Comparison of pS2 and cathepsin D in primary breast carcinomas

In oestrogen receptor positive breast cancer cell lines the synthesis of pS2 and cathepsin D is oestrogen regulated. Using immunohistochemistry the expression of pS2 and cathepsin D has been determined and compared in 194 primary breast carcinomas. The findings have been related to receptor status and pathological features. There was a significant association between pS2 and oestrogen receptor (p < 0.001) but not progesterone receptor, and no association between cathepsin D and oestrogen and progesterone receptor status. There was a significant association between pS2 and histological differentiation (p < 0.001), with a weaker association for cathepsin D (p = 0.02). Neither marker was associated with node status. Similar reactivities for pS2 and cathepsin D (negative, moderate, high) were found in 41.5% carcinomas, with greater reactivity for pS2 in 38.5% and for cathepsin D in 11 %. Oestrogen and progesterone receptor negative tumours had a higher frequency of being negative for pS2 and cathepsin D (0.02> p> 0.01), but no other relationship with receptor status was observed. Overall, pS2 had a closer relationship to oestrogen receptor than cathepsin D.