Vitolins, M.Z., Griffin, L., Tomlinson, W.V., Vuky, J., Adams, P.T., Moose, D., . . . Shaw, E.G. (2013). Randomized trial to assess the impact of venlafaxine and soy protein on hot flashes and quality of life in men with prostate cancer. Journal of Clinical Oncology, 31, 4092–4098.  

To determine the effectiveness of venlafaxine, soy, and a combination of venlafaxine and soy on hot flashes in men with prostate cancer

Participants randomly were assigned to one of four groups: daily placebo pill in the morning plus daily milk powder (20 g per day); daily venlafaxine (75 mg) in the morning plus daily milk powder (20 g per day); daily placebo pill in the morning plus daily soy powder (20 g with 160 mg isoflavones); or daily venlafaxine (75 mg) in the morning plus daily soy powder (20 g with 160 mg isoflavones). Venlafaxine was provided in extended-release capsules. Prior to enrollment, participants completed a seven-day prescreening period. The intervention was administered for 12 weeks. Patients kept a daily log of medications and were contacted via phone at week 2, 4, 8, and 12 to assess toxicities and complete study measures. Patients on venlafaxine were titrated off medication after the end of the study.

• N = 119
• MEAN AGE = 68.5 years
• AGE RANGE = 46–91 years
• MALES: 100%
• KEY DISEASE CHARACTERISTICS: Prostate cancer

• SITE: Single site    
• SETTING TYPE: Outpatient    
• LOCATION: United States

PHASE OF CARE: Late effects and survivorship

• RCT, double-blind, placebo-controlled, 2 x 2 factorial design

• Daily count of hot flashes
• Hot Flash Symptom Severity Score (HFSSS)
• Functional Assessment of Cancer Therapy-Prostate (FACT-P)
• Body mass index (BMI)

There was no significant difference in sample characteristics between the four groups including severity of disease, BMI, performance status, and type of treatment. Vasomotor symptoms decreased in all arms (p < 0.001). No differences existed between treatment arms at baseline and 4, 8, or 12 weeks. The severity of hot flashes decreased in all arms (p < 0.001). All four arms showed a decrease in the HFSSS (p < 0.001). Toxicities did not differ between groups and were mild. The study was ended by the Data Safety Monitoring Board due to a lack of effect. The placebo group had the largest decrease in HFSSS scores (55%).

In men with prostate cancer, venlafaxine, soy, and a combination of the two were no more effective than a placebo at decreasing the number and severity of hot flashes.

Venlafaxine, soy, and a combination of both are not effective at treating hot flashes in men with prostate cancer.