Colon Cancer

Colorectal cancer. Colon cancer. CRC. Bowel Cancer. These are all just different names for the cancer that grows in the colon or rectum (both of which are parts of the large intestine). For something that is often very painful, this adenocarcinoma of the rectum has quite humble origins.

The beginning

It usually begins as small clumps of cells called polyps, which form inside the colon. Now, this isn't something that is generally cancerous, but it is found that in most people who have had colon cancer at some point in their life, it started out in the form of a polyp. Gradually, it formed into what is now known as colon cancer. Let us find out together how to deal and fight against this, and how to prevent it.

The Colon

The colon is the first and longest part of the large intestine. The large intestine is the last part of the digestive system. The colon and by extension the large intestine is responsible for the passage of fecal matter, and is the last part of the alimentary canal. After absorption, the undigested matter is transferred to the large intestine, specifically the colon, from where the last part of the digestive cycle takes place—which is egestion.

Types of Colon Cancer:

• Gastrointestinal carcinoid tumors: A type of cancer that forms in the lining of the gastrointestinal (GI) tract. Carcinoid tumors develop in nerve cells called neuroendocrine cells, which help to regulate hormone production.
• Adenocarcinoma: The cancer starts in the inner lining of the colon and spreads gradually from there. It is mainly of two types—
  • Mucinous adenocarcinomas, where the composition is nearly 55% mucus. It can thus cause an aggravated form of the cancer and spread rather quickly.
  • Signet cell carcinoma, where the cancer is very rare and very difficult to detect. It is typically also very aggravated.
• Lymphoma: Cancer starts near/around the lymph nodes and gradually gets aggravated. It is typically not very common in the colon.
• Gastrointestinal stromal tumors: It is very rare and typically doesn't occur in the colon at all. It occurs in the GI tract, particularly in the stomach. Less than 7000 cases are reported each year of this cancer.
• Sarcoma: Cancer affecting the connective tissues around the colon.
• Colon and rectal melanomas: Melanomas are cancer in the melanocytes or the cells that give the cell its pigment. Though these are very rare in the colon it may occur so that the cancer has spread from the primary site to the colon.
• Colon and rectal leiomyosarcomas: It is the cancer affecting the smooth muscle cells of the colon and the rectum. It is very rare.
• Primary colorectal lymphomas: It is a type of non-Hodgkin Lymphoma, and typically affects the lymph nodes surrounding the colon and the lymphocytes around it. This colorectal cancer type usually develops later in life and is more common in men.

Symptoms:

Though the symptoms differ from person to person, there are a few that seem to be common for everyone. These include:—

• Pain in the abdomen
• Bloody stool
• Discomfort in passing stool
• Narrow stool
• Constipation; change in bowel movements; diarrhea
• Passing excessive amounts of gas
• "Lazed out" feelings or fatigue and (sometimes) anemia
• Abnormal weight loss
• Feeling that the bowel isn't coming all the way out during nature's call
• Black stool

These are just general symptoms. Needless to say, symptoms can differ for everyone.

Stages of Bowel Cancer:

Numeric grading (Stages 1-4):

