# Expression of Putative Cancer Stem Cell Markers in Oral Squamous Cell Carcinoma: Correlation with Clinicopathological Features

## TL;DR

This study examines cancer stem cell markers in oral cancer and finds correlations with tumor depth and salivary flow rates.

## Contribution

The study identifies CD133 and its co-expression with CD44 and CD166 as potential prognostic indicators in oral squamous cell carcinoma.

## Key findings

- CD44 expression was uniformly high in OSCC tissues.
- CD133 expression was low but correlated with tumor depth.
- Salivary flow rates were negatively correlated with CD166 and CD44/CD166 co-expression.

## Abstract

Oral squamous cell carcinoma (OSCC) is an aggressive epithelial malignancy with high local invasiveness and a tendency for early cervical lymph node metastasis. Conventional prognostic markers often lack precision. This study evaluated the expression of putative cancer stem cell markers—CD44, CD133, and CD166—in OSCC tissues and explored their associations with clinical parameters, including salivary flow rates. Twelve patients with histologically confirmed OSCC (9 males, 3 females; mean age: 65 years) were included. Clinical TNM staging and tumor dimensions were recorded. Depth of invasion was measured histologically. Tumor tissues were enzymatically dissociated to establish primary cell cultures, and flow cytometry was used to quantify putative cancer stem cell markers expression. Unstimulated salivary flow rates were measured using sialometry. CD44 expression was uniformly high (median: 96.4%) and CD166 showed moderate to high expression (median: 85.5%), while CD133 was low (median: 1.5%). Co-expression levels were the highest for CD44+/CD166+ (median: 86.6%). Triple-marker co-expression had a median of 2.0%. Depth of invasion was positively correlated with CD133+ and its co-expression with CD44+ and CD166+ (p ≤ 0.05). Salivary flow rates were negatively correlated with CD166+ and CD44+/CD166+ expression (p ≤ 0.01). These findings suggest putative cancer stem cell markers, particularly CD133, may have prognostic value in OSCC and warrant further investigation.