Flutamide in Treating Patients with Prostate Cancer on Androgen Suppression Undergoing Brachytherapy

Inclusion Criteria

• Histologically confirmed, localized (M0) adenocarcinoma of the prostate.
• Clinical stages T1c – T3b, Mx or M0.
• At least one biopsy core with Gleason 7 or higher disease.
• The patient has decided to undergo brachytherapy plus androgen suppression as treatment modality for his prostate cancer (with or without supplemental external beam radiation).
• Suitable volume of disease for biopsy, defined as one or more of the following: * Magnetic resonance imaging (MRI) scan of the pelvis with >= 1 identifiable lesion as being Prostate Imaging Reporting and Data System (PI‐RADS) 4 or 5, plus minimum of at least 0.5 cm in any dimension OR * Clinically palpable disease corresponding to (ipsilateral to) any involved core on biopsy.
• Signed study‐specific consent form prior to registration.

Exclusion Criteria

• Known hypersensitivity or allergic response to flutamide.
• Severe hepatic impairment (serum alanine aminotransferase [ALT] level > 2 x normal or serum aspartate aminotransferase [AST] level > 2 x normal).
• Pre-existing diagnosis of hypogonadism (serum total testosterone < 150 ng/dL) prior to starting hormone therapy for prostate cancer, or treatment with testosterone supplementation therapy within 12 months prior to enrollment.
• Major medical or psychiatric illness which, in the investigator’s opinion, would prevent completion of treatment and would interfere with follow up.