Early-Onset/Young-Onset Colorectal Carcinoma: A Comparative Analysis of Morphological Features and Biomarker Profile

Introduction Colorectal carcinoma (CRC) is one of the most common cancers that involve human body. Young-onset CRC (YO-CRC) or early-onset (EO-CRC) defined as develops before age 50 years, opposed to diagnosed after 50, referred late-onset (LO-CRC). EO-CRC sparsely studied in our population. Therefore, this study, we evaluated clinicopathological parameters and biomarker profile compared them with those LO-CRC. Methods This was a retrospective study conducted at Department Histopathology, Liaquat National Hospital, Karachi, Pakistan. A total 254 biopsy-proven cases CRC, reported over period nine were enrolled study. The specimens collected during surgery sent laboratory for histopathological immunohistochemical (IHC) status examinations. IHC staining performed using antibodies, namely, MutL protein homolog 1 (MLH1), postmeiotic segregation increased 2 (PMS2), MutS (MSH2), 6 (MSH6), epidermal growth factor receptor (HER2/neu), on representative tissue blocks. comparison morphological profiles between LO-CRC performed. Results mean diagnosis 46.27±17.75 female predominance (59.8%). significant difference two groups (EO-CRC LO-CRC) noted respect laterality, tumor site, grade, type, presence pre-existing polyps, perineural invasion (PNI), lymphovascular (LVI), markers. (as significantly affected left colon (92.6% vs. 72.9%, p<0.001), rectosigmoid being site majority (72.1% 61% LO-CRC). showed higher frequency PNI LVI than (42.6% 23.7%, p=0.001; 29.4% 18.6%, p=0.046, respectively). proportion EO-CRCs mucinous (42.6%) medullary (11.8%). Although (54.4%) grade tumors time diagnosis, 3 (44.1%) comparisons positive HER2/neu expression (27.1%) (13.2%). Conversely, loss microsatellite instability (MSI) markers more commonly seen LO-CRS EO-CRC. Conclusions We found relatively Moreover, LO-CRCs, associated prognostically poor histological parameters, such carcinoma, high-grade, PNI, LVI. Similarly, had intact MSI AO-CRC; all these characteristics indicate biological behavior