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Biological heterogeneity of er‐positive breast cancers in the post‐menopausal population
Author(s) -
Romain Sylvie,
Chinot Olivier,
Guirou Olivier,
Soullière Marc,
Martin PierreMarie
Publication year - 1994
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910590105
Subject(s) - breast cancer , estrogen receptor , population , medicine , endocrinology , progesterone receptor , receptor , biology , cancer , estrogen , cancer research , environmental health
In the natural history of post‐menopausal patients with primary breast cancer, high estrogen receptor levels (ER) have been associated with a poor recurrence‐free survival. The purpose of this study was to investigate whether there are any biological intratumoral characteristics to support this puzzling clinical observation. In a population of 542 post‐menopausal, primary‐breast‐cancer patients, 3 normal distributions fitted into the frequency distribution curve of the logarithmically transformed ER‐EIA values. The biological profiles of the low ER group, and of the intermediate and high ER groups identified in the ER‐positive population were compared. Parameters correlated with ER functional aspect (progesterone receptors and PS2), receptors of epidermal growth factor (EGFR), protease cathepsin D and tumor proliferation (deduced from thymidine kinase activity) were analyzed. As previously reported, the levels of progesterone receptors and PS2 increased significantly from the low to the high ER groups. The highest levels of cathepsin D and thymidine kinase which have been previously related to a poor prognosis in breast cancer were found in the low ER group, but high levels were, surprisingly, also found in the high ER group. This study indicates that the ER‐positive post‐menopausal population is biologically heterogeneous. The high levels of thymidine kinase found in the high ER group suggest that overexpression of ER may be associated with proliferation enhancement, partly explaining the poor spontaneous prognosis related to this subset.