Family history and cancer prevention screening

Family history is an important factor in assessing cancer risk. Studies show that about 5% to 10% of cancers have a hereditary tendency. If a first-degree relative (parent, child, or sibling) has cancer, an individual's cancer risk significantly increases. For instance, women whose mother or sister has had breast cancer have a 2 to 3 times higher risk of developing the disease than the general population.

Common hereditary cancer syndromes include: Hereditary Breast and Ovarian Cancer Syndrome (BRCA1/2 gene mutations), Lynch Syndrome (colorectal cancer), and Li-Fraumeni Syndrome (multiple cancers), among others. These syndromes are characterized by autosomal dominant inheritance, with a 50% chance of transmission to offspring.

Screening recommendations vary by cancer type. For breast cancer, women with a family history should start annual mammograms at age 40, and may combine with MRI if necessary. For colorectal cancer, those with a family history should begin colonoscopy at age 40 or 10 years before the earliest age of onset in the family, and repeat every five years. For gastric cancer, individuals with a family history are advised to start endoscopy at age 40 and repeat every 2 to 3 years.

Genetic testing can help identify hereditary cancer risks. It is recommended to undergo testing under the guidance of a professional genetic counselor, and to fully understand the significance, limitations, and possible outcomes of the test before proceeding. A positive result requires enhanced screening, while a negative result does not completely rule out the risk.

Preventive measures include maintaining a healthy lifestyle, avoiding risk factors such as smoking and excessive alcohol consumption, regular targeted screening, and considering preventive surgery when necessary, such as prophylactic mastectomy for BRCA mutation carriers.

By paying attention to family history and taking targeted preventive measures, the risk of cancer can be effectively reduced. It is recommended to communicate fully with a doctor to develop a personalized prevention plan.