Sex-divergent anatomic system concordance in second primary malignant neoplasms: a large-scale analysis

This large-sample study systematically reveals sex-based differences in the characteristics and associative patterns of SPCs. This study systematically defines sex-specific, high-risk cancer-system profiles (e.g., digestive-to-digestive in males, respiratory-to-respiratory and reproductive-to-reproductive in females) and establishes 'anatomic system concordance' as a fundamental principle in the development of SPCs. These findings provide a robust foundation for sex-specific and primary cancer type-guided surveillance strategies. Future clinical practice can utilize these findings to develop stratified management plans based on patient sex and initial primary cancer type, aiming to reduce the incidence and mortality of multiple primary malignant neoplasms.