“All you need to know about Colon Cancer”
— Get Well in India
Colon or colorectal (of colon and rectum) cancer occurs in the large intestine (colon) or the rectum (end of the colon i.e. the passageway that connects the colon to the anus). Colon is the area where water and salt from solid wastes are extracted. The waste then moves through the rectum and exits the body through the anus.
In the initial stages, when the formation of colon cancer takes place, there are non-cancerous (benign) clumps of cells called adenomatous polyps. Over a period of time some of these polyps can become cancerous causing cancer of the colon. This is the reason why doctors recommend regular screening tests to help prevent colon cancer by identifying and removing polyps before they turn cancerous.
The colon has three main functions:
- To digest and absorb nutrients from food
- To concentrate fecal matter by absorbing fluids
- To store and control expulsion of fecal matter
A point to be noted is that colon cancer and rectal cancer may occur together. This is called ‘colorectal cancer’. Rectal cancer originates in the rectum, which is located in end of the large intestine, closer to the anus.
Dr. Anil Heroor
Dr. Suresh Advani
The colon and rectum are parts of the digestive system or the gastrointestinal system. The colon and rectum make up the large intestine (or large bowel).
Most of the large intestine is made up of colon, a muscular tube about 5 feet long. The parts of the colon are named in the order the food matter is traveling in the body.
The first section is called the ascending colon, it begins with a pouch called the cecum, where undigested food is received from the small intestine, and extends upward on the right side of the abdomen.
The second section is called the transverse colon because it travels across the body from the right to the left side.
The third section is called the descending colon because it descends (travels down) on the left side.
The fourth section is called the sigmoid colon because of its ‘S’ shape, the sigmoid colon joins the rectum, which connects to the anus.
The ascending and transverse sections are collectively referred to as the proximal colon, and the descending and sigmoid colon are referred to as the distal colon.
The colon absorbs water and salt from the remaining food matter after it goes through the small intestine (small bowel). The waste matter that is left after going through the colon goes into the rectum, the final six inches of the digestive system, where it is stored until it passes out of the body through the anus.
Factors & Symptoms
Factors that may increase your risk of colon cancer include:
- Age: Majority of people diagnosed with colon cancer are over 50. Colon cancer can occur in younger people, but the frequency is very less.
- Race: African-Americans race have a greater risk of colon cancer as compared to people of other races.
- Personal history: If you have had colon cancer or adenomatous polyps in the past, you are more prone to having colon cancer in the future.
- Inflammatory intestinal conditions: Chronic inflammatory diseases of the colon, such as ulcerative colitis and Crohn’s disease, can increase your risk of colon cancer.
- Inherited syndromes: Genetically passed through generations can increase your risk of colon cancer.
- Family history of colon cancer: If you have a parent, sibling or child with colon cancer, you are at a greater risk. If more than one family member has colon cancer or rectal cancer, your risk is even higher.
- Low-fiber, high-fat diet: If your diet is low in fiber and high in fat and calories, you might have colon cancer. People eating red meat and processed meat are also at a greater risk.
- Sedentary lifestyle: If you are not inactive, you’re more likely to develop colon cancer. Getting regular physical activity may reduce your risk of colon cancer.
- Diabetes: People with diabetes and insulin resistance have an increased risk of colon cancer.
- Obesity: People who are obese have an increased risk of colon cancer and an increased risk of dying of colon cancer when compared with people considered normal weight.
- Smoking: People who smoke may have an increased risk of colon cancer.
- Alcohol: Heavy use of alcohol increases your risk of colon cancer.
Symptoms: If colon cancer is detected in its early stages, chances of having symptoms is negligible. Symptoms can also vary according to the location of the tumor within the colon. As advancements are made from early stage to next stage, you may watch for the following symptoms;
- Diarrhoea or constipation
- Bowel not clearing
- Blood (either bright red or very dark) in your stool
- Stools narrower than usual
- Frequent gas pains or cramps, or feeling full or bloated
- Weight loss without any reason
- Nausea or vomiting
- Rectal bleeding
- Change in bowel habits
- Loss of appetite
People with an average risk of colon cancer can consider screening, beginning of age of 50. But people with an increased risk, such as those with a family history of colon cancer, should consider screening sooner.
