Pre-diagnosis consumption of preserved vegetables and prognosis of invasive oesophageal squamous cell carcinoma: a prospective cohort study in one high-risk area in China

Abstract

Objective To investigate the prognostic effect of pre-diagnosis preserved vegetable consumption on oesophageal squamous cell carcinoma (ESCC) in Yanting County, China. Methods This prospective cohort study enrolled consecutive patients with ESCC. The pre-diagnosis diet consumption data were collected using a food frequency questionnaire at baseline. Preserved vegetable consumption was categorized into two groups: < 1/week and ≥1/week. Kaplan–Meier survival curve analysis with a log-rank test and a Cox proportional hazard regression model analysis were undertaken to compare the two consumption groups. Results The study enrolled 185 patients (121 males and 64 females) with ESCC. Patients consuming preserved vegetables ≥1/week had a median survival time of 41 months, but patients consuming preserved vegetables <1/week did not achieve a median survival time. The adjusted hazard ratio (HR) for an intake of ≥1/week was 1.58 (95% confidence interval [CI] 1.01, 2.47). Among ‘ever smokers’, the HR increased to 2.04 (95% CI 1.10, 3.77) and among ‘ever alcohol drinkers’, the HR increased to 2.50 (95% CI 1.33, 4.73). Among ‘never smokers’ or ‘never alcohol drinkers’, no significant association was observed. Conclusion A high consumption of preserved vegetables was associated with a poorer prognosis among patients with ESCC.