On May 30, 2023 the leading scientific journal dealing with basic and clinical breast cancer research “Breast Cancer Research (BCR)” published the Perspective Review paper  “Progesterone from ovulatory menstrual cycles is an important cause of breast cancer” by Herjan J.T. Coelingh Bennink, Iman J. Schultz, Marcus Schmidt, V. Craig Jordan, Paula Briggs, Jan F.M. Egberts, Kristina Gemzell-Danielsson, Ludwig Kiesel, Kirsten Kluivers, Jan Krijgh, Tommaso Simoncini, Frank Z. Stanczyk and Robert D. Langer.

The most important message of this narrative review paper is that progesterone from normal menstrual cycles causes most BCs, whereas estrogens and androgens may stimulate existing hormone receptor positive BC, but do not cause BC. Four authors of this paper are related to Pantarhei (HCB, IJS, JFME and JK) and the other nine authors are experts in the field of Reproductive Endocrinology and Oncology, supporting this rather thought-provoking paper, that will hopefully lead to a reappraisal and a turnaround of the medical view and opinion on the cause of breast cancer and change the negative perception of estrogens.

Abstract: Many factors, including reproductive hormones, have been linked to a woman’s risk of developing breast cancer (BC). We reviewed the literature regarding the relationship between ovulatory menstrual cycles (MCs) and BC risk. Physiological variations in the frequency of MCs and interference with MCs through genetic variations, pathological conditions and or pharmaceutical interventions revealed a strong link between BC risk and the lifetime number of MCs. A substantial reduction in BC risk is observed in situations without MCs. In genetic or transgender situations with normal female breasts and estrogens, but no progesterone (P4), the incidence of BC is very low, suggesting an essential role of P4. During the MC, P4 has a strong proliferative effect on normal breast epithelium, whereas estradiol (E2) has only a minimal effect. The origin of BC has been strongly linked to proliferation associated DNA replication errors, and the repeated stimulation of the breast epithelium by P4 with each MC is likely to impact the epithelial mutational burden. Long-lived cells, such as stem cells, present in the breast epithelium, can carry mutations forward for an extended period of time, and studies show that breast tumours tend to take decades to develop before detection. We therefore postulate that P4 is an important factor in a woman’s lifetime risk of developing BC, and that breast tumours arising during hormonal contraception or after menopause, with or without menopausal hormone therapy, are the consequence of the outgrowth of pre-existing neoplastic lesions, eventually stimulated by estrogens and some progestins.

Pantarhei Oncology proudly announces that its paper “Maintaining bone health by estrogen therapy in patients with advanced prostate cancer: a narrative review” “Maintaining bone health by estrogen therapy in patients with advanced prostate cancer: a narrative review” has been published in the journal Endocrine Connections after comprehensive review. This journal is an international peer-reviewed, scientific, open access journal in the field of endocrinology.

In this paper we review the new and safer estrogen therapies, including high dose estetrol (HDE4), to maintain bone mass and prevent fractures in advanced prostate cancer patients treated with androgen deprivation therapy (ADT).

Positive results of E4 co-treatment with androgen deprivation therapy for advanced prostate cancer has been published in European Urology Open Science

Pantarhei Oncology proudly announces that its paper ‘Estetrol Cotreatment of Androgen Deprivation Therapy in Infiltrating or Metastatic, Castration-sensitive Prostate Cancer: A Randomized, Double-blind, Phase II Trial (PCombi)’ has been published in the journal European Urology Open Science after comprehensive review. This journal is an international peer-reviewed, scientific, open access journal in the field of urology.

The research paper reports the results of the PCombi study, a phase II, double-blind, randomised, placebo-controlled, multi-centre study in males recently diagnosed with locally advanced or metastatic prostate cancer, who started ADT treatment with an LHRH agonist. The ADT-treated patients were co-treated for 24-weeks with 40 mg E4 or placebo. The high dose E4 treatment was well-tolerated and no treatment-related cardiovascular adverse events were observed. Patient treated with E4 reported fewer complaints of estrogen deficiency symptoms and better quality of life than patients who received placebo. With E4, 6% of the patients reported hot flushes compared to 55% of patients treated with placebo. Total and free testosterone, prostate-specific antigen (PSA), and follicle-stimulating hormone (FSH) were suppressed more rapid and profound, suggesting enhanced disease control by E4. In addition, bone turnover was substantially reduced in the E4-treated patient implicating a bone-sparing effect. The study results have now been published in European Urology Open Science (EUROS).