(P13-009-23) Molecular Subtypes and Dietary Patterns in Breast Cancer Patients: A Latent Class Analysis

Objectives: Breast cancer (BC) is the second most common cancer worldwide, with over 1.670.000 new cases estimated per year. Diet has been identified as a modifiable risk factor for BC development and prognosis. The Mediterranean diet (MD) has been shown to be inversely associated with multiple chronic degenerative diseases including BC. The aim of the present study was to assess dietary patterns according to BC molecular subtypes in a subgroup of patients at their baseline visit of a lifestyle trial conducted by our institute.

Methods: A principal component analysis (PCA) was conducted to assess the best lower-dimensional space where to summarize dietary information. An explorative unsupervised automatic clustering technique was performed to identify diet-risks groups. Final groups were analyzed as dietary patterns and characterized by main synthetic statistics comparison with univariate analysis.

Results: The first PCA factor was characterized mainly by vegetables (29.5%) and extra-virgin olive oil (19.9%) while sugars and sweets (26.4%), fats and dressings (24.6%) and potatoes (15.8%) were determinant for the second factorial axis. PCA showed different correlations between dietary variables in each molecular subtype, especially for triple negative subtype where the strongest component was from sweets & sugars (19.0%). Cluster 1 was mainly associated with potatoes, sugars and sweets, animal proteins and cereals. Cluster 3 was characterized by a higher Mediterranean diet score and with extra-virgin olive oil, vegetables, fruits, soy and legumes. Clusters 2 and 4 were more similar and are diametrically opposed to cluster 3.

Conclusions: Our findings showed two main patterns of diet consumed by BC patients at their baseline visit: one PCA-based pattern was characterized by sweets, sugar, animal proteins, fats and dressings and opposite to this a healthy diet with vegetables, extra-virgin olive oil and fish consumption. The latter profile is considered part of a healthy lifestyle based on a Mediterranean diet which is known to improve the metabolic and hormonal risk factors for BC.

Funding Sources: This work was sustained by Funds from the Italian Department of Health to Ricerca Corrente - Istituto Nazionale Tumori - IRCCS - Fondazione G. Pascale (Project L1/1).