Approximately 13% of women will be diagnosed with breast cancer at some point in their life. In 2024, there have so far been an estimated 310720 new cases of female breast cancer in the US and 42250 estimated deaths, representing nearly 7% of all cancer deaths in the country. While the death rate for breast cancer has been decreasing over the last few decades, the rate of new cases has been increasing.1
At the Endocrine Society’s 2024 annual meeting, held June 1 to 4 in Boston, Massachusetts, 2 posters presented at the conference looked deeper into breast cancer, examining excessive weight gain in survivors of breast cancer and how high insulin levels can impact outcomes for Black women with an aggressive form of the disease.
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In the first poster, a team of investigators from the Mayo Clinic conducted a retrospective study to describe weight trends in breast cancer survivors and to identify predictors of weight gain after a breast cancer diagnosis.2 Data for the study was gathered from the Mayo Clinic Breast Cancer Registry, which included over 10000 patients who were diagnosed with breast cancer within the last year. Data on weight was taken at baseline and at years 1, 4 and 6.
The study cohort included 4744 patients of which 95% were white, 43% had clinical stage 1 breast cancer, 83% had ER+ and 76% had PR+. Of those, 62% underwent breast preserving surgery, 54% received radiation, 36% received systemic chemotherapy, and 61% received endocrine therapy.
Investigators found that weight change at 1 year was negligible compared to baseline. However, at years 4 and 6, there were small but significant average weight increases. At years 1, 4 and 6, the percentage of breast cancer survivors who gained over 10% of their baseline weight was 10%, 15% and 18%, respectively. Additionally, baseline characteristics associated with weight gain at 6 years included lower baseline weight, younger age at diagnosis, more advance disease stage, and the use of either systemic chemotherapy or endocrine therapy.
“The variables we found to be associated with excess weight gain could be used as predictors of weight gain in this population,” Maria Daniela Hurtado Andrade, MD, PhD, lead author on the study, said in a release.2 “Identifying these patients early in the survivorship course will allow us to institute measures to prevent excess weight gain, thereby improving breast cancer and cardiovascular disease outcomes.”
In the second poster, investigators from the Icahn School of Medicine at Mount Sinai conducted a study to examine if Black women with triple negative breast cancer have worse outcomes due to tumor promoting effects of hyperinsulinemia through the insulin receptor signaling pathway.3 Data was gathered from a previous study of women with newly diagnosed breast cancer that was conducted by the researchers.
The study cohort included 93 female patients, of which 48 self-identified as White and 45 as Black. Investigators performed immunohistochemistry analysis of formalin-fixed-paraffin-embedded tumor samples and quantified the breast cancer expression of insulin receptor, IGF1R, pERK, and FOXO3a for intensity, with 0 being none, 1 being weak, 2 being moderate and 3 being intense.
Investigators found that insulin receptor staining was seen in 64% of patient samples: 74% for IGF1R, 68% for FOXO3a and 43.3% for pERK. Positive insulin receptor staining was seen to be higher in Black patients compared to White patients. Additionally, higher BMI, waist circumference and fasting insulin were all associated with positive insulin receptor staining.
“Obesity and type 2 diabetes, which are more common in Black women, are associated with poor breast cancer outcomes,” Alexis Engel, BA, of the Icahn School of Medicine at Mount Sinai, said in a release.3 “Black women have higher rates of triple-negative breast cancer and have a greater risk of death from breast cancer in comparison to white women… These results suggest that high insulin levels in Black women may be contributing to cancer growth and worse breast cancer outcomes.”
Click here for more of our coverage from ENDO 2024.
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