Clinical Characteristics of Gleason Score 10 Prostate Cancer on Core Biopsy without Distant Metastases at Initial Diagnosis

  Objective  To analyze the clinical characteristics of patients with Gleason score 10 prostate cancer on core biopsy and without distant metastases when first diagnosed, and to evaluate the effectiveness of external radiotherapy combined with hormone therapy in these patients.

  Methods  From January 2003 to March 2014, 9 patients were identified as Gleason score 10 prostate cancer without distant metastases when first diagnosed at Peking Union Medical College Hospital. All the patients were treated by whole pelvic external radiotherapy and long-term hormone therapy. The whole pelvic radiation dose was 50.0 Gy, the boost dose for the whole prostate, bilateral seminal vesicles, and regional positive lymph nodes ranged from 76.2 to 78.0 Gy. The hormone therapy used maximal androgen blockade, i.e. oral anti-androgen drugs plus monthly injection of luteinizing hormone-releasing hormone analogs. We assessed the clinical characteristics of the patients and the treatment outcomes of the combination therapy. Survival curves were calculated using the Kaplan-Meier method.

  Results  The median follow-up was 4.8 years (26-75 months). The median pre-treatment serum prostate specific antigen (PSA) level was 11.2 μg/L. The pre-treatment PSA levels were lower than 20 μg/L in 6 patients, and higher than 70 μg/L in 3 patients. The median percentage of positive biopsy cores was 90.9%. In TNM staging, 3, 4, and 2 cases were classified as T_2c, T_3a, and T_3b, respectively; 6 and 3 cases were classified as N₀ and N₁, respectively; and all the 9 cases were classified as M₀. Six patients developed biochemical failure, 5 of which progressed into distant metastasis. Four patients died during the follow-up period, 3 of which died of prostate cancer. The 5-year biochemical failure-free survival (BFFS), distant metastasis-free survival (DMFS), cancer-specific survival (CSS), and overall survival (OS) were 28.6%, 57.1%, 66.7%, and 57.1%, respectively. Five patients experienced grade 1-2 acute gastrointestinal (GI) toxicity and 6 patients developed grade 1-2 acute genitourinary (GU) toxicity due to radiotherapy. No late GI or GU toxicity was reported. No bone fracture, cardiovascular event, or other severe hormone therapy-related complications was detected.

  Conclusions  Gleason score 10 prostate cancer without distant metastases when first diagnosed may be often combined with high risk factors such as high percentage of positive biopsy cores, and advanced tumor stage. Timely and active comprehensive treatments including external radiotherapy and hormone therapy are usually necessary because these patients generally have unfavorable prognosis.