genetics related cancers
What Are Genetics Related Cancers?
Genetics related cancers are cancers that develop in connection with changes in genes that influence how cells grow, divide and repair damage. While cancer is common, only a proportion of cases are linked to an inherited genetic change passed through a family. Most cancers arise from genetic changes acquired during a person’s lifetime rather than inherited from a parent.
Inherited genetic changes can increase the likelihood of developing certain cancers, sometimes at a younger age or alongside a recognisable pattern of cancer within the family. For example, changes in genes such as BRCA1, BRCA2 and the mismatch repair genes associated with Lynch syndrome may be linked with an increased risk of particular breast, ovarian, bowel, prostate, pancreatic and endometrial cancers.
It is important to remember that carrying a genetic variant associated with cancer risk does not mean that a person will definitely develop cancer. Risk can vary according to the specific gene involved, family history, age, biological factors and other health or lifestyle considerations. Equally, a family history of cancer does not always indicate an inherited cancer syndrome.
A specialist review can help clarify whether a family pattern may warrant further investigation. This may include assessing diagnoses and ages of diagnosis across relatives, discussing the potential role of genetic testing, and considering appropriate screening or prevention options. If you are concerned about cancer in your family, our Cancer Genetic Counselling service can help you understand the next appropriate step. Where testing is clinically indicated, you can also learn more about Cancer Genetic Testing.
Inherited and Acquired Gene Changes in Cancer Development
Genetics related cancers can involve different types of gene changes. Some genetic changes are inherited through a family, while others develop during a person’s lifetime within individual cells. Understanding this distinction is important because inherited and acquired gene changes can have different implications for cancer risk, family members, genetic testing and clinical care.
Inherited Gene Changes (Germline Variants)
Inherited gene changes, also called germline variants, are present from birth and may be passed from one generation to the next. Certain inherited variants can increase the likelihood of developing particular cancers, including breast, ovarian, bowel, prostate, pancreatic and endometrial cancers. Examples include changes in the BRCA1 and BRCA2 genes, as well as genes linked to Lynch syndrome.
An inherited genetic variant does not mean that cancer is certain to develop. However, it may help explain a pattern of cancer in a family and guide discussions about screening, prevention and the potential value of genetic assessment. If you are concerned about a family history of cancer, Cancer Genetic Counselling can help clarify whether further evaluation may be appropriate.
Acquired Gene Changes (Somatic Mutations)
Most cancers develop as a result of acquired gene changes, known as somatic mutations. These changes arise during a person’s lifetime in specific cells rather than being inherited from a parent or passed on to children. They occur naturally as cells divide and age, and may also be influenced by environmental factors or other biological processes.
While somatic mutations contribute to tumour development, their presence does not typically indicate an inherited cancer predisposition in the family. In some circumstances, analysing these acquired changes through tumour genomic profiling can help the oncology team better understand the biological characteristics of a cancer and guide personalised treatment decisions.
Why the Difference Matters
Distinguishing between inherited and acquired gene changes is an important part of evaluating genetics related cancers. An inherited finding may have implications for an individual’s future cancer risk and, in some circumstances, for close relatives. An acquired tumour finding is generally more relevant to the cancer that is currently being treated and may help inform personalised oncology care.
A specialist review considers personal and family history alongside any available clinical information before deciding whether genetic testing may be useful. Where hereditary risk is suspected, Cancer Genetic Testing may be considered as part of an appropriate clinical pathway.
Not all genetic changes carry the same meaning. Inherited gene changes may help explain cancer patterns within a family, whereas acquired changes usually develop within a tumour over time. Identifying the relevant type of genetic change can support clearer risk assessment, more informed screening discussions and appropriate clinical next steps.
Types of Genetics Related Cancers and Hereditary Cancer Syndromes
Genetics Related Cancers can involve different cancer types and hereditary cancer syndromes. A hereditary cancer syndrome occurs when an inherited change in a particular gene increases a person’s likelihood of developing one or more cancers. The level of risk varies between genes and individuals, and carrying a disease-associated variant does not mean that cancer is certain to develop.
