When you think about obesity, you may not connect it to cancer. However, researchers long have suspected a link between certain cancers and weight. Among those are endometrial, ovarian, colon, liver, pancreatic and postmenopausal breast cancers, which together contribute to 15 to 20% of all cancer deaths in the U.S.

Cancer risk increases with obesity

More than one-third of adults in the U.S. are considered obese with a body mass index (BMI) of 30 or higher. BMI is the measure of body fat of body fat based on weight and height. The number of people with severe obesity, which is a BMI of 40 or higher, has increased significantly. According to one study in the New England Journal of Medicine, if a person's BMI goes up by even five points, their cancer risk increases by 10%.

Those who are obese are two times more likely to develop cancer than those of optimal weight. For example, the risk for endometrial cancer increases sevenfold with a BMI of more than 40.

The greater risk of cancer appears to be due to excess body weight in the form of fat. Obesity causes fat cells in the body to increase. As the number of these fat cells goes up, the body's release of hormones changes. These changes tend to increase pro-inflammatory hormones and estrogen. This chronic inflammatory state can lead to damage in cells and the DNA in them, increasing the risk of certain types of cancers.

Researchers are studying the role body fat plays in chronic inflammation. In addition, hormones like estrogen and insulin resistance can lead to chronic metabolic diseases, including diabetes. By 2050, the Centers for Disease Control estimates that 1 in 3 adults will have diabetes along with its associated health complications.

Bariatric surgery and reduction of cancer risk link

Researchers believe a decrease in inflammatory fat cells could reduce cancer risks, but more research is needed. And it's still unknown to what extent cancer risk is reversed with nonsurgical, also called intentional, weight loss.

But for anyone who has lost weight with lifestyle changes, the challenge is keeping it off. The body has many complex neurohormonal systems in place to avoid starvation, making it difficult to maintain weight loss.

At this time, bariatric or metabolic surgery is the most effective treatment for obesity available, even when compared with medications and intensive lifestyle therapy. After surgery, people typically lose 50 to 70% of their excess weight or 25 to 35% of their total body weight, which often is sustained for many years.

Continuing research

Several large studies have been conducted to explore the link between weight loss through bariatric surgery and the reduction of cancer risk.

In a 2019 article in the Annals of Surgery, more than 22,000 people who had bariatric surgery were compared with 66,000 who didn't. The study participants were matched by sex, age, study site, BMI and other factors. Statistical models were used to look at the incidence of cancer up to 10 years after bariatric surgery compared to nonsurgical participants.

Those who had undergone bariatric surgery had a 33% lower risk of developing any type of cancer during the follow-up period compared to those who didn't have bariatric surgery. The results were even stronger when the outcome was restricted to obesity-associated cancers.

A 2022 study in the Journal of the American Medical Association followed 30,000 people, all with a BMI greater than 35. The participants were divided into two groups and matched by factors including age and sex. One group of about 5,000 patients had undergone bariatric surgery; the other group of just over 25,000 patients didn't have surgery. The median follow-up period was about six years.

The follow-up showed that bariatric surgery was associated with a significant reduction in the risk of obesity-related and other cancers. It also showed that patients who had undergone bariatric surgery had a decrease in cancer-related deaths compared with those who didn't have the surgery.

Researchers continue to delve into why and how bariatric surgery is reducing the risk of cancer and diabetes, and more studies are needed to confirm these results. However, there is promise for patients struggling with obesity that bariatric surgery can decrease metabolic diseases like diabetes and possibly the risk of cancer.

If you're considering bariatric surgery, this new evidence about its effectiveness and benefits may help you decide. It's another topic to discuss with your primary care provider or bariatric surgery team.

Maria Linnaus, M.D., is a bariatric surgeon in Eau Claire, Wisconsin.

This article originally published on the Mayo Clinic Health System blog.

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DEAR MAYO CLINIC: My mom was diagnosed with breast cancer. During her care, she was found to have a BRCA2 mutation. Her doctor suggested that my brothers and I get tested for this mutation, too. I am a 26-year-old woman, and I am not sure what this means for me and my risk of cancer.

ANSWER: Having a loved one with a breast cancer diagnosis can be scary. It also can become confusing when you start to hear about genetic mutations. The good news is that the information can help guide your family regarding screening and future cancer risk.

BRCA2 is a genetic abnormality that can be passed down from a parent to children. It is autosomal dominant, which means there is a 50% chance that each of your mom's biological children could have the mutation. Being positive for the mutation would mean that you or your brothers may be at increased risk of developing certain cancers, compared to the general population.

In addition to breast cancer, these cancers are also known to be associated with BRCA2: ovarian cancer, melanoma, prostate cancer and pancreatic cancer.

To understand your risk, you would want to meet with a genetic counselor who can help you understand the implications of undergoing genetic testing and whether this is something you want to do. Typically, genetic testing is performed using a blood or saliva sample. The counselor would review the results with you and, if you are positive, recommend next steps to learn more about personalized screening and specific risk reduction options.

