Carbohydrate Restriction and Prostate Cancer Growth

Study Overview
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Brief Summary
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No treatments have been shown to slow prostate cancer progression after radical prostatectomy. We hypothesize that a carbohydrate restricted diet will slow prostate cancer growth. A total of 60 men with a rising prostate-specific antigen (PSA) after failed primary treatment will be recruited and randomized to either a low-carbohydrate diet (<20 grams carbohydrates/day) or a no-diet control (standard of care) for 6 months. The primary outcome is PSA doubling time.

Official Title
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A Randomized Controlled Clinical Trial of Carbohydrate Restriction Among Men With A Rising PSA After Failed Primary Therapy for Prostate Cancer

Conditions
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Prostate Cancer

Intervention / Treatment
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* Behavioral: Low carbohydrate diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Received prior radical prostatectomy or definitive local radiation for prostate cancer (either external beam radiation, brachytherapy, or combination) PSA within the past 3 months is between 0.4 and 20 if prior radical prostatectomy, or between 3 and 20 ng/ml if prior radiation therapy. PSA doubling time (PSADT) >3 months and <36 months Calculated based at least 2 values (at least 0.2) in the prior 2 years with the first and last PSA separated by at least 3 months Use all values in the last 2 years to calculate PSADT PSADT calculated while NOT on androgen deprivation therapy (ADT). If prior ADT use, then documented either A) normal testosterone or B) a testosterone within 50 points of normal and stable (defined as a second testosterone at least 6 weeks later that is equal or lower than the first testosterone) is required before starting to calculate PSADT. BMI >=24 kg/m2 Willing to be randomized to a no-diet control or a low-carbohydrate diet Reads, writes, and understands English Exclusion Criteria: Anticipate needing secondary prostate cancer therapy within the next 6 months (i.e. radiation, or hormonal therapy) Current use of weight loss medications including herbal weight loss supplements or enrolled in a diet/weight loss program Currently on therapy aimed at lowering testosterone levels (includes gonadotropin-releasing hormone (GnRH) agonist/antagonist, prior bilateral orchiectomy, oral anti-androgens, or 5-alpha reductase inhibitors). Testosterone replacement is allowed but treatment should be stable during the entire study. Known distant metastatic disease Already consuming a carbohydrate-restricted or vegetarian diet Unable or unwilling to adhere to a carbohydrate-restricted dietary intervention Weight loss >5% of body weight in the last 6 months Medical comorbidities that in the opinion of the investigator limits the patient's ability to complete this study

Ages Eligible for Study
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Minimum Age: 20 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Low carbohydrate, lifestyle counseling<br>The Low carbohydrate arm will receive counseling to follow a carbohydrate restriction diet (<20 grams per day) for 6 months. | Behavioral: Low carbohydrate diet<br>* The Low carbohydrate diet intervention recommends patients to limit carbohydrate intake to less than 20 gram per day.<br>|
| No Intervention: Control<br>The control arm will receive no dietary intervention. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PSA doubling time (change in PSA over time) | PSA doubling time will be estimated from PSA measured at baseline, 3 and 6 months post randomization. | Baseline, 3 and 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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diet, prostate cancer, carbohydrate, lifestyle