STK11 (Peutz-Jeghers Syndrome): Options for Managing Risk
Risk Management for People with Inherited Mutations
Experts at the National Comprehensive Cancer Network (NCCN) created guidelines for people with an inherited STK11 mutation to manage their cancer risk.
We recommend that you speak with a genetics expert who can look at your personal and family history of cancer and can help you decide on a plan for managing your risk.
NCCN recommends that all people with an STK11 mutation receive education on the signs and symptoms of related cancers. NCCN guidelines for specific cancers are listed below.
People with an STK11 mutation may also qualify for clinical trials looking for more effective screening or prevention for cancer.
Participate in Research
Beginning Age |
Recommendation |
8 years |
Girls should have an annual exam by a doctor to look for evidence of early-onset puberty. |
10 years continuing into adulthood |
Boys should have an annual exam by a doctor to look for cancer of the testicles or evidence of feminizing changes. |
8-10 years continuing into adulthood |
Boys and girls should have a colonoscopy, upper endoscopy and small bowel exam using CT, MRI or video capsule endoscopy with followup every 2-3 years depending on if abnormalities are found. |
Source: NCCN Guidelines: Genetic/Familial High-Risk Assessment: Colorectal, Endometrial, Gastric, v. 3, 2024. |
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Beginning Age |
Recommendation |
Additional Information |
25 |
Learn to be aware of changes in your breasts. |
Based on NCCN guidelines for women of average risk. |
25 |
Breast exam by doctor every 1-3 years. |
Based on NCCN guidelines for women of average risk. |
30 |
Breast exam by doctor every 6-12 months. |
|
30 |
Yearly breast MRI with and without contrast. |
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30 |
Yearly mammogram. |
|
No set age |
Discuss the benefits, risks and costs of double mastectomy with your doctor. |
Risk-reducing mastectomy lowers breast cancer risk by 90%, but has not been shown to improve survival. Even after double mastectomy, some breast tissue, and therefore cancer risk remains. |
No set age |
Discuss the benefits, risks and costs of medication to lower the risk for breast cancer with your doctor. |
Tamoxifen and other estrogen-blocking drugs may reduce breast cancer risk for high-risk women, but more research is needed to prove this in people with an STK11 mutation. |
Source: NCCN Guidelines: Genetic/Familial High-Risk Assessment: Breast, Ovarian, Pancreatic, Prostate, vs. 3 2025. |
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Beginning Age |
Recommendation |
Additional Information |
18-20 |
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Endometrial biopsy is recommended if there is any abnormal bleeding. |
After childbearing |
Have a discussion with your doctor about the risks, benefits and costs of removing your uterus (hysterectomy). |
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Source: NCCN Guidelines: Genetic/Familial High-Risk Assessment: Breast, Ovarian, Pancreatic, Prostate, v. 3, 2025; NCCN Guidelines: Genetic/Familial High-Risk Assessment: Colorectal, Endometrial, Gastric v. 3, 2024. |
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Beginning Age |
Recommendation |
18 |
Colonoscopy every 2–3 years or more frequently depending on number, size and type of polyps found. |
18 |
Upper endoscopy every 2–3 years or more frequently depending on number, size and type of polyps found. |
18 |
Small bowel exam using CT, MRI or video capsule endoscopy with followup every 2-3 years or more frequently depending on if abnormalities are found. |
Source: NCCN Guidelines: Genetic/Familial High-Risk Assessment: Colorectal, Endometrial, Gastric, v. 3, 2024. |
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Risk management for pancreatic cancer
There are two tests that are used to look for pancreatic cancer in high-risk people.
- MRCP (Contrast-enhanced magnetic resonance cholangiopancreatography) is a special type of imaging that looks closely at the pancreas, liver, gallbladder, bile duct and pancreatic duct to find abnormalities such as cancer.
- EUS (Endoscopic ) involves passing a tiny scope with an attached ultrasound probe down the esophagus to the stomach. This allows doctors to look closely at the pancreas.
Beginning Age |
Recommendation |
30-35 years (or 10 years younger than the earliest case of pancreatic cancer in the family) |
|
Source: NCCN Guidelines: Genetic/Familial High-Risk Assessment: Breast, Ovarian, Pancreatic, Prostate, vs. 3 2025. |
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Beginning Age |
|
18 |
Yearly testicular exam and observation for feminizing changes (e.g., breast enlargement). |
Beginning Age |
|
No set age |
Learn about the risks and signs of lung cancer and the benefits of quitting smoking. |
Other cancers
There has not been enough research to show a benefit from screening and prevention for other cancers in people who have a STK11 mutation. For this reason, experts recommend managing other cancer risks based on family history. Cancer screening and prevention research studies may be available for people with STK11 mutations.