Colorectal cancer, commonly called colon cancer, is a type of cancer that affects the large intestine or rectum. It usually develops from polyps (growths) in the colon’s inner lining.
It is concerning that the signs of colon cancer may be minor or non-existent and can not be detected during the early stages of the disease. The symptoms may start to appear usually in or after stage 2.
According to the American Cancer Society, colon cancer is the third most common cancer worldwide, accounting for approximately 10% of all cancer cases. It is also reported that it is the second leading cause of cancer-related death in the US.
However, with the advancement of technology and medicine, many screening tests have been developed. This has made the screening and diagnosis process easier. As a result, many people can get diagnosed and treated before entering the serious stage.
This blog covers everything you need to know about colon cancer, including its symptoms and diagnosis. You will also learn how it can be prevented and the treatment process of colon cancer.
What is Colon Cancer?
Colon cancer is a type of deadly cancer that affects the colon or large intestine of the human body. What is a colon exactly? It’s a part of our digestive system that is responsible for processing the food we eat for energy. It is the first and longest part of the digestive system.
Colon cancer occurs when normal cells surrounding the large intestine (or colon) start to grow and change uncontrollably. These cells eventually form a tumor in a process that takes years.
Who is more likely to develop Colon Cancer?
As mentioned before, colon cancer is the third most common cancer found in US citizens. Colorectal cancer usually affects both men and women aged above 50.
However, in the last few years, the number of people between the ages of 20 and 49 with colon cancer has spiked by 1.5% every year, and the cause for this sudden change is still unknown.
What Are the Stages of Colon Cancer?
When a person is diagnosed with colon cancer, doctors begin to find out how far it has spread. Staging helps the doctor determine how serious the cancer is and how it can be treated. As it’s apparent, the lower the number, the less the cancer has spread.
The following are the stages of colon cancer.
- Stage 0 – This is usually the early phase of the cancer. The doctors called this stage a Carcinoma in Situ. Stage 0 colon cancer is confined to the innermost lining of the colon, known as mucosa, where abnormal cells are found.
- Stage I – Stage I indicates that the tumor has formed in the mucosa and has spread to the muscle layer of the colon wall.
- Stage II – The colon cancer has spread through the muscle wall of the colon. This stage is further divided into stages IIA, IIB, and IIC.
- Stage III – Stage III colon cancer means it has expanded outside the colon to lymph nodes.
- Stage IV – This is the last stage of colon cancer and the deadliest. It means the cancer has spread through the blood to other body organs, such as the liver, lungs, or ovary (in females).
Symptoms and Signs of Colon Cancer
Generally speaking, you can have colon cancer without any visible signs or symptoms, i.e., they are asymptomatic.
Even if you notice these symptoms, you can’t be sure that these changes in your body are signs of colorectal cancer. Since some colon cancer symptoms are similar to symptoms of other less serious conditions.
Some of the common signs and symptoms of colon cancer are:
- Rectal bleeding (Usually dark red)
- Loose or narrow-shaped feces
- Weakness and fatigue
- Sudden weight loss
- Frequent changes in bowel habits
- Heavy abdominal pain
- Bloating in the stomach
- Non-stop vomiting
- Iron-deficiency anemia
These are the early symptoms of colon cancer. If the cancer spreads to a new area surrounding the belly, such as the liver, it may cause additional symptoms. For example, jaundice.
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What Causes Colon Cancer?
Generally, all colorectal cancers begin as non-cancerous polyps in the lining of the intestine and rectum. And then, these polyps gradually develop into cancer.
Colon cancer forms when the DNA in cells in the colon develops mutations that can make them unable to control growth and division.
In most cases, these mutated cells die or are attacked by the immune system.
However, some mutated cells may escape the immune system and grow out of control, forming a tumor in the colon.
Note that the exact cause of colon cancer is not known yet, however, certain risk factors are fully linked to an increased risk of developing this type of deadly cancer. Let’s get into it.
