Impact of obesity on the survival of patients with early-stage squamous cell carcinoma of the oral tongue.

ABSTRACT

BACKGROUND: Although obesity increases risk and negatively affects survival for many malignancies, the prognostic implications in squamous cell carcinoma (SCC) of the oral tongue, a disease often associated with prediagnosis weight loss, are unknown. METHODS: Patients with T1-T2 oral tongue SCC underwent curative-intent resection in this single-institution study. All patients underwent nutritional assessment prior to surgery. Body mass index (BMI) was calculated from measured height and weight and categorized as obese (≥ 30 kg/m(2) ), overweight (25-29.9 kg/m(2) ), or normal (18.5-24.9 kg/m(2) ). Clinical outcomes, including disease-specific survival, recurrence-free survival, and overall survival, were compared by BMI group using Cox regression. RESULTS: From 2000 to 2009, 155 patients (90 men, 65 women) of median age 57 years (range, 18-86 years) were included. Baseline characteristics were similar by BMI group. Obesity was significantly associated with adverse disease-specific survival compared with normal weight in univariable (hazard ratio [HR] = 2.65, 95% confidence interval [CI] = 1.07-6.59; P = .04) and multivariable analyses (HR = 5.01; 95% CI = 1.69-14.81; P = .004). A consistent association was seen between obesity and worse recurrence-free survival (HR = 1.87; 95% CI = 0.90-3.88) and between obesity and worse overall survival (HR = 2.03; 95% CI = 0.88-4.65) though without reaching statistical significance (P = .09 and P = .10, respectively) in multivariable analyses. CONCLUSIONS: In this retrospective study, obesity was an adverse independent prognostic variable. This association may not have been previously appreciated due to confounding by multiple factors including prediagnosis weight loss.