Sarcoma dominance in uterine carcinosarcomas was associated with decreased survival among women with stages I-IV uterine carcinosarcomas who underwent primary surgery, according to Dr Koji Matsuo, MD, PhD, of the Keck School of Medicine, University of Southern California, Los Angeles, and his colleagues .
The researchers additionally found that adding radiotherapy to chemotherapy may be an effective postoperative strategy for these patients.
Uterine carcinosarcomas are rare, high-grade endometrial cancers that represent 5% of all endometrial cancers. Sarcoma dominance was defined as having more than a 50% sarcoma component in the uterine tumor. In this study, the sarcoma component was grouped as homologous (endometrial stromal sarcoma, leiomyosarcoma, fibrosarcoma, and undifferentiated sarcoma) or heterologous (rhabdomyosarcoma, osteosarcoma, chondrosarcoma, and liposarcoma) types
Among 1,192 cases of uterine carcinosarcomas identified in a secondary analysis of a multicenter retrospective study, 906 cases were available for histopathology slide review. Of those, 889 cases had evaluation for sarcoma dominance. The most common group was homologous sarcoma without sarcoma dominance (39.5%), followed by heterologous sarcoma with sarcoma dominance (21.3%), homologous sarcoma with sarcoma dominance (19.7%) and heterologous sarcoma with sarcoma non-dominance (19.6%), they reported in a study published online in Surgical Oncology https://doi.org/10.1016/j.suronc.2018.05.017
On univariate analysis, sarcoma dominance was associated with decreased progression-free survival (PFS) and cause-specific survival (CSS) in homologous cases ( P less than 0.05) but not in heterologous cases. On multivariate models, both homologous and heterologous SD patterns remained independent prognostic factors for decreased PFS (adjusted-hazard ratio [HR] ranges: homologous/dominance 1.35-1.69, and heterologous/dominance 1.47-1.64) and CSS (adjusted-HR ranges: 1.52-1.84 and 1.66-1.81, respectively) compared to homologous/non-dominance (all, P less than 0.05).
In women with stage I-III disease, and tumors with sarcoma dominance, adding radiotherapy to chemotherapy was associated with improved PFS (adjusted-HR: homologous/dominance 0.49, and heterologous/dominance 0.45) and CSS (0.36 and 0.31, respectively) compared to chemotherapy alone (all, P less than 0.05); This association was not observed in women with tumors that lacked sarcoma dominance (all, P greater than 0.05), the researchers said.