Maule, Milena, Scélo, Ghislaine, Pastore, Guido, Brennan, Paul, Hemminki, Kari, Tracey, Elizabeth, Sankila, Risto, Weiderpass, Elisabete, Olsen, Jorgen H., McBride, Mary L., Brewster, David H., Pompe-Kirn, Vera, Kliewer, Erich V., Kee Seng Chia, Tonita, Jon M., Martos, Carmen, Jonasson, Jon G., Merletti, Franco, and Boffetta, Paolo
Background Survivors of childhood leukemia and lymphoma experience high risks of second malignant neoplasms. We quantified such risk using a large dataset from 13 population-based cancer registries. Methods The registries provided individual data on cases of leukemia, Hodgkin lymphoma, and non-Hodgkin lymphoma occurring in children aged 0–14 years and on subsequent second malignant neoplasms for different time periods from 1943 to 2000. Risks of second malignant neoplasms were assessed through standardized incidence ratios (SIRs) and corresponding 95% confidence intervals (CIs), using the incidence rates in the general populations covered by the registries as a reference. Cumulative absolute risks were also calculated. Results A total of 133 second malignant neoplasms were observed in 16540 patients (12731 leukemias, 1246 Hodgkin lymphomas, and 2563 non-Hodgkin lymphomas) after an average follow-up of 6.5 years. The most frequent second malignancies after leukemia were brain cancer (19 cases, SIR = 8.52, 95% CI = 5.13 to 13.3), non-Hodgkin lymphoma (nine cases, SIR = 9.41, 95% CI = 4.30 to 17.9), and thyroid cancer (nine cases, SIR = 18.8, 95% CI = 8.60 to 35.7); the most frequent after Hodgkin lymphoma were thyroid cancer (nine cases, SIR = 52.5, 95% CI = 24.0 to 99.6), breast cancer (six cases, SIR = 20.9, 95% CI = 7.66 to 45.4), and neoplasms of skin (non-melanoma) (six cases, SIR = 34.0, 95% CI = 12.5 to 74.0); and the most frequent after non-Hodgkin lymphoma were thyroid cancer (six cases, SIR = 40.4, 95% CI = 14.8 to 88.0) and brain cancer (four cases, SIR = 6.97, 95% CI = 1.90 to 17.9). Cumulative incidence of any second malignant neoplasm was 2.43% (95% CI = 1.09 to 3.78), 12.7% (95% CI = 8.29 to 17.2), and 2.50% (95% CI = 1.04 to 3.96) within 30 years from diagnosis of leukemia, Hodgkin lymphoma, and non-Hodgkin lymphoma, respectively. Conclusions This population-based study provides, to our knowledge, the most precise and up-to-date estimates for relative and absolute risks of second malignant neoplasms after childhood leukemia and lymphoma. [ABSTRACT FROM AUTHOR]