The Influence of Mucinous Histology on the Prognosis of Stage II and III Colorectal Cancers

Background and Objectives: Mucinous adenocarcinoma (MAC) and mucinous components (MCP) in colorectal cancers (CRC) have shown conflicting results regarding their prognostic impact. This study aims to evaluate survival differences between MAC, MCP, and non-mucinous adenocarcinoma (nMAC) in stage II and III CRC patients. Materials and Methods: 224 CRC patients who underwent surgery between 2013 and 2021 were analyzed retrospectively. Patients were classified as nMAC, MCP, or MAC based on the percentage of extracellular mucin. Those who received neoadjuvant therapy, had stage I or IV TNM disease, and emergency cases were excluded. Survival analysis was performed using Kaplan-Meier curves and Cox regression models. Results: MAC patients showed worse survival outcomes compared to nMAC (p = 0.025). No difference in survival was found between MCP and nMAC (p = 0.055). Multivariate analysis identified MAC (OR: 2.814; p = 0.014) and perineural invasion (PNI) (OR: 2.283; p = 0.008) as independent factors associated with worse survival. Kaplan-Meier analysis revealed MAC's worse prognosis than nMAC (p = 0.027). Conclusions: MAC was shown to have a worse prognosis than nMAC in stage II and III CRC patients, while MCP survival rates were similar with nMAC. These findings suggest that MAC requires more careful treatment approaches, while MCP and nMAC have better survival rates. Further studies focusing on molecular and genetic profiles are needed to better understand these outcomes.