This is to prospectively investigate whether the chemopreventive agent, MCS, may favorably alter biomarker expression, whether serum carotenoids levels are associated with biomarkers levels, and whether the alterations of biomarker expression may reflect the cancer risk as shown by cancer incidence at the end of the clinical trial.

Many epidemiological studies have shown that nutrients or elements from tomato or other plants, including lycopene and multi-carotenoids, may reduce the risk of prostate cancer, especially those of lethal cancer. Studies have also shown that multi-carotenoids may reduce serum PSA levels in prostate cancer patients. MCS is a patented, multi-carotenoids-rich, purely botanic agent. The investigators' previous Phase II and III clinical trials (US FDA and TFDA, 600 subjects, studies finished, data in analysis) have shown that there were no MCS-related serious adverse events (SAE). MCS may relieve urinary symptoms in men with BPH and PSA was reduced in men with elevated PSA. So, the investigators are initiating a large multi-center phase II randomized study (MCS-8, N=702) in Taiwan, to study if MCS can reduce the risk of prostate cancer. High risk patients will be assigned to take oral daily 30, 15, and 0 (placebo) mg of MCS (1:1:1). The investigators will compare the cumulative prostate cancer incidence among groups and the change from baseline in serum carotenoids levels.

(MCS-8-TWN-II Clinicaltrials.gov NCT02042807)

Inclusion criteria:

1. Subject of MCS-8 study inclusion criteria of MCS-8 study

1. high-risk subjects of prostate cancer.
2. Male subject with age from 50 to 75 years old.
3. No active urinary tract infection (UTI) or bacterial prostatitis.
4. Subject is able to understand and willing to comply with the study procedures and has signed the informed consent form (ICF).

exclusion criteria of MCS-8 study

1. Subjects' elevated PSA is deemed by the investigators solely to inflammation or infection of the prostate.
2. Subjects who are or will be taking long-term hormonal agents that may affect the normal physiology of sex hormone function.
3. Subjects with a PSA > 10.0 ng/ml.
4. Subjects with a history of prostate cancer.
5. Subjects are currently taking or planning to take oral bile acid sequestrants.
6. Subjects have malabsorption conditions.
7. Subject participated in another investigational agent study in the past 30 days or is planning to do so during the study period.
8. Subjects are considered ineligible for the study as judged by the investigator.
9. Other malignancies except non-melanoma skin cancer.

2. Subject is eligible for MCS-8 study but did not sign up for the MCS-8 study.

Exclusion criteria:

Subject is not able to understand and willing to comply with the study procedures and has not signed the informed consent form (ICF).

Note: (MCS-8-TWN-II Clinicaltrials.gov NCT02042807)

Subjects who are increased risk of prostate cancer