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.
Keywords
cancer stem cell - ALDH1 - colorectal cancer - adenoma - clinicopathological - stage
- dysplasia
