Does race influence survival for esophageal cancer patients treated on the radiation and chemotherapy arm of RTOG #85-01?
In reported retrospective non-randomized trials of treatment of esophageal carcinoma, blacks have a lower survival from esophageal cancer than whites. None of these studies has accounted for the extent of disease, or the methods and quality of treatment. We reviewed the data that included only patients treated on the chemoradiation arm of the RTOG-8501 esophageal carcinoma trial to see if there were differences in overall survival between black and white patients receiving the same standard of care. One hundred-nineteen patients, 37 blacks and 82 whites were evaluated who met the criteria for receiving chemoradiation of 5000 cGy and four courses of Cisplatin (75 mg/m2) and Fluorouracil (1000 mg/m2 for 4 days). Blacks had squamous histology only, with 86% of blacks having weight loss of 10 lbs. or more compared to 56% of whites (p = 0.001). In addition, blacks had larger tumors and more difficulty eating (p = 0.010). Overall, there was no difference in the Kaplan-Meier median survival estimate by race (p = 0.2757). Only when we limited the analysis to the "squamous histology" subgroup, stratified according to age >70 vs. <70 years (p = 0.0002), and nodal status (p = 0.0177) in a Cox regression model analysis, did race appear to be a significant factor (p = 0.0012). However, using the entire database, the age effect was found to be a "bimodal" effect, wherein the "youngest" (< age 60 years) and "oldest" patients (age > 70 years) did poorly. Because of the dramatic differences in the age and histology distributions between blacks and whites, this issue could not be resolved in the subset of squamous only who received chemoradiation. The increasing incidence of adenocarcinoma among white patients without a corresponding increase of this histology in blacks reflects a difference in diet and or lifestyle compared to blacks that deserves additional study. When treated aggressively with chemoradiation, race did not appear to be a statistically significant factor for overall survival.