Synchronous Colon Cancer Not Associated With Worse Survival in Stage I–III Disease
Synchronous colon cancer does not appear to adversely affect long-term outcomes compared with solitary tumors, according to a large multicenter population-based study from the Netherlands.
Synchronous colon cancer, defined as two or more primary tumors diagnosed simultaneously or within six months, accounts for 3% to 5% of cases and has historically been associated with increased postoperative morbidity. However, its impact on survival has remained uncertain. This retrospective analysis included 7,982 patients with stage I to III colon cancer who underwent curative resection between 2014 and 2015 across 50 hospitals.
Among the cohort, 269 patients (3.4%) had synchronous tumors. Most cases involved unilateral disease (71%), and 58% were right-dominant. Median follow-up exceeded five years, allowing for robust assessment of disease-free survival (DFS) and overall survival (OS).
At five years, no significant differences were observed between patients with synchronous and solitary colon cancer. DFS was 65.7% in the synchronous group compared with 70.0% in the solitary group (p = 0.10), while OS was 72.4% versus 75.5%, respectively (p = 0.59). These findings remained consistent after stratification by tumor stage.
Subgroup analyses also showed no differences based on tumor distribution. Outcomes were similar between unilateral and bilateral synchronous cancers, as well as between right- and left-dominant disease. The authors reported that “no differences between solitary and synchronous colon cancer were found in 5-year disease-free survival or overall survival.”
They concluded that synchronous disease “demonstrated no significant differences in 5-year disease-free or overall survival…nor between subgroups depending on tumor location.”
Reference
Rademaker E, Aktas BC, Snaebjornsson P, et al. Long-term survival outcomes of synchronous colon cancer: a cross-sectional population-based comparative analysis. Dis Colon Rectum. 2026;69(3):360-373. doi:10.1097/DCR.0000000000004052
