Mortality risk among 5-year survivors of childhood cancer in Germany-Results from the CVSS study (Cardiac and Vascular late Sequelae in long-term Survivors of childhood cancer study)

The growing population of long-term childhood cancer survivors is at increased risk for severe, therapy-related late effects and premature mortality. The cardiac and vascular late sequelae in long-term survivors of childhood cancer (CVSS) study is a cohort of patients from Germany diagnosed with a neoplasia prior to 15 years of age in the time period 1980 to 1990. Late mortality was evaluated in a total of 4505 individuals who survived 5 years or more after the initial diagnosis (5-year survivors). Survivors with a second primary tumor were excluded. Standardized mortality ratios (SMRs) were calculated. By December 2014, 400 patients had died. Available cause of death information from 188 individuals was used to estimate cause-specific mortality for all deceased persons. Compared to the population of (former) West Germany, we observed an excess overall mortality risk (SMR = 9.53, 95% confidence interval [CI] = 8.62-10.51). After correcting for missing cause of death information, an increased cancer mortality (SMR = 43.50, 95% CI = 25.79-73.50) in the 5-year survivors was detected. Cardiac death was ascertained in 14 individuals, resulting in an SMR of 10.85 (95% CI = 2.80-32.02) after correcting for missing values. In conclusion, childhood cancer survivors diagnosed in Germany in 1980 to 1990 have a higher mortality risk overall and an elevated risk of dying from cancer and cardiac causes in particular. The results are consistent with those of international cohort studies. However, the reported results are based on few cases and individuals with secondary cancers were excluded.