Finasteride - Generic Propecia

Correspondence: The phase 1 trials of finasteride (Propecia/Proscar; Merck) have shown that finasteride at 1 mg (Propecia) as well as finasteride at 5 mg (Proscar) blocks 5a-reductase.

The genetic, biochemical, epidemiological, experimental, and clinical reasons for my warning [1, 2] 3 years ago that use of finasteride promotes prostate cancer have been confirmed by the findings of a finasteride chemoprevention trial [Prostate Cancer Prevention Trial (PCPT)] involving 18,882 men followed up for 7 years.

The trial was stopped after 9,060 men underwent biopsy during the trial or at the end of 7 years. It was found that ‘finasteride prevents or delays the appearance of prostate cancer’ by 24.6% [fi nasteride, 803/4,368 (18.4%); placebo, 1,147/4,692 (24.4%)] but ‘increased the risk of highgrade prostate cancer’ by 67% [finasteride, 280/757 (37%); placebo, 237/1,068 (22.2%) (p  0.001)] in men diagnosed as having prostate cancer.

At 7 years 52% of the tumors in the finasteride treated men were high grade vs. 31% in the placebo group… If one looks at the positive biopsy rate in the patients with an elevated PSA (prostate-specific antigen) or abnormal digital rectal examination (DRE) (i.e. biopsied ‘for cause’), finasteride only reduced the positive biopsy rate in those patients by 10% (29.5% placebo vs. 26.5% finasteride).

The ‘end of study’ biopsies of the men who did not undergo biopsy during the 7 years (no PSA 4.0 ng/ml, no induration on DRE) showed a 60% increase in high-grade prostate cancer [finasteride, 92/364 (25.3%); placebo, 89/564 (15.8%) (p  0.001)].

Even with intensive screening, high-grade prostate cancer was promoted without warning by finasteride (Propecia). The suggestion by Dr. Peter Scardino in his editorial in the New England Journal of Medicine that young men (35 years old) might have the ‘added benefit of cancer prevention’ is not correct, as these men will have the added risk for promoting high-grade prostate cancer for over 50 years while using finasteride, 1 mg (Propecia, 1 mg).

Principal investigator Ian M. ‘Thompson, MD, also confused the issue of low dose finasteride (Propecia, 1 mg) and high-dose finasteride (Proscar, 5 mg) (Oncology Times, July 25, 2003, and August 10, 2003). The PCPT was stopped in March 2003 because finasteride promoted high-grade (Gleason scores 7, 8, 9, 10) prostate cancer.