Assess Gamma H2AX Positivity in Circulating Prostate Cancer Cells Before and After Radium 223

This is a prospective biomarker study on prostate cancer patients receiving Radium 223 as standard of care.

Participants will take part in this research study because they have chosen Radium 223 treatment for their prostate cancer that has spread to the bone and causing pain. Investigators want to find out if a blood test performed before and after the Radium 223 treatment will help to understand how prostate cancer cells react to this therapy.

In this pilot study, researchers want to find out if Radium 223 given as part of standard treatment for prostate cancer can decrease the number of circulating prostate cancer cells. Radium 223 kills prostate cancer cells by damaging their DNA. Other than looking at the changes in the number of circulating prostate cancer cells before and after Radium 223, researchers would also like to look at the changes in a DNA damage marker, called gamma H2AX, in the circulating prostate cancer cells before and after treatment with Radium 223. Assessing the DNA damage marker gamma H2AX is investigational. It is performed in the same tube of blood that is used for assessing the changes in the number of circulating prostate cancer cells.

In this pilot study, researchers want to find out if Radium 223 given as part of standard treatment for prostate cancer can decrease the number of circulating prostate cancer cells. Radium 223 kills prostate cancer cells by damaging their DNA. Other than looking at the changes in the number of circulating prostate cancer cells before and after Radium 223, researchers would also like to look at the changes in a DNA damage marker, called gamma H2AX, in the circulating prostate cancer cells before and after treatment with Radium 223. Assessing the DNA damage marker gamma H2AX is investigational. It is performed in the same tube of blood that is used for assessing the changes in the number of circulating prostate cancer cells.

Eligibility Criteria:
Inclusion Criteria:

* Male patients 18 years or older
* Histologically or cytologically confirmed adenocarcinoma of the prostate
* Receiving radium 223 as standard of care for symptomatic metastatic castration resistant prostate cancer to the bone as documented by bone scan or Sodium Fluoride positron emission tomography (PET) bone scan.
* No evidence of visceral metastasis
* Prior surgical castration or concurrent use of GnRH analogue (i.e., medical castration) with testosterone at screening \<50 ng/dL.
* Eastern Cooperative Oncology Group (ECOG) performance status 0 -2, ECOG 3 is allowed if due to pain
* Adequate organ function: Serum alanine aminotransferase (ALT) or aspirate aminotransferase (AST) must be \< 2.5 x upper limit of normal (ULN); Total bilirubin \< 1.5 s ULN; Estimated creatinine clearance must be \>40 mL/min; Absolute neutrophil count (ANC) \> 1500/l; Hemoglobin above 10 g/dl; platelet count \> 100,000/l.
* Stable medical condition, including the absence of acute exacerbations of chronic illnesses, serious infections or major surgery within 28 days prior to study enrollment
* Life expectancy of 6 months or more
* Must agree to practice effective barrier contraception during the entire study treatment period \& through for 6 months after the last dose of study drug, or agree to completely abstain from heterosexual intercourse
* Able to give written informed consent
* Have at least 2 CTCs at baseline

Exclusion Criteria:

* Exposure to radioisotope therapy (samarium 153, strontium 89) within 24 weeks or exposure to external beam radiation within 12 weeks of receiving the first dose of Radium 223
* Documented central nervous system metastases, has a history of seizure, stroke or transient ischemic attack (TIA)
* Treatment with any investigational compound within 30 days prior to the first dose of study drugs
* Diagnosis or treatment for another systemic malignancy within 2 years before the first dose of study drugs, or previously diagnosed with another malignancy \& have any evidence of residual disease. Patients with non-melanoma skin cancer or carcinoma in situ of any type are not excluded if they have undergone complete resection.
* New York Association Class III or IV heart failure
* Known human immunodeficiency virus (HIV) infection, active chronic hepatitis B or C, life threatening illness unrelated to cancer, or any serious medical or psychiatric illness that could, in investigators opinion, potentially interfere with participation in this study.
* Potential participants with delayed healing of wounds, ulcers, and/or bone fractures
* Inability to comply with protocol requirements