analysis, in addition to residual tumors, FIGO stage higher than stage IIIa, and non-endometrioid carcinomatous components, a history of BC (relative risk, 0.14), a history of TAM use (relative risk, 15.9), and a history of TOR use (relative risk, 16.9) were also identified as independently significant prognostic factors.

CONCLUSIONS: Our data suggest that a history of BC and hormone therapy for BC is a risk factor for developing UCS without obvious impacts on the characteristics of UCS. Both of these factors had statistically significant impacts on the prognosis of patients with UCS. Further studies are necessary to clarify and validate these associations.