• Stage 0, or carcinoma in situ: This is the first time the abnormal cells come into notice after running tests. It typically means that the cancer hasn't even developed properly yet. But the abnormal cells show signs consistent with those of cancerous cells.
• Stage 1: This means that the primary cell has developed but is no bigger than 1.8-2 cm in size. It has not spread to any part of the body apart from slowly infesting the lining of the affected organ.
  • It is advisable to start treatment from this stage itself to prevent anything serious.
• Stage 2A: The cancer hasn't spread to any organs, lymph nodes, or nearby tissues yet. But the tumor is steadily getting bigger. It will typically be around 2-4cm at this point.
  • If possible, surgery is the best choice in this stage to eliminate the cancer and its chances of spreading completely. If not possible, please at least start chemotherapy.
  • The cancer has grown into the outermost layers of the colon and rectum but hasn't grown through them yet. Neither has it spread to any nearby organs or lymph nodes.
• Stage 2B: The cancer has grown through the walls of the rectum and colon but hasn't spread to any organs or lymph nodes yet—but it's starting to show signs of metastasizing.
• Stage 2C: The cancer has attached to a nearby organ or tissue and attached there but hasn't gone to any distant organs or lymph nodes.
• Stage 3A: The cancer has grown through a lot of tissues and has at least spread towards the fat towards the lymph nodes—or, has affected 1-3 lymph nodes. In certain cases it can affect 4-6 lymph nodes as well.
• Stage 3B: The cancer has either spread through the walls of the colon to nearby organs and 4-6 lymph nodes; or spread to only 7 lymph nodes, not affecting any organs; or affected 4-6 lymph nodes without affecting any organs.
• Stage 3C: The cancer has grown through the outermost layer of the colon lining and affected >7 lymph nodes or the fat around them. Otherwise it has spread to one or more nearby organs and at least 1 lymph node.
• Stage 4A: The cancer might or might not have grown through the wall of the colon or rectum. It might or might not have spread to nearby lymph nodes. But it has definitely developed to 1 or more distant organs such as the lungs and liver.
• Stage 4B: The cancer might or might not have grown through the wall of the colon or rectum. It might or might not have spread to nearby lymph nodes. The tumor is of any size and has spread to more than 1 distant organ.
• Stage 4C: The cancer has definitely metastasized by this point. It has spread to distant organs such as the lungs and liver. It might or might not have grown through the lining of the colon or affected any lymph nodes. The survival rate by this stage is very low. Palliative care is recommended.

TNM STAGING:

• T— Size of the tumor and the extent.
  • T0: This means carcinoma in-situ. The cancer is at its earliest stage and only in the bowel lining (mucosal layer).
  • T1: The tumor is only in the inner lining of the bowel/colon.
  • T2: The tumor has grown into the muscle layer of the bowel wall but hasn't spread anywhere as much.
  • T3: The tumor has grown through the muscle layer of the bowel wall and into the tissues surrounding the bowel.
  • T4a: It means that the cancer has grown through the colon lining and spread to the outermost tissue of nearby organs.
  • T4b: The cancerous cells have spread to nearby organs fully.
• N—Whether or not the cancer has spread to nearby lymph nodes.
  • N0: Not spread to any lymph nodes.
  • N1a: At least 1 lymph node has cancerous cells.
  • N1b: At least 2-3 lymph nodes have cancerous cells.
  • N1c: Cancer cells are present in the tissue near the tumor and have a possibility of rapidly spreading to lymph nodes.
  • N2a: There are cancer cells in 4 to 6 nearby lymph nodes.
  • N2b: There are cancer cells in more than 7 nearby lymph nodes.
• M— Metastasis, whether the cancer has spread to other parts of the body.
  • M0: The cancer hasn't spread to any distant organs.
  • M1a: The cancer has spread to at least 1 distant organ but hasn't perforated the lining of the abdominal cavity or peritoneum yet.
  • M1b: The cancer has spread to at least 2 or more distant organs but hasn't perforated the peritoneum yet.
  • M1c: The cancer has spread to distant organs and perforated the peritoneum.

Risk Factors and/or Causes of Colon Cancer:

Doctors aren't exactly sure what the definite cause of bowel cancer is. See, cancer in the colon occurs when the cells in the colon constantly multiply, forming a tumor. Hence, we can conclude they're constantly changing/altering their DNA, since these cells are formed by mitosis process of cell division. But, some general causes or risk factors of bowel cancer include:—

• Environmental exposure: If your diet has low fiber and high fat content, you're most likely to develop bowel cancer.
• Alcohol use: If you drink liquor excessively, it can lead to colon cancer.
• Tobacco use: Some of the chemicals in tobacco smoke are carcinogenic, meaning they can cause genetic changes in cells of the colon and rectum, leading to the development of colorectal cancer.
• Radiation therapy may also lead to polyps formation in the rectum.
• Obesity and not enough exercise is the most common cause.
• Genetic history of colon cancer, and/or personal history of having it in the past.
• Lastly, a history of inflammable bowel disease like Crohn's disease may also be a cause.

