title: Cause-specific long-term mortality in survivors of childhood cancer in Switzerland: A population-based study.
abstract: Survivors of childhood cancer have a higher mortality than the general population. We describe cause-specific long-term mortality in a population-based cohort of childhood cancer survivors. We included all children diagnosed with cancer in Switzerland (1976-2007) at age 0-14 years, who survived ≥5 years after diagnosis and followed survivors until December 31, 2012. We obtained causes of death (COD) from the Swiss mortality statistics and used data from the Swiss general population to calculate age-, calendar year-, and sex-standardized mortality ratios (SMR), and absolute excess risks (AER) for different COD, by Poisson regression. We included 3,965 survivors and 49,704 person years at risk. Of these, 246 (6.2%) died, which was 11 times higher than expected (SMR 11.0). Mortality was particularly high for diseases of the respiratory (SMR 14.8) and circulatory system (SMR 12.7), and for second cancers (SMR 11.6). The pattern of cause-specific mortality differed by primary cancer diagnosis, and changed with time since diagnosis. In the first 10 years after 5-year survival, 78.9% of excess deaths were caused by recurrence of the original cancer (AER 46.1). Twenty-five years after diagnosis, only 36.5% (AER 9.1) were caused by recurrence, 21.3% by second cancers (AER 5.3) and 33.3% by circulatory diseases (AER 8.3). Our study confirms an elevated mortality in survivors of childhood cancer for at least 30 years after diagnosis with an increased proportion of deaths caused by late toxicities of the treatment. The results underline the importance of clinical follow-up continuing years after the end of treatment for childhood cancer.
authors.affiliation: Institute of Social and Preventive Medicine (ISPM), University of Bern, Finkenhubelweg 11, Bern, CH-3012, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schindler
authors.affiliation: Institute of Social and Preventive Medicine (ISPM), University of Bern, Finkenhubelweg 11, Bern, CH-3012, Switzerland.
authors.forename: Ben D
authors.initials: BD
authors.lastname: Spycher
authors.affiliation: Department of Pediatrics, University of Bern, Freiburgstrasse 4, Bern, CH-3010, Switzerland.
authors.forename: Roland A
authors.initials: RA
authors.lastname: Ammann
authors.affiliation: Department of Pediatrics, Oncology and Hematology Unit, Geneva University Hospital, Rue Willy-Donzé 6, CH-1205, Genève, Switzerland.
authors.forename: Marc
authors.initials: M
authors.lastname: Ansari
authors.affiliation: Department of Health Sciences and Health Policy, University of Lucerne, Frohburgstrasse 3, P.O. Box 4466, Lucerne, CH-6002, Switzerland.
authors.forename: Gisela
authors.initials: G
authors.lastname: Michel
authors.affiliation: Institute of Social and Preventive Medicine (ISPM), University of Bern, Finkenhubelweg 11, Bern, CH-3012, Switzerland.
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Kuehni
mesh_terms: D000293:Adolescent; D002423:Cause of Death; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D009369:Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000401:mortality* / Q000628:therapy; D011159:Population Surveillance; D012042:Registries; D012307:Risk Factors; D017741:Survivors / Q000706:statistics & numerical data*; D013557:Switzerland / Q000453:epidemiology
keywords: cancer registry; cancer survivors; cardiovascular; causes of death; childhood cancer; mortality; respiratory; second primary cancers