- Women who have a higher body mass index (BMI) are at an increased risk of breast cancer
- Overweight women do not detect their breast tumor until it has become larger than 2 cm
- Mammography need to be done early to prevent the development of tumor in the breast
Women with higher body mass index (BMI) are at an increased risk of cancer, as they do not detect their breast tumor until it has become large, reveals a new study.
The new study was presented at the annual meeting of the Radiological Society of North America (RSNA).
‘Women with higher BMI are at risk for a worse prognosis such as the molecular composition of the tumors and hormone receptor expression levels, which makes it harder to treat.’
The results show that women who have a higher BMI might require shorter intervals between mammography screenings.
Link between BMI and Breast Cancer
Body mass index (BMI) is used to measure body fat based on an individual's height and weight. Overweight is defined as having a BMI of 25 or more.
Higher BMI is found to be linked to specific health risks such as diabetes and heart disease. However, BMI has not been included in the screening guidelines for breast cancer.
The new study has been conducted at Karolinska Institutet, Sweden.
The research team aims to identify the risk factors that are linked to tumors, and also to examine the implications for long-term prognosis.
Tumors are mostly not detected until it becomes larger than 2 centimeters (cm) or is of the size of a peanut.
The size of the tumor is important, especially 2-cm, as it is one of the essential parameters used to differentiate between the stage I and stage II cancers.
Also, tumor size is known to be strongly linked to prognosis, revealed Fredrik Strand, M.D., a co-author and radiologist at the Karolinska University Hospital in Stockholm in Sweden.
Dr. Strand and colleagues have studied approximately 2,012 cases of invasive breast cancer, which appeared between 2001 and 2008.
The research team followed the patients of this study until the end of 2015. They investigated patients to check for the progression of the disease, and the relation between BMI and breast density.
BMI and Breast Density
At the time of screening, both BMI and breast density were found to be linked to having a large tumor.
However, for interval cancers or cancers that are discovered within two years of a normal mammogram, it was found that only BMI was associated with having a large tumor.
Women who had a higher BMI were found to have a worse prognosis when compared to those women with lower BMI among interval cancers. Whereas, breast density was found to show no significant link with the progression of disease.
Dr. Strand said that these findings provide physicians and patients with more information and help them in making decisions about optimal screening approaches.
"Our study suggests that when a clinician presents the pros and cons of breast cancer screening to the patient, having high BMI should be an important 'pro' argument," he said. "Also, our findings suggest that women with high BMI should consider shorter time intervals between screenings."
Besides these larger interval cancers, women who had higher BMI were found to be at risk for a worse prognosis such as the molecular composition of the tumors and hormone receptor expression levels, which makes it harder to treat, added Dr. Strand.
Need for Further Research
The study was carried out in Sweden. It had intervals of 18- to 24-months in between each screening, which was longer than the 12 months recommended by some U.S. organizations such as the American Cancer Society, but not the 24-month screening interval recommended by the United States Preventive Services Task Force (USPSTF).
Also, women with high BMI were much lesser in Sweden when compared to the U.S.
Dr. Strand intends to study further at how breast density is linked with delayed detection. In the long run, Dr. Strand wants to study if artificial intelligence could be a way to triage mammographic screening into different pipelines based on the risk of breast cancer and the detectability of a potential tumor.