Findings from a new study claim that proton therapy leads to a significantly lower risk of side effects severe enough to lead to unplanned hospitalizations for cancer patients when compared to traditional radiation.
Although cure rates between the proton therapy and radiation groups remain almost identical, the study conducted at the Perelman School of Medicine at the University of Pennsylvania revealed that the risk for proton therapy was lower within 90 days. The results were published today in JAMA Oncology.
Proton beam therapy has shown promise as an improved cancer therapy. But as a New York Times story detailed in 2018, the finances for health providers can be tricky. New proton therapy centers can cost tens of millions to hundreds of millions of dollars. Manufacturers of the systems include Varian Medical (NYSE:VAR), Hitachi’s (NYSE:HIT), Mevion and IBA Worldwide.
The study evaluated side effects including pain or difficulty swallowing, difficulty breathing, nausea or diarrhea, among others. Data from 1,483 cancer patients receiving radiation and chemotherapy at the same time was collected. Of that group, 391 received proton therapy, while the rest received radiation. All patients had non-metastatic cancer, including subjects with brain, head and neck, lung, gastrointestinal and gynecologic cancer.
The primary outcome was adverse side effects graded at a level three or higher within 90 days of treatment. Within the proton group, only 45 (11.5%) patients experienced side effects, while 301 (27.6%). A weighted analysis also uncovered that the relative risk of severe toxicity was two-thirds lower for proton patients. With survival remaining similar between the two groups, the researchers suggest that the lower toxicity in proton therapy did not reduce effectiveness.
Standard photon radiation therapy uses multiple X-ray beams to deliver radiation to the tumor target and deposits radiation in normal tissues beyond the target, while proton therapy is an FDA-approved alternative that directs positively charged protons at the tumor with almost no residual radiation delivered beyond the target.
“This is exciting because it shows that proton therapy offers a way for us to reduce the serious side effects of chemo-radiation and improve patient health and wellbeing without sacrificing the effectiveness of the therapy,” assistant professor of radiation oncology at Washington University School of Medicine and Penn and the study’s lead author Dr. Brian Baumann said in the release.
“We know from our clinical experience that proton therapy can have this benefit, but even we did not expect the effect to be this sizeable,” added Dr. James Metz, senior author and chair of radiation oncology at Penn.