Many people choose weight-loss surgery (also called bariatric surgery) to address health conditions such as type 2 diabetes or sleep apnea. However, in our bariatric surgery and oncology practices at Temple Health and Fox Chase Cancer Center, we’ve found that our patients are often surprised to learn that weight loss may do more than improve or resolve current health concerns. It may also reduce their risk for cancer in the years and decades.
Research has demonstrated a clear link between excess body weight and several types of cancer. Weight-loss surgery at Temple can help people reach and maintain a healthy weight, reducing that risk.
That matters. As we tell our patients, when it comes to cancer, prevention is the best medicine of all. That’s why we’re sharing the answers to some of the questions we often hear about the connection between weight and cancer — and how bariatric surgery can help.
How does excess weight raise the risk of cancer?
When we talk about obesity — a condition where the body stores too much fat — we often say fat is like a storage system, where the body keeps extra energy. While that's true, it's also important to know that the stored fat, called adipose tissue, is not inactive. It's very active and plays a complex role in hormone production and increased inflammation.
Adipose tissue is responsible for the increased production of estrogen, a sex hormone linked to an increased risk of breast and gynecologic cancers. High levels of estrogen can lead to breast cancer in women and men. Peripheral body fat can convert testosterone into estrogen.
Excess body fat also increases the production of insulin, another hormone. That can lead to type 2 diabetes, another risk factor for cancer. Insulin itself can lead to cancer. High blood levels of insulin or insulin-like growth factor-1 (IGF-1) appear to increase a person’s risk of colon, kidney, prostate, and endometrial cancers.
Adipose cells also increase inflammation by producing adipokine, a type of cytokine. Cytokines are proteins that affect the body’s immune system. Chronic inflammation is thought to put stress on the cells and damage the DNA, which increases the risk of cancer. Adipokines, such as leptin, act as hormones that stimulate cell growth. That may stimulate the growth of cancerous tumors.
Which cancers are linked to excess body fat?
Compared to people whose BMI is 25 or lower, those with a higher BMI are at increased risk for at least 13 kinds of cancer. That includes:
- Adenocarcinoma of the esophagus
- Breast cancer
- Cancer of the upper stomach
- Colon and rectal cancer
- Endometrial cancer (a cancer of the uterus)
- Gallbladder cancer
- Kidney cancer
- Liver cancer
- Meningioma, which is cancer of the brain or spinal membrane
- Multiple myeloma
- Ovarian cancer
- Pancreatic cancer
- Thyroid cancer
Almost 5% of new cancer cases in men and 10% of new cancer cases in women can be attributed to excess body weight.
When we discuss risk for cancer or other weight-related conditions with our patients, we look at the full picture of their health, not simply their weight or body mass index (BMI). But while BMI doesn’t reflect the complexities of an individual’s health, it’s a common metric used in studies investigating how much weight affects the risk for cancer. And those studies show that the risk for specific cancers increases significantly with BMI. For example, after menopause, the risk of breast cancer increases by 20% with every five-unit rise in BMI.
One particularly distressing fact is that cervical cancer screenings are less effective in women with higher weights. A study found higher rates of cervical cancer diagnoses in people with higher weights. However those patients had negative human papillomavirus screenings. Experts are still exploring why.
Does weight-loss surgery lower cancer risk?
Yes. Research is ongoing, but when people with excess body fat intentionally lose more than 5% of their body weight, their cancer risk appears to decrease. Bariatric surgery can help patients lose more weight than exercise and diet alone. At Temple, it’s common for patients to reduce their excess weight by 50% to 80%. The outstanding support patients at the Temple Bariatric Program receive before and after their surgery helps them to maintain their weight loss in the years ahead.
One recent study found that patients who reduced their body weight through bariatric surgery had a 32% lower risk of developing cancer and a 48% lower risk of cancer-related death compared to similar patients who did not have bariatric surgery. The effect is particularly strong among women with a 60% lower risk for certain cancers after bariatric surgery.
What if I’ve already been diagnosed with cancer?
Reaching and maintaining a healthy weight helps cancer survivors, too, during and after treatment.
Healthy weight loss can improve survival rates — and improve outcomes in other ways, too. Obesity raises the risk for certain treatment outcomes that can affect quality of life, including the risk of developing lymphedema, a build-up of fluid in an arm or leg that may occur as a result of cancer treatments, and the risk of experiencing incontinence after treatment for prostate cancer.
While more research is needed, there’s some evidence that maintaining a healthy weight may help reduce the risk that cancer, such as breast cancer, will recur.
And, importantly, the cancer survivors we treat tell us that they have a higher quality of life after bariatric surgery. They can be more active, improve their mood, and feel better.
It appears that excess weight can worsen cancer progression, prognosis, and risk of recurrence or developing another cancer. So, it’s never too late for cancer survivors to benefit from bariatric surgery.
What’s the next step?
Register for an upcoming live virtual seminar if you’d like to learn more about bariatric surgery and how it could help reduce your risk of cancer. An experienced bariatric surgeon will explain the process and answer your questions.
Helpful Resources
Looking for more information?
- Learn more about Bariatric Surgery at Temple
- Do I Qualify for Weight-Loss Surgery?
- Patient Support for Bariatric Surgery
