Correlative Study of Cytological Features in Grading of Invasive Breast Carcinoma

Fine-needle aspiration cytology (FNAC) is a proven diagnostic technique for establishing the benign or malignant character of breast lesions. Several cytological grading systems have been proposed for grading of carcinoma breast, with results similar to histologic grades.

This study sought to evaluate the prognostic value of FNAC in invasive ductal carcinoma of breast by correlating it with histological grade.

Tertiary care hospital, retrospective analytical study.

One hundred and fifty cases of breast carcinoma that underwent modified radical mastectomy consequent to an FNAC diagnosis were included in the study. Robinson's grading system and Elston-Ellis modification of Scarff-Bloom-Richardson grading system were used to assign cytologic and histologic grades, respectively.

The cytological grades were correlated with the histological grades using χ²-test and Spearman's rank correlation coefficient. The individual features of the cytological grades were correlated with the histological grades using Kappa coefficient and χ²-test. Values were considered significant at P < 0.05.

A statistically significant association was observed between cytologic and histologic grades (r = 0.97; P < 0.01) with sensitivity and specificity, respectively, of 100% and 93.95% for cytological grade 1, 100% and 100% for cytological grade 2 and 100% and 100% for cytological grade 3. Also, a positive correlation was found between each feature of the cytologic grade and the histologic grade (P < 0.05). Among these, a better correlation was demonstrated by cytological features like cell uniformity (Kappa coefficient = 0.50) and appearance of nucleoli (Kappa coefficient = 0.52).

Robinson's cytologic grading system is a reliable grading method on FNAC smears of cases of carcinoma breast. It correlates well with Elston-Ellis modification of Scarff-Bloom-Richardson grade in invasive ductal carcinoma of breast.