A Phase II Trial of a Soy Beverage for Subjects Without Clinical Disease With Rising Prostate-Specific Antigen After Radical Radiation for Prostate Cancer.
- Resource Type
- Article
- Authors
- Kwan, Winkle; Duncan, Graeme; Van Patten, Cheri; Liu, Mitchell; Lim, Jan
- Source
- Nutrition & Cancer. Feb/Mar2010, Vol. 62 Issue 2, p198-207. 10p. 6 Charts.
- Subject
- *PROSTATE cancer
*CANCER patients
*RADIOTHERAPY
*SOYMILK
*PROSTATE-specific antigen
- Language
- ISSN
- 0163-5581
Our objective was to evaluate the tolerability and effect of a daily soy beverage in prostate cancer patients with biochemical failure after radiotherapy. Patients with rising prostate-specific antigen (PSA) after radical radiation for prostate cancer were instructed to consume 500 ml of soy beverage daily for 6 mo. Tolerability of the soy beverage and compliance were assessed. PSA doubling times before and after the consumption of soy were compared. Thirty-four subjects were enrolled; 5 withdrew before 1 mo of soy for reasons unrelated to soy consumption. All remaining 29 subjects were included in the analysis. Mean consumption of the assigned soy beverage was 93%. Mild gastrointestinal upset (38%) not affecting soy consumption was the commonest side effect. PSA showed a declining trend in 4 patients (13.8%), and there was a > 100% prolongation of PSA doubling time in 8 patients (27.6%). However, PSA doubling time also showed a 50% or more shortening in 5 patients (17.2%). In our cohort of North American subjects, 6 mo of a daily soy beverage was well tolerated and was associated with a declining trend or more than 2 times prolongation of PSA doubling time in 41% of subjects. Confirmatory studies are warranted. [ABSTRACT FROM AUTHOR]