Currently, cancer screening can be done in various ways, such as imaging with medical devices like CT Scan or MRI, endoscopic examination of internal organs, and biopsy for pathological examination, which is a long-established standard method. However, there is now a newer, more advanced, and convenient technology called ctDNA (Circulating Tumor DNA) testing.
What is CtDNA?
CtDNA (Circulating Tumor DNA) refers to fragments of genetic material (DNA) that are released from cancer cells into the bloodstream. This may result from the death of cancer cells or direct secretion of DNA from cancer cells, causing patients to have higher than normal levels of CtDNA in their blood.
Generally, CtDNA can be detected using Next-Generation Sequencing (NGS) technology through a single blood draw (liquid biopsy). This method is convenient, fast, and reduces pain compared to traditional biopsy.
How many types of cancer can CtDNA screen for?
CtDNA testing technology can screen for multiple types of cancer simultaneously because each cancer type has unique genetic codes. This allows CtDNA testing to identify abnormalities and indicate which organ the cancer cells may originate from. The number of cancer types screened generally depends on the technology used and the service model of each healthcare facility. Typically, cancer screening covers 5 main types:
- Lung cancer
- Breast cancer
- Liver cancer
- Colorectal cancer
- Stomach cancer
For more comprehensive testing covering up to 10 types, it includes:
- Pancreatic cancer
- Ovarian cancer
- Endometrial cancer
- Esophageal cancer
- Head and neck cancer
Screening 5 major cancers with CtDNA testing at Elite Lifestyle Wellness Center
At Elite Lifestyle Wellness Center, Phyathai Phaholyothin Hospital, there is a cancer screening program using Circulating Tumor DNA (ctDNA) technology covering 5 main types of cancer:
- Liver cancer results from abnormalities in liver cells, which often show no symptoms in the early stages. When it progresses, symptoms may include abdominal fullness, right rib pain, jaundice, yellowing of eyes, weight loss, or abdominal swelling. Early detection increases the chance of successful treatment. CtDNA testing can help screen from the early asymptomatic stage.
- Breast cancer is the most common cancer in women, caused by abnormal division of breast tissue cells. It may be detected by lumps, changes in breast skin, or nipple deformities, but often has no clear symptoms early on. CtDNA testing detects DNA from breast cancer cells circulating in the blood, providing a convenient screening option beyond mammograms or breast ultrasounds.
- Lung cancer is one of the leading causes of cancer death. Major risk factors include smoking and exposure to toxins. Early symptoms may include chronic cough, blood in sputum, or difficulty breathing, but it is often detected late. CtDNA testing can identify gene abnormalities related to lung cancer, allowing earlier detection before symptoms appear.
- Colorectal cancer arises from abnormalities in the colon wall. Symptoms may include blood in stool, alternating constipation and diarrhea, or changes in stool shape. Some patients may have no clear symptoms. Standard screening usually involves colonoscopy, but CtDNA testing offers a more convenient alternative by detecting cancer cell DNA fragments in the blood.
- Stomach cancer often presents symptoms similar to gastritis, such as abdominal fullness, bloating, or indigestion, leading to delayed diagnosis. Patients may only notice unexplained weight loss. CtDNA testing can help detect the disease before severe symptoms develop.
CtDNA testing procedure
The ctDNA testing procedure is straightforward and uncomplicated as follows:
- The doctor will explain the overall concept of ctDNA testing to the patient, emphasizing that it detects DNA fragments from cancer cells in the bloodstream. The test has high specificity, meaning the chance of false positives is very low. However, sensitivity may be limited, especially in early-stage cancers.
- Blood sample collection by drawing 10-20 milliliters of blood from the arm into special tubes that prevent DNA degradation.
- The blood is centrifuged to separate plasma containing CtDNA, which is then extracted and analyzed using advanced genetic techniques to detect gene abnormalities indicative of cancer.
- The doctor will interpret the results along with the patient’s history and risk factors. If gene abnormalities related to cancer risk are found, such as liver, breast, lung, colorectal, or stomach cancer, the doctor will recommend further confirmatory tests as appropriate, such as CT scan, MRI, PET scan, or biopsy.
Accuracy of ctDNA testing
CtDNA testing is recognized for its high accuracy, especially in detecting early-stage cancer, as follows:
- Specificity is about 8%, meaning the chance of a positive result (cancer detected) when there is no cancer is very low, so false positives are rare.
- Sensitivity is about 1%, indicating the ability to detect actual cancer present in the body.
However, the accuracy may vary depending on the type and stage of cancer, as well as the amount of ctDNA in the blood.
Who should get ctDNA testing and limitations to be aware of
CtDNA (Circulating Tumor DNA) testing is an innovative, convenient, and highly accurate cancer screening method suitable for both health-conscious individuals and those at risk. Groups to consider testing include:
- Individuals aged 18 and over who want preventive screening, even without symptoms or family history of cancer.
- Those seeking proactive annual health check-ups to assess cancer risk.
- People aged 40 and above, as cancer risk increases with age.
- Individuals with a direct family history of cancer, such as parents or siblings.
- Those with risky behaviors, such as heavy smoking or regular alcohol consumption.
- People exposed to high-risk environments, such as industrial zones, mines, or prolonged exposure to carcinogens and dust.
- Individuals with chronic abnormal symptoms, such as persistent cough, ongoing abdominal or back pain, abnormal bowel movements, fatigue, or unexplained weight loss.
- Cancer patients for monitoring treatment response or recurrence surveillance.
- Those unable or unwilling to undergo biopsy.
Limitations of ctDNA testing
- Not suitable for pregnant women.
- Should not be performed on individuals who have had bone marrow transplants or blood transfusions within the past 3 months, as this may affect accuracy.
- Those awaiting cancer diagnosis should avoid testing, as ctDNA is designed for screening and monitoring, not for definitive diagnosis.
Follow-up and treatment planning if CtDNA abnormalities are found
CtDNA testing at Elite Lifestyle Wellness Center, Phyathai, not only helps screen for early cancer risk but also provides continuous care. If abnormalities are detected, patients receive comprehensive care as follows:
- Consultation with a specialist: If CtDNA results indicate abnormalities, an oncology specialist will explain the results in detail, analyze detected gene mutations to assess risk, and recommend appropriate further testing.
- Confirmatory testing: Using various tools as appropriate to confirm diagnosis and locate abnormalities.
- Treatment planning: A multidisciplinary medical team will collaboratively plan suitable treatment, including surgery, chemotherapy, radiation therapy, targeted therapy matching detected gene mutations, and immunotherapy.
- Treatment monitoring: CtDNA testing can track the amount of cancer genetic material in the blood. A decrease in ctDNA indicates effective treatment, while detection of minimal residual disease prompts treatment adjustment to reduce recurrence risk.
- Comprehensive care: Providing complete information to involve patients in decision-making with the medical team at every step.
If you have questions or are interested in CtDNA cancer screening, you can consult with our specialist team at Elite Lifestyle Wellness Center Phyathai Phaholyothin Hospital . We provide services based on the Value Care concept, focusing on value, comprehensiveness, and addressing health care in all dimensions, from prevention, screening, diagnosis, treatment, follow-up, to personalized health advice. We are ready to care for both your physical and mental health to ensure you and your loved ones have the best quality of life.
FAQ: Frequently Asked Questions about CtDNA testing
Q: How long does it take to wait for CtDNA test results?
A: Generally, it takes about 10-14 working days, depending on the laboratory processing the test.
Q: How often should CtDNA testing be repeated?
A: It depends on risk and the doctor’s discretion. Generally, it is recommended to repeat testing every 1-2 years for continuous screening.
Q: If the CtDNA test result is normal, is it still necessary to undergo other tests?
A: Yes, it is essential. CtDNA testing is only a supplementary screening method. Regular health check-ups and cancer screening as recommended by doctors, such as chest X-rays, mammograms, and colonoscopy, should still be performed.
Q: Can CtDNA testing be used for treatment purposes?
A: CtDNA testing is a tool for screening and monitoring, not direct treatment. However, the results can help doctors decide on appropriate and targeted treatment options, such as chemotherapy selection or treatment monitoring.
Dr. Kobkulya Jungprasertsri
Director of the Anti-Aging Medicine Center
Phyathai 2 Hospital and Phyathai Phaholyothin Hospital
