Intermediate estrogen receptor levels in breast cancer

Effect of tamoxifen on Ki67 labelling index in human breast tumours and its relationship to oestrogen and progesterone receptor status

This study aimed to investigate the effect of tamoxifen on breast tumour levels of oestrogen and progesterone receptor (ER and PR) and proliferation as defined by the Ki67 antibody. A group of primary breast cancer patients was randomised to receive either tamoxifen (n = 59) or placebo (n = 44) treatment in the interval between clinic and surgery (median 21 days). Frozen sections of breast tumour biopsies obtained before and after treatment were stained immunocytochemically to obtain the percentage of nuclei containing ER and PR, and a Ki67 labelling index (LI). Tamoxifen-treated patients had a median Ki67 LI of 5.6% in the first biopsy falling to 3.0% in the second biopsy (P < 0.001 by Wilcoxon's matched pairs test), whereas placebo-treated patients had a median Ki67 LI of 5.4% in the first biopsy and 5.75% in the second (no significant difference). No significant differences were observed when the median %ER or %PR staining before and after treatment were compared. The Ki67 LI tended to increase with increasing histological grade and was greater in tumours that were ER - ve compared to those that were ER + ve (> 5% nuclei stained), median 7.8% and 4.3% respectively (P = 0.011 by Mann-Whitney U-test). However, the decline in tumour Ki67 LI following anti-oestrogen treatment failed to correlate with ER and PR status or to predict recurrence over a short follow-up period. To our knowledge, this is the first time that tamoxifen treatment has been shown to reduce the Ki67 LI in human breast tumours in vivo. These data indicate that staining with the Ki67 antibody may be useful in monitoring response to anti-oestrogen therapy.

Hormone receptors in renal cancer: an overview

The current literature concerning hormone receptors in renal cell cancer is reviewed. Our own results of histochemical determination of estrogen receptors by means of monoclonal antibodies are presented. Based on the studies that have been reviewed and the differing results of the receptor assays, we conclude that there is a very limited basis to apply hormone therapy in renal cell cancer. However, the new immunohisto-chemical methods should be used to resolve the question about the hormone dependency of renal carcinoma.

Multiple microsample analysis of intratumor estrogen receptor distribution in breast cancers by a combined biochemical/immunohistochemical method

A multiple microsample analysis of estrogen receptors (ER) was performed on 81 samples obtained from 21 human breast cancers using a biochemical (BC) and immunohistochemical (IHC) method. Qualitative agreement occurred in 96% of the cases. Using both the percentage of cells staining specifically for ER as well as the intensity of staining (Histoscore) a semiquantitative correlation between the two analyses was obtained. Large variations in cellularity and the percentage of cells that stained specifically for ER existed within individual tumors. In most cases the variation in intensity of staining was minimal. Both the level and distribution of ER in different areas of individual tumors were calculated using a correction for differences in cellularity amongst samples. Heterogeneity in ER level as well as distribution was found in some tumors. In addition, a "checkerboard" type of staining with intermixed ER positive and ER negative cells was observed. This combined BC/IHC method may provide specific information about intratumor ER heterogeneity not available from either method alone.