Expression of oestrogen and progesterone receptors, Ki-67, p53 and BCL-2 proteins, cathepsin D, urokinase plasminogen activator and urokinase plasminogen activator-receptors in carcinomas of the female breast in an African population

To determine the expression of oestrogen (ER) and progesterone receptor (PgR), Ki-67, p53, bcl-2 proteins and the proteolytic enzymes cathepsin D (CD), urokinase-plasminogen activator (uPA) and its receptor (uPA-R) in primary carcinomas of the breast from indigenous Tanzanian female patients by immunohistochemistry. Prospective cross-sectional study. Muhimbili Medical Centre, Dar es Salaam, Tanzania. Sixty patients admitted between 1995 and 1997. Markers were found to be expressed as follows: ER (33.3%), PgR (18.3%), p53 (30%), bcl-2 (43.5%) and the median proliferation rate of Ki-67 was 15%. Proportion of tumours positive for ER, PgR and bcl-2 initially decreased to 12 months disease duration, after which it increased. The observed proliferation rate approaches that reported in developed countries. p53 expression did not influence the proliferation rate nor did bcl-2 expression. ER, PgR and bcl-2 were strongly co-expressed. CD was predominantly expressed in stromal macrophages than in cancer cells. The low expression of ER and PgR and their strong co-expression with bcl-2 might negatively influence response to hormonal therapy. The influence of bcl-2 on tumour response to anti-cancer therapy in patients with long disease duration requires urgent clarification. Determination of CD in stromal macrophages rather than in cancer cells may have greater prognostic significance in patients of this region.