Statement of the Problem: Squamous cell carcinoma (SCC) is the most frequent
oral cancer whose 5-year survival rate is 80% for early-detected lesions and nearly
30-50% for advanced lesions. Early detection of oral cancers and precancerous lesions
can improve the patient’s survival and decrease the morbidity.
Purpose: This study aimed to evaluate and compare the Ki-67 and MCM3 expression
in cytologic smear of oral SCC (OSCC).
Materials and Method: We examined 48 oral brush biopsies including 28 OSCC
and 20 healthy non-smoking samples. Immunocytochemistry staining was performed
for Ki-67 and MCM3 by using an EnVision-labeled peroxidase system, and labeling
index (LI) was calculated.
Results: Out of 28 OSCC cases, 27(96.4%) cases contained MCM3 positive cells
and 22(78%) cases contained Ki-67 positive cells. All normal mucosa were Ki-67
and MCM3 negative. MCM3 and Ki-67 LI were significantly higher in OSCC than
normal mucosa (p< 0.001). MCM3 LI was significantly higher than Ki-67 LI in
OSCC group (p< 0.001).
Conclusion: Immunocytologic evaluation of Ki-67 and MCM3 can be used for early
detection of OSCC. Furthermore, MCM3 may be a more sensitive cytologic biomarker
than Ki-67 in SCC patients