Hereditary Breast and Ovarian Cancer
Hereditary Breast and Ovarian Cancer, commonly referred to as HBOC, is most often associated with inherited changes in the BRCA1 and BRCA2 genes. These variants may increase the risk of breast and ovarian cancer and can also be associated with prostate and pancreatic cancer in some families.
Other genes, including PALB2, CHEK2 and ATM, may also be relevant when assessing inherited breast cancer risk. The appropriate genes to consider depend on the individual’s personal history, the types of cancer diagnosed in relatives and the age at diagnosis.
Lynch Syndrome
Lynch syndrome is an inherited condition linked to changes in genes involved in repairing errors in DNA. It is associated particularly with an increased risk of bowel and endometrial cancer, but may also be relevant to ovarian, stomach, urinary tract, pancreatic and other cancers.
A family history of bowel cancer at a young age, several relatives with bowel or endometrial cancer, or the presence of related cancers across generations may indicate that Lynch syndrome should be considered. The assessment of this type of risk may involve a detailed family history and, where clinically appropriate, specialist genetic evaluation.
Familial Adenomatous Polyposis
Familial adenomatous polyposis (FAP) is a rare hereditary condition commonly associated with changes in the APC gene. People with FAP may develop numerous polyps in the bowel, some of which can become cancerous if they are not identified and managed appropriately.
Because FAP can have significant implications for several members of a family, early recognition and specialist clinical management are important. Genetic information may help guide surveillance and support appropriate advice for relatives who may also be at risk.
Li-Fraumeni Syndrome
Li-Fraumeni syndrome is a rare hereditary cancer syndrome usually associated with changes in the TP53 gene. It can be linked to a range of cancers, sometimes developing at a younger age than expected. The types of cancer associated with this syndrome may include breast cancer, sarcomas, brain tumours, adrenocortical cancer and certain childhood cancers.
A combination of rare cancers, multiple cancer diagnoses in one person or cancer occurring at unusually young ages may prompt consideration of a hereditary cancer syndrome. However, these features do not confirm a diagnosis on their own and should be reviewed in the context of the wider family history.
Other Hereditary Cancer Syndromes
There are several other inherited conditions that may contribute to Genetics Related Cancers. These include hereditary diffuse gastric cancer, associated with changes in the CDH1 gene, and hereditary renal cancer syndromes involving genes such as VHL, FH or FLCN. Some inherited variants may also be associated with endocrine tumours, melanoma, prostate cancer or pancreatic cancer.
The relevance of a particular gene depends on the pattern of cancer in the family, the age at diagnosis and other clinical findings. This is why genetic risk should not be assessed by looking at a single diagnosis in isolation. A broader review may be needed to determine whether a hereditary cancer syndrome is likely.
How Hereditary Cancer Syndromes Are Evaluated
A hereditary cancer assessment usually begins with a review of the person’s own medical history and a detailed family history. This may include the type of cancer diagnosed, the age at diagnosis, the side of the family affected and whether several related cancers have occurred in close relatives.
Where the pattern suggests a possible inherited predisposition, a clinician or genetic counsellor may discuss the potential benefits, limitations and implications of genetic testing. Testing may involve a targeted analysis of a particular gene or a broader panel covering several genes associated with hereditary cancer.
For a wider overview of how inherited conditions are investigated, see our page on Hereditary Disease Testing. Where a family history involves uncommon or complex conditions, information about Rare Genetic Disorders Testing may also be relevant.
Understanding the type of hereditary cancer syndrome involved can help inform discussions about appropriate surveillance, risk-reduction options and whether other family members may benefit from clinical advice. Genetic findings should always be interpreted alongside the individual’s medical history and not considered in isolation.
When Should You Consider a Genetic Risk Assessment?
A genetic risk assessment may be appropriate when your personal or family history suggests a possible inherited predisposition to cancer. It does not mean that you have a hereditary cancer syndrome or that cancer is inevitable. Instead, it provides an opportunity to review relevant risk factors and consider whether genetic counselling, genetic testing or enhanced screening may be appropriate.
Hover over each box for more detailed information!
