Health-related quality-of-life measurements demonstrated that both proton and photon radiation therapy led to excellent and similar impacts on quality of life for patients with breast cancer undergoing comprehensive nodal irradiation, according to findings from the phase III RadComp trial that was presented in a press briefing during the American Society for Radiation Oncology (ASTRO) 67th Annual Meeting (Abstract LBA 01).
“Patients should feel reassured that they can receive high-quality care with either photon or proton therapy,” said study clinical chair and presenting author Shannon MacDonald, MD, FASTRO, Medical Director at the Southwest Florida Proton Center. “More than a thousand patients in our trial have now shown that, with contemporary treatments, we can deliver curative radiation in a way that preserves multiple aspects of quality of life.”
Rationale and Study Methods
Photon therapy is the most common form of external-beam radiation therapy, which is typically administered to patients with breast cancer following surgery to prevent cancer recurrence. Photon therapy carries a risk of radiation reaching surrounding organs, including the heart and lungs, for potential severe long-term adverse effects. Proton therapy, on the other hand, limits incidental exposure to nearby organs, but has limited availability as specialized facilities and training are required, making it much more expensive for patients.
“Radiation oncologists have debated whether photon or proton therapy is the better choice for treating breast cancer, and there has been little high-quality evidence to guide those decisions,” Dr. MacDonald said.
The large, randomized, controlled, unblinded phase III RadComp trial was designed to prospectively test if proton therapy could achieve similar cancer control levels as photon therapy with reduced adverse effects. The study enrolled 1,239 patients with nonmetastatic breast cancer, and they were randomized to receive either proton or photon therapy to their internal mammary lymph nodes.
Findings presented at the ASTRO meeting focused on patient-reported quality-of-life outcomes. The primary health-related quality-of-life endpoints in the study were PROMIS Fatigue, Satisfaction with Breast Cosmetic Outcomes, BREAST-Q adverse effects of radiotherapy, and FACT-B. Secondary quality-of-life endpoints included FACIT-TS-G and PRO-CTCAE (severity, interference, frequency of chest pain, and shortness of breath).
For the self-reported quality-of-life measurements, patients completed several questionnaires at baseline, at the end of radiotherapy, and at 1 and 6 months after radiation.
Key Study Findings
At 6 months, 86.5% of patients had completed the FACT-B questionnaires.
No clinically meaningful differences were reported between treatment arms for the PROMIS Fatigue total score, Satisfaction with Breast Cosmetic Outcomes score, BREAST-Q total score, and FACT-B trial outcome index score. Self-reported PRO-CTCAE severity of shortness of breath favored proton therapy when comparing scores of 0 vs 1-4 (odds ratio [OR] = 0.74; 95% confidence interval [CI] = 0.59–0.93; P < .01), but there was no noted difference when comparing scores of 0-2 vs 3-4.
FACIT quality-of-life measurements also favored proton therapy in terms of willingness to recommend treatment (OR = 0.13; 95% CI = 0.08–0.22; P < .001) and willingness to choose the treatment again (OR = 0.11; 95% CI = 0.07–0.18; P < .001).
“Quality-of-life research often gets overlooked, but patient-reported outcomes are an essential endpoint for modern trials,” Dr. MacDonald said. “They help us see how well our patients are living after treatment and can also reflect other important outcomes.”
Disclosure: For full disclosures of the study authors, visit amportal.astro.org.
