Accuracy of cytological grading in the carcinoma breast and its correlation with pathological prognostic parameters

Abstract

Background: Breast carcinoma is a significant contributor to cancer deaths worldwide. Tumor grade is an important parameter in planning out the treatment. Histology is the gold standard for grading the carcinoma breast. However, fine-needle aspiration cytology (FNAC) is still an important first-line diagnostic procedure in many parts of the world. Grading on cytology will help in pre-operative management. Although cytological grading of the carcinoma breast is a topic of research for many years, it is not yet included as a part of routine cytology reports.

Materials and methods: A prospective study was conducted over a period of 1 year at Kalinga Institute of Medical Sciences. A total of 42 cases of carcinoma breast, diagnosed on FNAC and subsequently confirmed on histology, were included. Cytological grading was performed using Robinson's grading system, and the results were compared with the histological grade. Also, the cytological grades were correlated with various pathological prognostic parameters such as tumor size, lymph node status, lympho-vascular invasion, estrogen and progesterone receptor status, Her-2-neu expression, and Ki-67 index. The kappa measure of agreement and Fisher's exact test were used for statistical analysis.

Results: A moderate kappa measure of agreement (k = 0.415) was found between cytological and histological grades with an overall concordance rate of 66.67%. The accuracy of cytological grading was higher with increasing cytological grade. Except for estrogen receptor expression, none of the other prognostic parameters have a statistically significant correlation with cytological grade.

Conclusions: Tumor grading on cytology can be helpful in planning treatment, especially in resource-constrained settings. Subjective variation in assessing different parameters and non-inclusion of mitosis in this system might be the reasons behind wrong grading in some cases. Inclusion of mitosis in the scoring system can improve the accuracy of cytological grading and its importance in prognosis.