Study to Detect Changes in Urinary and Gut Microbiome During Androgen Deprivation Therapy and Radiation Therapy in Patients With Prostate Cancer

Pilot Study to Describe Changes in Urinary and Gut Microbiome During Androgen Deprivation and Radiation Therapy for Prostate Cancer

This study collects urine and stool samples to determine the ability to identify changes in the microbiome (bacteria, fungi, and viruses that live in the gut and urine) of patients with prostate cancer during androgen deprivation therapy and radiation therapy. Radiation therapy has the potential to harm the genitourinary area or the bowel, causing a feeling of urgency or increased inflammation in the area. The radiation therapy is designed to not irradiate the bowel and bladder areas, but there is still some radiation exposure. The gut microbiome has been associated with differences in inflammation as well as producing molecules that influence healing. The purpose of this study is to see whether the microbiome may contribute to the healing of the organs exposed to radiation. Information learned from this study may help researchers discover a new risk factor that could be manipulated to improve the quality of life in patients with prostate cancer.

PRIMARY OBJECTIVE:

I. To determine the feasibility of identifying changes in urine and gut microbiomes during androgen deprivation therapy and radiation therapy for prostate cancer.

SECONDARY OBJECTIVE:

I. To explore associations between baseline microbiomes and urinary or gastrointestinal radiation toxicity by Common Terminology Criteria for Adverse Events (CTCAE) and Patient Reported Outcomes (PRO).

OUTLINE:

Patients undergo collection of stool and urine samples within 2 weeks before hormone therapy or radiation therapy, after hormone therapy but before start of radiation therapy, and after completion of radiation therapy. Patients also complete a series of questionnaires prior to starting radiation therapy, mid-way through radiation therapy, and after completion of radiation therapy (within 1-3 weeks, at 3 months, and then every 6 months until 3 years from radiation completion). Patients' medical records are also reviewed.

Inclusion Criteria:

• Pathologically confirmed prostate cancer, with a plan to receive radiation therapy for either definitive (cohort A) or salvage (cohort B) therapy. Patients without planned androgen deprivation therapy (ADT) will be accrued to cohort C

  • Cohort A will be restricted to Gleason grade group 3 or higher (4+3 or 8-10) so that androgen deprivation will be indicated
  • Cohort B will not be restricted by Gleason grade but will require rising prostate-specific antigen (PSA) and a plan for ADT with salvage radiation
  • Cohort C will be prostate cancer patients in whom definitive or salvage radiation is planned without ADT

• Patients must be age 18 or older

• Willing to provide urine and stool samples at specified time points

Exclusion Criteria:

• Men with inflammatory bowel disease or pre-existing cystitis will be excluded