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

ABSTRACT 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.