CAPS2: Carbohydrate Restriction and Prostate Cancer Growth

Study Details

Study Description

Brief Summary

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.

Condition or Disease	Intervention/Treatment	Phase
Prostate Cancer	Behavioral: Low carbohydrate diet	N/A

Study Design

Study Type:

Interventional

Actual Enrollment :

83 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Single (Outcomes Assessor)

Primary Purpose:

Treatment

Official Title:

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

Actual Study Start Date :

Dec 16, 2013

Actual Primary Completion Date :

Aug 20, 2018

Actual Study Completion Date :

Aug 20, 2018

Arms and Interventions

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

Arm

Intervention/Treatment

Active Comparator: Low carbohydrate, lifestyle counseling

The Low carbohydrate arm will receive counseling to follow a carbohydrate restriction diet (<20 grams per day) for 6 months.

Behavioral: Low carbohydrate diet

The Low carbohydrate diet intervention recommends patients to limit carbohydrate intake to less than 20 gram per day.

No Intervention: Control

The control arm will receive no dietary intervention.

Outcome Measures

Primary Outcome Measures

PSA doubling time (change in PSA over time) [Baseline, 3 and 6 months]
PSA doubling time will be estimated from PSA measured at baseline, 3 and 6 months post randomization.

Eligibility Criteria

Criteria

Ages Eligible for Study:

20 Years and Older

Sexes Eligible for Study:

Male

Accepts Healthy Volunteers:

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

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Cedars-Sinai Medical Center	Los Angeles	California	United States	90048
2	Duke University Medical Center	Durham	North Carolina	United States	27702
3	Durham VA Medical Center	Durham	North Carolina	United States	27705