Evaluation and Clinicopathological Correlation of ALDH1 in Colorectal Adenoma with Low-/High-Grade Dysplasia and Carcinoma.

Abstract

Colorectal carcinoma (CRC) stands as one of the most prevalent malignant neoplasms, carrying significant morbidity and mortality implications. Within colorectal carcinogenesis, cancer stem cells are recognized as key contributors, infusing tumors with aggressive traits, including chemoresistance. A group of enzymes known as ALDH1 exhibits stem cell properties, potentially playing a role in colorectal neoplasms. This study aims to evaluate ALDH1 expression in colonic neoplasms and its correlation with clinicopathological parameters. The research encompasses 50 consecutive cases, involving CRC (30) and colorectal adenoma (20), gathered prospectively from September 2019 to August 2021, as well as archived cases from January 2018 to August 2019. Histological examination was conducted on CRC cases to assess tumor type, grade, lymphovascular invasion, perineural invasion, mitosis, and necrosis, while colorectal adenomas were subjected to histological grading. ALDH1 immunohistochemistry was performed on both CRC and adenoma specimens. Statistical analysis utilized SPSS 20 software, employing the chi-squared test and Fischer's exact test. A higher count of adenoma cases displayed positive staining (p = 0.0005) and greater expression (p = 0.036) in comparison to carcinoma cases. The other clinicopathological parameters didn't demonstrate notable associations. Adenomas with low-grade dysplasia exhibited a higher frequency of positive ALDH1 staining and expression than those with high-grade dysplasia. In malignant cases, a higher proportion of positive staining was observed in lower-stage disease compared to higher-stage disease. The heightened staining and expression outcomes of ALDH1 in adenomas versus carcinomas, as well as their presence in lower-stage carcinomas, suggest the potential acquisition of novel mutations and the proliferation of distinct clonal stem cell subsets during disease progression. The absence of ALDH1 in adenoma/carcinoma could indicate a poorer prognosis and an increased likelihood of disease progression to a higher stage. Comprehensive multi-institutional and validation studies are needed to enhance our understanding of ALDH1's role in colorectal oncogenesis, as well as its viability as a targeted or personalized therapy option.