Smoking is a poor prognostic factor for male nasopharyngeal carcinoma treated with radiotherapy.

Abstract

To evaluate the effect of smoking on prognosis of male nasopharyngeal carcinoma by comparing the treatment outcomes between smokers and non-smokers. A total of 2450 nasopharyngeal carcinoma patients were enrolled, including 1865 male patients. Matching was performed between smokers and non-smokers in male patients according to age, UICC clinical stage, T stage, N stage and treatment. Survival outcomes were compared using Kaplan-Meier analysis and Cox regression. Smoking index was calculated by multiplying cigarette packs per day and smoked time (year). In male patients, smokers had significantly lower 5-year overall survival (70.1% vs. 77.5%, P<0.001) and locoregional recurrent free survival (76.8% vs.82.4%, P = 0.002) compared with non-smokers. Matched-pair analysis showed that smokers kept a high risk of death compared with non-smokers (HR = 2.316, P<0.001). High degree of smoking index (>15 pack-years) had a poor effect on overall survival (HR = 1.225, P = 0.016). When smoking index was more than 45 and 60 pack-years, the risk for death increased to 1.498 and 1.899 fold compared with non-smokers (P = 0.040, 0.001), respectively. Smoking was a poor prognostic factor for male nasopharyngeal carcinoma. The heavier the patients smoked, the poorer prognosis they suffered.