Does diabetes increase cancer risk? Type 2 diabetes is linked to a higher risk of some cancers, but not all of them, and a link is not the same as a cause. The American Cancer Society (ACS) says people with type 2 diabetes can have a higher risk of colorectal, liver, gallbladder, breast, pancreatic, and endometrial cancer. ACS also says that having type 2 diabetes does not mean you will get cancer, and that many people with type 2 diabetes never develop it.
Key takeaways
- The American Diabetes Association (ADA) says diabetes is associated with a higher risk of cancers of the liver, pancreas, endometrium, colon and rectum, breast, and bladder.
- A 2020 pooled analysis of 151 studies found risks ranging from lower for prostate cancer to more than double for liver cancer. These are group numbers, not predictions for one person.
- Part of the link comes from shared risk factors such as older age, excess weight, inactivity, and smoking. Researchers also study insulin, inflammation, and high blood sugar.
- Most research is about type 2 diabetes. A 2010 consensus report said few studies had looked at type 1.
- ADA and ACS both point to recommended cancer screening and to the same everyday habits: a healthy weight, regular activity, no tobacco, and little or no alcohol.
Diabetes and Cancer: The Short Answer
- There is a link for some cancers. The link is strongest for liver, pancreatic, and endometrial cancer.
- A link is not proof of cause. ACS says researchers are still working to understand exactly how type 2 diabetes and cancer are connected.
- Shared risk factors explain part of it. Weight, inactivity, diet, age, and smoking raise the risk of both.
- One cancer, prostate, is less common in people with diabetes. Researchers are still working out why.
- Many people with type 2 diabetes never develop cancer. The habits and screenings below are the steps ACS and the ADA point to for lowering risk.
Which Cancers Are Linked to Diabetes?
| Cancer | What the sources say |
|---|---|
| Liver | One of the strongest links: about twofold or higher in the 2010 ADA and ACS consensus report, and a relative risk of 2.23 in a 2020 meta-analysis |
| Pancreas | About twofold or higher in the 2010 report. The link runs both ways, because pancreatic cancer can also cause diabetes (see our guide on whether diabetes can be a sign of pancreatic cancer) |
| Endometrium (lining of the uterus) | About twofold or higher in the 2010 report. ACS lists metabolic syndrome, which usually includes obesity, diabetes, and high blood pressure, as linked to higher endometrial cancer risk |
| Colon and rectum | A smaller increase, about 1.2 to 1.5 times, in the 2010 report. ACS says the risk stays higher in type 2 diabetes even after weight and inactivity are taken into account |
| Breast | A smaller increase, about 1.2 to 1.5 times, in the 2010 report |
| Bladder | A smaller increase, about 1.2 to 1.5 times, in the 2010 report |
| Prostate | Less common in men with diabetes in the 2010 report and the 2020 meta-analysis (relative risk 0.83) |
| Lung | The 2010 report said lung cancer does not appear to be more common in diabetes |
| Kidney, non-Hodgkin lymphoma | The 2010 report called the evidence inconclusive |
The lists from different groups are not identical. The ADA's Standards of Care in Diabetes—2026 name bladder cancer, and ACS's type 2 diabetes page names gallbladder cancer instead. Both agree on liver, pancreas, endometrium, colon and rectum, and breast. Different lists reflect which studies each group summarized.
How Big Is the Increase?
A relative risk compares two groups. A relative risk of 2 means a cancer was diagnosed about twice as often in people with diabetes as in people without it. It does not tell you how likely any one person is to get that cancer. When a cancer is uncommon to begin with, even a doubling leaves most people never developing it.
The 2010 consensus report, written by an expert panel convened by the ADA and ACS, put the increase at about twofold or higher for liver, pancreas, and endometrium and about 1.2 to 1.5 times for colon and rectum, breast, and bladder. The report's recommendations are the authors' opinions and not an official position of either organization. A 2020 meta-analysis in Diabetes Care pooled 151 cohorts covering more than 32 million people and 1.1 million cancer cases. It found type 2 diabetes was linked to cancer risk ranging from a relative risk of 0.83 for prostate cancer (95% confidence interval 0.79 to 0.88) to 2.23 for liver cancer (95% confidence interval 1.99 to 2.49).
