Abstract:
Gastric cancer (GC) is the second most common cause of cancer-related death worldwide. Multiple
malignancies overexpress CD90, making it a helpful diagnostic and prognostic marker. CD133 is suggested to be related
to poor prognosis in GC. Tropomyosin-1 (TPM1) tumor-suppressor gene low expression may predict poor survival in
GC. Our study aimed to investigate CD90, CD133, and TPM1 immunohistochemical expression in GC in relation to
diagnosis, prognosis, and Helicobacter pylori (H. pylori) infection. Methods: 144 paraffin blocks containing gastric
cancerous (108 cases), and non-cancerous (36 cases) tissue were analyzed histopathologically for the type of lesion,
grade, and stage of malignancy and by using an immunohistochemical assay for studying the expression of CD90,
CD133, and TPM1. Data analysis was carried out using the Statistical Package for the Social Sciences (SPSS) version
20.0. Results: The obtained results showed a significantly higher expression of CD90 and CD133 while showing
a significantly lower expression of TPM1 in malignant samples compared to benign ones. CD90 was significantly
higher in grade-3, stage-3, and N3 (p<0.05), with no significant difference concerning positive and negative H. pylori
samples. CD133 percentage and H-score were significantly higher in grade-2 and stage-4 tumors than in other grades
and stages, while being insignificantly higher in N3 and H. pylori-positive cases. TPM1 expression levels were
significantly downregulated in GC and H. pylori-positive cases (p<0.05). TPM1 downregulation was associated with
grade progression, increased depth of invasion, and tumor node metastasis. Conclusion: CD90, CD133, and TPM1
immunohistochemical expression in the gastric biopsy are related firmly to grades and stages of GC as well as H. pylori
infection, so they could be of prognostic value. Further studies on a larger sample size are recommended.
