What Is the STK11 Gene?
STK11, also sometimes known as LKB1, is a gene that tells your body to make an enzyme called serine/threonine kinase 11.
People who have a change, or mutation, in their STK11 gene, develop Peutz-Jeghers syndrome (PJS) — a condition that causes noncancerous and sometimes cancerous growths to form in the gastrointestinal tract. (1)
If You Carry an STK11 Mutation, What Cancers Are You at Risk For?
PJS may increase the risk of certain cancers, such as:
- Breast cancer
- Colon cancer
- Pancreatic cancer
- Stomach cancer
- Small bowel cancer
- Cervical cancer
- Endometrial cancer
- Ovarian cancer
- Lung cancer (2,3)
Additionally, PJS can cause cancerous or noncancerous tumors to form on the ovaries or testicles. You can inherit an STK11 abnormality from your parents. (4)
How Does STK11 Increase Your Risk for Cancer?
A normal STK11 gene produces serine/threonine kinase 11, which has several important jobs: (3,4)
- It acts as a tumor suppressor, which means it stops cells from growing uncontrollably or dividing too quickly.
- It helps certain cells correctly position themselves within tissues.
- It assists in determining how much energy a cell uses.
- It promotes a type of apoptosis — a process in which damaged cells die rather than replicate themselves and their genetic errors.
Can You Be Tested for STK11?
Yes, you can be tested for an STK11 gene mutation. Your doctor might recommend genetic testing if you have a family history of PJS, develop STK11-related tumors, or have other risk factors.
Genetic testing involves providing a sample of blood for doctors to analyze in a lab.
Not all people with PJS have mutations in the STK11 gene, so it’s important to remember that you can still have the condition without a positive result.
Testing during pregnancy can be done to see if your baby could be affected by an STK11 gene mutation.
You may want to see a genetic counselor if you’re thinking about testing. These experts can help you understand the pros and cons of having the test. (5)
Why Is It Important to Know if You Are at Risk for STK11?
Knowing you have an STK11 abnormality can help you determine your risk for developing certain cancers. This information is also helpful for family members who might be at risk, too.
If you have an STK11 mutation, you have a 50 percent chance of passing it on to each of your children. (4)
History of the STK11 Gene: When Was It Discovered?
The STK11 gene was first identified in 1998.
PJS was originally described in a pair of twin sisters back in 1895. But it didn’t become a named syndrome until 1954. (4)
What Do You Do if You Test Positive for STK11?
Finding out you have a genetic mutation can be scary. But identifying the STK11 abnormality could help you understand your cancer risk and alert other family members about their risks.
If you test positive for an STK11 mutation, your doctor will suggest you have earlier and more frequent cancer screening procedures. These may include any of the following:
- Yearly physicals
- CT scans, MRIs, upper endoscopies, and colonoscopies
- Breast exams, mammograms, and breast MRIs
- Imaging of the pancreas and bile ducts
- Pap smears, vaginal exams, and transvaginal ultrasounds
- Testicle exams and ultrasounds
Talk to your doctor about when you should start and how often you should continue having these tests.
Because your cancer risk is higher if you have an STK11 mutation, it’s a good idea to adopt healthy lifestyle habits. Eating lots of fruits and vegetables, getting plenty of exercise, and avoiding smoking are some simple ways to stay healthy. (5)