Several Relatives with Cancer
Cancer Diagnosed at a Young Age
Related Cancers in the Family
A Known Genetic Variant in the Family
Multiple or Unusual Cancer Diagnoses
Uncertainty About Your Family History
Assessment is the first step, not a diagnosis. A genetic risk assessment brings together your personal history, family history and relevant clinical information to clarify whether an inherited cancer risk should be investigated and what options may be appropriate next.
What Happens During a Genetics Related Cancer Assessment?
A genetics related cancer assessment is designed to understand whether your personal or family history may indicate an increased risk of an inherited cancer syndrome. The process is not limited to reviewing a single diagnosis. It considers the wider pattern of cancer within your family, the ages at which relatives were diagnosed and any relevant genetic or medical information.
1. Discussion of Your Personal and Family History
The assessment usually begins with a detailed discussion of your own health history and any known cancer diagnoses among your relatives. You may be asked about the type of cancer, the age at diagnosis, treatments received and whether a relative has already had genetic testing.
Where several family members are affected, a broader review may be helpful. Our Family Genetic Counselling service can support families who need to understand how a possible inherited risk may affect more than one relative.
2. Review of Cancer Patterns and Potential Risk Factors
The specialist will consider whether the pattern of cancer in your family is consistent with a recognised hereditary cancer syndrome. Factors may include cancer at a younger-than-usual age, several related cancers in one family, multiple primary cancers in one person or a known genetic variant in a relative.
This review does not establish a diagnosis by itself. Instead, it helps determine whether the available information justifies further investigation and what type of assessment may be appropriate.
3. Estimating Your Individual Genetic Risk
Your personal and family history may be used to estimate the likelihood of an inherited genetic predisposition. This can help distinguish between a pattern that is more likely to occur by chance and one that may require specialist genetic evaluation.
A Genetic Risk Assessment may be particularly useful when the family history is complex, incomplete or involves more than one type of cancer. The assessment should take account of the limitations of the available information and should not create unnecessary anxiety or false reassurance.
4. Discussing Whether Genetic Testing May Be Appropriate
If the assessment suggests that an inherited cancer risk may be relevant, the specialist can explain whether genetic testing should be considered. This discussion may cover the possible benefits, limitations and implications of testing, including what different results could mean for you and your relatives.
Testing is not automatically required for everyone with a family history of cancer. In some cases, the most informative approach may be to test a relative who has had cancer, if that person is available and willing to be assessed.
5. Understanding Possible Test Results
Before testing, it is important to understand the possible outcomes. A result may identify a pathogenic variant associated with increased cancer risk, find no clinically significant variant, or identify a variant whose significance is currently uncertain.
The meaning of a result depends on the gene involved, the strength of the evidence, your personal history and the wider family pattern. A genetic result should therefore be interpreted in its clinical context rather than considered in isolation.
6. Planning Appropriate Next Steps
Following the assessment, the next step may involve genetic testing, a screening discussion, further review of medical records or referral to another specialist. If an inherited variant is identified, relevant relatives may also be advised to seek appropriate clinical assessment.
The outcome may also be that no genetic testing is recommended at present. This does not mean that your concerns are dismissed; genetic knowledge and testing criteria can change over time, and reassessment may be appropriate if new cancer diagnoses or medical information emerge.
From Assessment to Informed Decisions
A genetics related cancer assessment does not predict with certainty whether someone will develop cancer. Its purpose is to clarify the available evidence, identify whether an inherited risk may be present and support informed discussions about testing, screening and family communication.
The most appropriate pathway will depend on your individual circumstances, the quality of the family history and any existing genetic or tumour-related results.
How Genetic Risk Information Can Support Screening and Risk Management
Genetic risk information can help individuals and families understand whether they may have an increased likelihood of developing certain cancers. When interpreted alongside personal and family history, it may support more informed discussions about screening, prevention and appropriate long-term risk management. A genetic result does not predict cancer with certainty and should always be considered within the wider clinical context.
Understanding Your Level of Risk
Genetic information may help clarify whether your risk is likely to be close to that of the general population or increased because of an inherited genetic variant. The interpretation depends on the specific gene, the type of variant, your personal history and the pattern of cancer within your family.
