Introduction: Cancer of cervix is the second most common cancer among women worldwide. Various methods have been applied to determine the cell kinetic characteristics of excised tumour. In this study Ki-67 staining was carried out in cervical lesions and correlation of its expression was studied with histological grading of cervical carcinoma.
Materials and methods: A total of 100 cases comprising 25 non-malignant and 75 malignant lesions of cervix (SCC) were included. H&E and IHC staining were performed. For IHC, monoclonal antibody to Ki-67 nuclear antigen of mouse origin was used as primary antibody in 1:100 dilution and biotinylated goat antimouse as secondary antibody. Subsequently, Ki-67 labeling index was evaluated.
Results: Ki-67 positive cells were present in 1/3 basal layer in cases of cervicitis and squamous metaplasia with Ki-67 labeling index of 11% and 13% respectively. In low grade CIN, Ki-67 labeling index was 38% with positive cells in basal and middle layer of squamous epithelium. In high grade CIN, Ki-67 positive cells were present throughout whole thickness of squamous epithelium and labeling index 60%. Ki-67 labeling index was highest in poorly differentiated squamous cell carcinoma (37.4), least in well differentiated squamous cell carcinoma (23.4) and 31.2 in moderately differentiated.
Conclusion: Ki-67 immunostaining is helpful in grading CIN into low grade and high grade.
It has linear correlation with histological grading of squamous cell carcinoma.
CIN, Ki-67, Squamous cell carcinoma.