C-erb B2 oncoprotein expression. Correlation with the Ki-67 labeling index and AgNOR counts in breast carcinoma on fine needle aspiration cytology.

OBJECTIVE

To evaluate the expression of C-erb B2 on-coprotein and study its correlation with the Ki-67 labeling index and silver-stained nucleolar organizer region (AgNOR) counts on fine needle aspiration cytology (FNAC) of breast carcinoma.

STUDY DESIGN

In a prospective study, FNAC was done on 60 cases of infiltrating ductal carcinoma of the breast. Smears from aspirates were either air dried and methanol fixed for May-Grüwald-Giemsa and silver staining for AgNORs or wet fixed for Papanicolaou and immunocytochemical staining for Ki-67 and C-erb B2.

RESULTS

Breast carcinoma showing overexpression of C-erb B2 had higher Ki-67 labeling indexes (mean, 21.43) and higher AgNOR counts (mean, 37.92). A statistically significant correlation (r = .8) was seen between AgNOR counts and the Ki-67 labeling index.

CONCLUSION

FNAC proved suitable for studying C-erb B2 oncoprotein expression and the Ki-67 labeling index by immunocytochemistry. These parameters supplement the cytologic diagnosis.