Slowing Breast Cancer Tumor Growth Rate in Double Positive [Estrogen Receptor (ER) and Progesterone Receptor (PR)] BRCA Diagnosed Women  – The Potential for a Combination Drug Therapy: Tamoxifen AND Progesterone

Reporter: Aviva Lev-Ari, PhD, RN

This post is on the study published in Nature on 08 July 2015 in which it is reported that PR functions as a molecular rheostat to control ERα chromatin binding and transcriptional activity.

These findings on the effects observed in the study that has used Progesterone and not its derivatives in

Mohammed H. et al. Progesterone receptor modulates estrogen receptor-α action in breast cancer, Nature (2015), DOI:10.1038/nature14583

should be read differently and not be confused with studies on contraceptives, and certain forms of Hormone Replacement Therapy, contain derivatives of progesterone (e.g. medroxyprogesterone acetate, MPA) – these seem to act differently.

So headlines claiming that a hormone ‘found in The Pill slows growth of tumours’ are slightly inaccurate.]

http://scienceblog.cancerresearchuk.org/2015/07/08/solving-a-breast-cancer-mystery-why-do-double-positive-women-do-better/

• The Potential for a Combination Drug Therapy: Tamoxifen AND Progesterone requires clinical trials.
• Every diagnosis of Breast Cancer in Women needs to be accompanied by testing for Double Positive: [Estrogen Receptor (ER) and Progesterone Receptor (PR)] in every Woman diagnosed with BRCA.
• Treatment for a Woman’s diagnosis with a Double Positive should be different than triple negative
• Understanding the progesterone receptor’s role as a molecular handbrake on oestrogen-fuelled growth could also explain the observation that breast cancers frequently evolve to get rid of their progesterone receptors – this is an advantage to cancer, helping it grow quicker.

  This new research offers a unique opportunity to exploit the braking action of the receptor with hormone therapy to improve breast cancer outcomes. According to Dr Carroll, this is precisely what needs to be done, and the next steps are obvious.

  “The results are pretty clear and potentially have direct benefits for many women with breast cancer,” he told us.

  “We’re already discussing a clinical trial to test whether giving women with ER/PR double-positive breast cancer progesterone, alongside oestrogen-blocking drugs, helps more women survive this disease”.

  If proven successful, they suggest that it could benefit up to half of women diagnosed with the disease.

http://scienceblog.cancerresearchuk.org/2015/07/08/solving-a-breast-cancer-mystery-why-do-double-positive-women-do-better/

REFERENCES

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14583.html#access

Other related articles in this Open Access Online Scientific Journal include the following:

Mutation D538G – a novel mechanism conferring acquired Endocrine Resistance causes a change in the Estrogen Receptor and Treatment of Breast Cancer with Tamoxifen

http://pharmaceuticalintelligence.com/2013/11/12/mutation-d538g-a-novel-mechanism-conferring-acquired-endocrine-resistance-causes-a-change-in-the-estrogen-receptor-and-treatment-of-breast-cancer-with-tamoxifen/

MIT Scientists Identified Gene that Controls Aggressiveness in Breast Cancer Cells

http://pharmaceuticalintelligence.com/2013/07/03/mit-scientists-identified-gene-that-controls-aggressiveness-in-breast-cancer-cells/

Role of Progesterone in Breast Cancer Progression

http://pharmaceuticalintelligence.com/2013/06/25/role-of-progesterone-in-breast-cancer-progression/

All articles on Breast Cancer in the Journal

http://pharmaceuticalintelligence.com/?s=Breast+Cancer