BJUI Compass (Nov 2020)

Potential effectiveness of local radiotherapy for extending survival and reducing symptomatic local events in patients with de novo metastatic prostate cancer

  • Naoki Terada,
  • Takashi Mizowaki,
  • Toshihiro Saito,
  • Akira Yokomizo,
  • Naoki Kohei,
  • Ken‐ichi Tabata,
  • Masaki Shiota,
  • Atsushi Takahashi,
  • Toru Shimazui,
  • Takayuki Goto,
  • Yasuhiro Hashimoto,
  • Masato Fujii,
  • Ryotaro Tomida,
  • Toshihiko Sakurai,
  • Kohei Hashimoto,
  • Sadafumi Kawamura,
  • Shogo Teraoka,
  • Shinichi Sakamoto,
  • Takahiro Kimura,
  • Manabu Kamiyama,
  • Shintaro Narita,
  • Nobumichi Tanaka,
  • Takuma Kato,
  • Masashi Kato,
  • Takahiro Osawa,
  • Takahiro Kojima,
  • Takahiro Inoue,
  • Mikio Sugimoto,
  • Hiroyuki Nishiyama,
  • Toshiyuki Kamoto,
  • Japanese Urological Oncology Group

DOI
https://doi.org/10.1002/bco2.35
Journal volume & issue
Vol. 1, no. 5
pp. 165 – 173

Abstract

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Abstract Objectives To evaluate the association between the use of local radiotherapy (RT) with the survival of patients with de novo metastatic prostate cancer and symptomatic local events (SLEs). Patients and methods Patients were initially diagnosed with metastatic prostate cancer between 2008 and 2017 at 30 institutes in Japan. Prostate‐specific antigen (PSA) progression‐free survival (PSA‐PFS) under initial androgen deprivation therapy and overall survival (OS) was compared between patients receiving local RT (RT group) and no RT (no‐RT group) by multivariate Cox proportional hazard analyses. The occurrence rate of grade ≥2 SLEs was compared by multivariate logistic regression analyses. Propensity score matching (PSM) analyses were performed to compare PSA‐PFS and OS of the groups in the high and low metastatic burden cohort. Results Two hundred and five (7%) of 2829 patients received RT before PSA progression. Median PSA‐PFS and OS were significantly longer in the RT group than in the no‐RT group and the difference was significant in multivariate analyses (HR = 0.44, 95% CI = 0.33‐0.57 and HR = 0.40, 95% CI = 0.27‐0.60, respectively). The occurrence rate of grade ≥2 SLEs was significantly lower in the RT group (2%) than the no‐RT group (9%) and the difference was significant in multivariate analyses (HR = 0.28, 95% CI = 0.10‐0.76). Using PSM analyses, PSA‐PFS and OS remained significantly different (HR = 0.64, 95% CI = 0.46‐0.89 and HR = 0.47, 95% CI = 0.30‐0.72, respectively), between the RT (n = 182) and the no‐RT (n = 182) groups. The difference in OS was significant in the high metastatic burden cohort (HR = 0.55, 95% CI = 0.37‐0.81). Conclusions Addition of local RT to standard treatment for de novo metastatic prostate cancer patients tends to have the potential to extend survival, even in patients with high metastatic burden, and to reduce SLEs.

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