Clinical, molecular characteristics, and outcomes of early-onset vs. late-onset colon cancer: A single-center experience.

Abstract

e15692 Background: The incidence of colon cancer is increasing in those under 50 years of age(Early Onset Colon cancer {EOCC}). We evaluated clinical, molecular characteristics, and outcomes in patients above 50 years of age(Late Onset Colon cancer {LOCC}) and in EOCC especially those under 45 years. Methods: We conducted a Retrospective study of colon cancer patients aged 18 years or above seen at our center from January 2020 to December 2024. 129 Medical records were retrieved, 22 were excluded due to missing data. We used Descriptive Statistics. Results: Baseline characteristics are included in the table. 17/107(15.9%) had EOCC and 90/107(84.1%) had LOCC. 8/17(47%) were under 45 years of age. 7/17 (41.2%) EOCC had Stage III, 5/17 (29.4%)Stage IV, 2/17(11.8%) Stage I and 3/17(17.6%)Stage II. Of the 8 under 45 years, 2 had Stage II, 4 Stage III, and 2 Stage IV. (6 left-sided and 2 right-sided). 3/90(3.3%) with LOCC had stage 0, 25/90(27.8%) Stage I, 20/90(22.2%) Stage II, 30/90(33.3%) Stage III, and 12/90(13.3%) Stage IV. 12/17(70.6%) of EOCC were Left sided and 5/17(29.4%) were Right sided. 51/90(56.7%) of LOCC were Left sided and 39/90(43.3%) were Right sided. The mean BMI in EOCC was 30.77. 2/17 patients with EOCC were noted to have MSI-H and 1/90 with LOCC had MSI-H. KRAS mutations were seen in 3/17 EOCC and 14/90 LOCC. BRAF mutation was not seen in EOCC and in one with LOCC. 2/17 with EOCC were Her 2 + (Both were under 45). 2/17 were APC and TP53 positive. 2/90 with LOCC were Her 2 + and 2/90 were APC and TP53 positive. 2/17 with EOCC progressed to become metastatic and the mean time to metastases was 23 months. 15/90 patients with LOCC became metastatic and the mean time to metastases was 34.8 months. Two deaths were reported in the EOCC group and the mean time to death was 10 months. Five deaths were reported in the LOCC group and the mean time to death was 3.4 years. Conclusions: A significant proportion of patients who presented with sporadic colon cancer were under 45 years. Majority of the EOCC patients had left-sided tumors and advanced stage (III or IV). The mean BMI and CEA levels were higher in patients with EOCC. The mean duration to become metastatic and mean duration to death from diagnosis were shorter in EOCC. Based on our center’s experience, we suggest having patient-centered approach for colon cancer screening, especially in those who are under 45 years of age with higher BMI levels. Further studies are needed to better understand the risk factors and tumor biology of younger patients so we can modify our prevention, diagnostic, and treatment strategies to improve colon cancer outcomes in EOCC. Characteristics EOCC (<50)n= 17 <45n= 8 LOCC (>50)n= 90 Male 6 4 48 Female 11 4 42 African American 6 2 39 Hispanic 9 5 36 Caucasian 2 1 13 Asian 0 0 2 BMI Mean (Range) 30.8 (18.5 to 65) 34.8 (22.3 to 65) 27.9 (16-45) BMI Median 28.8 30.1 26.6 CEA Mean (Range) 207 (0.4 to 2700 48.7 (0.4 to 374) 20.97 (0.4 to 447) CEA Median 2.10 1.4 3.10