Preventive measures:

Colon cancer can be prevented easily (apart from genetic causes) by a well balanced lifestyle—

• Reduced drinking and smoking.
• High fiber diet.
• Regular exercise.
• Supplements for regular bowel movements.
• Frequently visiting your doctor.
• Having regular health checkups.

These are some ways to prevent it. As such, frequent visits to the doctor can also help in detecting this type of cancer in the early stage. However, prevention is better than cure, so it is better to avoid things (as listed above) which may cause CRC.

Diagnosis of colon cancer:

• Stool tests: These are nearly the safest method to detect colon cancer. It involves taking a sample of your stool and uses different blood tests and microscopes to look and examine your stool for any abnormalities. It involves—
  • Fecal occult blood test: It tests for blood inside the stool. It is of two types, the guaiac-based fecal occult blood test and the fecal immunochemical test.
  • To ensure that you know definitively whether or not you have colon cancer and to detect its stage, take the fecal occult blood test at least once a year. 90% of the time, colon cancers can be detected through this test.
  • DNA test in the stool: It looks for any abnormalities in the DNA which are indicative of cancer or are precancerous growths.
• Colonoscopy: It involves a long, thin rod connected with a camera into the colon through the anus. It looks for any physical abnormalities or deformities in the colon associated with cancer.
• Biopsy: A sample of tissue is taken from the colon and looked at and examined for any abnormalities. It helps your medical adviser to understand how fast the cancer is spreading and what is the extent of it.
• CT Scans: The colon must be cleaned properly before this procedure. A series of pictures from the colon and rectum are taken and arranged by a computer to check for any abnormalities of any kind.

Treatment and management:

Typically, cancers can be quite fatal if fully developed. However, depending on the stage of the cancer, colon cancer is treatable.

• Surgical procedures:
  • Removing the part where the cancer is situated in the colon or just scrapping the colon in general. It is known as colectomy.
  • Removal of the lymph node to detect if the cancer or the tumor has spread, for people who have had it or are having it.
• Medication:
  • Of course, chemotherapy is an option as it is for all cancers. However this should be done keeping all factors in mind and at a board certified doctor's discretion as it may not be effective in all cases but trigger other defensive mechanisms which may be harmful to the person.
  • In such a case, chemotherapy protective drugs would work well.
• Laparoscopy: A small incision is made in the abdominal cavity and a camera is out through the incision to check for any abnormalities or polyps, to judge the stage and extent of the cancer.
• Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy—also called HIPEC. It is used only in the peritoneum. All the cancer cells are surgically removed first and then the affected area is splurged with chemotherapy drugs to kill off any cancerous cells left.
• Hepatic artery infusion pump therapy—also called HAIP therapy, it focuses on cancer cells that have metastasized to the liver. In such a treatment a pump is installed in the abdominal cavity from where a catheter is installed and chemotherapy drugs are pumped to the liver through the hepatic artery.
• Polypectomy: A polypectomy involves removing polyps with tools during a colonoscopy. It mainly focuses on removal of any cancerous polyps.
• Besides this, treatments typically associated with cancer such as chemotherapy, radiotherapy and target therapy can work well at any stage depending on the individual.
• Palliative care: This is also used when the cancer is well developed, but can be preferably used through any stage of the cancer development. It is aimed at making you feel better rather than intensively curing cancer.

FAQs:

Q) What should I eat to prevent colon cancer?

(Or) Q) How do I alter my eating habits?

First and foremost, your diet should be rich in fiber.

