Late Effects of Treatment for Childhood Cancer (PDQ®): Treatment - Health Professional Information [NCI] - General Information
Late effects also contribute to an excess risk of premature death among long-term survivors of childhood cancer. Several studies of very large cohorts of survivors have reported early mortality among individuals treated for childhood cancer compared with age- and gender-matched general population controls. Relapsed/refractory primary cancer remains the most frequent cause of death, followed by excess cause-specific mortality from subsequent primary cancers and cardiac and pulmonary toxicity.[12,13,14,15,16,17,18]; [Level of evidence: 3iA] Despite high premature morbidity rates, overall mortality has decreased over time.[20,21] This reduction is related to a decrease in deaths from the primary cancer without an associated increase in mortality from subsequent cancers or treatment-related toxicities. The former reflects improvements in therapeutic efficacy, and the latter reflects changes in therapy made subsequent to studying the causes of late effects. The expectation that mortality rates in survivors will continue to exceed those in the general population is based on the long-term sequelae that are likely to increase with attained age. If patients treated on therapeutic protocols are followed for long periods into adulthood, it will be possible to evaluate the excess lifetime mortality in relation to specific therapeutic interventions.
Previous studies have shown excess late mortality in childhood cancer survivors. In a population-based study in Finland, the long-term mortality risks from major nonmalignant diseases in 5-year survivors of childhood and adolescent and young adult (AYA) cancer diagnosed before age 35 years were evaluated and included more than 6,000 AYA cancer survivors. In this study, standardized mortality rates (SMRs) were 90% higher for nonmalignant diseases (SMR, 1.9; 95% CI, 1.7–2.2) than expected for the entire cohort, with SMRs similarly elevated for patient subgroups with circulatory disease and respiratory disease. These risks remained elevated for Hodgkin and non-Hodgkin lymphoma survivors diagnosed between the ages of 15 and 34 years. The risk of death from respiratory disease was significantly elevated by 140% (SMR, 2.4; 95% CI, 1.3–4.1) in young adult patients diagnosed with cancer between the ages of 20 and 34 years.
Monitoring for Late Effects
Recognition of both acute and late modality–specific toxicity has motivated investigations evaluating the pathophysiology and prognostic factors for cancer treatment–related effects. The results of these studies have played an important role in changing pediatric cancer therapeutic approaches and reducing treatment-related mortality among survivors treated in more recent eras.[20,21] These investigations have also informed the development of risk counseling and health screening recommendations of long-term survivors by identifying the clinical and treatment characteristics of those at highest risk for treatment complications. The common late effects of pediatric cancer encompass several broad domains including growth and development, organ function, reproductive capacity and health of offspring, and secondary carcinogenesis. In addition, survivors of childhood cancer may experience a variety of adverse psychosocial sequelae related to the primary cancer, its treatment, or maladjustment associated with the cancer experience.