Is cancer hereditary in my family? 10 signs and how genetic counseling works (explained step by step)

There is a very specific moment that many families describe in the same way: the diagnosis arrives, you start thinking about your treatment… and, suddenly, another worry appears that is harder to put off: “What if this runs in the family? What if my children, my siblings or my nephews are also at risk?”

If you’re at that point, the important thing is to bring order to the situation logically and without drama. Because here’s a key idea: not all cancers are hereditary , but when there’s a family predisposition, it can be detected and, above all, addressed in time with personalized monitoring and prevention.

This article explains what genetic counseling does and, finally, what each result means and what practical steps are taken afterwards.

What is “hereditary cancer” (and what it is NOT)

When we talk about hereditary cancer, we are referring to families in which there is an inherited genetic alteration (a “mutation” or pathogenic variant) that increases the likelihood of developing certain tumors throughout life. This can be related to breast, ovarian, colon, endometrial, prostate, pancreatic, melanoma, and other cancers.

But be aware: having family members with cancer doesn’t automatically mean it’s hereditary . Sometimes it’s a coincidence, sometimes shared habits or chance play a role. That’s why genetic counseling for cancer exists : to measure the actual risk and decide, based on medical criteria, whether a genetic test would be useful.

The 10 signs that make a hereditary cancer assessment advisable

If you recognize yourself in one or more of these, a genetic counseling consultation is worthwhile:

1. Varios familiares con el mismo tipo de cáncer (por ejemplo, varios cánceres de mama u ovario).
2. Diagnósticos a edades jóvenes (antes de lo habitual en ese tumor).
3. Una misma persona con dos tumores primarios distintos a lo largo de su vida.
4. Tumores bilaterales o múltiples (por ejemplo, cáncer de mama en ambos pechos).
5. Cánceres poco frecuentes (como cáncer de mama en varón) o tumores raros.
6. Acúmulo de cánceres en la misma rama familiar, ya sea materna o paterna (sí, la rama paterna también cuenta).
7. Varias generaciones afectadas por tumores relacionados entre sí.
8. Un familiar con una mutación genética ya conocida relacionada con cáncer.
9. Una combinación característica de tumores (por ejemplo, colon y endometrio en la familia, que puede sugerir ciertos síndromes).
10. Dudas importantes sobre “qué controles necesito” porque la historia familiar genera ansiedad o incertidumbre constante.

It is not necessary to meet “every” criterion. Sometimes a single strong sign justifies an evaluation, especially if the diagnosis was made early or there is a confirmed mutation in a family member.

What happens in a genetic counseling session (no mystery and no scares)

At Nexus Oncology, the approach isn’t simply “taking a test and that’s it,” but rather providing you with rigorous yet personalized support to transform your uncertainty into a plan. The process typically follows these steps:

1. Escuchamos tu historia (personal y familiar).
   Hablamos de los cánceres en la familia, edades al diagnóstico, tratamientos, y cualquier dato que pueda orientar.
2. Construimos un árbol genealógico.
   Es una representación de varias generaciones que ayuda a identificar patrones y calcular riesgo de forma ordenada.
3. Estimamos el riesgo de predisposición hereditaria.
   Con herramientas clínicas y experiencia, valoramos si el riesgo es bajo, moderado o alto.
4. Decidimos si una prueba genética tiene sentido.
   Aquí está lo diferencial: solo se solicitan pruebas cuando realmente pueden aportar respuestas útiles, no por rutina.
5. Elegimos el estudio adecuado (no siempre es “BRCA y listo”).
   Según el caso, se puede indicar un panel centrado en un tipo de tumor (mama–ovario, colon–endometrio) o paneles más amplios que analizan muchos genes a la vez.
6. La muestra es sencilla.
   Suele ser sangre o saliva. No es un procedimiento complejo.
7. Explicamos el resultado con lenguaje claro y un informe útil.
   No te dejamos con un papel lleno de siglas: te explicamos qué significa para ti y para tu familia, y entregamos un informe entendible para ti y para tu médico de referencia.

“I take the test… and then what?” Understanding the results without anxiety

This is where most people get stuck, so let’s get down to business:

Resultado positivo (se identifica una mutación hereditaria)

This means that there is a genetic predisposition and, therefore, we can get ahead of it : design a surveillance plan, assess risk reduction measures in selected cases and guide family members who could benefit from a study (what is called a “cascade study”).

Resultado negativo (no se identifica una mutación)

It can be reassuring, but it depends on the context. If the family history is highly suggestive, the familial risk can sometimes remain higher than that of the general population even if no specific mutation is detected. Therefore, interpretation should always be done with a specialist.

“Variante de significado incierto” (VUS)

This is a common and confusing result: it means that a genetic change has been found, but there isn’t yet enough evidence to determine whether or not it increases risk. Generally, drastic decisions aren’t made based solely on a VUS; it’s interpreted cautiously and reviewed over time if science reclassifies it.

If I already have cancer: can genetics change my treatment?

In some cases, yes. Knowing about a hereditary predisposition can influence medical decisions (for example, follow-up strategies, surgical options, or specific therapies depending on the type of tumor and the gene involved). Therefore, genetic counseling is not “just prevention”: it can also provide relevant information during cancer management.

What plan is designed next: prevention, early detection and family

If a clear mutation or familial aggregation exists, the goal is to transform the result into a realistic and personalized plan, which may include:

• Cribado intensificado (por ejemplo, mamografía y/o resonancia mamaria antes y con más frecuencia; colonoscopias más tempranas y con intervalos más cortos).
• Pruebas adaptadas a cada situación (ecografías ginecológicas, analíticas específicas u otras).
• Medidas de reducción de riesgo, siempre individualizadas (cirugía preventiva en casos muy seleccionados, determinados fármacos, recomendaciones de estilo de vida).
• Recomendaciones para familiares: quién debería estudiarse, a qué edad iniciar vigilancia y cómo comunicarlo de forma cuidadosa.

And importantly: the plan isn’t static . It’s reviewed based on your progress, your preferences, and the latest scientific evidence.

Request your hereditary cancer consultation and genetic counseling at Nexus Oncology

If you are worried about hereditary cancer, if you have a family history, if you have been diagnosed with cancer at a young age, or if there is a known mutation in the family, you don’t have to live with the doubt.

At Nexus Oncology, we have a dedicated hereditary cancer and genetic counseling unit to calmly assess your case, decide if a genetic study is appropriate, and, above all, turn the information into a personalized prevention and early detection plan for you and your family.

Request your genetic counseling consultation at Nexus Oncology and take the most important step: moving from vague fear to a clear plan.