PV QA 4 - Poster Viewing Q&A 4
TU_33_3646 - Patterns of Care and Outcomes of Hypofractionated Radiation Therapy (HFRT) Alone in Patients with Stage III Non-Small Cell Lung Cancer (NSCLC)
Tuesday, October 23
2:45 PM - 4:15 PM
Location: Innovation Hub, Exhibit Hall 3
Patterns of Care and Outcomes of Hypofractionated Radiation Therapy (HFRT) Alone in Patients with Stage III Non-Small Cell Lung Cancer (NSCLC)
A. F. Shepherd, A. Wild, A. J. Wu, D. Gelblum, and A. Rimner; Memorial Sloan Kettering Cancer Center, New York, NY
Purpose/Objective(s): Patients with unresectable locally advanced NSCLC who refuse or are not candidates for chemotherapy often receive radiation therapy (RT) alone. HFRT regimens are becoming increasingly common due to convenience, resource limitations and health-care costs. A database analysis was performed to evaluate the practice patterns and outcomes of HFRT.
Materials/Methods: The National Cancer Database was queried for patients with stage III NSCLC who received definitive external beam RT (50 Gy-80 Gy) to the chest without chemotherapy or surgical resection from 2004-2015. Patients received conventionally fractionated RT (CFRT): 180-200 cGy/fraction (fx) or HFRT: 210-400 cGy/fx. Baseline characteristics were compared using t-test, chi square test and non-parametric tests when necessary. Kaplan Meier method was used for overall survival (OS) and Cox-proportional hazards were used for uni- and multivariable analyses (UVA/MVA).
Results: A total of 10,112 patients were evaluated: 8,107 CFRT and 2,005 HFRT. Patients treated with HFRT were more likely to be older (median age: 77 yo vs. 76 yo, p<0.01), live farther from the treatment facility (8.2 vs. 7.3 miles, p<0.01), receive RT at an academic center (29.8 vs. 25.1%, p<0.01) and were more recently diagnosed (2010-2014: 44 vs. 40.1%, p<0.01). They were more likely to have high T-stage (cT3/T4: 53.8 vs. 49.8%, p<0.01) and Stage IIIB (41.7 vs. 38.5%, p=0.019), but lower N-stage (cN2/3: 69.9 vs. 75.5%, p<0.01). There was no difference in race, insurance, income, education, urban dwelling, Charlson-Deyo Comorbidity Score (CDCS), tumor location, histology, or grade. For the CFRT and HFRT groups, the median RT doses and dose/fx were 64.8 Gy; 200 cGy/fx and 58.5 Gy; 250 cGy/fx, respectively. The median and 2-yr rates of OS were 12.0 mos and 23.9% for CFRT vs 10.4 mos and 20.1% for HFRT (p<0.01). On UVA and MVA, (data shown for MVA: HR, p-value), age (1.01, <0.01), female gender (0.85, <0.01), white race (1.06, 0.045), Medicare (1.12, <0.01), urban dwelling (0.89, <0.01), treatment at an academic center (0.94, 0.013), CDCS (1: 1.07, <0.01, 2: 1.20, <0.01, 3: 1.34, <0.01), diagnosed 2010-2014 (0.86, <0.01), upper lobe location (0.85, <0.01), squamous histology (1.06, 0.012), T3/T4 stage (1.28, <0.01), N2/N3 stage (1.20, <0.01), stage IIIB (1.06, 0.009) and HFRT (1.15, <0.01) were associated with OS.
Conclusion: The practice patterns noted above are consistent with the trend for prioritizing convenience and cost-effectiveness of HFRT as patients were more likely to receive this treatment if they were more recently diagnosed, lived farther away and were treated in an academic center. Patients who received HFRT had slightly inferior OS rates, which may be due to unaccounted confounders such as baseline performance status and aggressiveness of disease.
Author Disclosure: A.F. Shepherd: None. A. Wild: None. D. Gelblum: None. A. Rimner: Research Grant; Astra Zeneca, Pfizer, Boehringer Ingelheim, Varian Medical Systems. Advisory Board; Merck, Astra Zeneca.