Only half of the survivors exposed to pulmotoxic treatment have been followed up with PFT in Switzerland. We need to optimize, update, and implement monitoring guidelines.

Background: Childhood cancer survivors are at increased risk for pulmonary morbidity and mortality. International guidelines recommend pulmonary function tests (PFT) during follow-up care. This nationwide study assessed how many children received PFT within five years after pulmotoxic treatment in Switzerland, types of tests, and predictors for testing. Methods: We included all children from the Swiss Childhood Cancer Registry who were diagnosed with cancer from 1990-2013 at age 0-16 years, survived for ≥2 years from diagnosis and had pulmotoxic chemotherapy with bleomycin, busulfan, nitrosoureas and/or chest radiotherapy. We searched medical records in all Swiss pediatric oncology clinics for PFT (spirometry, plethysmography, diffusion capacity of carbon monoxide [DLCO]) and treatment details. Results: We found medical records for 372 children, of whom 147 had pulmotoxic chemotherapy and 323 chest radiotherapy. Only 185 had plethysmography and/or spirometry (50%), 122 had DLCO (33%). Testing varied by cancer center from 3% to 79% (p=0.001). Central nervous system tumor survivors and those not treated according to study protocols had less plethysmography and/or spirometry (odds ratio (OR): 0.3 and 0.3), lymphoma survivors and those who were symptomatic had more PFTs (plethysmography and/or spirometry: OR: 5.9 and 8.7; DLCO: OR: 3.4 and 2.3). Cumulative incidence of PFT (CuI) was 52% in the first five years after pulmotoxic treatment; most of the tests were done in the first two years after treatment (CuI 44%). 6 Conclusion: Only half of survivors exposed to pulmotoxic treatment have been followed up with PFT in Switzerland. We need to optimize, update, and implement monitoring guidelines.