What Are The Risk Factors of Colon Cancer?
Researchers have found several contributing factors that may increase the risk of colorectal cancer. Some risk factors include:
- Older age (>45): Older age is the main risk factor for most cancers. However, colon cancer can occur at any age. The chance of getting colon cancer rises as people get older.
- Family history of colon cancer: People who have a blood relative with colon cancer are likely to get colon cancer. In fact, having more than one family member who has rectal cancer increases the risk even more.
- Alcohol consumption: Drinking too much alcohol, around 3-4 glasses per day, can further increase the risk.
- Personal history of colorectal polyps: Having a personal history of high-risk adenomas (colorectal polyps that look abnormal under a microscope) increases the chance of colon cancer.
- Inflammatory bowel diseases: Conditions that cause swelling and pain of the bowel can increase the risk of colorectal cancer. For example, ulcerative colitis and Crohn’s disease.
- Hereditary syndrome: Some DNA changes or mutations that increase the risk of colon cancer run in families. One of the most common hereditary syndromes are familial adenomatous polyposis (FAP) and Lynch syndrome.
- Frequent smoking: Smoking cigarettes often can lead to an increased risk of colon cancer.
- Back race: Black people in the US and other countries have a higher risk of developing colon cancer compared to those of other races.
- Obesity: People who are overweight are more likely to get colon cancer. It is found that obese people have a low chance of getting treated. Hence, they usually die of colon cancer.
- Diabetes: People with insulin resistance or diabetes are more likely to develop colorectal cancer.
- Low-fiber and high-fat diet: Research has found that colorectal cancer might be linked to a Western diet. A typical Western diet includes red meat, which has low fiber content and is high in fat. As a result, people who consume more red and processed meat tend to have a high risk of colon cancer.
- Lack of exercise and physical activity: Not engaging in any physical activity or exercise may increase the risk of colon cancer in people.
Colon Cancer: Screening and Diagnosis
Colon cancer screening identifies early cancers and polyps in the large intestine before cancer can spread. Regular screening is the best way to reduce the potential complications or death from colorectal cancer.
Often, the symptoms of colon cancer are invisible. That’s why it’s important to test them before the polyps become invasive. Colon cancer screening is a method that helps doctors to find and remove polyps before they become cancerous.
It’s particularly important for people who have a family history of colon cancer. The American College of Physicians recommends colon cancer screening for people of age between 50-75 years.
However, the regularity of screening depends on a person’s level of risk and stage of colon cancer.
Colon Cancer Screening tests:
- Colonoscopy: A colonoscopy is a screening test where a thin tube with a light is inserted through the anus into the colon to examine the internal parts clearly. If any abnormal lump or polyp is found, a piece of it can be taken out and checked in the laboratory for cancer cells.
- Biopsy: A biopsy is a simple procedure where a sample of cancerous tissue is removed for further examination in the laboratory.
- Endorectal ultrasound: This method is done within the rectum. During the procedure, a small stick is moved around the skin. It gives off the ultrasound waves and picks up the echoes as they bounce off tissues. The echoes are made into an image on a screen.
- CT scan: A CT scan is similar to an X-ray but in a more detailed way. CT scans are also used in biopsy and show if the cancer has spread across.
Treatment of Colon Cancer
The treatment option for colon cancer usually depends on the type and stage of colon cancer. Further, the patient’s age, overall health, and other conditions can also play a vital role in deciding the best treatment option.
Surgery is the most common option for treating colon cancer in patients. Depending on the colon cancer screening, various types of surgery are available:
- Polypectomy – If the cancer is only present in the polyp, patients may just require a minor surgery called polypectomy to remove the cancerous polyp.
- Colonoscopy – Stage 0 colon cancer can be treated by effortlessly removing the tumor using endoscopy surgery. This is called colonoscopy and is most common among patients with early diagnosis.
- Colectomy – If the cancer spreads all over the colon, then a colectomy is performed. During this surgery, the doctor will remove the part of the colon that has cancer or maybe the entire colon.
