One of the greatest difficulties to reach a successful treatment of mucoepidermoid carcinoma
(MEC) and primary squamous cell carcinoma (PSSC) of salivary glands is the resistance to different
therapeutic procedures which advocate the existence of a subpopulation of cancer stem cell (CSC).
In salivary gland tumors the hypothesis of cancer stem cell has not been fully understood.
Aim: To assess the expression of cancer stem cell markers CD44 and SOX2 in low and highgrades
MEC and PSSC and to determine whether the expression of these markers can be used to
predict tumor aggressiveness.
Materials and Methods: 4μm sections were prepared from paraffin-embedded blocks of
16 samples of MEC and 16 samples of PSSC of salivary glands (8 low-grade and 8 high- grade
carcinomas for each of them). Staining of each specimen with hematoxylin and eosin, CD44 and
SOX2 was done.
Results: All lesions of MEC and PSSC showed membranous CD44 and nuclear SOX2
expression. CD44 and SOX 2 expression were significantly higher in high-grade tumors than in
low-grade tumors. A strong positive correlation between CD44 and SOX2 expression was detected.
Conclusion: Cancer stem cells can be identified in MEC and PSS C using CD44 and SOX 2
markers and may participate in tumor aggressiveness. The present study also suggests that patients
with MEC and PSS C may benefit from therapies that comprise a combination of the two markers.