A new study reveals that weight loss surgery (bariatric surgery) in appropriately selected patients may substantially reduce their risk of breast cancer.
Increased weight and obesity have been linked to an elevated risk of many cancers, including breast cancer in postmenopausal women.Read More
Breast Cancer: The Disease & Its Risk FactorsSecond only to skin cancer, breast cancer is the most common cancers among American women. The American Cancer Society estimates there will be around 300,000 new breast cancer cases in 2023. The precursor to breast cancer, ductal carcinoma in situ (DCIS), will be diagnosed in an additional 55,720 women during the same year. And 2023 will also see 43,000 breast cancer-related deaths.
The risk factors for breast cancer are well-studied. These factors are divided into non-modifiable factors that you cannot change, and modifiable factors that you can influence.
Some Non-Modifiable Risk Factors:
- Genetic Mutations: Although BRCA1 and BRCA2 mutations are the most well-known, there are numerous known and unknown genetic mutations that may influence the risk for breast cancer.
- Age: Your risk for breast cancer increases with age. On average, women are diagnosed with the disease at around 62 years of age. The risk is low for those younger than 45 years old.
- Reproductive and menstrual history: Women who start menstruation before 12 years of age or continue menstruating at age 55 or older are at higher risk of getting the disease.
- Family history of breast or ovarian cancer, especially if the afflicted family members are mothers, sisters, or daughters (termed first-degree relatives). Having other family members with cancers may also increase the risk.
Some Modifiable Risk Factors:
- Being overweight or obese: Post-menopausal women who are overweight or obese have a higher risk of developing breast cancer as compared to someone with a healthier weight.
- Alcohol use or abuse: The more alcohol a woman drinks, the higher her risk of developing getting breast cancer.
- Reproductive and breastfeeding history: Women who have never experienced pregnancy or breastfed are at higher risk.
- Hormone use: Some women may use estrogen and progesterone to manage symptoms of menopause. Birth control pills and other methods may contain these hormones as well. Exposure to such therapies over a few years may raise the risk of breast cancer.
Excess Weight & Breast Cancer: It's A Little Complicated
At least thirteen different cancers have been linked to being overweight or obese. Breast cancer is one of them.
The link between weight and breast cancer has been extensively studied. However, this relationship is not very straightforward.
Studies link being overweight or obese before menopause to a 10-20% lower risk of breast cancer. However, after menopause, this relationship is reversed. Women who are overweight or obese after menopause are at a 20-60% higher risk for breast cancer than lean women.
Despite the dual relationship, the American Cancer Society advises women to maintain a healthy weight throughout their lives. This stems from the fact that most breast cancers start after menopause and weight gain from younger years can carry over into the older years.
Why There Is an Increased Breast Cancer Risk in Postmenopausal Women
The hormone estrogen is one of the major links between obesity and cancer.
The ovaries produce most of the estrogen in women prior to menopause. After menopause, the ovaries stop producing estrogen and the fat stores take over this role. They do so by converting androgens, which are hormones produced by the adrenal glands, into estrogen using aromatase, an enzyme present in fat cells.
The more fat a woman has, the more estrogen she is exposed to. This abnormal hormonal exposure can drive the formation of breast cancer.
Obesity can also lead to the development of insulin resistance and, eventually, type II diabetes, which is characterized by severely depressed insulin sensitivity. Both conditions cause increased blood insulin levels, which have been linked to an increased breast cancer risk in premenopausal women.
The Latest Study
Researchers and physicians have been investigating whether weight loss can reverse the increased risk in post-menopausal women. Furthermore, they want to know if the method of weight loss, such as physical activity, dietary modifications, or surgical interventions, has any bearing on the risk as well.
In the recent study, published in the journal JAMA Surgery, researchers selected 69,260 women without any history of breast cancer between 2019 and 2016. Of these, 13,852 underwent bariatric surgery for weight loss, while 55,408 did not.
These surgical and nonsurgical groups were further divided into 4 groups according to their body mass indexes (BMI, which is a measure of body weight in relation to height) for comparison purposes.
There were 659 cases of breast cancer during the study period. Women with normal BMIs one year after their surgeries had the same risk of breast cancer as those who started out with normal BMIs.
Notably, women who had overweight, obese, and very obese BMIs after their surgeries had a lower risk of breast cancer than those who had comparable BMI and did not receive surgery.
Where Does This Leave Us?
While the study does not tell us exactly why it happens, it demonstrates the positive effect of this weight loss surgery on breast cancer risk reduction. This should encourage eligible patients to discuss their candidacy for this surgery.
However, they should keep in mind that reducing the risk of breast cancer is not the main objective of this surgery. It is an extra perk.
Bariatric surgery is a major surgery. Potential candidates should thoroughly understand the risks, benefits, and implications of undergoing the procedure.
They may need to permanently alter their physical activities and eating habits post-surgery to reap all the benefits. They may also need additional supplements, as the surgery can affect their ability to absorb certain nutrients from their gastrointestinal tract.
Patients also need a good follow-up with their physicians, who can guide them as their bodies change and adapt after the surgery.
Lastly, the surgery can be a significant financial undertaking. While most insurance plans cover at least a part of this surgery, how much patients pay out-of-pocket can vary significantly.
- BMI > 40.
- BMI > 35 with significant health issues caused by obesity. These can include heart and kidney disease, diabetes, and sleep apnea.
- BMI > 30 with a health condition, such as diabetes, that is uncontrolled despite lifestyle and diet changes, and medical interventions.
Notably, these criteria do not currently include surgery for cancer risk reduction.
Questions To Ask Your Doctor?
It is a good idea to discuss how your current weight puts you at risk for breast cancer with your physician. Some questions to guide this discussion could include:
- Does my weight put me at an increased risk for breast cancer?
- Will losing weight help decrease my risk?
- Should I use lifestyle modifications, such as diet and exercise, alone to reduce my weight?
- Should I consider bariatric surgery?
- Am I a good candidate for the surgery?
- What benefits will I derive from the surgery?
- What will my risk of breast cancer be after the surgery?