Subsequently, the doctor can remove the surrounding lymph nodes to lower the risk of spreading.
Following this, he will either re-attach the healthy portion of the colon or develop a stoma (surgical opening in the wall of the abdomen), depending on the extent of the colectomy.
Another effective way to treat colon cancer is via chemotherapy. Chemotherapy is highly popular, but it may have many side effects. The procedure involves taking up the prescribed medicines to kill cancerous cells.
It can be either one type of medicine or a combination of medicines. Moreover, Chemotherapy is advised for people with stage III colon cancer. They receive chemotherapy after surgery for three to six months. This is referred to as adjuvant chemotherapy.
Although the tumor has been removed by surgery, chemotherapy is given to treat any cancer cells that may remain in the colon part.
3. Radiation Therapy
Radiation therapy is another treatment option for colorectal cancer. It involves the use of high doses of radiation to kill cancer cells and prevent them from spreading further.
4. Targeted Therapy
Targeted therapy involves the use of drugs that block the growth of cancer by inhibiting the targets (molecules) responsible for tumor growth and spread. It may be given as pills or injected into a vein.
Cryotherapy or cryosurgery is a form of surgery that uses a thin metal probe to freeze and destroy abnormal tissue. It is performed with the help of ultrasound.
The best way to treat any disease is to take preventive measures. Here are a few tips to follow to prevent yourself from colon cancer:
- Exercise regularly – Try to spend at least 30 minutes of your day for exercise or any other physical activity. Keeping your body healthy and active is very important to prevent any kind of disease.
- Eat healthy diets – Consume more fruits, vegetables, and whole grains as a part of your healthy diet. Foods rich in vitamins, minerals, and fibers help prevent cancer. So try to include more of them.
- Avoid eating red and processed meats – Generally, red and processed meats are high in fat and calories but low in fiber. Research has shown that people who have more red meat have a high risk of colon cancer.
- Avoid smoking or using tobacco – If you are a person who smokes often, you have to quit no matter what. Talk to your doctor for suggestions.
- Maintain a healthy weight – Work on your weight management with a healthy diet and daily exercise. Start making a weight loss or weight gain routine and follow it strictly to prevent yourself from any disease.
- Abstain from having alcoholic drinks – If you can’t avoid drinking, try to limit the amount to no more than one drink a day. Keep it in moderation.
- Go for regular colon cancer screening – If you notice a few signs of colon cancer, consult a healthcare provider. Ask them when and how often you should come for colon cancer screening. The doctor may then recommend the colon cancer screening details and guidelines depending on your symptoms.
- Having polyps removed before they can become cancerous.
Colorectal cancer is the third most common cancer in the US. It’s also the second fatal cancer affecting both men and women. This blog covered everything you need to know about colon cancer, its causes, and risk factors.
It also explored various screening, treatment, and preventive tips to consider to avoid the chances of developing colon cancer.
1. What is the main cause of colon cancer?
Ans: There are many reasons that cause colon cancer. It usually occurs when the cells in the colon develop changes in their DNA, and these cells start to multiply quickly, affecting the healthy cells and eventually forming a tumor.
2. Is colon cancer curable?
Ans: Yes. The colon cancer is completely curable when localized to the colon. Surgery is the way to treat this type of cancer as it involves the removal of cancerous cells. So far, it has cured almost 50% of patients with colorectal cancer.
3. What are the early signs of colon cancer?
Ans: The early signs of colon cancer include frequent diarrhea or constipation, blood in feces, weakness, weight loss, continuous discomfort in the stomach like cramps, etc.
4. How long can someone live with colon cancer?
Ans: Studies have shown that the median survival rate of colon cancer patients is 63% for about 24 months. However, if the cancer is diagnosed at a localized stage, the survival rate is estimated to be 91%.
5. What is usually the first symptom of colon cancer?
Ans: The most common and first symptoms can be seen when there is frequent diarrhea or constipation.