335P Early-onset colorectal cancer: A single centre experience

Abstract

Early-onset colorectal cancer (EOCRC) is defined as colorectal cancer (CRC) occurring in patients (pts) aged <50 years. EOCRC incidence has been rising worldwide over the past four decades and is associated with significant mortality. Clinicopathological characteristics, risk factors and molecular pathways have been explored in the literature, but UK data is still limited. A retrospective single-centre data collection was performed on EOCRC pts who were referred for treatment at a large tertiary cancer hospital (Christie NHS Foundation Trust) over seven years (2013-2019). The analysis focused on clinical features, tumour characteristics, risk factors, pathology, molecular drivers, treatment, and survival. The collected data were compared to the National Bowel Cancer Audit (NBOCA) data for EOCRC. Kaplan-Meier methodology was used to calculate median overall survival (OS) and progression-free survival (PFS). This study included 85 EOCRC pts representing approximately 8.5% of all CRC pts. Mean age at diagnosis was 41 years (yrs) (range = 27 to 49yrs) and 57.6% of the pts were males. Family history of CRC was described in 36.5% of the pts and hereditary conditions accounted for 7%. Median duration of presenting symptoms was 3 months and females presented at a younger age (40yrs for females vs 42yrs for males, p = 0.035). Left-sided tumours accounted for 62.4%, and 76.5% of the pts presented with de-novo metastatic disease. There was no significant correlation between prolonged symptom duration and the presence of metastasis at diagnosis (p = 0.36). Median OS was 24 months (95% CI 18.25 – 29.75), and PFS post 1st line chemotherapy was 6 months (95% CI 4.6 – 7.4). The 2-year OS for pts with de-novo metastatic disease was 41.5% compared to 37.4% in the NBOCA EOCRC group. Right-sided cancers had 1.94 times increased risk of death (HR 1.94, 95% CI 1.12 – 3.36, p = 0.017) compared to left-sided after controlling for resection status and presence of metastasis at diagnosis. The vast majority of EOCRC pts presented with metastatic disease despite a relatively short duration of symptoms, potentially indicating more aggressive biology. Lowering the age of national CRC screening and raising public awareness could improve EOCRC outcomes, but further research is urgently needed.