Following a cancer diagnosis, one of the first concerns for many patients is the potential hereditary risk. To address this topic with maximum precision, this article has been reviewed and developed in collaboration with Dr. Esther Martín Holgado, an oncologist at GenesisCare, who helps us clarify the most common questions regarding genetics and family prevention.
Could my children or siblings develop the same disease?
From a genetic standpoint, most cancers are not inherited. They occur sporadically as a result of mutations that accumulate throughout life, influenced by cellular aging and environmental factors. Only a small percentage of cases—between 5% and 10%—correspond to hereditary forms.
Knowing whether a genetic component exists allows for the evaluation of family risk and, when necessary, the design of personalized prevention and monitoring strategies.
What is the difference between non-genetic and hereditary cancer?
Non-genetic (sporadic) cancer develops through the progressive accumulation of somatic mutations over time. These mutations may be due to normal biological processes, cellular aging, or external factors such as tobacco, ultraviolet radiation, or exposure to carcinogens.
In contrast, hereditary cancer occurs when a person is born with a genetic mutation (germline mutation) that increases their susceptibility to developing certain tumors.
Note: Having this predisposition does not mean cancer will definitely appear, but it does imply a higher risk, which is why closer surveillance and prevention measures are recommended.
The 5–10% Rule: Why most cancers are NOT inherited
- Only 5% to 10% of cancers have a hereditary origin.
- The remaining 90–95% are related to lifestyle and/or environmental causes.
This means that, in the vast majority of cases, family members do not face a higher risk than the general population.
Red Flags: When to visit a Genetic Counseling Unit?
There are certain situations where a genetic study is recommended:
- Early onset of cancer: For example, breast cancer diagnosed before age 40.
- Family history: Several first-degree relatives affected by the same type of tumor.
- Bilateral tumors: Cancer occurring in both breasts, both kidneys, etc.
- Known genetic syndromes: A family diagnosis of syndromes such as BRCA (breast and ovarian) or Lynch syndrome (colon).
If any of these signs are identified, it is advisable to consult a Genetic Counseling Unit.
What does a genetic study involve?
The genetic test is simple: it is usually performed through a blood or saliva analysis, which is quick and painless.
However, the most important part is not the test itself, but the expert interpretation of the results. This must be carried out by a geneticist within the clinical and family context of each patient.
Knowledge is Power
At IVOQA, we believe that clear information is the best tool against uncertainty. Although most cancer cases are not hereditary, knowing your genetic profile can be a key piece in your care and that of your loved ones.
If, after reading this article, you feel your family history fits any of the red flags, we recommend requesting a specialized consultation. At IVOQA, we work to connect you with the best professionals and accompany you through every step of your health journey.
