Treatment-related cancers after gynecologic malignancy.

Second malignancies are one of the known complications of cancer treatment. Several recent studies which have quantified the risk of treatment-induced cancers following gynecologic malignancies are reviewed. After cervical cancer, there is a 9% excess risk of second cancers, of which only 5% could be attributed to radiation therapy. Most of the treatment-related malignancies after cervical or endometrial cancer are solid tumors occurring within the radiation field. Following both cervical and endometrial cancer, there is a small increased risk of leukemia associated with radiation therapy. In contrast, after ovarian cancer, there is significantly increased risk of leukemia related to treatment with alkylating agents, which varies by drug type and total dose. The cumulative risk of leukemia and preleukemia following single agent melphalan is 11.2% +/- 2.6% at ten years; the risk after cyclophosphamide is 5.4% +/- 3.2%. Overall, the risk of second malignancies following treatment of gynecologic cancers is small.