The authors also tested how much unmeasured factors, such as weight, could change the results. They concluded that the findings strongly suggest a causal association between type 2 diabetes and liver, pancreatic, and endometrial cancer, and that the associations with other cancers were less robust. In plain terms, shared risk factors could explain more of the smaller increases.
Why Might Diabetes and Cancer Be Linked?
ACS describes two kinds of explanation, and says the connection is complex and more research is needed.
Shared risk factors. ACS lists excess body weight, not getting enough physical activity, an unhealthy diet, and smoking as risk factors for both. The ADA names older age, obesity, and physical inactivity. The 2010 report added that the link between diabetes and some cancers may partly reflect these shared factors.
Changes in the body in type 2 diabetes. ACS says these may also help explain the higher risk:
- High insulin levels. People with type 2 diabetes often have a lot of insulin in the blood, especially early on, and insulin can act like a growth signal.
- High IGF-1. High insulin leads the body to make more of this growth protein.
- Ongoing low-level inflammation. Over time this can damage DNA.
- High blood sugar. ACS says researchers are still studying how much of a direct role blood sugar plays on its own.
The ADA adds that diabetes treatments or underlying disease physiology could play a part, although it says evidence for these links is scarce. Our guide on whether diabetes medicines affect cancer risk covers what is known about medicines.
What About Type 1 Diabetes?
The 2010 consensus report said the association with cancer was seen mainly in type 2 diabetes and that few studies had explored type 1. Most of the numbers in this guide describe type 2. If you have type 1 diabetes, the screening and lifestyle steps below still apply to everyone, and your care team can say what applies to you. Our guide to type 1 versus type 2 diabetes explains the differences.
Why Prostate Cancer Is the Exception
The 2010 report found that prostate cancer is the only common cancer linked with a lower risk in diabetes. It was seen both before and after PSA blood testing became common, so differences in testing do not explain it. The report said some metabolic factors in diabetes, such as reduced testosterone levels, may be involved, although testosterone levels have not been consistently tied to prostate cancer. This is a pattern researchers are still explaining. It does not mean diabetes protects anyone.
What You Can Do
ACS lists these steps for people with type 2 diabetes who want to lower their cancer risk. The ADA points to the same modifiable risk factors: obesity, physical inactivity, alcohol use, and smoking.
| Step | What the sources say | Learn more |
|---|---|---|
| Follow your diabetes plan | ACS lists keeping blood sugar under control by following your treatment plan | Starting type 2 diabetes medication |
| Get to and stay at a healthy weight | The ACS diet and activity guideline says to keep weight within a healthy range and avoid weight gain in adult life | Insulin resistance and belly fat |
| Be physically active | The ACS guideline says adults should get 150 to 300 minutes of moderate activity or 75 to 150 minutes of vigorous activity each week, and limit sitting time | Post-meal walking |
| Eat a healthy pattern | ACS describes vegetables, fruits, whole grains, and legumes, and limiting red and processed meats, sugar-sweetened drinks, and highly processed foods | Insulin resistance diet |
| Avoid tobacco | Both ACS and the ADA list smoking as a modifiable risk factor | Smoking and blood sugar |
| Limit or avoid alcohol | The ACS guideline says it is best not to drink alcohol, and that anyone who does should have no more than 1 drink a day for women or 2 for men | Can diabetics drink alcohol? |
| Get recommended screening | The ADA says people with diabetes should be encouraged to get age- and sex-appropriate cancer screening, coordinated with their primary care clinician | Which cancer screenings do people with diabetes need? |
No habit guarantees that a cancer will not happen. ACS describes these as steps that help lower risk. The 2010 report also said that healthful diets, physical activity, and weight management reduce the risk and improve outcomes of type 2 diabetes and some forms of cancer, which is why they are worth doing for both reasons.
If You Have Diabetes and Cancer
The Centers for Disease Control and Prevention (CDC) says nearly 1 in 5 people with cancer also has diabetes. ACS says that if you have type 2 diabetes and have been diagnosed with cancer, your diabetes doctor and your cancer care team should work together on your care.
