Carcinosarcoma is a rare tumour. Only about 1 in 50 women with cancer of the uterus (womb) have this type of cancer.

To understand what carcinosarcoma is, it is important to understand how cancers arise. A cancer is the uncontrolled, abnormal growth of cells in the tissue of an organ. Cancers most commonly arise from the tissue that lines the inner and outer surfaces of organs, this is called epithelial tissue. These cancers of epithelial tissue are called carcinomas. Most uterine cancers are epithelial cancers, arising from the inner lining of the uterus (the endometrium). Sarcomas are rarer cancers that arise from other tissues in organs, such as fibrous tissue, muscle and fat. Carcinosarcomas are made up of a mix of both of these two different types of tumour tissue: carcinoma and sarcoma. Carcinosarcomas and mixed mullarian tumours are different names for the same cancers. They are also sometimes called mixed mesodermal tumours.

Carcinosarcomas cause the same symptoms and spread in much the same way as the far commoner endometrial (uterus) cancer. Carcinosarcomas are however often more 'aggressive' or faster growing than endometrial cancers. The individual outlook for any particular woman's cancer however, depends on a host of other things including how far the tumour had spread by the time it was diagnosed and the way the cells of the tumour look under the microscope.

Surgery is most often the first treatment for carcinosarcoma, usually with removal of the uterus, fallopian tubes, ovaries, and some lymph nodes. Treatment after surgery depends on the findings of the surgeon during the operation. In those women in whom the tumour has not spread outside the pelvis, radiotherapy may be recommended after surgery. The radiotherapy is thought to reduce the risk of recurrence of the tumour in the pelvis. Radiotherapy is given in the same way as it is for endometrial carcinomas. Chemotherapy is advised for some patients in whom the cancer is more advanced, usually the drugs used include cisplatin, ifosfamide, or Adriamycin (doxorubicin).