Cancer incidence (2000-2020) among individuals under 35: an emerging sex disparity in oncology.

Background: Aggressive malignancies, such as pancreatic cancer, are increasingly impacting young, female populations. Our investigation centered on whether the observed trends in cancer incidence were unique to pancreatic cancer or indicative of a broader trend across various cancer types. To delve deeper into this phenomenon, we analyzed cancer incidence trends across different age and sex groups. Furthermore, we explored differences in cancer incidence within specific young subgroups aged 18 to 26 and 27 to 34, to better understand the emerging incidence trend among young individuals.

Methods: This study collected cancer incidence data from one of the Surveillance, Epidemiology, and End Results cancer registry databases (SEER22), with 10,183,928 total cases from 2000 to 2020. Data were analyzed through Joinpoint trend analysis approach to evaluate sex- and age-specific trends in cancer incidence. Exposure rates were reported as Average Annual Percentage Changes (AAPCs).

Results: The analysis revealed significant age and sex-specific disparities, particularly among individuals aged 18-26 and 27-34. Pancreatic cancer incidence rates increased more in females aged 18-26 (AAPC, 9.37% [95% CI, 7.36-11.41%]; p < .0001) than in males (4.43% [95% CI, 2.36-6.53%]; p < .0001). Notably, among gender, age, and other malignancies, young females had the highest AAPCs for pancreatic cancer. Additionally, the incidence of gastric cancer, myeloma, and colorectal malignancies also showed higher AAPCs in young females compared to males.

Conclusions: Recognizing emerging risk populations for highly lethal malignancies is crucial for early detection and effective disease management.