CDC explains that cancer treatment can change blood sugar in different directions. Chemotherapy side effects such as nausea and loss of appetite may make it hard to eat and could cause low blood sugar. Radiation can cause a spike in blood sugar. Hormone therapy can cause nausea and fatigue that make it harder to eat well and stay active. Steroids, which are often given with chemotherapy to lessen nausea and vomiting, raise blood sugar. Our guide on whether prednisone raises blood sugar covers that effect. CDC adds that managing blood sugar could benefit cancer treatment by lowering the risk of infections.
Questions to Ask Your Care Team
- Which cancer screenings are due for me at my age?
- Do my family history or other risk factors change that schedule?
- Do any of my medicines carry cancer-related warnings I should know about?
- Which of the steps above fit into my current plan?
- If I were ever treated for cancer, who would manage my blood sugar?
Frequently Asked Questions
Does diabetes cause cancer?
Diabetes is linked to a higher risk of some cancers, but a link is not proof of cause. ACS says researchers are still working to understand how type 2 diabetes and cancer are connected, and that shared risk factors and changes in the body both appear to play a part. ACS also says having type 2 diabetes does not mean you will get cancer.
Which cancers are most linked to diabetes?
The ADA lists cancers of the liver, pancreas, endometrium, colon and rectum, breast, and bladder. A 2010 consensus report found the largest increases, about twofold or higher, for liver, pancreas, and endometrium. ACS also lists gallbladder cancer.
Does type 1 diabetes raise cancer risk?
Most of the research is about type 2 diabetes. A 2010 consensus report said few studies had explored type 1, so the evidence is limited. Recommended cancer screening applies to people with type 1 diabetes the same way it applies to everyone of the same age and sex.
Does controlling blood sugar lower cancer risk?
ACS lists following your diabetes treatment plan among steps that help lower cancer risk, but it also says researchers are still studying how much of a direct role blood sugar plays on its own. No source cited here shows that a particular A1C target prevents cancer.
Do diabetes medicines change cancer risk?
The evidence is limited. The ADA says metformin and sulfonylureas may have anticancer properties, that data for pioglitazone are mixed, and that GLP-1 receptor agonists have not been shown to be associated with cancer in humans so far. Do not stop or change a medicine without asking your prescriber.
Should I get extra cancer screening if I have diabetes?
The ADA and the 2010 consensus report both say people with diabetes should get the screening recommended for everyone of the same age and sex. Family history, genetic factors, and other risks can change a screening plan, so ask your clinician what applies to you.
References
- American Cancer Society. "Type 2 Diabetes and Cancer." Accessed October 2026.
- Giovannucci E, Harlan DM, Archer MC, et al. "Diabetes and cancer: a consensus report." Diabetes Care. 2010;33(7):1674–1685. Accessed October 2026.
- Ling S, Brown K, Miksza JK, et al. "Association of type 2 diabetes with cancer: a meta-analysis with bias analysis for unmeasured confounding in 151 cohorts comprising 32 million people." Diabetes Care. 2020;43(9):2313–2322. Accessed October 2026.
- American Diabetes Association Professional Practice Committee for Diabetes. "4. Comprehensive Medical Evaluation and Assessment of Comorbidities: Standards of Care in Diabetes—2026." Diabetes Care. 2026;49(Suppl. 1):S61–S88. Accessed October 2026.
- American Cancer Society. "American Cancer Society Guideline for Diet and Physical Activity for Cancer Prevention." Accessed October 2026.
- American Cancer Society. "Colorectal Cancer Risk Factors." Accessed October 2026.
- American Cancer Society. "Endometrial Cancer Risk Factors." Accessed October 2026.
- Centers for Disease Control and Prevention. "I Have Diabetes and Cancer. What Can I Eat?" Accessed October 2026.
Next Steps
At your next visit, ask which cancer screenings are due and whether your family history changes the schedule. Add the one habit from the table above that is easiest to start this week.
For adults with type 2 diabetes or prediabetes who want lifestyle education alongside clinical care, the Done With Diabetes™ program, a natural protocol for type 2 diabetes, organizes learning about meals, movement, sleep, and stress. It does not diagnose or treat cancer or diabetes, recommend screening, interpret test results, change medicines, or replace your care team.