Scientists have long known that smoking increases the risk of many types of cancer, including pancreatic cancer.
But a new study by researchers at the University of Michigan Health Rogel Cancer Center now explains exactly how smoking makes pancreatic cancer more aggressive and harder to treat.
Their findings could change how doctors treat smokers who are diagnosed with this deadly disease.
Pancreatic cancer is one of the most dangerous cancers because it grows quickly, spreads easily, and is often found too late.
Many patients don’t show symptoms until the cancer is advanced. This makes it very hard to treat. On top of that, people who smoke are not only more likely to get pancreatic cancer but also tend to have worse outcomes.
In this new study, scientists gave a chemical found in cigarette smoke to mice that already had pancreatic tumors. They wanted to see how this chemical affected a protein in the body called interleukin-22, or IL22. This protein is made by certain immune cells and plays a role in how tumors grow.
What they found was alarming. The cigarette chemical made the tumors grow much larger and spread to other parts of the body. This showed the researchers that smoking-related toxins can make pancreatic cancer grow faster. But the most interesting part came when they looked at how the immune system was involved.
The scientists discovered that a special type of immune cell called a T-regulatory cell, or Treg, was playing a big role. These cells usually help keep the immune system from attacking healthy parts of the body.
But in this case, they were doing two harmful things. First, they were producing a lot of IL22, which helped the tumor grow. Second, they were stopping the immune system from attacking the tumor. This created a perfect environment for cancer to spread.
When researchers removed these Treg cells from the mice, the tumors stopped growing even when the mice were still exposed to the cigarette chemical. This proved that these immune cells were a key part of the problem.
The researchers then looked at human cells and samples from people with pancreatic cancer. They found the same thing: smokers had more of these harmful Treg cells than non-smokers. Even more promising, when they used a drug that blocked the cigarette chemical, the tumors started to shrink.
This discovery could lead to new treatments. If scientists can create drugs that block the effects of cigarette toxins or stop the harmful immune response, they may be able to help people with pancreatic cancer—especially smokers.
This research also suggests that smokers with pancreatic cancer may need different treatment plans than non-smokers. It may also be wise to screen smokers more carefully for signs of pancreatic cancer.
The disease is hard to detect early, but warning signs can include back pain, yellowing skin, or sudden weight loss. People with a family history of pancreatic cancer or other pancreas problems should be especially careful and avoid smoking.
This study adds to the growing body of evidence showing how dangerous smoking can be—not just for causing cancer, but also for making it harder to treat. It also highlights the importance of understanding how environmental toxins like cigarette smoke can change the body’s immune response.
Review and analysis: This study shows that chemicals in cigarettes can wake up a dangerous type of immune cell that helps tumors grow and stops the body from fighting back. The discovery of this “super suppressive” cell gives scientists a new target for future treatments.
Blocking the signal from cigarette toxins could not only stop tumors from growing but might also help existing cancer therapies work better. Future research will look at turning these discoveries into real treatments and screening tools for those most at risk.
If you care about cancer, please see recent studies about new way to increase the longevity of cancer survivors, and results showing new way to supercharge cancer-fighting T cells.
For more information about health, please see recent studies about how drinking milk affects risks of heart disease and cancer and results showing that vitamin D supplements could strongly reduce cancer death.
The study is published in Cancer Discovery.
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