Non-Colorectal Cancer-Related Deaths in Patients With Early-Onset Colorectal Cancer: A Population-Based Study.

[BACKGROUND] We assessed causes of death in patients with early-onset colorectal cancer (EOCRC) and factors associated with non-CRC-related deaths.

[METHODS] SEER database was screened between 2000 and 2020 for patients with EOCRC. Causes of death were classified into CRC-related and non-CRC-related, and stratified by demographics, disease location, and stage. The main study outcome was the cause of death in EOCRC.

[RESULTS] A total of 67 353 patients (53.9% male) had EOCRC. In total, 13.2% of 25 441 deaths were unrelated to CRC. The most common cause of non-CRC-related deaths was medical conditions (36.1%), mainly heart disease (16.6%). CRC was more often the cause of death in patients aged < 30 years, female, and stages III and IV disease; whereras medical conditions accounted for more deaths in patients aged 40-50 years, males, and Black. Other primary cancers were more often the cause of death in patients aged 45-50 years, female patients, and Asian patients. Death due to causes other than CRC was significantly more likely when surgery for CRC was performed (OR: 2.35; p = 0.028) and when CRC was one of multiple primary cancers (OR: 3.7; p < 0.001).

[CONCLUSIONS] Most common causes of non-CRC-related deaths were medical conditions and other primary cancers accounting for more deaths in patients aged 40-50 years, males, Black and Asian patients, and with early-stage CRC.