Improved survival shown in early-stage Hodgkin's Disease patients who receive radiation therapy
Patients with stage I and II Hodgkin's Disease who receive consolidated radiation therapy (RT) have a higher 10-year survival rate of 84 percent, compared to 76 percent for patients who did not receive RT; and, the data also shows a decrease in utilization of RT, according to research presented today at the American Society for Radiation Oncology's (ASTRO's) 56th Annual Meeting.
Researchers evaluated clinical features and survival outcomes among 41,502 patients diagnosed with stage I and II Hodgkin's Disease from 1998 to 2011 from a prospectively collected database—the National Cancer Data Base (NCDB), which is comprised of cases from 1,500 sites and represents >75 percent of all cancers diagnosed in the U.S. The average patient age was 37 (range: 18 – 90), with a median follow-up of 7.5 years. The association between RT use, co-variables and outcome were assessed in a multivariate Cox proportional hazards model. Survival was estimated using the Kaplan-Meier method.
Multi-agent chemotherapy was administered to 96 percent (39,842) of the patients, and 49 percent (20,441) of patients received a median RT dose of 30.6 Gy. The 10-year overall survival of the entire group was 80.8 percent, with patients receiving RT having a statistically significant improved overall survival rate at 10 years, when compared to those not receiving RT (84.4 percent vs. 76.4 percent; p<0.00001). Additionally, the omission of RT was related to higher rates of salvage transplant procedures performed.
Despite this benefit, the utilization of RT for patients with early-stage Hodgkin's Disease decreased at the study sites from 56 percent to 41 percent between 1998 and 2011; and in 88.4 percent of the patients, the physician-reported reason given for not administering RT was that it was not part of the planned initial treatment strategy. The research also indicated that RT use was associated with younger patients (≤40 years), who are in a higher socioeconomic status, who had access to health insurance, and who received treatment at comprehensive cancer centers (all p<0.0001).
"Multiple prospective, randomized trials have shown a significant improvement in disease control with the addition of RT, however previous trials were limited by low patient numbers and limited follow-up and thus, were unable to demonstrate an overall survival benefit," said lead study author Rahul R. Parikh, MD, a radiation oncologist at Mount Sinai Beth Israel and an Assistant Professor of Radiation Oncology at Icahn School of Medicine at Mount Sinai. "This is the largest dataset in this patient population to demonstrate a survival benefit with the addition of RT. Given that the utilization of RT was associated with younger age, insurance status, higher socioeconomic status, and treatment at comprehensive cancer centers, we have highlighted ongoing disparities in Hodgkin's Disease treatment and it is important that we recognize these findings as potential barriers to care. Given the survival benefit demonstrated in this study, radiotherapy should be included in the combined modality approach of multi-agent chemotherapy followed by consolidation RT in order to maintain high overall survival rates for this curable disease."