This paper studied the association between metabolic syndrome and risk of a second breast cancer event and mortality. 

Metabolic syndrome is defined as having 3 or more of these characteristics: increased weight,  high blood pressure, low HDL-cholesterol (good cholesterol), high triglycerides (fats), and diabetes or impaired glucose tolerance (elevated blood sugar levels). Metabolic syndrome increases the risk of developing breast cancer and appears to increase the risk for adverse outcomes after breast cancer. 

This study analyzed the association between metabolic syndrome and risk of second breast cancer events. Second breast cancer events include recurrence (return of cancer) and a second primary breast cancer. 

4,216 women who had completed surgery for stage I or II breast cancer were analysed. Data was collected on their risk factors and breast cancer characteristics. Metabolic syndrome risk factors included  weight risk (having a body mass index >27.7 kg/m2), high blood pressure, low good-cholesterol, high triglycerides and diabetes or impaired glucose tolerance. The patients were followed-up for an average of 6.3 years. 

At the start of the study, 9% of women had 3 or more metabolic conditions present. During follow up, 26% of women had  3 or more metabolic conditions. 13% of the 4,216 women experienced a second breast cancer event. 415 women had recurrent breast cancer and 143 had a second primary breast cancer.

Women with 3 or more metabolic sydrome factors had a 50% increased risk of any second breast cancer event compared to women without any metabolic syndrome factors. Weight risk independently increased the risk of a second breast cancer event by 37%.

In particular, compared to those with no metabolic syndrome factors present, the risk of recurrence was 65% higher in women with 3 or more metabolic syndrome factors present and 49% higher for women with weight risk.  

Women with 3 or more metabolic syndrome factors had a 65% increased risk of breast cancer-related death compared to those with no metabolic syndrome factors. In particular, women with weight risk had a 36% increased risk of breast cancer-related death.

Overall, compared to those with no metabolic syndrome factors, women with 1 metabolic factor were at 17% increased risk of overall mortality (death). Women with 2 metabolic syndrome factors were at 1 36% increased risk of overall mortality. Women with 3 or more metabolic syndrome factors were at 81% increased risk of overall mortality respectively. 

The authors concluded that metabolic syndrome is associated with increased risk of a second breast cancer event and mortality. 

Talk to your doctor about the metabolic syndrome factors as discussed above, and establish a strategy for treatment or prevention of these conditions.