Birgitta Versluijs

25 Pulmonary complications of childhood cancer treatment Prevalence of pulmonary complications in childhood cancer survivors In a questionnaire-based study, Mertens reported on pulmonary complications in a large cohort of 12,390 childhood cancer survivors. 6 The prevalence of the pulmonary conditi- ons covered in the questionnaire was 0-25.8%. Compared with a control group (consis- ting of nearest age siblings) the survivors had a significantly increased relative risk for lung fibrosis, emphysema, recurrent pneumonia, chronic cough, need for supplemental oxygen, chest wall abnormalities and exercise induced shortness of breath. This was es- pecially true after chest irradiation. The association with pulmonary toxic chemotherapy was less evident (Figure 3). 6 Several studies described the health outcomes of childhood cancer survivors as recorded after full medical assessment according to standardized screening protocols, using CT- CAE criteria for chronic health conditions. Geenen looked at the severity and total burden of late effects in a cohort of 1362 survi- vors (median age 24.4 years, median follow up 17 years after diagnosis). 3 At least one adverse event was found in the majority of survivors (74.5%). In 36.8% of patients these adverse events were severe, disabling or life threatening. Pulmonary adverse events ac- counted for 5% of all events. In this study no pulmonary function tests [PFTs] were done, and events were only recorded by history taking and physical examination. 3 The same group further analysed the prevalence of pulmonary injury with PFTs in a subset of high- risk adult childhood cancer survivors treated with potentially pulmotoxic therapy. 7 They found PFT abnormalities in 44% of survivors, most frequently in patients treated with radiotherapy, bleomycin or thoracic surgery, especially when these treatment modalities were combined. 7 Others reported comparable findings, and showed a clear increase in PFT abnormalities with longer follow up and aging of survivors. 2 Mortality from pulmonary causes in childhood cancer survivors has been studied in a few population based studies, in which mortality among 5 years survivors was compa- red to the age adjusted expected survival rates of the general population, expressed as the standardized mortality ratio (SMR). In the USA the childhood cancer survivor study (CCSS) showed an overall SMR of 10.8. The SMR for death from pulmonary causes (pneumonia, fibrosis or other) was 8.8 (95% CI 6.8-11.2, p<0.01). In survivors of acute myeloid leukaemia, astrocytoma, Hodgkin’s disease and neuroblastoma, pulmonary SMR was even higher. Specific treatment related risk factors for pulmonary death were not mentioned. 4 In a study of childhood cancer survivors in the Nordic countries, overall SMR was 8.3, with large variations depending on follow up time and decade of diagno- sis. Pulmonary causes comprised 16.2% of non-cancer causes of death. This was not expressed as SMR. 5 2