In the January 7, 2009 issue of the Journal of the American Medical Association, Dr. Scott Lippman and associates presented the results of the Selenium and Vitamin E Cancer Prevention Trial (SELECT). This is a phase 3 randomized, prospective, placebo controlled trial evaluating 4 arms; placebo, selenium (200μg/day), vitamin E (400IU/day), or both for prostate cancer (prostate cancer) prevention. The trial rationale was based on the observation that these compounds tested for chemoprevention in other trials suggested benefit. Surprisingly, SELECT was stopped early as no benefit was demonstrated on interim analysis.

The plan was for a minimum of 7 years of treatment and it included men age 50 years or older for African Americans and age 55 years or older for all other races. Men were without a diagnosis of prostate cancer, had a PSA <4ng/ml and a digital rectal examination not suspicious for prostate cancer.

SELECT was activated in 2001 and participants had office visits every 6 months. The primary end point was prostate cancer incidence as determined by routine clinical management. Guidelines for PSA screening were not enforced, as PSA screening was controversial at the time of study design. The trial design was intent-to-treat.

A total of 35,533 men were accrued and randomly assigned at 427 centers in the US. Important risk factors were well-balanced among the groups and median overall follow-up was 5.46 years. Adherence to both study agents averaged 65% at 5 years. In September, 2008 the independent data and safety monitoring committee met and reviewed data for interim analysis. They recommended study discontinuation as there was no evidence of benefit from either study agent and no possibility of a benefit to the planned degree with additional follow-up. The 5-year incidence of prostate cancer in the 4 groups was; placebo 4.43%, selenium 4.56%, vitamin E 4.93%, and both agents 4.56%. There was a concern over the statistically non-significant increase in prostate cancer in the vitamin E alone group and a non-significant increase in diabetes mellitus associated with selenium. The study agents had no significant effects on the overall incidence of cardiovascular events.

Lippman SM, Klein EA, Goodman PJ, Lucia MS, Thompson IM, Ford LG, Parnes HL, Minasian LM, Gaziano JM, Hartline JA, Parsons JK, Bearden JD 3rd, Crawford ED, Goodman GE, Claudio J, Winquist E, Cook ED, Karp DD, Walther P, Lieber MM, Kristal AR, Darke AK, Arnold KB, Ganz PA, Santella RM, Albanes D, Taylor PR, Probstfield JL, Jagpal TJ, Crowley JJ, Meyskens FL Jr, Baker LH, Coltman CA Jr

Source: UroToday