Want to take quizzes and track your credits?
Can proton therapy reduce the risk of severe adverse events associated with unplanned hospitalizations compared with photon therapy for patients undergoing concurrent chemoradiotherapy?
In this comparative effectiveness study of 1483 adults with nonmetastatic cancer and treated with curative intent, proton therapy was associated with a two-thirds reduction in adverse events associated with unplanned hospitalizations, with no difference in disease-free or overall survival.
These findings suggest that, in adults with locally advanced cancer, proton therapy with concurrent chemoradiotherapy may significantly reduce severe adverse events compared with photon therapy, with comparable oncologic outcomes.
Concurrent chemoradiotherapy is the standard-of-care curative treatment for many cancers but is associated with substantial morbidity. Concurrent chemoradiotherapy administered with proton therapy might reduce toxicity and achieve comparable cancer control outcomes compared with conventional photon radiotherapy by reducing the radiation dose to normal tissues.
To assess whether proton therapy in the setting of concurrent chemoradiotherapy is associated with fewer 90-day unplanned hospitalizations (Common Terminology Criteria for Adverse Events, version 4 [CTCAEv4], grade ≥3) or other adverse events and similar disease-free and overall survival compared with concurrent photon therapy and chemoradiotherapy.
Design, Setting, and Participants
This retrospective, nonrandomized comparative effectiveness study included 1483 adult patients with nonmetastatic, locally advanced cancer treated with concurrent chemoradiotherapy with curative intent from January 1, 2011, through December 31, 2016, at a large academic health system. Three hundred ninety-one patients received proton therapy and 1092, photon therapy. Data were analyzed from October 15, 2018, through February 1, 2019.
Proton vs photon chemoradiotherapy.
Main Outcomes and Measures
The primary end point was 90-day adverse events associated with unplanned hospitalizations (CTCAEv4 grade ≥3). Secondary end points included Eastern Cooperative Oncology Group (ECOG) performance status decline during treatment, 90-day adverse events of at least CTCAEv4 grade 2 that limit instrumental activities of daily living, and disease-free and overall survival. Data on adverse events and survival were gathered prospectively. Modified Poisson regression models with inverse propensity score weighting were used to model adverse event outcomes, and Cox proportional hazards regression models with weighting were used for survival outcomes. Propensity scores were estimated using an ensemble machine-learning approach.
Among the 1483 patients included in the analysis (935 men [63.0%]; median age, 62 [range, 18-93] years), those receiving proton therapy were significantly older (median age, 66 [range, 18-93] vs 61 [range, 19-91] years; P < .01), had less favorable Charlson-Deyo comorbidity scores (median, 3.0 vs 2.0; P < .01), and had lower integral radiation dose to tissues outside the target (mean [SD] volume, 14.1 [6.4] vs 19.1 [10.6] cGy/cc × 107; P < .01). Baseline grade ≥2 toxicity (22% vs 24%; P = .37) and ECOG performance status (mean [SD], 0.62 [0.74] vs 0.68 [0.80]; P = .16) were similar between the 2 cohorts. In propensity score weighted–analyses, proton chemoradiotherapy was associated with a significantly lower relative risk of 90-day adverse events of at least grade 3 (0.31; 95% CI, 0.15-0.66; P = .002), 90-day adverse events of at least grade 2 (0.78; 95% CI, 0.65-0.93; P = .006), and decline in performance status during treatment (0.51; 95% CI, 0.37-0.71; P < .001). There was no difference in disease-free or overall survival.
Conclusions and Relevance
In this analysis, proton chemoradiotherapy was associated with significantly reduced acute adverse events that caused unplanned hospitalizations, with similar disease-free and overall survival. Prospective trials are warranted to validate these results.
Sign in to take quiz and track your certificates
JN Learning™ is the home for CME and MOC from the JAMA Network. Search by specialty or US state and earn AMA PRA Category 1 CME Credit™ from articles, audio, Clinical Challenges and more. Learn more about CME/MOC
Accepted for Publication: August 29, 2019.
Corresponding Author: Brian C. Baumann, MD, Department of Radiation Oncology, Washington University in St Louis, 4921 Parkview Pl, Lower Level, St Louis, MO 63110 (firstname.lastname@example.org).
Published Online: December 26, 2019. doi:10.1001/jamaoncol.2019.4889
Author Contributions: Dr Baumann had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Concept and design: Baumann, Gabriel, Bekelman, Metz.
Acquisition, analysis, or interpretation of data: Baumann, Mitra, Harton, Xiao, Wojcieszynski, Gabriel, Zhong, Geng, Doucette, Wei, O’Dwyer, Metz.
Drafting of the manuscript: Baumann, Wojcieszynski, Gabriel, Zhong, Geng, Bekelman, Metz.
Critical revision of the manuscript for important intellectual content: Baumann, Mitra, Harton, Xiao, Wojcieszynski, Gabriel, Doucette, Wei, O’Dwyer, Bekelman, Metz.
Statistical analysis: Mitra, Harton, Wojcieszynski, Zhong, Bekelman.
Obtained funding: Metz.
Administrative, technical, or material support: Baumann, Xiao, Wojcieszynski, Geng, Doucette, O’Dwyer, Metz.
Supervision: Baumann, Mitra, Metz.
Conflict of Interest Disclosures: Dr Bekelman reported receiving personal fees from the Centers for Medicare & Medicaid Services and from CVS Health outside the submitted work. Dr O’Dwyer reported serving as a paid consultant for Boehringer Ingelheim, Genentech, Inc, and Celgene Corporation and has provided expert testimony for Bayer, Inc. Dr Metz reported personal fees from Varian Medical Systems, Ion Beam Applications, and Provision outside the submitted work. No other disclosures were reported.
Funding/Support: This study was supported exclusively by research development funds from the department of Radiation Oncology, University of Pennsylvania.
Role of the Funder/Sponsor: The sponsor had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
You currently have no searches saved.