Worse OS in Colitis-Associated mCRC, Especially for Younger Patients

Dr Villarreal and colleagues also found that patients with colitis-associated mCRC had shorter OS than those with sporadic mCRC. 

In the validation cohort, the median OS for patients with colitis-associated mCRC was significantly shorter than for patients with sporadic mCRC — 31 months and 39 months, respectively (hazard ratio [HR], 1.24; 95% CI, 1.05-1.47; P =.01). 

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Among patients with early-onset mCRC, the median OS for those with colitis-associated mCRC was significantly shorter than for patients with sporadic mCRC — 26 months and 40 months, respectively (HR, 1.55; 95% CI, 1.18-2.02; P =.001).

Additional factors (tumor-sidedness, sex, etc.) had no impact on median OS for early-onset mCRC cases. 

For patients with late-onset mCRC, the difference in median OS between colitis-associated mCRC and sporadic mCRC was not as great as in the early-onset group. The median OS was 35 months and 38 months, respectively. 

Implications for Practice

Although unrecognized factors can confound results in a retrospective study, these data suggest that patients with colitis-associated mCRC may have significantly worse outcomes than mCRC patients without colitis.  

Moreover, young patients with colitis-associated mCRC have shorter OS than young patients with sporadic mCRC or patients with IBD who develop mCRC in their later years. 

Dr Villarreal noted that additional research is warranted, but the current study supports the hypothesis that approximately 10% of patients with early-onset mCRC may have a subclinical, unrecognized colitis-related tumorigenic process. 

Since SRC/M histology is correlated with both colitis-associated mCRC and early-onset mCRC, a finding of SRC/M histology could be used to gauge prognosis and guide treatment decisions in this high-risk patient population. 

Disclosures: Dr Villarreal reported having no disclosures.


1. Villarreal OE, Zeineddine F, Chacko R, et al. Outcomes in colitis-associated metastatic colorectal cancer and intersection with early-onset and signet ring cell carcinoma. Presented at AACR Special Conference: Colorectal Cancer. October 1-4, 2022. Abstract PR005.

2.  Annese V, Beaugerie L, Egan L, et al. European evidence-based consensus: inflammatory bowel disease and malignancies. J Crohns Colitis. 2015;9(11):945-65. doi:10.1093/ecco-jcc/jjv141