Measurement of Natural Killer Cell Activity in Whole Blood in Men Being Screened for Prostate Cancer With Biopsy

Inclusion Criteria:

1. Male aged ≥ 18 years old
2. Able to read and sign an approved informed consent form
3. Soon to be undergoing a needle prostate biopsy for suspected prostate cancer; patients with a history of prior biopsy are not excluded provided the biopsy was negative
4. All prior and current recorded PSA levels are \< 11 ng/mL (minimum of 2 values must be available)
5. Digital Rectal Exam performed or scheduled to be performed prior to biopsy

Exclusion Criteria:

1. Any other established malignancy with the exception of basal cell carcinoma
2. At time of blood collection, an active infection (eg bacterial, viral etc.) as declared by the patient
3. Chronic inflammatory condition requiring anti-inflammatory treatment such as rheumatoid arthritis, Crohn's or ulcerative colitis, Lupus or any connective tissue condition which, in the opinion of the investigator, might affect the immune response
4. Presently taking any of the following classes of medications on a regular basis:

   * 5-alpha reductase inhibitors
   * Anti-inflammatories, with the exception of low dose (81 mg) acetylsalicylic acid
   * Anti-androgens
   * Testosterone replacement therapy