ASCO 2019: Proton Therapy Versus Conventional Photon Therapy in Locally Advanced Cancer
Posted: Tuesday, June 18, 2019
The standard-of-care treatment for many types of cancer—concurrent chemotherapy and traditional photon (x-ray) radiation therapy—is associated with considerable morbidity. Research presented at the 2019 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago (Abstract 6521) has revealed that proton therapy may significantly reduce severe acute adverse events compared with photon therapy in patients with locally advanced cancers (including lung cancer), with similar survival rates.
“Proton therapy was associated with a substantial reduction in the rates of severe acute side effects—those that cause unplanned hospitalizations or trips to the emergency room—compared with conventional photon, or x-ray, radiation,” explained Brian C. Baumann, MD, of Washington University in St. Louis, in an institutional press release. Although Dr. Baumann and colleagues expected a reduction in side effects with proton therapy, “we were somewhat surprised by the large magnitude of the benefit.”
The prospective trial included 1,483 patients treated at the University of Pennsylvania for locally advanced lung, brain, head and neck, gastrointestinal, and gynecologic cancers. Participants received either proton (n = 391) or photon (n = 1,092) chemoradiotherapy. The investigators noted that patients receiving proton therapy were significantly older with less favorable comorbidity scores.
Proton chemoradiotherapy was associated with a significantly lower relative risk of 90-day grade ≥ 3 adverse events (11.5% vs. 27.6%) and 90-day grade ≥ 2 adverse events. As for photon chemoradiotherapy, it was associated with a poorer performance status during treatment (P < .01). The rates of disease-free and overall survival were similar between the cohorts.
Disclosure: The study authors’ disclosure information may be found at coi.asco.org.
