Jhawar SR, et al. - Whether combined modality therapy (CMT) with chemotherapy and radiotherapy vs chemotherapy alone provides any advantage in terms of survival in pediatric Hodgkin lymphoma (HL) was investigated using data from a large cancer registry. After 5 years of treatment, improved overall survival was observed in association with the use of CMT in pediatric patients with early-stage HL. With regard to the use of CMT, a nationwide decrease in the use was seen, which may reflect the bias of ongoing clinical trials designed to avoid consolidation radiotherapy. This is the largest data set inquiring the impact of CMT in pediatric HL.

Methods

• Researchers used data from the National Cancer Database for this observational cohort study.
• Participants were 5,657 pediatric patients (age, 0.1-21 years) who got a diagnosis of stage I or II HL in the US from January 1, 2004, to December 31, 2015.
• They carried out statistical analysis from May 1 to November 1, 2018.
• Definitive treatment with chemotherapy or CMT (defined as chemotherapy followed by radiotherapy) was administered to patients.
• They assessed overall survival via Kaplan-Meier survival curves; using multivariable Cox proportional hazards regression models, they examined the link between CMT use, covariables, and overall survival.
• They also evaluated use of radiotherapy over time.

Results

• A total of 5,657 patients (3,004 females, 2,596 males, and 57 missing information on sex; mean [SD] age, 17.1 [3.6] years) with stage I or II classic HL were analyzed among the overall 11,546 pediatric patients with HL in the National Cancer Database.
• CMT was used to treat 2,845 (50.3%) patients.
• Use of CMT vs chemotherapy alone was found to be related to younger age (<16 years, 1,102 of 2,845 [38.7%] vs 856 of 2,812 [30.4%]; P < .001), male sex (1,369 of 2,845 [48.1%] vs 1,227 of 2,812 [43.6%]; P < .001), stage II disease (2,467 of 2,845 [86.7%] vs 2,376 of 2,812 [84.5%]; P=.02), and private health insurance (2,065 of 2845 [72.6%] vs 1,949 of 2,812 [69.3%]; P =.002).
• For patients who received chemotherapy alone and for those who received CMT, the estimated 5-year overall survival was 94.5% (confidence limits, 93.8%, 95.8%) and 97.3% (confidence limits, 96.4%, 97.9%), respectively, which continued to be significant in the intention-to-treat analysis and multivariate analysis (adjusted hazard ratio for CMT, 0.57; 95% CI, 0.42-0.78; P < .001).
• CMT offered the greatest benefit in the low-risk cohort (stage I-IIA) and adolescent and young adult patients (adjusted hazard ratio, 0.47; 95% CI, 0.40-0.56; P < .001), as revealed in the sensitivity analysis.
• From 2004 to 2015, a decrease by 24.8% was noted in the use of CMT (from 59.7% [271 of 454] to 34.9% [153 of 438]).