Dietary patterns and oesophageal cancer: a multi-country latent class analysis

Background: The considerable differences in food consumption across countries pose major challenges to the research on diet and cancer, due to the difficulty to generalise and reproduce the dietary patterns identified in a specific population. Methods: We analysed data from a multicentric case-control study on oesophageal squamous cell carcinoma (ESCC) carried out between 1992 and 2009 in three Italian areas and in the Canton of Vaud, Switzerland, which included 505 cases and 1259 hospital controls. Dietary patterns were derived applying LCA on 24 food groups, controlling for country membership, and non-alcoholic energy intake. A multiple logistic regression model was used to derive odds ratio (ORs) and corresponding 95% CIs for ESCC according to the dietary patterns identified, correcting for classification error. Results and conclusion: We identified three dietary patterns. The 'Prudent' pattern was distinguished by a diet rich in fruits and vegetables. The 'Western' pattern was characterised by low consumption of these food groups and higher intakes of sugar. The 'Lower consumers-combination pattern' exhibited a diet poor in most of the nutrients, preferences for fish, potatoes, meat and a few specific types of vegetables. Differences between Italy and Switzerland emerged for pattern sizes and for specific single food preferences. Compared to the 'Prudent' pattern, the 'Western' and the 'Lower consumers-combination' patterns were associated with an increased risk of ESCC (OR=3.04, 95% CI=2.12-4.38 and OR=2.81, 95% CI=1.65-4.76)