Measurement of steroid hormone receptors in breast cancer patients on tamoxifen

  title={Measurement of steroid hormone receptors in breast cancer patients on tamoxifen},
  author={Carlos A. Encarnacion and D. R. Ciocca and William L. McGuire and Gary M. Clark and Suzanne A. W. Fuqua and C. Kent Osborne},
  journal={Breast Cancer Research and Treatment},
SummaryEstrogen (ER) and progesterone receptor (PgR) positive breast tumors often respond to tamoxifen, but ultimately progress as they become tamoxifen resistant. An accurate assessment of receptor status in specimens from tamoxifen-resistant patients could help to understand potential mechanisms of resistance and to predict response to second line hormonal therapies. However, since tamoxifen itself can affect ER and PgR determinations, assay results can be misleading. We measured ER and PgR… 

Molecular markers for predicting response to tamoxifen in breast cancer patients

Overall, from numerous studies, the data indicate that in addition to ERα bcl-2 is a potential candidate to help further improve the ability to predict response to tamoxifen.

Steroid hormone receptors as prognostic markers in breast cancer.

It is suggested that more large-scale clinical studies must be made to analyze systematically the expression of steroid hormone receptors and their respective isoforms in breast cancer patients in order to determine how these receptors interact with each other and in turn affect cancer progression.

Progesterone Receptor Quantification as a Strong Prognostic Determinant in Postmenopausal Breast Cancer Women under Tamoxifen Therapy

The results show that the PR level in ER positive postmenopausal women is a strong prognostic marker in post menopausal breast cancer women under tamoxifen therapy.

Differences in immunoreactivity of estrogen receptor (ER) in tamoxifen-sensitive and -resistant breast carcinomas: preclinical and first clinical investigations

An enzyme-immunoassay that discriminates between tamoxifen-sensitive and -resistant tumors is developed and interesting changes occurring with the ER of tam-resistant tumors that are to be explained by further mutational or protein-chemical analysis.

Tamoxifen Resistance in Breast Cancer

Results indicate a prominent role for alternative growth control pathways independent of ER signalling in intrinsic tamoxifen resistance of ER-positive breast carcinomas.

Mechanisms of tamoxifen resistance

Pure steroidal antiestrogens such as ICI 182,780 are capable of reversing tamoxifen- Stimulated as well as estrogen-stimulated growth of these resistant tumors, and are now in clinical trials for this purpose.

Tracking progesterone receptor-mediated actions in breast cancer.

Role of the Androgen Receptor in Human Breast Cancer

The presence of structurally altered AR in breast cancers may account for unresponsiveness to MPA treatment following failure of tamoxifen therapy, and identification of androgen-regulated genes may lead to new possibilities for the hormonal treatment of breast cancer.

Steroid Receptor Imaging in Breast Cancer.

Molecular changes in tamoxifen-resistant breast cancer: relationship between estrogen receptor, HER-2, and p38 mitogen-activated protein kinase.

  • M. GutiérrezS. Detre M. Dowsett
  • Medicine, Biology
    Journal of clinical oncology : official journal of the American Society of Clinical Oncology
  • 2005
C Crosstalk between ER, HER-2, p38, and ERK may contribute to tamoxifen resistance and may provide molecular targets to overcome this resistance.



Increase of progesterone receptor by tamoxifen as a hormonal challenge test in breast cancer.

It is suggested that, in ER-positive cases responding to tamoxifen by increase of PR, the simultaneous or sequential administration of both antiestrogen (rescuing PR) and progestagen (decreasing PR) may allow better hormonal control of the disease.

Effects of tamoxifen on estrogen and progesterone receptors in human breast cancer.

The results suggest that tamoxifen interacts with the estrogen receptor system in human breast cancer tissue and may be estrogenic during short treatment, while longer treatment results in an antiestrogenic response.

Endocrine therapy for advanced carcinoma of the breast: relationship between the effect of tamoxifen upon concentrations of progesterone receptor and subsequent response to treatment.

It is indicated that some effect of tamoxifen upon PR can be demonstrated in human mammary tumors in vivo and that, by taking a second biopsy for PR estimation during treatment with tamoxIFen, a more precise indication of subsequent response is obtained.

Tamoxifen and the isomers of 4-hydroxytamoxifen in tamoxifen-resistant tumors from breast cancer patients.

This study clearly demonstrates a wide range of tumor tamoxifen levels and accumulation of the less antiestrogenic cis isomer of 4-hydroxytamox ifen in some patients on tamoxIFen therapy.

Changes of steroid hormone receptor content by chemotherapy and/or endocrine therapy in advanced breast cancer

ER and PgR contents of breast cancer gradually became negative as the malignancy progressed, and with some kinds of treatments particularly including endocrine therapy.

Effects of endocrine therapy on steroid-receptor content of breast cancer.

The results indicate that relapse following successful endocrine treatment in breast cancer does not appear to be due to the emergence of RE-negative tumour cells, and the fall in RE content during response to endocrine therapy may bedue to reduced tumour-cell content of the biopsy.

Estrogen control of progesterone receptor in human breast cancer: role of estradiol and antiestrogen.

Tamoxifen is found to have dual dose-dependent estrogenic/antiestrogenic properties and the action of the antiestrogen nafoxidine is not biphasic in MCF-7 cells; it does not induce PgR over a wide dose range and at high doses, the compound inhibits cell growth.

Multiple estrogen receptor assays in human breast cancer.

There was no significant relationship between the time interval between sequential biopsies and the rate of discordance, and marked decreases in ER levels and 78% discordance were seen if rebiopsy was performed within 2 months of tamoxifen treatment.