Abstract
BACKGROUND: In cancer, age and sex are often studied individually, but the impact of the intersection of these factors on cancer incidence and survival remains unclear. Using population-level data, we provide an up-to-date analysis of the impact of sex and age on cancer incidence and survival. METHODS: Using data from the United States Cancer Statistics public use research database and the Centers for Disease Control and Prevention's National Program of Cancer Registries Survival database, we assessed sex and age differences in the incidence and survival of malignant cancers diagnosed from 2001 to 2020. RESULTS: Males experienced higher cancer incidence than females in all sites and age groups, excluding 20-29- and 30-39-year-olds. The highest Male-to-female (M:F) age-adjusted incidence rates (IRR) were observed in mesothelioma within ages 80+ (IRR: 5.48; 95% CI: 5.25-5.71; p < 0.001), and lowest in endocrine cancer within ages 20-29 years (M:F IRR: 0.20; 95% CI: 0.20-0.21; p < 0.001). Among all sites and age groups, excluding 0-9 years, males experienced worse survival than females, particularly within ages 20-29 years (Hazard Ratio (HR): 2.19; 95% CI: 2.15-2.23; p < 0.001). Highest M:F HRs were observed in endocrine system cancers within ages 20-29 (HR: 3.52; 95% CI: 3.15-3.94; p < 0.001), and lowest among lymphomas within ages 0-9 (HR: 0.74; 95% CI: 0.63-0.87; p < 0.001). CONCLUSIONS: Significant age and sex differences in cancer incidence and survival were observed across the US from 2001 to 2020. Males had a higher cancer incidence compared to females, with notable exceptions for younger age groups among certain types, suggesting age may be a critical component in further understanding the biology of sex differences in cancer.