Colorectal cancer symptoms and high-risk groups? What foods can be eaten to prevent it? Is finding a polyp cancer?
Interviewed Expert: Dr. Qiu Hanmo, Director of the Comprehensive Diagnosis and Treatment Department of National Taiwan University Hospital and Clinical Professor of Internal Medicine, Department of Medicine, National Taiwan University College of Medicine
Is colorectal cancer incidence rising and death rates falling?
According to the latest data released by the Taiwan Ministry of Health and Welfare, the number of new cases of colorectal cancer in 2019 was 17,302, ranking first among the top ten cancers. The standardized incidence rate increased slightly by 1.1 compared with the previous year. Judging from the incidence rate of colorectal cancer alone, it has fluctuated in recent years. The reasons are complicated. On the one hand, risk factors in the environment still exist. On the other hand, the country’s promotion of screening has also helped to identify more asymptomatic early-stage colorectal cancer. cancer.
Due to the increase in the proportion of early screening, colorectal cancer mortality has shown a gentle downward trend in recent years. Looking at the survival rates of colorectal cancer stages, the 5-year survival rate of stage 0 colorectal cancer is close to 100%, that of stage 1 is 93%-94%, and that of stage 4 is only 15%. More importantly, about half of the colorectal cancer patients detected through screening are in stage 0-1. On the other hand, about 20% of those who seek medical diagnosis only after showing obvious symptoms are in stage 4.
Therefore, although the total number of people has increased, the proportion of early-stage colorectal cancer has increased, and the mortality rate has actually decreased. As of now, nearly 70% of Taiwanese people over the age of 50 have received at least one fecal occult blood screening test, which clearly shows the positive impact of screening penetration on reducing mortality.
What are the symptoms of colorectal cancer? At what age do you need regular screening?
The most common symptoms of early-stage colorectal cancer patients are actually “asymptomatic”, and obvious symptoms usually occur only after the disease progresses to stage 2-3. The “warning symptoms” most directly related to colorectal cancer are gastrointestinal bleeding (blood in the stool), anemia, significant weight loss, etc. Other clinical symptoms such as diarrhea and changes in bowel habits may also be caused by life stress.
The prognosis for early detection of colorectal cancer is very good, so you should not rely on symptoms to judge your physical condition. Anyone who reaches a certain age should undergo related screening tests such as fecal occult blood. Regular screening is recommended for Taiwanese over 50 years old. The United States has recently moved up the starting age for regular colorectal cancer screening to 45 years old.
High-risk groups for colorectal cancer? Men who love red meat are more dangerous?
Although aging is one of the reasons for the increase in cancer, the increase in the proportion of colorectal cancer among those aged 40-49 is not limited to Taiwan. Similar phenomena are seen in neighboring countries such as Japan, South Korea, Hong Kong, Singapore, and many Western countries. Among them, about 20% have family history or hereditary colorectal cancer, and the remaining 7 to 80% are so-called “sporadic” colorectal cancer. The risk factors include smoking, obesity, high cholesterol and high blood lipids, metabolic syndrome, wide waist circumference, and exercise. deficiencies, etc., and men are at higher risk than women.
In addition, whether excessive antibiotic exposure in early childhood affects intestinal bacteria and thereby increases the risk of colorectal cancer has also been discussed recently. Observational studies have found that for the generation born after 1960, due to the widespread use of medical care and the widespread use of antibiotics, the diversity of intestinal bacteria may be destroyed by antibiotics. As a result, those who were exposed to more antibiotics in childhood may have an increased risk of colorectal cancer when they grow up. But there is no clear conclusion.
Currently, young adults aged 40 to 49 who have risk factors such as smoking, obesity, inactivity, eating red meat, and being male should be more alert to colorectal cancer.
Is colorectal cancer related to diet? Suggested ways to prevent it?
“Red meat” is listed as the first-level carcinogen of colorectal cancer by the World Health Organization, especially red meat cooked in a barbecue method or processed meat such as bacon, ham, etc. It is best to avoid eating it every day. You should consume more white meat, fish, etc. Balance risks in your diet. In addition, in the past, we compared the distribution of fast food restaurants with cancer maps and found that areas with denser stores (symbolizing areas with a more Westernized diet) have a relatively higher incidence of colorectal cancer.
The best way to prevent colorectal cancer is to eat more fresh fruits and vegetables, especially “superfoods” with powerful antioxidant effects, such as cauliflower, sweet potatoes, mushrooms, grapes, deep-sea fish, turmeric, etc. You should also pay attention to a normal daily routine, exercise more and drink more water, and regular screening is a top priority.
Is colorectal cancer related to polyps? How often to track
Colorectal polyps are not necessarily colorectal cancer. About half of Taiwanese people over the age of 50 will have “hyperplastic polyps”, which are not related to colorectal cancer, while nearly 1/4 to 1/3 will have “adenomatous polyps”. Adenomatous polyps are neoplastic polyps that are larger than 1 cm or have villous components when observed under a microscope, which are considered high-risk adenomas. At present, medical technology cannot predict which polyps will become larger or cancerous. Therefore, as long as adenomatous polyps are judged to be adenomatous polyps under colonoscopy, preventive resection will be performed to prevent them from turning into cancerous lesions in the future.
Under normal circumstances, intensive colonoscopy is not encouraged, but patients with positive fecal occult blood should undergo colonoscopy. More and more evidence shows that even if the polyp is larger than 1 cm, as long as the biopsy confirms that there is no risk of cancer, it can be followed up after 3 years. If there are less than three adenomatous polyps and no lesions larger than one centimeter, 5-year follow-up is enough.
However, if the biopsy shows that the polyp cells contain villous components or a high degree of cellular atypia, it is considered a high-risk adenomatous polyp. Even if it is removed now, it is easy for new lesions to grow in other parts of the body. This requires Relatively short tracking observation intervals.
What are the current treatments for colorectal cancer? Is chemotherapy definitely needed?
Treatment methods for colorectal cancer vary depending on the stage of the disease. Stage 0 colorectal cancer only requires endoscopic resection; stage 1 tumors require surgery; stage 2 colorectal cancer has deeper tumor invasion but has not yet invaded lymph nodes. Mainly surgical treatment;
Stage 3 colorectal cancer indicates that the tumor has invaded the lymph nodes. After surgical resection, it is still considered that the cancer cells may have spread in the blood, and chemotherapy must be added. Stage 4 indicates that the tumor has metastasized to distant sites. Nowadays, it is treated with chemotherapy or labeling. Target therapy is the main approach. The latter will perform genetic testing to determine which target drug is suitable for use, and is currently covered by health insurance.
Due to the large number of patients with colorectal cancer, there are unified and standardized treatment methods and drug combinations internationally, and the efficacy has been confirmed through clinical trials. There is less room for ambiguity, so there is no need to worry about under- or over-treatment. Today’s medical development trend is “precision medicine”, which hopes to use treatments on patients who can really get help, avoiding unnecessary side effects and ineffective treatments that increase the patient’s physical and economic burden.
In short, the key to preventing and treating colorectal cancer still lies in regular screening and early detection. There is no need to be discouraged once colorectal cancer is diagnosed. Colorectal cancer is a cancer with a relatively good prognosis. As long as patients avoid risk factors, pay attention to a normal diet, exercise more, and maintain good living habits, they are still the key to reducing the risk of recurrence and preserving the results of treatment.
Further reading:
