The Link Between Diabetes and Cancer

The link between diabetes and heart disease or kidney health is often discussed, and many people work with their doctors to take a proactive approach to both. But did you know that diabetes is also related to certain types of cancer? The relationship between cancer and diabetes is not definitive; just because you have diabetes does not mean that you are guaranteed to be diagnosed with cancer. Still, it's important to understand so you can watch for warning signs and focus on early prevention. Here, we'll explore the link between diabetes and cancer and some steps to help reduce your risk.

What is Diabetes?

Diabetes is a chronic condition that affects how your body handles blood sugar; you either don't make enough insulin or your body can't use it well. This can cause sugar to build up in your bloodstream, resulting in various complications. While type 1 and type 2 diabetes are most common, several other forms exist as well.

Type 1 diabetes usually starts in childhood or young adulthood, but it can also occur in adults. This is when the body’s immune system attacks the insulin-producing cells in the pancreas, so people make little or no insulin. Those with type 1 diabetes must take insulin shots every day to live.

Type 2 diabetes is the most common form, affecting about 90% to 95% of all individuals with diabetes. While it's more common in adulthood, type 2 diabetes in younger individuals is on the rise. It occurs when the body doesn't use insulin properly and builds a resistance to it. Type 2 diabetes is often linked to obesity, but there are several risk factors; weight is not the only determining factor. It can sometimes be managed with diet and exercise, but many people need diabetes medication or insulin over time.

Other types of diabetes include gestational diabetes, type 3c diabetes, cystic fibrosis diabetes, maturity onset diabetes of the young (MODY), and more. In all cases, high blood sugar over time can lead to things like heart disease, vision loss, kidney problems, and other complications. This is why managing blood sugar is so important.

What is Cancer?

Cancer is very different from diabetes. It refers to various diseases where cells grow uncontrollably and invade other tissues. In a healthy body, cells grow and die in a controlled way. Cancer cells ignore the normal “stop” and “die” signals; they multiply without control and can spread (metastasize) to other parts of the body. This uncontrolled growth can result in tumors or problems with nearby organs. Typically, the risk of cancer increases as people age, partly because the body becomes less capable of fixing DNA damage. There is also a relationship between diabetes and some cancers.

How Having Diabetes May Increase Cancer Risk

Research has found that diabetes may be a risk factor for the development of cancer. In fact, one study found that people with diabetes had about a 20% higher overall cancer risk compared to similar people without diabetes. The cancer incidence for liver and pancreatic cancers was especially notable, potentially because these organs are closely linked to insulin and diabetes. The study also found moderately higher risks for colon, kidney, and reproductive (uterine) cancers. There were also increases in bladder cancer, breast cancer, and other cancers that seem to be associated with diabetes.

A recent UK study found that people newly diagnosed with type 2 diabetes had much higher odds of some cancers: men had about a 48% higher risk of “obesity-related” cancers and women about 24% higher, compared to similar people without diabetes. In that study, the risk of liver cancer was nearly four times higher in men and almost five times higher in women with new-onset diabetes; pancreatic cancer risk was about 1.7–2× higher, and the risk of bowel cancer was 30% higher.

Other studies have reported similar findings in the past. Some reports note that diabetes is linked to higher rates of liver, pancreas, colon, uterine (endometrial), breast, and bladder cancers. Either way, the American Diabetes Association and the American Cancer Society seem to agree with this consensus, although more research is necessary.

By contrast, some cancers, like prostate or lung, do not seem to be higher in diabetes, and men with diabetes have slightly lower prostate cancer rates than men without diabetes. Still, people with diabetes are at an increased risk of several specific cancers, so it's important to talk to your doctor about early screening.

