The impact of surgical resection in early onset colorectal cancer patients with liver limited disease.

e15569 Background: Recent studies have shown an increased incidence of early-onset CRC (EO-CRC), particularly in advanced stages and with metastatic disease. Our study aimed to evaluate the role of metastasectomies related to the clinical and molecular characteristics of EO-CRC patients with liver metastases compared to late-onset CRC (LO-CRC) patients. Methods: We retrospectively collected data from 1123 stage IV colorectal cancers, including 782 with liver metastases, from 5 different Italian institutions. The main objective of the study was to compare the overall survival of liver metastatic EO-CRC and LO-CRC patients who underwent metastasectomy versus those who were not resected. Results: Liver resected EO-CRCs patients showed a statistically significant lower mOS than liver resected LO-CRCs (44.0 vs 64.0 months, p < 0.0001 ). mPFS was also statistically significant lower in EO-CRCs (13.0 vs 17.0, p < 0.0001 ). Same outcomes were found in RAS mut subgroup (37.0 vs 52.0 months, p < 0.0001) and in RAS/BRAF wild-type subgroup (50.0 vs 81.0 months, p < 0.0001). EO-CRC patients showed a higher prevalence of TP53 alterations (56.2%) and a lower of APC mutation (29.9%). EO-CRCs presented a higher frequency of ARID1A (4.4%) and CTNNB1 (3.0%) alterations. Conclusions: The results indicate a worse overall prognosis for EO-CRC patients undergoing metastasectomy compared to late-onset patients. This outcome appears to occur independently of the molecular status. These observations could have a considerable impact on clinical practice and research.