This research trial studies molecular characterization of circulating tumor cells (CTCs) and
circulating tumor (ct) deoxyribonucleic acid (DNA) in blood and plasma samples from patients
with prostate cancer that has spread to other places in the body and/or has not responded to
previous treatment with hormones. Studying samples of blood and plasma collected from
patients with prostate cancer before, during, and/or after treatment in the laboratory may
help doctors learn more about changes that occur in DNA and identify the development of drug
I. Perform molecular analysis of plasma samples from 25 patients with metastatic prostate
cancer collected before and during treatment of the disease with abiraterone acetate
(Zytiga) or enzalutamide (Xtandi).
II. Perform molecular characterization of circulating tumor cells (CTCs) and plasma
collected from 75 patients with progressing advanced metastatic prostate cancer.
OUTLINE: Patients are assigned to 1 of 2 groups based on the timing of specimen collection.
GROUP I: Previously collected plasma samples are analyzed for ctDNA via polymerase chain
reaction (PCR) and next generation sequencing (NSG).
GROUP II: Patients undergo collection of blood samples before and following systemic therapy
for analysis of CTC enumeration, ribonucleic acid (RNA) expression, and ctDNA via PCR and
- GROUP I: Samples for Group I will be selected from existing sample sets obtained from
concluded studies (USC IRB #'s 10-00006 and 11-00450)
- GROUP I: Excess plasma collected and stored in these trials from patients treated
with abiraterone or enzalutamide will be used for the molecular analysis of the
- GROUP II: The second group of samples (Group 2) will involve prospective collection
of peripheral blood from patients with advanced, treatment-resistant metastatic
- GROUP II: Histologic documentation of prostate cancer
- GROUP II: Metastatic cancer diagnosed by imaging and other clinical criteria
- GROUP II: Treatment-resistance determined by at least one of the following factors:
increase in prostate-specific antigen (PSA) value over a baseline measurement;
increase in size or number of metastatic deposits determined on imaging; and/or
progression in cancer related symptoms