Understanding the Connection Between Diabetes and Cancer

Scientists think several factors explain the diabetes–cancer link. However, the association between diabetes and cancer has not been confirmed as causal, meaning that having diabetes does not inherently cause cancer. Instead, it's more likely that, since they share many of the same risk factors, type 2 diabetes and cancer are interconnected. Things that raise your risk of diabetes also raise your risk of cancer, which is why being proactive is so important. Some of the primary risk factors for both diabetes and cancer include:

High Blood Sugar

Living with diabetes means that there's an increased risk of having high amounts of glucose in the blood. While diabetes management can help keep these stable, prolonged periods of high blood sugar can damage cells and DNA over time. Cancer cells also tend to "eat" sugar and thrive on glucose, a concept known as the Warburg effect. So, high rates of blood sugar could increase the risk for cancer cells to grow out of control.

High Insulin Levels

In the early stages of type 2 diabetes, the body often responds to insulin resistance by making extra insulin. Insulin is a growth hormone that tells cells to grow and divide. Many cancer cells have insulin receptors, so high insulin can act like a fertilizer for tumors. Studies note that increased insulin levels promote cancer growth because certain cancers respond to insulin.

Excess Body Fat and Hormone Changes

About 90% of people with type 2 diabetes are overweight or obese. And fat isn't just inert; it makes hormones. This means that extra fat can increase estrogen and insulin in the body, which can encourage cancers of the breast, uterus, liver, and others. Fat can also create low-level chronic inflammation throughout the body, further increasing cancer risk by damaging cells and DNA. Chronic inflammation can also be triggered by high blood sugar.

Shared Lifestyle Factors

Finally, many people with diabetes share common cancer risk factors. For example, older age raises both diabetes and cancer risk, and lack of exercise and poor diet similarly increase both. Smoking and heavy alcohol use also raise the risk of type 2 diabetes as well as many cancers.

In short, experts believe that diabetes creates a body environment where cells get extra fuel and growth signals, and inflammation and hormones work in favor of tumor growth. This combination of high sugar, high insulin, extra fat, and chronic inflammation helps explain why certain cancers occur more often in people with diabetes. Still, more research is needed to understand the connection.

Reducing Your Cancer Risk with Diabetes

The good news is that many diabetes management or type 2 diabetes prevention steps also lower cancer risk. Some of the most important measures to take include the following:

Maintain a Healthy Weight

Being overweight can make you more likely to develop certain types of cancers and increase your risk of diabetes or diabetes-related complications. Even losing just 5% to 10% of your body weight can substantially impact. Always talk to your doctor before embarking on a weight-loss journey, and try to lose weight by focusing on a healthy diet with plenty of vegetables, fruits, whole grains, and lean proteins. Crash diets can be dangerous, especially when living with diabetes, so it's not worth the risk.

Increase Your Physical Activity

Regular activity helps keep blood sugar in check and can reduce abdominal fat. The CDC notes that meeting the 150-minute per week goal (or more) lowers risks for heart disease, diabetes, and cancer. Even breaking exercise into short 10-minute walks throughout the day can help.

Quit Smoking and Limit Alcohol

Smoking is the leading cause of many cancers, and it also increases the risk of diabetes and associated complications. If you smoke, quitting is one of the single best things you can do for your health. The same goes for drinking alcohol in excess. If you're struggling with either, talk to your doctor for recommendations or referrals to specialists.

Manage Blood Glucose Levels

Managing diabetes is also extremely important, so always work with your doctor and take any medications or insulin as prescribed. It's also important to continue monitoring your blood sugar levels. Although some research suggests that the diabetes drug metformin may lower cancer risk, possibly because it improves insulin sensitivity, always follow your doctor’s advice on medication.

Undergo Regular Cancer Screenings

Regular cancer screenings help catch cancer early when it’s most treatable. People with diabetes should be especially vigilant about recommended tests (like colonoscopy, mammogram, Pap smear, or prostate exams as appropriate by age and sex). Don’t skip these check-ups; early detection saves lives.

When to See Your Doctor

While preventative tips can help you reduce your risk, cancer may still occur. That's why working with your doctor and undergoing screenings based on your risk factors and family history is important. If you do receive a diagnosis, starting cancer treatment early can make a big difference in long-term prognosis. To help with diabetes management, Byram Healthcare is here. We carry a range of diabetes supplies that can be discreetly delivered to your door. Explore our diabetes products or contact us today to learn more about how Byram can help you stay proactive about your health.