Several screening options exists, each with its own benefits and drawbacks. Your doctor will guide you through that and will suggest a suitable test based on your symptoms.
Stages & Treatment Details
Treatment will depend on the type and stage of the cancer, and the age, health status, and other characteristics of the patient.
There is no single treatment for any cancer, but the most common options for colon cancer are surgery, chemotherapy, and radiation therapy. Treatments seek to remove the cancer and relieve any painful symptoms.
Surgery: Surgery is the most common initial medical treatment for colorectal cancer. During surgery, the tumor, surrounding healthy intestine, and adjacent lymph nodes are removed. The surgeon then reconnects the healthy sections of the bowel. In patients with rectal cancer, the rectum sometimes is permanently removed if the cancer arises too low in the rectum. The surgeon then creates an opening called colostomy, on the abdominal wall through which solid waste from the colon is excreted. For most people with early stage colon cancer (stage I and most stage II), surgery alone is the only treatment required.
However, once a colon cancer has spread to local lymph nodes (stage III), the risk of the cancer returning remains high even if all visible evidence of the cancer has been removed by the surgeon. This is due to an increased likelihood that tiny cancer cells may have escaped prior to surgery and are too small to detect at that time by blood tests, scans or even direct examination. Their presence is deduced from higher risk of recurrence of the colon cancer at a later date (relapse). Cancer oncologists recommend additional treatments with chemotherapy in this case to lower the risk of the cancer’s return.
Chemotherapy: It utilizes chemicals that interfere with the cell division process by altering proteins or DNA in order to damage and kill cancer cells.
These treatments target any rapidly dividing cells, even the healthy ones too. However, the healthy cells can usually recover from any chemically-induced damage, but cancer cells cannot. Chemotherapy is generally used to treat cancer that has spread because the medicines travel through the whole body. Treatment occurs in cycles, so the body has time to heal between doses.
Common side effects include:
- Hair loss
Combination therapies often mix multiple types of chemotherapy or combine chemotherapy with other treatments.
Radiation: This treatment focuses on high-energy gamma-rays to kill the cancer cells.
Radioactive gamma-rays are emitted from metals such as radium, or from high-energy x-rays. Radiotherapy is the only treatment to shrink a tumor or destroy cancer cells, or alongside other cancer treatments.
Radiation treatments are opted for until a later stage. They may be preferred only if early stage rectal cancer has penetrated the wall of the rectum or traveled to nearby lymph nodes.
Side effects may include:
- Mild skin changes resembling sunburn or suntan
- Appetite and weight loss
Most side effects resolve a few weeks after completing treatment.
You will be encouraged to sit soon after your operation, and also to walk around the ward several times a day as soon as you are able too.
To prevent blood clots you will be given compression stockings and blood thinning injections. You should also do frequent leg exercises while sitting in the chair or lying in bed.
Your physiotherapist will show you how to do deep breathing exercises which would aid in your well being. These exercises will help clear secretions from your lungs and help prevent a chest infection. Some patients develop coughing post surgery, but breathing exercises will help clear up your chest. Gently supporting the abdomen with a towel or pillow will make it more comfortable.
Pain relief is very important in the first few days and weeks. It will help you to move around comfortably and speeden your recovery.
You will be allowed to eat and drink soon after your return to the ward. Digestion process might take time, hence you will need to eat in small portions and preferably low-fibre foods for easy digestion. You may be given plenty of supplements to drink.
You may be prescribed a low-fibre or low-residue diet for a few weeks to allow your bowel to heal. If you have a permanent or temporary stoma, you will be visited on a regular basis by the stoma nurse specialist to give you specific dietary advice, and help you to care for your stoma.
Eating and drinking well, walking around the ward, climbing stairs are some of the indicators of your wound being healed. If you feel very tired for several weeks and sometimes months after your surgery then you should try and do the following:
- Avoid sitting for long hours
- Walking around the house on an hourly basis
- Building up to walking outside for fresh air
Your recovery will depend on how fit you were before surgery and your will power.
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