• Insoluble fiber: Volumizes the feces and makes it easier to move through the intestine. Prevents constipation. Good sources of insoluble fiber include wholegrains such as brown rice, wheat and spelt as well as nuts, seeds, potatoes in skins and dried figs.
• Soluble Fiber: For easier movement of fecal matter through the anus and mineral absorption. Good sources of soluble fiber include oats, barley, beans, peas, lentils, chickpeas, apples and carrots.
• Eat at least five portions of vegetables and fruit every day
• Choose wholegrain varieties of bread, rice and pasta
• Eat more pulses, such as beans and lentils
• Eat some fish, chicken, eggs and vegan protein like tofu, but limit red meat and avoid processed meat.
• Drink some milk and eat other dairy foods, but choose low sugar and fat options. (Obviously, don't consume if you're lactose intolerant).
• Choose unsaturated oils and spreads instead of butter, and use in small amounts.
• Avoid food and drinks high in fat or sugar, such as sweets, cakes and fizzy drinks.
• Research shows that eating processed meats is linked to an increase in the risk of developing bowel cancer because these meats have been preserved by smoking, curing, salting or adding preservatives, which adversely affect one's gut health.
• Incorporate more probiotics, prebiotics, and postbiotics for better digestion. A good, low fat, low sugar probiotic option is Greek Yogurt.
• Take small mouthfuls and chew your food slowly.
• Drinking peppermint water, fennel seed water etc may help relieve gas.
• Reduce the amount of caffeine you have in a day. Caffeine can stimulate the bowel and make diarrhea worse.
• Drink plenty of fluids - at least 2 liters a day.
• Take Vitamin supplements after consulting your doctor.

Q) What is the extent and Statistics of colon cancer across the world?

Colon cancer is the second leading cause of cancer-related deaths worldwide. In 2020, more than 1.9 million new cases of colorectal cancer and more than 930,000 deaths due to colorectal cancer were estimated to have occurred worldwide. Large geographical variations in incidence and mortality rates were observed. The incidence rates were highest in Europe and Australia and New Zealand, and the mortality rates were highest in Eastern Europe. By 2040 the burden of colorectal cancer will increase to 3.2 million new cases per year (an increase of 63%) and 1.6 million deaths per year (an increase of 73%). Males are slightly more likely to develop colon cancer than females. Colon cancer affects more people who are Black than people who are members of other ethnic groups or races.

Q) Why does colon cancer typically have such a high death rate?

This is due to the fact that there isn't enough research on colon cancer, regarding its causes, prevention and treatment. As a result even when colon cancer is detected it is very hard to work on it as it is typically detected when advanced.

Q) How to Tell the Difference Between Hemorrhoids and Colon Cancer?

Hemorrhoids are swollen veins developed under the skin around the anus (external hemorrhoids) or inside the rectum (internal hemorrhoids). These are far less serious than colon cancer and at best cost you some hemorrhoid cream and a trip to the doctor.

Colon cancer, on the other hand, is far more serious. It is when cancerous cells develop and form a tumor in your colon, the end part of the large intestine where the stool is stored. It starts typically as a polyp. Over time it progresses and becomes more aggressive and in a lot of cases fatal.

Q) What are the side effects of colon cancer treatment?

The side effects typically include—

• Nausea
• Vomiting
• Diarrhea
• Feverish feelings or a fever
• Dehydration
• Irritation in skin
• Fatigue
• Inflammation of the digestive tract lining
• Loss of appetite
• Anemia

Q) How do I cope with these side effects?

You can tackle these issues by—

• Drinking adequate water
• Taking a lot of electrolytes
• Using mild skin creams, cold creams, cool showers and cotton socks for the skin issues
• Talking to your doctor frequently about any issues you might have.
• If you have a very low blood count, consider blood transfusions and changes in your lifestyle
• Nutritional replacements and taking smaller but more frequent meals might help with loss of appetite.
• Saltwater rinses, anesthetics, coating agents, diet modifications, and pain medication
• Usage of anti-epileptics, anti-depressants, acupuncture, creams, and temperature adjustments. (ONLY USE THESE AFTER THOROUGHLY CONSULTING WITH YOUR DOCTOR)
• Palliative care and emotional therapy might also help.