Planning Appropriate Cancer Screening
Where an increased risk is identified, genetic information may support discussions about whether screening should begin earlier, take place more frequently or involve a different approach. Screening recommendations vary according to the relevant gene, cancer type, age and individual clinical circumstances.
Considering Risk-Reduction Options
Some people may wish to discuss ways of managing an increased cancer risk with their clinical team. Depending on the circumstances, this may include enhanced surveillance, preventive medication, risk-reducing procedures or lifestyle measures. These options should be discussed individually and should never be based on a genetic result alone.
Supporting Informed Family Decisions
An inherited genetic finding may have implications for biological relatives. Appropriate genetic guidance can help individuals understand what information may be relevant to family members and whether relatives should consider their own clinical assessment. Any communication should respect privacy, consent and each person’s individual circumstances.
From information to informed action: Genetic risk information is most useful when it is interpreted by an appropriately qualified professional and translated into practical, clinically suitable recommendations. It can support discussions about screening and risk management, but it does not replace regular medical care or guarantee that cancer will or will not develop.
When Might Genetics Related Cancers Require Further Assessment?
Certain personal or family-history patterns may suggest that an inherited cancer predisposition should be considered. These indicators do not confirm a hereditary cancer syndrome, but they may provide a reason to discuss your history with an appropriately qualified healthcare professional.
| Personal or Family-History Indicator | Why It May Be Relevant | Possible Next Step |
|---|---|---|
| Cancer Diagnosed at a Relatively Young Age | Cancer occurring earlier than expected for that cancer type may sometimes be associated with an inherited genetic predisposition, particularly when there is also a relevant family history. | Consider a review of the personal and family history to determine whether genetic risk assessment may be appropriate. |
| Several Close Relatives with Cancer | Several biological relatives with cancer, especially on the same side of the family, may indicate a pattern that warrants further clinical review. | Record the cancer types, ages at diagnosis and family relationships before discussing the history with a healthcare professional or genetic counsellor. |
| Related Cancers in One Family | Combinations such as breast and ovarian cancer, bowel and endometrial cancer, or breast and prostate cancer may be relevant when considering hereditary cancer syndromes. | A specialist review may help determine whether the family pattern is consistent with an inherited cancer risk. |
| More Than One Primary Cancer | Developing separate primary cancers, or cancer affecting both paired organs, may be clinically relevant when assessing inherited susceptibility. | Discuss the full medical history and any previous pathology or genetic results to establish whether further assessment should be considered. |
| A Rare Cancer or Unusual Cancer Pattern | Certain rare cancers, unusual combinations of cancers or cancer diagnoses at unexpected ages can sometimes be associated with a hereditary cancer syndrome. | Seek an individual clinical review rather than relying on general risk information or online family-history tools. |
| A Known Genetic Variant in the Family | If a biological relative has an identified variant associated with hereditary cancer risk, other relatives may have a reason to discuss whether the same finding could be relevant to them. | Where possible, obtain the relative’s laboratory report and discuss targeted familial assessment with a qualified professional. |
| Limited or Incomplete Family History | Adoption, estrangement, missing records or relatives who are no longer available may make it difficult to assess the family pattern accurately. | A lack of information does not automatically exclude inherited risk. Discuss what is known and what additional information may be useful. |
Important: Having one of these indicators does not mean that you have a hereditary cancer syndrome. Cancer risk assessment considers the complete personal and family history, and any recommendation for genetic testing should be based on individual clinical circumstances.
Discuss Your Genetics Related Cancer Risk with a Specialist
Understanding your genetics related cancer risk can be difficult, particularly when you have a personal or family history of cancer, a known familial genetic variant or questions about a previous genetic result. A specialist consultation can help place this information in context and identify the most appropriate next step for your circumstances.
At London Genetics, we review the relevant details of your personal medical history, family history and any available clinical or genetic information. We explain whether further assessment, genetic testing or discussions about screening may be appropriate, while helping you understand the potential benefits and limitations of each option.
The consultation is tailored to your individual situation and does not assume that cancer is hereditary or that genetic testing will necessarily be required. Where relevant, the discussion may also consider the implications of genetic information for close relatives and how it could support more informed clinical decisions.
