Second malignancies following cancer therapy.

In the absence of proper treatment, essentially all patients with disseminated malignancy and a substantial number of those with more localized disease will die of their cancer. Unfortunately, effective cancer therapy usually results in exposure to treatment that, in itself, may be carcinogenic. The long-term risks attributed to such therapy, however, must be balanced against the benefits of therapy for a life-threatening disease. The risk of treatment-related malignancies is under intensive investigation. As the follow-up time increases on various treatment regimens, our knowledge of these late effects will be advanced significantly.