Generally speaking, it is recommended that women who have a BRCA2 mutation begin monthly breast self-examinations, beginning at 18. Clinical breast examinations are recommended every six months, beginning at 25, or before if there is an earlier breast cancer in the family. Annual breast MRIs should begin at 25. Tomosynthesis mammograms are recommended annually, beginning at 30. They are usually alternated with breast MRIs every six months. Based on risk and family history, some woman may choose to undergo a preventive mastectomy to remove their breast tissue and hopefully decrease their risk of developing breast cancer.

There is no screening test for ovarian cancer. However, women can have transvaginal ultrasounds and a blood test called CA 125 every six to 12 months, beginning at ages 30–35, while their ovaries are still in place.

If desired, women can undergo surgery to remove their ovaries and fallopian tubes once they are done having children. Ideally, this would occur between the ages of 40–45. As this surgery results in women going through menopause, some women may be started on hormone therapy until ages 50–51 to alleviate menopausal symptoms and offset some long-term risks associated with early menopause.

Research has shown that many ovarian cancers begin in the fallopian tubes. With this knowledge, women have recently been having surgery to remove their fallopian tubes and delay surgery to remove their ovaries for a few years ― though the recommended age for a woman to have her ovaries removed is still 40–45 in a BRCA2 mutation carrier. The benefit of removing just the fallopian tubes is that this allows women to preserve their natural hormonal function longer. The safety of this strategy is being studied, and this type of surgery is being performed as part of clinical trials.

Women who undergo surgery to remove their ovaries before menopause have a 50% reduction in their risk of developing breast cancer. In addition to surgeries, there are medications that can be given to help decrease the risk of developing breast and ovarian cancers. Selective Estrogen Receptor Modulators (SERMS) and Aromatase Inhibitors (AIs) are types of medications that can reduce the risk of developing breast cancer. Oral contraceptives can decrease the risk of developing ovarian cancer by 50%.

Since the BRCA2 mutation can be passed down to offspring, understanding your status ― and that of a future partner ― is important, as there is a genetic condition called Fanconi anemia that can occur if both the male and female partners have a BRCA2 mutation.

Thus, for men and women who test positive for BRCA2 and have not yet had biological children, it may be worthwhile to meet with a specialist in reproductive endocrinology and infertility to discuss options.

There are no standard screening guidelines for pancreatic cancer or melanoma. Based on your situation, a consultation with a pancreatic specialist may be worthwhile to discuss whether to pursue MRI or endoscopic ultrasound. Likewise, a referral to a dermatologist can be made to initiate skin cancer screenings.

Understandably, you may be nervous about your risk for cancer, given your mother's diagnosis. However, you are young, and you should not feel rushed to make any decisions regarding genetic testing. If you choose to undergo testing and are found to have a BRCA2 mutation, your health care providers will give you the information that you need so that you can begin to think about what makes sense for your life and your priorities. — Casey Swanson, physician assistant, Gynecologic Surgery, Mayo Clinic, Rochester, Minnesota

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Related Articles 

• Mayo Clinic Q and A: Family health history information published 12/20/20
• Science Saturday: The benefits of genetic testing for healthy people published 12/19/20
• Mayo researchers recommend all women with breast cancer diagnosis under age 66 be offered genetic testing published 3/2/20
• Living With Cancer: Emotional and psychological considerations before genetic testing for breast cancer risk published 12/6/19
• Expert Alert: Genetic testing can lead to better cancer screening, interventions published 6/3/19
• Housecall: Genetic testing — is it right for you? published 4/22/19

The post Mayo Clinic Q and A: Genetic abnormalities and cancer risk appeared first on Mayo Clinic News Network.

When cancer returns: How to cope with a recurrence 
A cancer recurrence happens because, despite the best efforts to help you become cancer-free, some cancer cells remained. Cancer can recur in the same place it was located originally, or it can spread to other parts of the body. Cancer recurrence can bring back many of the same emotions you felt when you were first diagnosed with cancer. Learn more about the science behind cancer recurrence, and how to handle the anger, distress and self-doubt you may feel if your cancer returns.

Treating lung cancer 
Lung cancer is the leading cause of cancer deaths in the U.S. Lung cancer claims more lives each year than colon, prostate, ovarian and breast cancers combined. Treatment options for lung cancer include surgery, radiation therapy, chemotherapy, radiosurgery, targeted drug therapy and immunotherapy. You and your health care provider will choose a cancer treatment plan based on a number of factors, such as your overall health, the type and stage of your cancer, and your preferences. Learn more about each of these treatment options and which might be best for you.

The post Living With Cancer: 7 steps to reduce your risk of cancer appeared first on Mayo Clinic News Network.

ANSWER: This is a wonderful question. Although each individual’s risk of cancer is different, depending on factors such as medical history, family history and ethnic background, research clearly shows there are several significant lifestyle changes that can lower the risk of cancer.

