To estimate the contribution of the prostate gland and prostatic urethral inflammation to urinary symptoms after radiation therapy for prostate cancer, we performed a secondary analysis of urinary toxicity after primary radiation to an intact prostate vs. postprostatectomy radiation to the prostatic fossa in protocols RTOG 94-08 and 96-01, respectively.
Patients randomized to the radiation-alone arms (without hormone therapy) of the 2 trials were evaluated, including 104 men receiving primary prostate radiation to 68.4Gy on RTOG 94-08 and 371 men receiving 64.8Gy to the prostatic fossa on RTOG 96-01. Acute and late urinary toxicity were scored prospectively by RTOG scales. Chi-square test/logistic regression and cumulative incidence approach/Fine-Gray regression model were used for analyses of acute and late toxicity, respectively.
Grade≥2 acute urinary toxicity was significantly higher after primary prostatic radiation compared with postprostatectomy radiation (30.8% vs. 14.0%; P<0.001), but acute grade≥3 toxicity did not differ (3.8% vs. 2.7%; P = 0.54). After adjusting for age, primary radiation resulted in significantly higher grade≥2 acute urinary toxicity (odds ratio = 3.72; 95% CI: 1.65-8.37; P = 0.02). With median follow-up of 7.1 years, late urinary toxicity was not significantly different with primary vs. postprostatectomy radiation (5-year grade≥2: 16.7% vs. 18.3%; P = 0.65; grade≥3: 6.0% vs. 3.3%; P = 0.24).
Primary radiation to an intact prostate resulted in higher grade≥2 acute urinary toxicity than radiation to the prostatic fossa, with no difference in late urinary toxicity. Thus, a proportion of acute urinary toxicity in men with an intact prostate may be attributable to inflammation of the prostatic gland or urethra.
Urologic oncology. 2016 Jul 02 [Epub ahead of print]
Raymond H Mak, Daniel Hunt, Jason A Efstathiou, Niall M Heney, Christopher U Jones, Himu R Lukka, Jean-Paul Bahary, Malti Patel, Alexander Balogh, Abdenour Nabid, Mark H Leibenhaut, Daniel A Hamstra, Kevin S Roof, Robert Jeffrey Lee, Elizabeth M Gore, Howard M Sandler, William U Shipley
Harvard Radiation Oncology Program, Dana Farber/Brigham and Women׳s/Cancer Center, Boston, MA., NRG Oncology Statistics and Data Management Center, Philadelphia, PA., Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA., Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, MA., Sutter Cancer Research Consortium, Roseville, CA., Division of Radiation Oncology, Juravinski Cancer Centre, Hamilton Health Sciences, Hamilton, Ontario, Canada., Department of Radiation Oncology, CHUM-Hospital Notre-Dame, Montreal, Québec, Canada., Division of Radiation Oncology, Juravinski Cancer Centre, Hamilton Health Sciences, Hamilton, Ontario, Canada., Division of Radiation Oncology, Tom Baker Cancer Centre, Calgary, Alberta, Canada., Department of Nuclear Medicine and Radiobiology, Centre Hospitalier Universitaire de Sherbrooke-Fleurimont, Sherbrooke, Québec, Canada., Sutter Cancer Research Consortium, Roseville, CA., Department of Radiation Oncology, University of Michigan Health System-Cancer Center, Ann Arbor, MI., Southeast Cancer Control Consortium, Inc., CCOP, Winston-Salem, NC., Intermountain Medical Center, Murray, UT., Department of Radiation Oncology, Froedtert and the Medical College of Wisconsin, Milwaukee, WI., Department of Radiation Oncology, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA., Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA. Electronic address: .