Blood in the stool, increased defecation, anal pain etc. are the common symptoms of piles. Many people are embarrassed to see a doctor as the symptoms are not fatal and appear in their private area. They would take some medications on their own. Unbeknownst to them, these are also symptoms of colorectal cancer and may have developed into the late-stage when diagnosed.
Colorectal Cancer refers to the cancer on the colon, it is also known as colon cancer or rectal cancer depending on the origin. Adenocarcinoma is the most common type of colorectal cancer while squamous cell carcinoma is the least common type. Among all colorectal cancers in China, rectal cancer is the most common one, followed by colon cancer (sigmoid colon, cecum, ascending colon, descending colon, and transverse colon).
Colorectal Cancer Patients are getting Younger
The colorectal cancer patients are getting significantly younger. The average age of onset in China is 55 which is 10 years younger than that of 65 in other countries. More and more young adults are diagnosed with colorectal cancer, of which 40% of them are below 50. Young adults with colorectal cancer are often more malignant and more difficult to treat.
The number of young adults visiting colorectal surgery centres has increased in the past 5 years and the trend of people suffering from colorectal cancer is significantly getting younger. Always staying up late, irregular meal timing, binge eating, alcohol abuse etc. can directly or indirectly induce the occurrence colorectal cancer. These are the common lifestyle of young adults and has led to a trend that more and more younger people are suffering from colorectal cancer.
Early Symptoms of colorectal cancer
The early symptoms of colorectal cancer are subtle, with only slight discomfort, indigestion, hidden blood in the stool etc. The symptoms will be more significant as the cancer develops, including change in bowel habits, abdominal pain, blood in the stool, abdominal mass, bowel obstruction etc. sometimes with anaemia, fever, weight loss etc. As the cancerous tumour has metastasized and infiltrated, it will affect other organs and show different symptoms depending on the its origin.
- 1. Right-sided Colorectal Cancer
The symptoms of right-sided colorectal cancer are loss of appetite, nausea, vomiting, anaemia, fatigue, and abdominal pain. Cancer in this area will cause iron-deficiency anaemia, which is characterised by fatigue, loss of energy, shortness of breath etc. This is a type of colorectal cancer that is usually diagnosed at a later stage as the right-sided colon has a larger lumen. Symptoms will only show when the cancerous tumour has developed into a certain size.
- 2. Left-sided Colorectal Cancer
The left-sided colon has a smaller lumen than the right-sided one, it will cause bowel obstruction of different degrees. The bowel obstruction changes the bowel habits and lead to conditions such as constipation, bloody stool, diarrhoea, abdominal pain and cramp, bloating, etc. Fresh bleeding stools indicate that the tumor is located in the left-sided colon. This type of colorectal cancer can be diagnosed earlier than the right-sided one.
- 3. Rectal Cancer
The major symptoms of rectal cancer are bloody stool, changes in bowel habits, and bowel obstruction. Patients who have cancerous tumours in a lower area, and the stool is hard, may have blood in their stool as the stool and the tumour may rub against each other and cause bleeding. The stool will not mix with the blood but become bright red or dark red as the blood stays. This is usually confused with the condition of bleeding piles. Secondary infection will appear as the cancerous tumour is festered and being repeatedly irritated by the stool. The infection stimulates defecation reflex frequently and can easily be misdiagnosed as gastroenteritis or bacillary dysentery. As the cancerous tumour grows in a circular shape, the lumen will be partially blocked and cause the change in form and size of the stool in the early stage, and bowel obstruction in the late-stage.
- 4. Tumour Infiltration and Metastasis
Metastasis is the most common way that colorectal cancer spreads and it will invade its surrounding tissues or organs and cause corresponding clinical symptoms. Bowel incontinence, persistent lower abdominal and lower back pain are the result of cancerous cells invading the nerves in abdominopelvic cavity. The transcoelomic metastasis of the cancer cells in the pelvic cavity will cause different symptoms. As the transcoelomic metastasis will form ascites, a digital rectal exam can help to examine whether there is mass in the bladder and rectum or in the uterus and rectum. Lymphatic metastasis and hematogenous metastasis are the two major ways that the cancer cells spread, in which cancer cells enter the lymph nodes through the lymphatic vessels or to other organs like liver, lung, bones etc. through blood circulation.
7 Risk Factors of colorectal cancer
The exact cause of colorectal cancer is not known, but the following 7 risk factors are strongly linked to the disease:
- Carnivore Diet
A carnivore diet is a significant risk factor of colorectal cancer. As the meat releases carcinogens during digestion and breaks down into insoluble fibres, resulting in slow peristalsis and accumulation of the carcinogens in the intestine.. The accumulation will irritate the intestinal mucosa and become cancerous.
- Over-seasoned food
Spicy and tongue-numbing, sour, salty, fried, smoked, and barbecue are the ways of cooking and seasoning that will give you cancer. Having the aforementioned food as well as late-night supper will further irritate the intestines and increase the risk of having colorectal cancer.
- Pickled food
Pickled food is also a risk factor of colorectal cancer. People who love eating pickled food are at high risk of having colorectal cancer.
- Prolonged sitting
Sitting in the office for hours and lack of exercise will slow down the bowel movement, accumulate the harmful substances in the stool and irritate the intestines.
- Fast Food
The monotonous diet of fast food that is high in calories and low in dietary fibre increases the risk of having colorectal cancer.
- Smoking and Alcohol Consumption
Smoking and alcohol consumption are the two major risk factors for all cancers. Researchers have found that smoking can produce long-term, continuous chronic stimulation of the colon, thereby triggering colorectal cancer.
It is estimated that heredity is a significant risk factor in around 20% of colorectal cancer patients. Hereditary colorectal cancer is more common than rectal cancer.
Prevention of colorectal cancer
It is recommended to exercise more, have regular daily routes and a better weight-control.
Lastly, and most importantly, having regular body checks is crucial for colorectal cancer prevention. An early remedy can be made with early diagnosis of colorectal cancer precancerous lesions. The World Health Organisation recommended people who are 45-74 years old to take a faecal occult blood test every two years; people who are over 40 years old to take a colonoscopy every 5 years. Inflammatory bowel disease patients (including ulcerative colitis and Crohn's disease), and people who have colon polyps should take a colonoscopy every 1 to 2 years.
Early diagnosis, early prevention, early remedy and regular check-ups are extremely important in preventing colorectal cancer, especially for people who have had polyps, ulcerative colitis, proctitis, constipation, or a family history of colorectal cancer. They are at high risk of having colorectal cancer and they are recommended to take tests and look out for the cancer.
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