Breast cancer patients with estrogen receptor-negative/progesterone receptor-positive tumors: being younger and getting less benefit from adjuvant tamoxifen treatment

Abstract

Our results indicate that patients with ER-/PgR+ tumors are mainly premenopausal and young. Although patients with ER-/PgR+ tumors are generally considered as candidates for endocrine therapy clinically, the ER-/PgR+ group gains less benefits from adjuvant TAM treatment than ER+/PgR+ group.

Do Clinical Features and Survival of Single Hormone Receptor Positive Breast Cancers Differ from Double Hormone Receptor Positive Breast Cancers?

“…Similarly in our study, the ER-PR+ patients derive a better overall survival when on tamoxifen compared to those who were not taking Tamoxifen. However this beneficial effect of tamoxifen was not seen in other studies, (Rakha et al, 2007;Yu et al, 2008b) which concluded ER-PR+ patients gain less benefit than patients with ER+PR+ tumors when they were on tamoxifen.…”

“…However, the significance of the single hormone receptor positive phenotype, which includes the ER+PR-and ER-PR+ tumors, is still poorly understood. The proportion of ER+PR-tumors has been reported to be 12-17% (Dunnwald et al, 2007;Rakha et al, 2007;Rakha et al, 2010) while the proportion of ER-PR+ tumors is much less, reported to be 1-10% (Rakha et al, 2007;Yu et al, 2008a;Rakha et al, 2010). Hormone therapy has been found to be less effective in the single hormone receptor positive phenotype and they have a survival outcome between double-positive and double-negative phenotypes (Bardou et al, 2003;Rakha et al, 2007).…”

Lack of Either Estrogen or Progesterone Receptor Expression Is Associated with Poor Survival Outcome among Luminal A Breast Cancer Subtype

“…tumors were associated with premenopausal women, younger age at diagnosis, larger tumor size, higher grade, positive p53 and P-cadherin, basal cytokeratins expression, and higher mortality, which was similar to results of the present study. 9,25,26 Although technical issues are another possible explanation for the existence of single receptor-positive phenotype, interlaboratory assay variance among institutions and the lack of determination of details of ER/PR expression except positive or negative status in the KBCS dataset allow only limited interpretation of the present study. [14][15][16]28 Consistent with previous studies, however, biologically and clinically distinct characteristics of single receptor-positive tumors were demonstrated among immunohistochemically defined luminal A subtype tumors.…”

“…tumors have been reported to account for 2-11 % of breast cancers. 16,25,26 Several possible explanations for the ER-/PR? phenotype have been proposed, including abnormally functional ER activating estrogen pathway without estrogen binding to its receptor, but none of these suggestions have been confirmed.…”

ER, PR and HER2 testing in breast cancer

“…2 ER negative tumours in general do not show benefit from 5-year adjuvant tamoxifen therapy, but some benefit may occur in a small subgroup of ER negative disease with PR positivity. 3 Historically, ER and PR have been assessed using dextrancoated charcoal/ligand binding assay method. This has been followed by other testing methods such as enzyme immunoassay and enzyme-linked immunosorbent assay.…”