Is colon cancer hereditary?

Most colorectal cancers are not inherited, but in recent years, the medical community has discovered that some cancers show obvious family characteristics, such as hereditary non-polyposis colorectal cancer, which is an autosomal dominant family tumor syndrome. According to estimates, the incidence of hereditary non-polyposis colorectal cancer in the United States may be between 1/200 and 1/1000, which may account for 15% of colorectal cancers.

According to current research, hereditary non-polyposis colorectal cancer has a very obvious familial aggregation phenomenon, and its penetrance is usually 80%, which means that 80% of gene carriers may develop colon or extra-intestinal tumors in their lifetime.

1. This type of cancer is highly malignant and many patients are already in the late stages when they discover it.

2. This type of colon cancer is more common in the right colon. The patient's age of onset is low, with an average of around 45 years old, which is different from general sporadic cancers that are more common in the elderly.

3. The age of onset of hereditary non-polyposis colorectal cancer is getting earlier with each generation. In large families involving more than three generations in China, the average age of tumor onset in the next generation is about 10 years earlier than that in the previous generation.

4. Patients with this family history are also prone to extraintestinal malignancies, including endometrial cancer, gastric cancer, ovarian cancer, pancreatic cancer, ureteral cancer, renal pelvis cancer, skin cancer, lymphatic and blood system malignancies and various sarcomas.

5. Patients often have synchronous or metachronous primary cancers. That is, after the patient's primary colorectal cancer is removed, another colorectal cancer may be found in another location a few years later. Statistics show that the probability of hereditary non-polyposis colorectal cancer recurring within 10 years is 40%.