Late effects of childhood cancer: life-threatening issues.

Improvements in therapies for childhood cancers have increased the number of survivors. However, with this prolonged survival, the late effects of disease and anti-cancer therapy are becoming increasingly important. Approximately two-thirds of survivors of childhood cancer will have at least one late effect, and about one-third will have a late effect that is severe or life-threatening. A second neoplasm is one of the most severe late effects in survivors of childhood cancer. Compared with normal populations, persons with a history of childhood cancer have a 10- to 20-fold greater risk of a second malignant neoplasm. Patients who have undergone radiation therapy or been given specific chemotherapeutic agents and patients with a known genetic predisposition to malignancy have been shown to be at higher risk for a second malignant neoplasm. Cardiac problems are another serious late effect for survivors of childhood cancer. Anthracycline-induced cardiotoxicities are common in these patients. A cumulative dose of anthracycline greater than 300 mg/m2 is associated with an 11-fold higher risk of clinical heart failure compared with a cumulative dose of less than 300 mg/m2. Serial monitoring of cardiac functioning in children receiving anthracycline allows early identification of cardiac damage. One cardioprotectant (dexrazoxane) has proven effective in adult patients, but larger trials are needed to determine its efficacy in children. It is important to recognize that it may not be best to categorize surviving patients by primary diagnosis. Instead, strategies for surveillance of survivors should be based on the treatment each patient received.