Hereditary bowel cancer: high malignancy.
Most colorectal cancers are not hereditary, but in recent years, the medical community has discovered that some cancers show obvious family characteristics, like hereditary non-polyposis colorectal cancer, which is a family tumor syndrome with autosomal dominant inheritance. Liu Shaojie said, according to estimates, the incidence of hereditary non-polyposis colorectal cancer in the United States may range from one in two hundred to one in a thousand, and may account for 4 to 13 percent of colorectal cancers.
From the current study, hereditary nonpolyposis colorectal cancer has a clear familial clustering phenomenon, with an epizootic rate of 80 percent. That is, 80% of gene carriers may develop colon or extraintestinal tumors in their lifetime. Liu Shaojie pointed out that hereditary non-polyposis colorectal cancer has the following characteristics.
1.This kind of colon cancer is mostly seen in the right colon, and the age of patients is low, averaging about 45 years old, unlike general sporadic cancer which is mostly seen in the elderly.
2. Patients are often accompanied by simultaneous or heterochronic primary cancer. In other words, after the patient’s primary colon cancer is removed, another bowel cancer may be found in another location in a few years. Statistics show that the chance of recurrence of hereditary non-polyposis colorectal cancer within 10 years is 40%.
3.The malignancy of this cancer is very high, and many patients are already in advanced stage when they are found.
4.Patients with such 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 hematologic malignancies and various sarcomas.
5.The age of onset of hereditary non-polyposis colorectal cancer is shown to be advanced generation by generation. In large families involving more than three generations in China, the average age of tumor occurrence in the next generation of patients is about 10 years earlier than that of the previous generation.
How to confirm the diagnosis of hereditary bowel cancer?
How to identify whether a patient’s bowel cancer is general disseminated bowel cancer or hereditary bowel cancer? Liu Shaojie said that there are two international diagnostic criteria, which are mainly combined with the patient’s family history to confirm the diagnosis. One criterion is called Amsterdam Diagnostic Criteria, according to which three people in a family with colorectal cancer, one of whom is a first-degree relative of the other two, and at the same time, the colorectal cancer involves two generations, one of whom is diagnosed at an age less than 50 years, can be diagnosed as hereditary non-polyposis colorectal cancer.
However, since modern society is mostly dominated by small families, there are few opportunities to find three colon cancers in one family, and it would be too strict to use the Amsterdam criteria for a blanket diagnosis.
For this reason, the clinic now generally applies another criterion, whose diagnostic criteria include.
1.Patients with relatives, especially first-degree relatives, who have colorectal cancer.
2. Age less than 50 years old.
3. Right-sided cancer is more common.
4. Simultaneous and heterochronic multiple primary cancers.
5.Malignant tumor with organs other than colorectal cancer.
Anyone who has the first one and any one of the remaining four can be initially diagnosed as hereditary non-polyposis colorectal cancer.
Family history is found, and regular cancer screening is required!
The introduction of this diagnostic criterion is of great clinical importance because this hereditary cancer is highly malignant and can only be detected at an early stage to improve the efficacy. If the patient can be diagnosed, then other relatives should be screened for abdominal tumors every 1-2 years. The main means of screening include colonoscopy, barium enema, gastroscopy, barium meal, abdominal ultrasound, tumor markers, etc.