Hearing that a close family member has been diagnosed with cancer often sparks fear and uncertainty about one’s own health. Many people immediately assume that cancer is inevitable if it runs in the family, but medical experts say this belief is largely driven by misunderstanding rather than science. Having a family history can increase risk, but it does not automatically mean a person will develop cancer.
To shed light on the reality of hereditary cancer, Dr Randeep Singh, Director and Senior Consultant in Oncology Services at Narayana Hospital, Gurugram, explains that genetics is only one piece of a much larger puzzle. According to him, confusion around genetic risk frequently leads to unnecessary anxiety. While inherited genes do influence how cells grow, divide, and repair themselves, they are rarely the sole cause of cancer.
Dr Singh emphasises that lifestyle and environmental factors such as smoking habits, diet, physical activity, infections, pollution exposure, and ageing play a major role in cancer development. Even when a faulty gene is inherited, cancer is not guaranteed. Understanding genetic risk should empower individuals to focus on prevention rather than fear, through healthy living, regular check-ups, and timely screenings.
A key misconception is that most cancers are hereditary. In reality, inherited genetic mutations account for only a small share of total cases. Dr Singh notes that roughly five to fifteen per cent of cancers are linked to inherited mutations, while the majority develop due to non-genetic causes over time. Recognising this fact can significantly reduce emotional stress and redirect attention toward controllable risk factors.
Doctors become more alert to possible hereditary cancer when patterns appear in a family’s medical history. These include cancer affecting parents or siblings, multiple relatives with the same or related cancers, or diagnoses occurring at a younger age, usually before 50. Certain cancers are more commonly associated with inherited risk, including breast, ovarian, colon, uterine, and prostate cancers.
Genetic testing can help clarify risk, but it is not meant for everyone. Dr Singh advises testing for individuals already diagnosed with cancer who also have a strong family history, as well as for healthy people with close relatives affected by cancer. However, he acknowledges that the idea of genetic testing can be emotionally overwhelming, especially when concerns arise about passing risk to children or other family members.
To manage this stress, genetic counselling plays a vital role. Counselling before testing helps individuals understand what the test looks for and what the results could mean. After testing, counselling helps interpret outcomes and guides families on preventive steps, monitoring, or treatment options if needed. With the right information and support, fear can be replaced with informed decision-making and proactive health care.