Age- and latency-specific patterns of subsequent malignant brain and other nervous system tumors after cancer diagnosed before age 40 years.
To describe age- and latency-specific patterns of excess incidence of malignant brain and other nervous system tumors after cancer diagnosed before age 40 years.
We studied first primary malignancies other than brain and other nervous system cancers in SEER 8 (1975-2023). Standardized incidence ratios (SIRs) compared observed with population-expected events across diagnosis age groups and latency intervals. A supplementary competing risk analysis estimated cumulative incidence.
Among 276,844 individuals contributing 3,970,462 person-years, 345 tumors occurred versus 236.97 expected (SIR, 1.46; 95% confidence interval [CI], 1.31-1.62; excess absolute risk [EAR], 2.72 per 100,000 person-years). SIRs were 5.20 at ages 0-14, 1.84 at 15-19, 1.17 at 20-29, and 1.23 at 30-39 years. Age patterns varied by latency (interaction p = .0012). At 10 or more years, the childhood SIR was 4.64 (95% CI, 3.22-6.49). The 20-year cumulative incidence after the 2-month landmark was 0.257% (95% CI, 0.193-0.341%) after childhood cancer.
In this population-based descriptive analysis, childhood cancer survivors had the greatest relative excess incidence, which remained evident beyond 10 years. Absolute excess and cumulative incidence were small. Joint assessment of diagnosis age and latency characterized patterns obscured by the overall estimate.
We studied first primary malignancies other than brain and other nervous system cancers in SEER 8 (1975-2023). Standardized incidence ratios (SIRs) compared observed with population-expected events across diagnosis age groups and latency intervals. A supplementary competing risk analysis estimated cumulative incidence.
Among 276,844 individuals contributing 3,970,462 person-years, 345 tumors occurred versus 236.97 expected (SIR, 1.46; 95% confidence interval [CI], 1.31-1.62; excess absolute risk [EAR], 2.72 per 100,000 person-years). SIRs were 5.20 at ages 0-14, 1.84 at 15-19, 1.17 at 20-29, and 1.23 at 30-39 years. Age patterns varied by latency (interaction p = .0012). At 10 or more years, the childhood SIR was 4.64 (95% CI, 3.22-6.49). The 20-year cumulative incidence after the 2-month landmark was 0.257% (95% CI, 0.193-0.341%) after childhood cancer.
In this population-based descriptive analysis, childhood cancer survivors had the greatest relative excess incidence, which remained evident beyond 10 years. Absolute excess and cumulative incidence were small. Joint assessment of diagnosis age and latency characterized patterns obscured by the overall estimate.