Data collection and statistical analysis
We collected data on tumor
extension, surgical margins, associated procedures, nasogastric tube
and/or gastrostomy, length of hospitalization, complications, need for
adjuvant treatment, and swallowing. Descriptive statistics were used to
summarize data. The Chi-square test or the Fisher’s exact test, as
appropriate, was used to determine an association between categorical
variables. The one-way analysis of variance or the independent sample
t-test was used to determine differences between means. We tested for
normality using the Shapiro-Wilk test of normality and for homogeneity
of variances using Levene’s test. The Kruskal-Wallis or the Mann-Whitney
U non-parametric tests were used when the normality assumption was not
met. Survival curves were estimated using the Kaplan–Meier method. All
statistical analyses were performed with Stata, version 14.2 software
(StataCorp LLC). Significance was set at P ≤ .05.