🧬 What You Need to Know
When we think about cancer, we often think of it as something unpredictable. But in some cases, cancer can run in families due to inherited gene mutations. If someone in your family has been found to carry a gene that increases cancer risk, their siblings need to consider hereditary cancer screening.
Here’s why it matters—and how it can empower you to take control of your health.
- Siblings Share More Than Childhood Memories—They Share Genes
Siblings typically share about 50% of their DNA. So, if one sibling is found to carry a harmful mutation in a gene linked to cancer (such as BRCA1, BRCA2, or MLH1 in Lynch syndrome), there’s a 50% chance that their brother or sister also carries that same mutation.
This means that even if you’re feeling healthy now, you could still be at increased risk of developing cancer in the future, just because of your genes.
- Screening Can Catch Cancer Early—or Help Prevent It Altogether
Knowing whether you carry a genetic mutation can change your health path for the better.
Here’s how:
- You may start cancer screenings earlier than most people.
- You might get tested more frequently.
- Doctors may recommend preventive medications or even risk-reducing surgeries to stop cancer before it starts.
For example: - If you carry a BRCA1 or BRCA2 mutation, your doctor might recommend breast MRIs and mammograms starting in your 20s or 30s, and possibly preventive surgery to remove ovaries or breasts later on.
- If you have Lynch syndrome, you might begin colonoscopies every 1–2 years starting in your 20s.
- The goal is simple: find cancer early when it’s easier to treat, or prevent it entirely.
- Knowledge Gives You Power Over Your Health
Testing positive for a hereditary cancer gene can be scary, but it also gives you a chance to make powerful decisions:
• Regular screenings can help catch problems early.
• You can consider preventive treatments based on your doctor’s advice.
• You can adopt a healthier lifestyle—quitting smoking, improving your diet, exercising more—all of which may reduce your cancer risk even further.
- It’s About Family, To
If one sibling carries a mutation, that information can help other family members take action:
• Other siblings can get tested.
• Parents and children may also be at risk and benefit from screening.
• Your entire family can become better informed and take steps to stay healthy.
What Happens If You Test Positive?
If your screening shows you have a gene mutation linked to cancer, here’s what typically happens next:
Genetic Counselling
You’ll meet with a genetic counsellor who will explain the results and what they mean for your health.
Personalised Screening Plan
Your doctor will recommend a screening schedule tailored to your specific gene mutation. This may involve earlier and more frequent tests, depending on your risk.
Preventive Options
In some cases, you may consider:
• Medications to lower cancer risk
• Preventive surgeries to remove at-risk tissue (such as ovaries or breasts in high-risk women)
Lifestyle Support
You may also receive advice on diet, exercise, and other healthy habits to support your overall well-being.
What If You Test Negative?
If you do not carry the mutation:
• That’s great news—you likely have the same cancer risk as the general population.
• You can follow standard screening guidelines (like mammograms after age 40 or colonoscopies after age 45).
• It also brings peace of mind and prevents unnecessary medical procedures.
Thoughts: It’s a Life-Changing Test Worth Considering
Hereditary cancer screening might sound technical, but at its heart, it’s about protection, prevention, and peace of mind. If your sibling—or any close family member—has a known cancer gene mutation, getting tested yourself is one of the most important things you can do.
It’s not just about cancer. It’s about knowing your risks, planning ahead, and giving yourself the best chance to stay healthy for the long run.
🧬 What is Hereditary Cancer Panel Testing?
Hereditary cancer panel testing is a genetic test that checks for inherited mutations in multiple genes that can increase a person’s risk for various types of cancer.
These panels range from small, focused tests to broad ones that screen over 100 genes.
Smaller panels (around 30–60 genes) focus on well-understood mutations with strong clinical guidelines.
Comprehensive panels (up to 150 genes) also include genes still being researched but suspected to influence cancer risk.
The goal is to help individuals and their families understand their inherited risk of cancer and guide medical decisions before cancer develops.
🔍 Genes and Syndromes Covered
Today’s panels screen for mutations across a wide range of cancer types and hereditary syndromes, including:
Breast and Ovarian Cancer: Genes like BRCA1, BRCA2, PALB2, CHEK2, ATM, BARD1, RAD51C, RAD51D, CDH1, and TP53.
Colorectal and Endometrial Cancer (Lynch Syndrome): Includes MLH1, MSH2, MSH6, PMS2, and EPCAM.
Colorectal Polyposis Syndromes: Includes APC (linked to FAP) and MUTYH (linked to MAP).
Stomach/Gastric Cancer: CDH1, associated with hereditary diffuse gastric cancer.
Pancreatic and Prostate Cancer: Involves BRCA2, ATM, PALB2, and STK11.
Other Rare Cancers: Some panels cover genes related to melanoma, brain tumours, kidney cancers, endocrine tumours, and more.
✅ Who Should Get Tested?
Genetic testing is not just for individuals with cancer. It is highly recommended for people who:
Have been diagnosed with certain cancers at a young age (e.g., breast, ovarian, colon, pancreatic, or prostate before age 50).
- Have a personal or family history of multiple cancers, especially across generations.
- Have a close relative (parent, sibling, child) who tested positive for a cancer-related gene mutation.
- In many cases, testing starts with the family member who has or had cancer to identify whether there is an inherited mutation.
🛠 What Results Mean
1. Positive Result (Pathogenic or Likely Pathogenic Mutation)
This means a harmful mutation was found that significantly increases your risk for one or more types of cancer.
It does not mean you have cancer.
It does mean you may need early, frequent screenings, preventive options, or lifestyle changes.
2. Negative Result
This means no harmful mutation was found in the genes tested.
If a known family mutation exists and you test negative, this is considered a “true negative.”
If no known mutation exists in the family, a negative result doesn’t completely rule out genetic risk.
3. Variant of Uncertain Significance (VUS)
A change was found in a gene, but it’s not clear whether it’s harmful.
VUS results are not used to guide clinical care.
These findings are monitored over time as research evolves.
🩺 What Happens After Testing Positive?
Genetic Counselling
A certified genetic counselor will explain your results, walk you through what they mean, and help create a medical management plan.
Personalised Screening and Risk-Reduction
Depending on the gene mutation, your doctor may recommend:
Earlier or more frequent cancer screenings (e.g., mammograms, colonoscopies, MRIs)
Risk-reducing surgeries (e.g., mastectomy, oophorectomy, colectomy)
Medications to reduce risk (e.g., tamoxifen)
Lifestyle changes such as a healthy diet, exercise, and quitting smoking
Preventive Options
If your lifetime cancer risk is high, you may consider more proactive steps like preventive surgery or chemoprevention.
4. Cascade Testing for Family Members
Relatives can be tested specifically for the same mutation you carry. This process, called cascade testing, allows family members to take action based on their own results.
🎯 Benefits & Limitations
Benefits
- Enables early detection and better prevention.
- Provides actionable insights for managing your health.
- Helps protect your family members through shared knowledge.
Limitations
- A VUS result can cause confusion without clear guidance.
- Testing may not identify all inherited risks.
- Not everyone with a mutation will develop cancer.
- May cause emotional or psychological stress and impact insurance in some countries (though protection laws exist in many).
🧠 In Summary
Hereditary cancer panel testing is a powerful tool that goes far beyond BRCA1/2. It screens for a wide range of gene mutations linked to different cancers. If someone in your family—especially a sibling—has tested positive, there’s a real chance you carry the same mutation.
Testing can help you take control of your health through targeted screening, preventive care, and informed decision-making. It’s not just about cancer—it’s about prevention, peace of mind, and family empowerment.