Heavy Consequences: The Role of Obesity in Breast Cancer Development

A recent study has found that obesity increases the risk of breast cancer, while metabolic syndrome raises the mortality rate from breast cancer.

The study investigating the impact of obesity and metabolic syndrome on the incidence and mortality risk of breast cancer was published in the Cancer Journal.

Breast cancer is the most common cancer among women, accounting for 24.2% of all female cancers. Family history, hormone therapy, radiation exposure, high-fat diet, smoking, and drinking work as major causes of breast cancer. In addition, endocrine and metabolic disorders that lead to obesity and metabolic syndrome influence the onset of breast cancer.

The researchers tracked and observed 63,330 women without a history of breast cancer for 20 years to investigate the impact of obesity and metabolic syndrome on the incidence of postmenopausal breast cancer. During the 20 years, 4,562 women developed breast cancer, of which 659 died from the disease.

The researchers assessed obesity and metabolic syndrome based on body mass index (BMI) and a metabolic score calculated from 0 to 4. BMI is calculated by dividing weight by height squared and is considered obese if it’s 25 or higher. The metabolic score is measured based on waist circumference, blood sugar, blood pressure, and cholesterol levels, with higher scores indicating a greater association with metabolic syndrome.

The study found that both metabolic syndrome and obesity influence the possibility of breast cancer, but they have different impacts.

Women with a high metabolic score of 3 to 4 had a higher risk of developing estrogen receptor (ER) positive, progesterone receptor (PR) negative breast cancer, which has a poor prognosis. These women had a 53% higher risk of death after breast cancer diagnosis and a 44% higher mortality rate from breast cancer than other women.

In detail, obese women had a higher overall risk of developing breast cancer, which included both ER positive, PR positive breast cancers with a good prognosis. These women had a higher risk of death after breast cancer diagnosis, but the mortality rate from breast cancer was only higher in those with severe obesity.

In addition, African American women had a higher risk of developing aggressive triple-negative breast cancer compared to women of other races.

Based on these results, the researchers concluded that controlling obesity can lower the chance of breast cancer while controlling metabolic syndrome can reduce the mortality rate from breast cancer.