Colorectal cancer in young patients: An institutional experience.

Abstract

e15140 Background: The incidence of colorectal cancer (CRC) in young patients (<50 years) is increasing but little is known about disease characteristics and treatment outcomes in this patient population. Methods: CRC patients diagnosed at < 50 years of age (UF registry 2000-2017) constituted the IRB approved study cohort. Statistical methods included descriptive statistics, uni-variable cox proportional hazard regression model, Pearson chi-square exact and Wilcoxon rank-sum test. Results: Young CRC patients (n= 286) comprised 16% of total CRC patients (n= 1806) treated at our institution. (See Table for demographics and tumor characteristics). The median age at diagnosis was 45 years (range 17-50) with 74% diagnosed between age 40-50. One third (35.7%) of patients had rectal primary. DNA mismatch repair gene deficiencies (dMMR) and/or microsatellite instability (MSI) was tested in 60.1%; 10.5% had MSI-H or dMMR tumors and 11 of those had confirmed Lynch syndrome. Next generation sequencing (n= 71) or mutational analysis (n= 79) was performed. Most common mutation was exon 12 of K- ras (40.7%, n = 61) followed by TP53 (7.33%; n = 11) and PIK3CA (5.33%; n = 8). BRAF V600E was seen in 5 patients. Patients who underwent curative resections had better hemoglobin (p=0.005), albumin levels (p <0.001) and lower CEA level (p<0.001). Factors associated with poor survival were low albumin ≤34 g/l, advanced primary tumor (T3/T4), nodal disease (N1/N2) and presence of diffuse metastases. For stage 4 disease, the cancer-specific survival (CSS) at 1 year was 77.2%, 3-year CSS was 46.1% and 5-year CSS was 29%; survival was better (HR=0.4; 95% CI 0.2-0.6, p<0.001) among patients who underwent metastatectomy. Conclusions: Our results reveal that the most young CRC were 40-50 years age group with a female preponderance. Young CRC patients were more likely to be managed in an aggressive manner with a higher proportion of early stage patients receiving perioperative therapy. A suggestion of an improved CSS was seen in advanced stage disease even with similar prognostic factors. Review of larger data sets are warranted. [Table: see text]