CORRELATED EXPRESSION OF BCL-2 PROTEIN, ESTROGEN-RECEPTOR, CATHEPSIN-D AND LOW GROWTH FRACTION (PCNA) IN INTRACYSTIC PAPILLARY BREAST-CARCINOMA

The expression of BCL-2 protein was evaluated immunohistochemically in 23 intracystic papillary carcinomas (IPCs) of the breast. Twenty-two patients were female and one male, aged 49-90 years (median 72). Twent y-one cases had a benign behaviour, while two cases developed local re currence. Of the 23 tumours, 19 (82%) were immunoreactive for BCL-2, t he majority of positive carcinomas showing intense cytoplasmic stainin g of more than 50% neoplastic cells. The intensity of BCL-2 expression was significantly correlated with prognostic markers such as estrogen receptor (ER) positivity (p = 0.001), cathepsin D (CD) reactivity in the neoplastic cells (p = 0.001) and low growth fraction, evaluated by proliferating cell nuclear antigen (PCNA) immunostaining (p = 0.008). An inverse relationship was also found between BCL-2 and p53 protein (p = 0.001). Three cases of high grade (G3) IPC expressed p53, high PC NA index, and CD (the latter only in the stromal cells), but no immuno staining for BCL-2 and ER. Thus, absence of BCL-2 expression in high g rade LPC was associated with ER-negative, rapidly proliferating and p5 3-positive immunophenotype. All high grade tumours showed invasion of the cystic wall. Local recurrence developed in one of these. The autho rs conclude that BCL-2 immunoreactivity in IPC is related with tumour grade and with a range of molecular markers of favourable prognosis su ch as ER positive status, CD expression in the neoplastic cells, and l ow PCNA index. These findings are consistent with the indolent clinica l course and the very favourable prognosis of IPC of the breast.