Case: Testicular oligometastasis from prostate cancer — Report of rare isolated recurrence after radiotherapy and intermittent androgen-deprivation therapy

Abstract

Testicular oligometastasis secondary to prostate cancer is rare. We present a case where a patient with locally advanced prostate cancer was treated with high-dose external beam radiotherapy and two years of androgen-deprivation therapy, followed by intermittent androgen suppression. Three and a half years after initial diagnosis, he was found to have a painless testicular mass. Orchiectomy was performed and histopathology demonstrated metastatic prostatic adenocarcinoma. He remains in clinical remission on intermittent androgen suppression eight years following initial treatment, and over four years after presentation with testicular metastasis. CaseA 61-year-old Caucasian male presented to his family physician for urinary frequency and nocturia in 2008. He denied gross hematuria, dysuria, or any changes in stool or bowel function. Serum prostate-specific antigen (PSA) level was 20.3 ng/mL, which led to a prostate biopsy. Histopathology showed adenocarcinoma with a Gleason score of 4+5 (9/ 10) involving 80% of the tissue submitted. There was no extraprostatic, perineural, lymphatic, or vascular spread. A computed tomography (CT) scan of the abdomen and pelvis was performed for staging and showed left obturator lymphadenopathy, without evidence of distant metastasis. Excisional biopsy confirmed the presence of metastatic prostate carcinoma in this obturator node. On examination, he had a markedly enlarged prostate in keeping with a T3a lesion. Therefore, his prostate cancer was staged as T3a N1 M0.He commenced androgen deprivation therapy (ADT) with an anti-androgen agent followed by luteinizing hormone-releasing hormone (LHRH) agonist in 2008, followed by a course of external beam radiation therapy delivered with a dose of 7000 cGy in 35 fractions. His PSA nadir in 2009 was 0.1 ng/mL. After 2 years of ADT, he opted for intermittent androgen