Trial Outcomes & Findings for Role of Soy Supplementation in Prostate Cancer Development (NCT NCT00255125)

NCT ID: NCT00255125

Last Updated: 2019-06-18

Results Overview

Total testosterone (ng/ml) serum levels were measured at the time of enrollment(baseline), after two weeks on soy supplement(time point 1), and just prior to prostatectomy (time point 2). All patients must have completed at least two week of soy supplement or placebo and time point 3 varied depending on date of planned prostatectomy. Results were analyzed and are reported at the two week time period, comparing between patients receiving soy supplement or placebo.

• Recruitment status: COMPLETED
• Study phase: PHASE3
• Target enrollment: 86 participants
• Primary outcome timeframe: Two weeks
• Results posted on: 2019-06-18

Participant Flow

Participant milestones

Measure	Arm Soy Supplement Soy Supplement Soy Supplement: Soy protein supplement will be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).	Arm Placebo Placebo Placebo: Placebo will consist of a capsule without the soy protein added to be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).
Overall Study STARTED	42	44
Overall Study COMPLETED	42	44
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Role of Soy Supplementation in Prostate Cancer Development

Baseline characteristics by cohort

Measure	Arm Soy Supplement n=42 Participants Soy Supplement Soy Supplement: Soy protein supplement will be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).	Arm Placebo n=44 Participants Placebo Placebo: Placebo will consist of a capsule without the soy protein added to be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).	Total n=86 Participants Total of all reporting groups
Age, Continuous	62 Years STANDARD_DEVIATION 12 • n=5 Participants	62 Years STANDARD_DEVIATION 7 • n=7 Participants	62 Years STANDARD_DEVIATION 12 • n=5 Participants
Sex/Gender, Customized Male	42 participants n=5 Participants	44 participants n=7 Participants	86 participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=5 Participants	2 Participants n=7 Participants	3 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	41 Participants n=5 Participants	42 Participants n=7 Participants	83 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=5 Participants	4 Participants n=7 Participants	5 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	3 Participants n=5 Participants	9 Participants n=7 Participants	12 Participants n=5 Participants
Race (NIH/OMB) White	38 Participants n=5 Participants	31 Participants n=7 Participants	69 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Region of Enrollment United States	42 Participants n=5 Participants	44 Participants n=7 Participants	86 Participants n=5 Participants

PRIMARY outcome

Timeframe: Two weeks

Total testosterone (ng/ml) serum levels were measured at the time of enrollment(baseline), after two weeks on soy supplement(time point 1), and just prior to prostatectomy (time point 2). All patients must have completed at least two week of soy supplement or placebo and time point 3 varied depending on date of planned prostatectomy. Results were analyzed and are reported at the two week time period, comparing between patients receiving soy supplement or placebo.

Outcome measures

Measure	Arm Soy Supplement n=42 Participants Soy Supplement Soy Supplement: Soy protein supplement will be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).	Arm Placebo n=44 Participants Placebo Placebo: Placebo will consist of a capsule without the soy protein added to be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).
Effect of Soy Isoflavones on Serum Testosterone Levels.	376 ng/ml Interval 124.0 to 528.0	405 ng/ml Interval 232.0 to 576.0

SECONDARY outcome

Timeframe: Two weeks

Samples of the prostate cancer tissue (paraffin embedded) were sectioned and placed on a glass slide. Using immunohistochemistry and an estrogen receptor antibody, sections were stained and assess to determine the extent of estrogen receptor expression. Patients in the soy supplement arm's samples results were compared to placebo arm results.

Outcome measures

Measure	Arm Soy Supplement n=42 Participants Soy Supplement Soy Supplement: Soy protein supplement will be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).	Arm Placebo n=44 Participants Placebo Placebo: Placebo will consist of a capsule without the soy protein added to be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).
Effect of Soy Isoflavones on Estrogen Receptor Status	130 pg/mL Standard Deviation 58	131 pg/mL Standard Deviation 56

SECONDARY outcome

Timeframe: One year

Population: Data and project staff no longer available to determine results.

Using a tissue microarray targeting the cell cycle, selected fresh prostate cancer samples were evaluated in patients in the soy supplement arm compared to the placebo arm.

Outcome measures

Outcome data not reported

Adverse Events

Arm Soy Supplement

Serious events: 2 serious events

Other events: 9 other events

Deaths: 0 deaths

Arm Placebo

Serious events: 6 serious events

Other events: 4 other events

Deaths: 0 deaths

Serious adverse events

Measure	Arm Soy Supplement n=42 participants at risk Soy Supplement Soy Supplement: Soy protein supplement will be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).	Arm Placebo n=44 participants at risk Placebo Placebo: Placebo will consist of a capsule without the soy protein added to be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).
Gastrointestinal disorders Mild gastrointestinal symptoms	4.8% 2/42 • Number of events 2	13.6% 6/44 • Number of events 6

Other adverse events

Measure	Arm Soy Supplement n=42 participants at risk Soy Supplement Soy Supplement: Soy protein supplement will be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).	Arm Placebo n=44 participants at risk Placebo Placebo: Placebo will consist of a capsule without the soy protein added to be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).
Gastrointestinal disorders GI symptoms	21.4% 9/42 • Number of events 9	9.1% 4/44 • Number of events 4

Additional Information

Dr. Peter Van Veldhuizen

Kansas City VA Medical Center

Phone: 816-861-4700

Email: peter.vanveldhuizen@va.gov

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place