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Favorable 10‐year outcomes of image‐guided intensity‐modulated radiotherapy combined with long‐term androgen deprivation for Japanese patients with nonmetastatic prostate cancer
Author(s) -
Tomita Natsuo,
Soga Norihito,
Ogura Yuji,
Furusawa Jun,
Tanaka Hiroshi,
Koide Yutaro,
Tachibana Hiroyuki,
Kodira Takeshi
Publication year - 2019
Publication title -
asia‐pacific journal of clinical oncology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.73
H-Index - 29
eISSN - 1743-7563
pISSN - 1743-7555
DOI - 10.1111/ajco.13097
Subject(s) - medicine , prostate cancer , androgen deprivation therapy , radiation therapy , urology , genitourinary system , oncology , cancer , cumulative incidence , prostate , retrospective cohort study , gastroenterology , cohort
Aim To investigate 10‐year outcomes of high‐dose image‐guided intensity‐modulated radiation therapy (IG‐IMRT) combined with long‐term androgen deprivation therapy (ADT) for Japanese patients with nonmetastatic prostate cancer. Methods A retrospective analysis was performed on 208 Japanese patients with T1–4N0M0 prostate cancer, who underwent definitive IG‐IMRT from 2006 to 2010 at our single institution. The median dose was 78 Gy (74–78) and median ADT time was 32 months (6–151). The risk stratification followed the National Comprehensive Cancer Network criteria. A biochemical relapse was defined as nadir plus 2.0 ng/mL. Toxicity was scored with the Radiation Therapy Oncology Group morbidity scale. Results The median follow‐up time was 102 months. For low‐, intermediate‐, high‐, and very‐high‐risk groups, the 10‐year biochemical disease‐free survival rates were 100%, 84%, 90%, and 72%, respectively ( P = 0.008); clinical relapse‐free survival rates were 100%, 100%, 100%, and 81%, respectively ( P < 0.001); and cancer‐specific survival rates were 100%, 100%, 100%, and 89%, respectively ( P = 0.13). The independent prognostic factors influencing biochemical relapse were younger age, Gleason score ≥ 8, and radiation dose < 78 Gy in the multivariate analysis ( P = 0.006, 0.014, and 0.013). The 10‐year cumulative incidence of late grade 2 or higher gastrointestinal and genitourinary toxicities were 12% and 13%, respectively. No events of grade 4 or 5 were observed. Conclusions This study suggest that high‐dose IG‐IMRT combined with long‐term ADT is effective and implementable, leading to excellent 10‐year outcomes for Japanese patients with nonmetastatic prostate cancer.