Breast Cancer: High Fat Diet Raises Risk of Hormone Sensitive Cancer Interview with:
Sabina Sieri, PhD
Epidemiology and Prevention Unit
Department of Preventive & Predictive Medicine
Fondazione IRCCS Istituto Nazionale dei Tumori
20133 Milan – Italy What are the main findings of this study?

Dr. Sieri: In our study we found that there was an increased risk of developing breast cancer from high saturated fat intake. High total and saturated fat intake were associated with greater risk of ER PR positive breast cancer. High saturated fat intake was also associated with a greater risk of HER2 negative disease. So, a high-fat diet increases breast cancer risk and, most conspicuously, a high saturated fat intake increases the risk of developing hormone-sensitive diseases, suggesting saturated fat involvement in the etiology of hormone-sensitive breast cancer. Were any of the findings unexpected?

Dr. Sieri: No, but I am surprised by the congruousness of the results that we found. We found a positive association between fat intake and breast cancer risk and a greater effect of fat on receptor positive breast cancers and HER2 negative tumors. All these breast cancer subtypes are more influenced by risk factors known to be linked to estrogen metabolism. It has been hypothesized that high dietary fat intake may raise endogenous estrogen levels which stimulates the proliferation of breast cancer cells. What should clinicians and patients take away from your report?

Dr. Sieri: Saturated fatty acids intake should be as low as is possible within the context of a nutritionally balanced diet. The percentage of total calories from saturated fat should not exceed the 10% limit suggested by main dietary recommendations What recommendations do you have for future research as a result of this study?

Dr. Sieri: It is important that these finding be replicated in other studies focusing on breast cancer subtypes instead of overall breast cancer.


Dietary Fat Intake and Development of Specific Breast Cancer Subtypes JNCI J Natl Cancer Inst dju068 doi:10.1093/jnci/dju068 first published online April 9, 2014

Sabina Sieri, Paolo Chiodini, Claudia Agnoli, Valeria Pala, Franco Berrino, Antonia Trichopoulou, Vassiliki Benetou, Effie Vasilopoulou, María-José Sánchez, Maria-Dolores Chirlaque,  Pilar Amiano, J. Ramón Quirós,Eva Ardanaz, Genevieve Buckland, Giovanna Masala, Salvatore Panico, Sara Grioni,Carlotta Sacerdote, Rosario Tumino, Marie-Christine Boutron-Ruault, Françoise Clavel-Chapelon, Guy Fagherazzi, Petra H. M. Peeters, Carla H. van Gils, H. Bas Bueno-de-Mesquita, Henk J. van Kranen, Timothy J. Key, Ruth C. Travis, Kay Tee Khaw, Nicholas J. Wareham, Rudolf Kaaks, Annekatrin Lukanova, Heiner Boeing, Madlen Schütze, Emily Sonestedt, Elisabeth Wirfält, Malin Sund, Anne Andersson, Veronique Chajes, Sabina Rinaldi, Isabelle Romieu, Elisabete Weiderpass, Guri Skeie, Engeset Dagrun, Anne Tjønneland, Jytte Halkjær, Kim Overvard, Melissa A. Merritt, David Cox, Elio Riboli, and Vittorio Krogh

JNCI J Natl Cancer Inst Advance Access 10.1093/jnci/dju068

Last Updated on April 11, 2014 by Marie Benz MD FAAD