Consuming a high-fat diet may increase the risk of certain types of breast cancer, according to a recent study.

Researchers found that high total and saturated fat intake were associated with greater risk of estrogen receptor- and progesterone receptor-positive (ER+PR+) breast cancer (BC), and human epidermal growth factor 2 receptor-negative (HER2-) disease.

For the study, researchers analyzed data from 10,062 breast cancer patients from the EPIC study with 11.5 years of follow-up. The EPIC cohort study consisted of 337,327 women living in 10 European countries, which creates a heterogeneous cohort both in terms of geography-related dietary fat intake patterns in terms of molecular subtype.

To correct the dietary questionnaire data for measurement errors, researchers calibrated intake data with standardized 24-hour dietary recall interviews on administered to a random sample of 8 percent of the cohort. Cox proportional hazard modeling included various known risk factors as covariables.

Researchers reported that high total and saturated fat intake were associated with greater risk of ER+PR+ BC. High saturated fat intake was also associated with greater risk of HER2- disease.

"A high-fat diet increases BC risk and, most conspicuously, that high saturated fat intake increases risk of receptor-positive disease, suggesting saturated fat involvement in the etiology of receptor-positive BC," researchers said.

Researchers said published data from epidemiological and case-control studies on the association between high fat intake and breast cancer risk have been conflicting.

They said this may be attributable to difficulties obtaining accurate information on fat intake and because of limited heterogeneity of intake within specific geographic area from which the study cohorts live. Also, breast cancer is now classified clinically into subtypes by ER, PR, and HER2 expression status and each subtype has its own prognosis and set of risk factors, which may also contribute to the inconsistencies in the published reports on this relationship.

The findings were recently published in the Journal of the National Cancer Institute.