Statistical Analysis
squamous cell vs, weight loss
ONCOLOGY, ADENOCARCINOMA, PRIMARY TUMOR
All data analyses were performed between March 2022 and February 2023 using SAS, version 9.4 (SAS Institute Inc). A 2-sided Local-regional failure and DF were estimated in the univariable analysis using the cumulative incidence method, and dichotomized RT duration and RT interruptions were compared using the Gray test.For the multivariable analyses, after RT duration or RT interruptions and the NRG Oncology trial were forced into the models, a stepwise selection procedure was used to choose other variables using an α ≥ .05 level as the entry and exit criteria for the model building. The following additional variables were assessed in the models: age (continuous); sex (male vs female); race and ethnicity, which were derived from electronic health records and categorized as White vs other (including Black, Asian, and other in the RTOG 8501 trial; Black or African American, Hispanic, Native American [Aleutian, American Indian, and Eskimo], Native Hawaiian or other Pacific Islander, and Asian [Chinese, Japanese, Korean, and Southeast Asian] in the RTOG 9405 trial; and American Indian or Alaska Native, Asian, Black or African American, more than 1 race, and unknown in the RTOG 0436 trial); Zubrod performance status score (0 vs 1 or 2); histological subtype (squamous cell vs adenocarcinoma); primary tumor size (<5cm vs ≥5 cm); weight loss (<10% vs ≥10%); N category (NX or N1 vs N0); and 80% or greater of protocol-specified concurrent chemotherapy (yes vs no).