Prostate Cancer

Prostate cancer (click on a topic)

Introduction

5-alpha-reductase

prostate cancer symptoms

staging of prostate cancer

prostate cancer survival

prostate cancer treatment

prostate cancer prevention

what's new with prostate cancer

Introduction:

Prostate cancer is common. In fact for men above 50 it is the most common cancer in the U.S., where more than 200,000 new prostate cancer patients are diagnosed every year. It is twice as common in black American men than in white American men, but Japanese and Chinese men have 70-fold less cancer of he prostate than the North American men (Ref. 2 and 3). This difference has been studied extensively and likely is due to two factors: a different diet and a lower concentration of the enzyme 5-alpha-reductase in the prostate gland. Let me explain: The Chinese and Japanese diet is rich in cancer protective agents, the North American diet is a high fat diet and is insufficient in unprocessed fruit and vegetables (which is where the cancer protective agents can be found).

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Five-Alpha-Reductase is an enzyme within prostatic tissue and in the hair follicles. In the prostate it metabolizes testosterone into dihydrotestosterone (=DHT). DHT is the "culprit" that is responsible in stimulating the prostate to grow 2-3 times the normal size after the male menopause, which occurs at about the age of 50. This condition of prostate enlargement is called benign prostate hyperplasia or benign prostate hypertrophy (see details under this link). After many years of having an enlarged prostate areas of abnormal cells develop within the enlarged prostate gland and eventually cancer occurs. This pathophysiology explains why the prostate cancer rate is higher in men that are older. Carcinogenesis (=the development of cancer) takes about 25 to 30 years.

The same enzyme (5-alpha-reductase) is present in androgen susceptible hair follicles on the scalp and it converts testosterone to DHT. Too much of this leads to premature hair loss, but fortunately this can now be remedied as described under hair loss.

About 3% of all deaths in men older than 55 years are due to prostate cancer. However, autopsy studies showed that 29% of North American men in their 50's have histological proof of existing prostate cancer and men in their 80's were 67% positive on autopsy. This led to an erroneous concept of distinguishing between "clinically important" versus "clinically unimportant" prostate cancer. This created confusion among the urologists for about 15 to 20 years and there are still urologists and health care providers who hold on to this useless distinction (Ref.1).

Fact is that these males who were proven positive for prostate cancer by autopsy would eventually have succumbed to their occult prostate cancer, had they not died of another disease first. But as the prostate gland is contained in a very tough capsule, the prostate cancer is also contained for a very long time (stage A and B) until the cancer eats its way through and turns into stage C. From here it is only a short step to stage D (distant metastases). Instead of ignoring stage A and B cancer of the prostate and calling it "clinically unimportant" it is better to do a selective radical prostatectomy and get rid of prostate cancer for good. This would give these men at least a chance to live much longer.

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Disclaimer:

This outline is only a teaching aid to patients and should stimulate you to ask the right questions when seeing your doctor. However, the responsibility of treatment stays in the hands of your doctor and you.

References:

The following references were used apart from my own clinical experience:

1. Cancer: Principles &Practice of Oncology, 4th edition, by V.T. De Vita,Jr.,et. al J.B. LippincottCo.,Philadelphia, 1993.Vol.1: Chapter on Prostate cancer.

2. The Merck Manual, 7th edition, by M. H. Beers et al., Whitehouse Station, N.J., 1999.Chapter 233, p.1918-1919.

3. Cancer: Principles&Practice of Oncology. 5th edition, volume 1. Edited by Vincent T.DeVita, Jr. et al. Lippincott-Raven Publ., Philadelphia,PA, 1997. Chapter on prostate cancer.

4. A Waghray et al. Cancer Res 2001 May 15;61(10):4283-4286.

5. BM Fisch et al. Urology 2001 May;57(5):955-959.

6. CC Parker et al. BJU Int 2001 May;87(7):629-637.

7. B Aschhoff Drugs Exp Clin Res 2000;26(5-6):249-252.

Last Modified: Nov. 19, 2006