When cancer recurs in the family... Are genes or environmental factors to blame?

Recurring cancer cases in a family raise fears of heredity, but experts confirm that only 5-10% of cases are genetic, while the majority are linked to environmental and behavioral factors such as smoking and obesity.

The scientific article addresses the issue of recurring cancer within a single family and debunks the common belief that a family history inevitably means the disease is hereditary. The article is based on statements by Dr. Tawfiq bin Omran, head of the genetic medicine department at Sidra Hospital in Doha, who confirms that most cancer cases result from non-genetic factors such as aging, smoking, and obesity. Data from the US National Cancer Institute indicates that only 5% to 10% of cases are due to inherited genetic changes. The article explains that the recurrence of the disease in a family may be due to shared environmental and behavioral factors, such as diet and exposure to smoking. It also provides guidance on indicators that warrant genetic counseling, such as the onset of cancer at a young age or the involvement of several relatives. It emphasizes that genetic testing is not a definitive prediction tool but helps in assessing risk levels and developing preventive plans.