Metabolic syndrome increases the risk of breast cancer recurrence and death

Metabolic syndrome increases the risk of breast cancer recurrence and death

New research presented at this year's European Congress on Obesity (ECO 2025, Malaga, Spain, May 11-14), published inThe Journal of Internal Medicineshows that in breast cancer survivors, an unhealthy metabolic profile, or so-called “metabolic syndrome,” increases the risk of breast cancer recurrence by 69% and subsequent breast cancer mortality by 83%. The study comes from Dr. Sixten Harborg, Department of Oncology, Aarhus University/Aarhus University Hospital, Aarhus, Denmark. and Department of Nutrition, Harvard Th Chan School of Public Health, MA, USA and colleagues.

Metabolic syndrome was characterized according to the American Heart Association, which includes the presence of three of five abnormal findings among risk factors: high blood pressure, high triglycerides (blood fats), low-density lipoprotein (HDL) or "good" cholesterol, high fasting glucose), and central or abdominal abdominal drainage.

Data were obtained from observational studies and randomized controlled trials in which survival statistics and survival rates were used to examine how the presence of metabolic syndrome at the time of breast cancer diagnosis is associated with survival. Study data from 42,135 breast cancer survivors were pooled using statistical modeling to assess the relationship between an unhealthy metabolic profile and breast cancer survival. The pooled estimates showed that breast cancer survivors had a 69% increased risk of recurrence and an 83% increased risk of breast cancer mortality at the time of their breast cancer diagnosis compared to breast cancer survivors without metabolic syndrome.

Breast cancer survivors with metabolic syndrome were found to be 57% more likely to have a breast cancer event (recurrence, new cancer, or death) during follow-up than breast cancer survivors without metabolic syndrome.

Interestingly, the authors examined potential differences in association according to geographic location of included studies' continent of origin and found that the association between worse outcomes in breast cancer survivors with metabolic syndrome was consistent across Europe, North America, and Asia.

The authors conclude:“In breast cancer survivors, metabolic syndrome was associated with worse breast cancer outcomes. The results of this study highlight the importance of metabolism for breast cancer survivors. Future research should focus on evaluating how controlling blood lipids, reversing diabetes, and achieving a healthy lifestyle can reduce the prevalence of metabolic syndrome in this population and ultimately improve breast cancer survival. “

They add that the exact mechanisms by which metabolic syndrome increases breast cancer risk and recurrence remain unclear but are thought to involve chronic inflammation and hormonal imbalances.

You say: "One possible explanation suggests that the excess body fat associated with metabolic syndrome leads to increased levels of circulating estrogen, which can stimulate the growth of breast cancer cells. Additionally, obesity can induce changes in the tumor microenvironment that facilitate cancer metastasis or spread. Chronic systemic inflammation, a hallmark of metabolic syndrome, may further contribute to tumor progression by promoting cancer cell survival and impairing immune surveillance. Although our study did not examine the biological basis of the observed associations, it is likely that multiple interacting mechanisms dictated by obesity-induced molecular changes and chronic inflammation that are the link between metabolic syndrome and poor breast cancer outcomes.“

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