title: Heavy smoking history interacts with chemoradiotherapy for esophageal cancer prognosis: a retrospective study.
abstract: Smoking is a well-known risk factor for esophageal cancer. However, there are few reports that directly evaluate smoking as a prognostic factor for esophageal cancer. Moreover, scarce evidence is available on whether smoking interacts with major treatment modalities of esophageal cancer. In this study we retrospectively analyzed 364 patients with esophageal squamous cell cancer who were treated between 2001 and 2005 at our institution. Background characteristics, including smoking history, were analyzed as potential prognostic factors. Of the 363 patients, 76 patients (20.9%) were non-smokers or light smokers (non-heavy), whereas 287 patients (79.1%) were heavy smokers. The 5-year survival rate for non-heavy smokers and heavy smokers was 61.8% (95% confidence interval [CI]: 49.1-72.2) vs 44.6% (95% CI: 38.2-50.9), respectively. In a multivariate Cox model (adjusted for age, gender, performance status, alcohol consumption, histology, tumor length, International Union Against Cancer [UICC] stage, and treatment), the hazard ratio for heavy smokers in comparison with non-heavy smokers was 1.73 (95% CI: 1.12-2.68; P = 0.013). When we stratified by treatment method, heavy smoking was significantly associated with poor survival only in patients treated by chemoradiotherapy (hazard ratio, 2.43; 95% CI: 1.38-4.27; P = 0.002). More importantly, a statistically significant interaction between heavy smoking history and treatment modality was observed (P = 0.041). Our results indicated that smoking history is strongly associated with poor prognosis in patients with esophageal cancer, especially those treated by chemoradiotherapy. Further investigation is warranted to explain this different prognosis.
authors.affiliation: Department of Clinical Oncology, Aichi Cancer Center Hospital, Aichi, Japan. kouheis0824@yahoo.co.jp
authors.forename: Kohei
authors.initials: K
authors.lastname: Shitara
authors.forename: Keitaro
authors.initials: K
authors.lastname: Matsuo
authors.forename: Shunzo
authors.initials: S
authors.lastname: Hatooka
authors.forename: Takashi
authors.initials: T
authors.lastname: Ura
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takahari
authors.forename: Tomoya
authors.initials: T
authors.lastname: Yokota
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Abe
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kawai
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tajika
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kodaira
authors.forename: Masayuki
authors.initials: M
authors.lastname: Shinoda
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tajima
authors.forename: Kei
authors.initials: K
authors.lastname: Muro
authors.forename: Hideo
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D004938:Esophageal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D016896:Treatment Outcome