As part of the NI Cancer Strategy, Action 27, we are aiming to identify more patients who are at risk of having an underlying cancer predisposition syndrome. This will have benefits for patients and their families.
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What is Tumour Profiling?
Tumour profiling, also known as molecular profiling, is a type of testing that examines the DNA in cancer cells to identify genetic changes (variants). These changes can guide treatment decisions and provide valuable information for patients and their families.
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Why is Tumour Profiling Important?
Understanding Cancer: It helps doctors understand the genetic changes driving the cancer.
Guiding Treatment: It may guide the use of targeted therapies, precision medicines, or determine eligibility for clinical trials.
Future Health & Family Health: It can reveal inherited genetic changes indicating a cancer predisposition syndrome. This is can be useful information for the patient and their family members, as they may be able to access cancer screening or therapies to reduce future cancer risk.
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What is a Cancer Predisposition Syndrome?
A cancer predisposition syndrome is a genetic condition that increases an individual’s risk of developing certain types of cancer. These syndromes are caused by inherited genetic changes (germline mutations) that are present in all cells of the body. Identifying these syndromes is crucial for early detection, prevention, and management of cancer in both patients and their families.
Key Genes Associated with Cancer Predisposition Syndromes:
- BRCA1 and PALB2: Mutations in these genes significantly increase the risk of breast and ovarian cancers.
- BRCA2: Mutations in this gene are linked to an increased risk of breast, ovarian and prostate cancer.
- Lynch Syndrome: Caused by mutations in genes such as MLH1, MSH2, and MSH6, Lynch syndrome increases the risk of colorectal, endometrial and some other cancers.
Identifying these genetic changes through tumour profiling can provide valuable information for guiding treatment decisions, implementing preventive measures, and informing family members about their potential cancer risks.
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How is Tumour Profiling Done?
Sample Collection: Tumour profiling is performed on tumour tissue obtained during surgery or a biopsy.
No Additional Procedures: No extra procedures are needed beyond routine pathology testing.
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What Types of Genetic Changes Might Be Identified?
Somatic Changes: These are acquired changes that occur only in the tumour cells and are not inherited. They may help guide treatment decisions and inform prognosis.
Germline Changes: These are inherited changes present in all cells of the body. They may indicate a cancer predisposition syndrome which increases the lifetime risk of certain cancers in the patient, and potentially some of their family members.
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How is Tumour Profiling Different from Existing Testing?
Compared to Standard Molecular Profiling of Tumours:
- Standard Molecular Profiling: Focuses on identifying somatic (acquired) genetic changes in tumour cells to guide treatment and prognosis.
- Tumour Profiling for Cancer Predisposition Syndromes: Identifies both somatic and germline (inherited) genetic changes, revealing underlying cancer predisposition syndromes. This dual approach aids in treatment decisions and long-term family health management.
Compared to Traditional Methods of Identifying At-Risk Patients:
- Traditional Methods: Relies on clinical judgment based on age of onset, histology, and family history, often missing many at-risk individuals.
- Tumour Profiling for Cancer Predisposition Syndromes: Uses advanced genetic testing of tumour samples to uncover inherited genetic changes, ensuring more comprehensive identification of individuals with genetic cancer risks.
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Which Genes Will Be Analysed in My Tumour?
Specific genes linked to an increased risk of cancer and for which screening or risk-reducing measures are available are analysed. The genes routinely analysed include BRCA1, BRCA2, MLH1, MSH2, MSH6, PALB2, and others depending on the type of cancer.
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What Are the Possible Results of Tumour Profiling?
- No Significant Genetic Changes Found: Even if no significant changes are identified, this information can still help your doctors make treatment decisions. If there is a strong family history of cancer, you may still be referred to a clinical genetics service for further evaluation.
- A Significant Genetic Change Found at a Low Level (Somatic): If the change is present only in the tumour and at a low level, it may influence your treatment options. This type of change is not inherited, so additional testing for you or your family members is not typically needed.
- A Significant Genetic Change Found at a Higher Level: If a genetic change is found at a level suggesting it might be inherited, you will be offered germline testing. Germline testing, usually done using a blood sample, confirms whether the change is inherited. If confirmed, this may indicate a cancer predisposition syndrome. This information can help identify cancer risks for your relatives and guide screening or prevention strategies for your family.
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What If the Results Are Not Related to My Current Cancer?
Occasionally, molecular profiling may uncover an inherited genetic change that is unrelated to your current cancer, but associated with an increased risk of other types of cancer. Even if this result does not affect your treatment, it is important for your long-term health and may have implications for your family members. Your healthcare team will provide support and guidance to help you and your family understand these findings.
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How Are Results Handled?
Patients who may benefit from a genetics referral are flagged with the oncology multidisciplinary team (MDT) or a clinician involved in the patient’s care. This does not confirm a cancer predisposition syndrome, but prompts further genetic testing and discussion. Once referred, patients will be seen in a rapid clinic to discuss genetic testing.
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I am a Clinician, How Should I Consent a Patient for This Type of Testing?
This extension of standard tumour profiling can be easily incorporated into your current consenting process. When obtaining consent for tumour profiling, key points you may want to cover:
Purpose: Explain that tumour profiling examines the DNA in cancer cells to guide treatment and identify inherited genetic risks.
Process: Inform the patient that the test uses tumour tissue from surgery or a biopsy, with no additional procedures needed.
Types of Genetic Changes: Clarify that the test identifies both somatic (acquired) and germline (inherited) changes.
Possible Results:
- No Significant Changes: Information still useful for treatment decisions.
- Somatic Changes: May influence treatment options; no additional family testing needed.
- Germline Changes: Further testing offered if potential inherited changes are found.
- Unrelated Findings: Mention that the test may uncover inherited changes unrelated to the current cancer, but which could still be important for the patient’s long-term health and family members.
Follow-Up: Explain that significant findings will lead to a referral to genetics for further discussion and testing. The genetics team will see patients promptly.
Information leaflet: Feel free to direct patients to our information leaflet.
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Key Messages for Clinicians
- We are making better use of data generated through traditional tumour profiling to help detect genetic cancer predisposition syndromes.
- Identifying these syndromes can prevent future cancers in patients and their relatives.
- See the guidance above regarding consent and our patient information leaflet.
- Clinicians may receive requests to refer patients to genetics to discuss results. These patients will be seen quickly.
- Clinicians are always welcome to contact the genetics team to discuss cases.