Significant impact of biochemical recurrence on overall mortality in patients with high-risk prostate cancer after carbon-ion radiotherapy combined with androgen deprivation therapy.

Abstract

BACKGROUND:

Whether biochemical recurrence (BR) is a significant predictive factor of mortality after definitive radiation therapy for prostate cancer remains unknown. The aim of the current study was to investigate the relation between BR and overall mortality (OAM) in high-risk prostate cancer patients who were treated with carbon-ion radiotherapy (CIRT) and had long-term follow-up in 2 prospective trials.

METHODS:

In the 2 phase 2 clinical trials, which involved 466 prostate cancer patients who received 63.0 to 66.0 Gy of CIRT (relative biological effect) in 20 fractions between 2000 and 2007, 324 patients who were deemed to be at high risk on the basis of the modified D'Amico classification criteria and received CIRT along with androgen-deprivation therapy (ADT) were examined. The OAM rate was adjusted for the ADT duration, and multivariate analyses using a Cox proportional hazards model were performed for OAM with BR as a time-dependent covariate.

RESULTS:

The median follow-up period was 107.4 months, and the 5- and 10-year OAM rates after adjustments for the ADT duration were 7.0% (95% confidence interval [CI], 4.0%-9.4%) and 23.9% (95% CI, 16.4%-26.2%), respectively. A multivariate analysis revealed that the presence of BR (hazard ratio, 2.82; 95% Cl, 1.57-5.08; P = .001) was one of the predictive factors for OAM. On the other hand, the duration of ADT had no impact on OAM.

CONCLUSIONS:

BR after CIRT combined with ADT is an independent predictive factor for OAM in high-risk prostate cancer patients. The results of this study could be applied to other high-dose radiation therapies. Cancer 2016;122:3225-31. © 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

• Authors: Goro Kasuya, Hitoshi Ishikawa, Hiroshi Tsuji, Takuma Nomiya, Hirokazu Makishima, Tadashi Kamada, Koichiro Akakura, Hiroyoshi Suzuki, Jun Shimazaki, Yasuo Haruyama, Gen Kobashi, Hirohiko Tsujii, Working Group for Genitourinary Tumors
• Journal: Cancer (Cancer) Vol. 122 Issue 20 Pg. 3225-3231 (Oct 15 2016) ISSN: 1097-0142 [Electronic] United States
• PMID: 27351298 (Publication Type: Clinical Trial, Phase II, Journal Article, Multicenter Study)
• Copyright: © 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

Chemical References

• Androgen Antagonists

Topics

• Aged
• Aged, 80 and over
• Androgen Antagonists (therapeutic use)
• Combined Modality Therapy
• Follow-Up Studies
• Heavy Ion Radiotherapy (mortality)
• Humans
• Male
• Middle Aged
• Neoplasm Grading
• Neoplasm Recurrence, Local (mortality, pathology, therapy)
• Neoplasm Staging
• Prognosis
• Prospective Studies
• Prostatic Neoplasms (mortality, pathology, therapy)
• Radiotherapy Dosage
• Radiotherapy, Conformal (mortality)
• Risk Factors
• Survival Rate