Take the next step towards understanding your genetics related cancer risk. Arrange a confidential consultation with a specialist clinical geneticist for clear, evidence-based guidance.
Book a Cancer Genetics ConsultationIn this section you can check frequently asked questions.
What proportion of cancers are considered genetics related or inherited?
Most cancers develop due to acquired genetic changes (somatic mutations) that occur over a lifetime as a result of ageing, lifestyle and environmental factors. Only around 5% to 10% of all cancer cases are estimated to be hereditary, meaning they are directly linked to an inherited gene change passed down through generations.
If I carry an inherited gene change linked to cancer, will I definitely develop cancer?
No. Carrying an inherited genetic variant (such as in the BRCA1, BRCA2 or Lynch syndrome genes) significantly increases the lifetime risk of certain cancers, but it does not guarantee that cancer will occur. In clinical genetics, this principle is known as incomplete penetrance. Other non-genetic and environmental factors also influence overall health outcomes.
Can genetics related cancer risks be inherited from both my mother and father?
Yes. With very few exceptions, hereditary cancer gene alterations can be inherited equally from either parent. A common misconception is that breast or ovarian cancer risk is only relevant if it comes from the mother’s side; in reality, father-side lineage is equally significant when evaluating risk.
What are the key signs that suggest a cancer in my family may be genetics related?
A personal or family history may warrant genetic risk assessment if there are:
- Multiple close relatives diagnosed with the same or biologically related cancers (e.g., breast and ovarian, bowel and endometrial).
- Cancers diagnosed at an unusually young age (often below the age of 50).
- A single individual diagnosed with more than one separate primary cancer.
- Rare cancer types, such as male breast cancer or specific endocrine tumours.
- A known pathogenic genetic mutation already identified in a biological relative.
What is the difference between an NHS referral and a private cancer genetics consultation?
NHS clinical genetics services are world-class but operate under strict referral eligibility criteria and may involve waiting times. A private cancer genetics consultation in London offers timely, direct access to a consultant clinical geneticist without the need for strict criteria-based gating. It allows for an in-depth review of complex family histories and personalised testing pathways when NHS criteria may not be met.
What happens if a family member with cancer is no longer alive to be tested?
While it is often most informative to test an affected family member first, modern multi-gene panel testing and advanced risk calculation models (such as BOADICEA or Tyrer-Cuzick) allow clinical geneticists to assess your risk and provide valuable testing options even if affected relatives are deceased or unavailable.
What is a ‘Variant of Uncertain Significance’ (VUS) in cancer genetic testing?
A Variant of Uncertain Significance (VUS) is a genetic alteration identified during testing where current scientific evidence is not yet conclusive enough to determine whether it is harmful (disease-causing) or a harmless natural variation. Clinical guidelines recommend that no irreversible medical or surgical decisions should be based on a VUS alone. Over time, as research evolves, many of these variants are reclassified.
How does knowing I have a genetics related cancer risk help protect my health?
Identifying an inherited risk enables proactive, tailored clinical management. Rather than waiting for symptoms, you and your clinical team can implement:
- Enhanced Surveillance: Earlier and more frequent imaging (such as annual breast MRI or colonoscopy).
- Chemoprevention: Medications that reduce the likelihood of developing specific cancers.
- Risk-Reducing Surgery: Preventive options where clinically indicated.
- Cascade Screening for Relatives: Providing crucial information that allows family members to understand and manage their own risk.
Will taking a cancer genetic test affect my life insurance or mortgage in the UK?
In the UK, the Code on Genetic Testing and Insurance (an agreement between the UK Government and the Association of British Insurers) ensures that, in the vast majority of cases, insurance companies cannot ask for or use predictive genetic test results for standard life, critical illness, or income protection policies up to substantial financial limits (with very specific exceptions for certain rare conditions like Huntington’s Disease on high-value policies).
How do I prepare for a genetics related cancer consultation?
To gain the most value from your consultation, gather as much accurate family medical history as possible. Key information includes:
- Specific cancer types diagnosed in first- and second-degree relatives (both maternal and paternal).
- The approximate ages at which relatives were diagnosed.
- Any existing genetic test reports or histopathology summaries from relatives, if safely accessible.
