Early onset metastatic colorectal cancer patients as a distinctive clinical and molecular phenomenon.

Background: Despite a reduction of both incidence and mortality from CRC, recent studies have shown an increase in the incidence of early-onset CRC (EO-CRC). Data on this setting are limited. The aim of our study was to evaluate the clinical and molecular profiles of metastatic EO-CRC patients in order to identify differences compared to a late-onset CRC (LO-CRC) control group.

Methods: We retrospectively collected data from 1272 metastatic colorectal cancers from 5 different Italian Institutions. The main objective was to the evaluate clinical outcome for EO-CRC patients in comparison to patients included in the control group.

Results: In the overall population, mOS was 34,7 in EO-CRC pts vs 43,0 months (mo) (p < 0,0001). In the RAS/BRAF mutated subgroup mOS in EO-CRC pts was 30,3 vs 34,0 mo (p = 0,0156). In RAS/BRAF wild-type EO-CRC mOS was 43,0 vs 50,0 mo (p = 0,0290). mPFS was 11,0 in EO-CRC pts vs 14,0 mo (p < 0,0001).

Conclusion: Findings indicate a general worse prognosis for patients with early-onset colorectal cancer compared to late-onset patients. Interestingly this seems to occur regardless of the molecular status. These observations might have a considerable impact on clinical practice and research.