Sex Differences in Cancer-Specific Survival Are Pronounced during Adolescence and Young Adulthood: A SEER Population-Based Study.

Sex differences in cancer survival may be related to hormonal changes during puberty and menopause; therefore, we investigated sex differences in the cancer-specific survival rates of children, adolescents and young adults (AYAs), and older adults with sex-nonspecific cancers. We interrogated the November 2019 submission of the SEER 18 database and included microscopically confirmed cases of first primary malignant tumors. We stratified the dataset into children (<15 years), AYAs (modified; 15-49 years), and older adults (≥50 years). For each age group, we used the Kaplan-Meier method to estimate the sex-stratified 5-year all-site cancer-specific survival probabilities. Of 3,386,276 eligible patients, 45,124 (1.3%) were children, 548,158 (16.2%) were AYAs, and 2,792,994 (82.5%) were older adults. The 5-year all-site cancer-specific survival probabilities were 84.0% (95% CI, 83.5%-84.5%) for boys, 84.8% (95% CI, 84.3%-85.3%) for girls, 70.4% (95% CI, 70.2%-70.6%) for male AYAs, 80.8% (95% CI, 80.6%-81.0%) for female AYAs, 52.0% (95% CI, 51.9%-52.1%) for older adult men, and 52.2% (95% CI, 52.1%-52.3%) for older adult women. The all-site survival rate for female patients with cancer is markedly higher than for male patients with cancer during adolescence and young adulthood, although this difference diminishes in older adulthood.