A Potential Effective Chemotherapy Does Exist for Men with Untreatable Terminal Advanced Prostate Cancer!

BALTIMORE, Sept. 23, 2019 /PRNewswire-PRWeb/ -- Androgen-independent advanced prostate cancer ("castrate resistant prostate cancer"; CRPC) is a terminal cancer that is the major cause of the 30,000 prostate cancer deaths/year in the U.S., and the 350,000 cancer deaths/year worldwide. An effective chemotherapy that terminates this malignancy has not existed, and these patients will generally have a survival of 5 years or less.

Men who are diagnosed with advanced prostate cancer are likely to search the internet for information about a "treatment for advanced prostate cancer" or "treatment of castrate resistant prostate cancer". Most likely, the various sources of information will seemingly be confusing and/or conflicting. The confusion exists mainly due to the different types of "advanced prostate cancer". The confusion exists for patients, and also medical professionals (including urologists and oncologists). It is essential that this confusion issue be reconciled.

"Androgen–dependent" advanced prostate cancer results from the testosterone-promoted malignancy in the prostate gland, and progressed to metastases. It is generally treated with hormonal androgen ablation, which depletes the production and availability of testosterone in blood plasma. Chemotherapy for inhibition of androgen receptor is often included to prevent the effects of any testosterone that might be available in plasma. The treatment suppresses and attenuates the androgen-dependent malignancy that resides in the prostate gland and also metastatic sites. However, this leads to the development and progression of "androgen-independent" malignancy; which is the malignancy of terminal advanced prostate cancer, for which no treatment has been available.

Therefore, the important issue has been, "what causes the manifestation of androgen-independent malignancy?" The resolution of that issue is required to identify potential targets for its chemotherapy. A PubMed search of "treatment for androgen independent prostate cancer" reveals 3782 citations since 1984. A PubMed search for "androgen receptor and androgen independent prostate cancer" reveals 2330 citations since 1984. Thus, 62% of the citations since 2018 have focused on androgen receptor as a target for treatment of androgen-independent prostate cancer. This demonstrates that dysfunctional androgen receptor has been and continues to be considered the major factor in the development of androgen-independent advanced prostate cancer; and has been the dominant focus for the search of effective chemotherapy. However, the decades of the investment of time and resources have failed to provide an effective chemotherapy for terminal advanced prostate cancer. This is compelling evidence that "androgen receptor is not a major factor in the manifestation of androgen-independent malignancy!"

Normal and malignant prostate cells are regulated by testosterone and by prolactin. Testosterone provides the "primary" regulation, and prolactin regulation is manifested when testosterone is not available. That relationship exists following androgen ablation; so that terminal androgen-independent advanced prostate cancer develops and progresses as "prolactin-dependent" advanced prostate cancer. Consequently, an effective chemotherapy for terminal advanced prostate cancer is best achieved by the suppression of plasma prolactin concentration. This was verified in a patient with expected survival of 21 months, and was treated with cabergoline (inhibitor of pituitary production of prolactin). Cabergoline treatment decreased the plasma prolactin concentration 88%; and terminated the androgen-independent advanced prostate cancer. That might be the first reported case of a successful treatment for terminal advanced prostate cancer.

Unfortunately, many urologists and oncologists do not recognize or have elected to ignore the compelling evidence of the major role of prolactin in the development and treatment of terminal advanced prostate cancer. For example, in two recent review articles containing 502 cited references relating to androgen-independent advanced prostate cancer, there was no mention of prolactin.

The consequences of the disregard of the importance of prolactin are that: the search for an efficacious chemotherapy targeted at androgen receptor will continue, and will most likely fail; the successful treatment with cabergoline will not be applied to other terminal advanced prostate cancer patients; and the deaths due to untreatable terminal advanced prostate cancer will continue. It is now important for the medical community to inform the public that "untreatable" advanced prostate cancer can be terminated by a treatment such as cabergoline, which will suppress the level of prolactin in blood.

The cited case report: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6578577/pdf/nihms-1019063.pdf.

This press release was prepared by LC Costello, PhD. and RB Franklin, PhD. Department of Oncology and Diagnostic Sciences; School of Dentistry; University of Maryland, Baltimore.

SOURCE University of Maryland, Baltimore