Overweight Women At Risk Of Breast Cancer Recurrence

Obesity has been blamed for a huge number of diseases that plague mankind. Some of the major categories of diseases, namely the cardiovascular diseases, diabetes and cancer have also been linked to obesity.

It is a long known fact that obese women run a higher risk of developing breast cancer. However, an important research study, which was published in the journal Cancer, a peer reviewed journal of the American Cancer Society, has found that the risk of recurrence of breast cancer is also higher in obese women.

Research at College of Medicine's Montefiore Medical Center

The research study was led by Dr Joseph Sparano, from the Albert Einstein College of Medicine's Montefiore Medical Center, Bronx, NY, along with his colleagues. They included around 7000 women in their study. All of these women had had stage 1 to 3 breast cancer in the past and had participated in three trials (E1199, E5188, and E3189) run by the National Cancer Institute. Apart from the breast cancer, these women had normal heart, kidney, liver, and bone marrow function and did not suffer from any other significant health problem. 

This criterion was important for the selection of the participants in order to study the effect of obesity on the potential recurrence of breast cancer and the survival rate of the patients. The researchers found that 5000 of these patients had received chemotherapy for their condition which included regimens of doxorubicin and cyclophosphamide as per their body weights. Researchers noted that one third of these 5000 women were obese, while another one third had a body mass index that indicated that they were overweight. Following the chemotherapy treatment, it was seen that the cancer recurred in one-fourth of the women. A total of 891 women lost their lives within eight years of chemotherapy, out of which 695 deaths were due to breast cancer.

Sparano and his colleagues found that obese women had a 40 percent higher risk of suffering from a breast cancer recurrence compared to women with a BMI in the normal weight range. It was also seen that the obese women were 69 times more likely to die. The cause of death could be breast cancer or any other disease.

Another important aspect of this study was that obesity was strongly associated with the recurrence of breast cancer when the tumor was an estrogen receptor (ER) positive type. It is to be noted that ER positive tumors are the most common type of breast cancers, accounting for more than two third of the cases. In other types of cancers, which are not estrogen dependent, the link between obesity and recurrence could not be clearly established.