Cytologic evaluation of cyclin D1 expression in primary breast carcinoma

Preoperative assessment of the biologic characteristics of primary breast carcinoma is important because neoadjuvant medical therapy is being used increasingly. In the current study, the authors attempted to evaluate the validity of cyclin D1 assay in fine-needle aspiration (FNA) samples from patients with primary breast carcinoma.

FNA samples were obtained prior to therapy and multiple slides were stored at -80 degrees C for subsequent immunocytochemical analysis (ICA). ICA for cyclin D1 protein was performed on FNA samples from 51 breast carcinoma patients and 20 samples from patients with benign breast disease. In 45 breast carcinoma patients who had undergone surgery, sections were taken from paraffin blocks and stained by ICA for cyclin D1 validation. Possible correlations between cyclin D1 expression in the FNA samples and the biologic data of the patients also were analyzed.

Cyclin D1 expression was detected in 37 FNA samples from 51 breast carcinomas (72.5%) whereas expression of cyclin D1 was detected in 8 FNA samples from 20 patients with benign breast disease (40%). In histologic sections after surgery, 26 cases of breast carcinoma (65%) showed a positive reaction to cyclin D1. Concordance for the presence of cyclin D1 between FNA samples and histologic samples was 75%. Cyclin D1 expression was high in patients with the tumors that expressed estrogen receptor (ER) (30 of 34 vs. 5 of 11; P = 0.028) and progesterone receptor (PR) (33 of 38 vs. 2 of 7; P = 0.007). There was no significant relation found between cyclin D1 expression and tumor size or lymph node metastasis. Cyclin D1 expression within invasive ductal carcinoma was observed in > 80% of low or intermediate nuclear grade tumors but its expression decreased to 61.5% (8 of 13 cases) in tumors with high nuclear grade (P = 0.023). All 14 breast carcinomas in which the S-phase fraction was 15% showed cyclin D1 expression. Cyclin D1 expression was found to be correlated inversely with proliferative activity in breast carcinoma (P = 0.023).

The results of the current study show that cyclin D1 expression can be measured by ICA in FNA samples with reasonable concordance with the results of histologic section. Cyclin D1 expression was found to be associated with ER/PR status and cell differentiation. The results of the current study indicate that the measurement of novel molecular markers could be performed adequately in FNA samples as well as in histologic sections.