Abstract
The emergence of effective cancer chemotherapy is one of the major medical advances of the second half of the 20th century. In certain neoplasms — such as gestational choriocarcinoma, childhood acute lymphoblastic leukemia, and subgroups of Hodgkin's disease and non-Hodgkin's lymphoma — chemotherapy is often curative, and the promise of long-term survival makes therapy well worth the risk of adverse effects and the financial costs. Moreover, adjuvant chemotherapy for breast, colon, or lung cancer can augment the survival benefit afforded by surgical management. Even in patients with advanced solid tumors or recurrences despite surgery, chemotherapy can offer lengthened survival of worthwhile quality. In these patients, however, the therapeutic index is narrow: responses are usually partial, often disappointingly brief, and unpredictable. These circumstances highlight the limitations of traditional cytotoxic chemotherapy.