A recent study by the American Cancer Society found that 45 percent of cancer deaths and about 40 percent of diagnosed cancer cases can be attributed to risk factors you can do something about.

Not surprisingly, the one that has the biggest effect is smoking and other forms of tobacco use. Awareness about the health risks of smoking has grown significantly. Accordingly, the number of lung cancer deaths attributed to smoking is declining. But smoking remains the largest preventable cause of cancer.

The best approach to smoking is not to start. If you smoke, however, stopping now will make a difference. Quitting smoking or other use of tobacco significantly lowers your risk of lung cancer, as well as cancers of the mouth, throat and esophagus; bladder; kidney; and pancreas.

Another lifestyle factor to consider is sun exposure. Unlike lung cancer, which is decreasing, skin cancer is rising. Many cases of skin cancer are related to the effects of too much time in the sun without proper skin protection. Take precautions whenever you’re in the sun. Wear a broad-spectrum sunscreen with a sun protection factor, or SPF, of at least 30. Reapply it often. Avoid the midday sun. Wear protective clothing, sunglasses and a hat with a wide brim. If you’re a parent, take extra care to shield your children from the sun. People who have multiple blistering sunburns as children are at high risk for developing melanoma — a particularly dangerous form of skin cancer.

A third way you can lower your risk of cancer is to be careful with the amount of alcohol you drink. Excessive alcohol has been shown to contribute to liver, stomach, mouth and throat cancer. To stay in the low-risk range, women should have no more than three drinks in any one day and no more than seven drinks a week. For men, it is no more than four drinks a day and no more than 14 drinks a week.

Controlling your weight makes a difference, too. This risk affects men and women, but it seems to have a greater effect on women. Research has found that women who are obese are at increased risk for breast and uterine cancer. Several other factors often act in conjunction with weight to raise cancer risk. They include a diet high in fats, lack of regular exercise and a sedentary lifestyle. When these factors are combined, they increase the risk of multiple types of cancer in men and women.

Vaccinations also help prevent certain types of cancer. Vaccination against the hepatitis B virus decreases the risk of liver cancer. The HPV vaccine is recommended for all boys and girls before they become sexually active because it can prevent the most common cause of cervical cancer and penile cancer, as well as cancers of the throat and mouth.

Although the factors mentioned here are not the only ones that affect your cancer risk, they are some of the most significant, modifiable risk factors that apply to everyone. If you’d like to learn about your specific cancer risk, have a discussion with your health care provider about your individual risk factors and how you may be able to lower your overall risk for cancer. — Dr. Timothy Moynihan, Medical Oncology, Mayo Clinic, Rochester, Minnesota

The post Mayo Clinic Q and A: Lifestyle changes that can lower your risk of cancer appeared first on Mayo Clinic News Network.

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Need practical advice on diet and exercise? Want creative solutions for stress and other lifestyle issues? Discover more healthy lifestyle topics at mayoclinic.org.

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Here's the Mayo Clinic Radio podcast.

The post Hepatitis C / Food Allergies / Hemorrhoids / Cancer and Luck: Mayo Clinic Radio appeared first on Mayo Clinic News Network.

On Mayo Clinic Radio, infectious diseases specialist Dr. Stacey Rizza outlines the risk factors for contracting hepatitis C, especially for people born between 1945 and 1965. Also on the program, allergy specialist Dr. Rohit Divekar explains why it's important to diagnose food allergies before they lead to life-threatening reactions. Colorectal surgeon Dr. John Pemberton discusses the causes of hemorrhoids and how they're treated. And, does luck play a role in whether or not you get cancer? Oncologist Dr. Timothy Moynihan reviews studies that analyze luck and cancer risk.

The post 4/16/16 #MayoClinicRadio Podcast: Hep C, Food Allergies, Hemorrhoids appeared first on Mayo Clinic News Network.

Myth or Matter-of-Fact: Hepatitis C is one of the leading causes of liver cancer, and the primary reason for liver transplant.

Listen to the program on Saturday, April 16, at 9:05 a.m. CDT, and follow #MayoClinicRadio.

Mayo Clinic Radio is on iHeartRadio.

Access archived shows.

Mayo Clinic Radio is a weekly one-hour radio program highlighting health and medical information from Mayo Clinic.

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Myth or Matter-of-Fact: Hepatitis C is one of the leading causes of liver cancer, and the primary reason for liver transplant.

Listen to the program on Saturday, April 16, at 9:05 a.m. CDT.

Miss the show?  Here's the Mayo Clinic Radio podcast.

Follow #MayoClinicRadio, and tweet your questions.

Mayo Clinic Radio is on iHeartRadio.

Mayo Clinic Radio is a weekly one-hour radio program highlighting health and medical information from Mayo Clinic.

Access archived shows.

The post Mayo Clinic Radio: Hepatitis C / Food Allergies / Hemorrhoids / Cancer and Luck appeared first on Mayo Clinic News Network.

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