Sequence of Colorectal Cancer Diagnosis Is Related to Overall and Cancer-Specific Survival

Wignakumar A, Emile SH, Dourado J, et al. Does the Sequence of Colorectal Cancer Diagnosis Matter for Patients with Multiple Primary Cancers? A Surveillance, Epidemiology, and End Results Database Cohort Study. J Am Coll of Surg. 2025; in press.

What differences exist between isolated primary colorectal cancer (CRC) and CRC presenting in sequence with multiple primary cancers?

This cohort study used 20 years of SEER data (2000–2020) to determine features and outcomes in 592,063 patients with stage I-IV colorectal adenocarcinoma, classified as having CRC as the only malignant condition (71.8%) or the first (11.9%) or second of multiple primary cancers (16.3%).

Those with CRC as the only malignant condition were most likely to have elevated pretreatment carcinoembryonic antigen levels, liver metastases, lung metastases, and T4 tumors. They also underwent significantly more systemic adjuvant treatments and fewer surgical treatments.

Patients with CRC as the first of multiple cancers were most likely to have left-sided CRC, be offered surgery, and undergo systematic adjuvant therapy in CRC stages III and IV. 5-year mean overall and cancer-specific survival (50.4 and 51.2 months) were also longest in this group.

CRC diagnosed as the second of multiple primary cancers suggested patients were likely to have right-sided colonic cancer and had the worst overall and cancer-specific survival (39.2 and 39.8 months).