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Cancers

Colorectal Cancer

As the name suggests, colorectal cancer refers to cancer of the colon and/or rectum. The colon is the last 5 feet of the large intestine before the rectum and the rectum is the last 5-6 inches which starts at the colon and ends at the anus.

Colorectal cancers can be subdivided into either colon or rectal cancers depending on the where they start.

Colorectal cancers typically start with growths on the inner lining of the colon or rectum. These growths are called polyps. Polyps can turn into cancer, but not all polyps become cancerous.

There are 2 main types of polyps

Risk factors for polyps developing into cancer

  • Finding more than 2 polyps
  • Finding a polyp(s) that is more than 1 cm in diameter.
  • The presence of dysplasia.

Colon Cancer

Colon Cancer
Colon cancer is cancer that originates in the colon, the colon can be found between the rectum and the end of the small intestine. The colon is approximately 5 feet long when stretched out.

To help better understand the colon cancer we must first under stand the colons anatomy and shape. As mentioned the colon is the last 5 feet of the large intestine, before the rectum. It is part of the digestive system and its role is to pass digested food from the small intestine, absorb waters and salt from the partially digested food and the waste that is left is passed to the rectum to be expelled.

The colon can be divided into 4 sections

  • Ascending Colon – This is the first part of the colon where the food enters from the small intestine. The colon’s first chamber where food enters is called the cecum. As its name suggested, this part of the colon extends upwards on the right side of the abdomen.
  • Transverse Colon – The second part of the colon also slightly ascends from right to left across the abdomen.
  • Descending Colon – As the name suggests, this part of the colon extends downward on the left side of the body.
  • Sigmoid Colon – This section joins the colon to rectum. It is called sigmoid because of its “S” shape.

Types of colon cancers

  • Adenocarcinoma – This type of cancers makes up over 95% of all colon cancers. These cancers start in the cells that make the mucus that lubricates the intestinal walls .
  • Carcinoid tumor – These tumors start in cells in the colon called neuroendocrine cells. These cells can are not exclusive to the colon. They serve the purpose of acting as nerve cells as well as the production of certain hormones.
  • Gastrointestinal stromal tumor – These tumors start in the Interstital cells of the Cajal.
  • Lymphoma – This type of cancer stems from immune cells of the body. The formation of lymphoma in the colon can be most typical with Non-Hodgkin Lymphoma.
  • Sarcomas – Sarcomas start in the soft and connective tissue of the colon. This could be the muscle, blood vessels and other connective tissues.

Colorectal cancer risk factors

  • Male
  • African decent
  • Old Age
  • Fair Skin
  • Inflammatory intestinal conditions
  • Previous history of colon cancer
  • Low fiber and high fat diet
  • Sedentary lifestyle
  • Obesity
  • Immune disease such as HIV / AIDS
  • Diabetes
  • Genetic factors

Colorectal cancer symptoms

  • Sudden and persistent change in bowel habits. This could include, diarrhea, constipation or any change in the consistency of your stool.
  • Blood in stool
  • Abdominal discomfort such as pain, cramps or gas
  • Persistent weakness or fatigue
  • Unexplained weight loss

Colorectal cancer diagnosis

  • Colonoscopy – Using a long flexible tube with a tiny camera on the tip, a doctor is able to insert the camera into the colon and view the entire colon and rectum. If any suspect areas are found, the doctor can note them or cut them out immediately for biopsy to test for cancerous cells.
  • Blood Test – Blood tests cannot definitely tell that you have colon cancers, but coupled with a colonoscopy, and other examination techniques the doctor can tell your over all health. Doctors can also test for carcinoembryonic antigen which is a substance that is produced by colon cancers.

Rectal Cancer

Rectal cancer is cancer that originates in the rectum. The rectum can be found between the anus and the end of colon. The colon is approximately 5-6 inches long.

As the name implies, rectal cancer starts in the rectum. As noted, the rectum is the last 5-6 inches of the large intestine. This is where stool is stored until a bowel movement evacuates the waste.

It takes a trained eye to see where the rectum ends and the colon begins. Rectal cancer is far more dangerous than colon cancer because the rectum lacks what is called the serosa that lines the colon. The serosa is a protective outer layer of the colon. This helps prevent cancer cells from metastizing beyond the intestinal wall.

Since the rectum lacks the serosa, rectal cancer is 10 times more likely to come back in the same place after treatment than is colon cancer. Rectal cancers typically have approximately 20% recurrence rate as opposed to colon cancer which only has about a 2% recurrence rate.

Types of Rectal Cancers

  • Adenocarcinoma – This type of cancers makes up over 95% of all rectal cancers. These cancers start in the cells that make the mucus that lubricates the intestinal walls .
  • Carcinoid tumor – These tumors start in cells in the colon called neuroendocrine cells. These cells can are not exclusive to the rectum. They serve the purpose of acting as nerve cells as well as the production of certain hormones.
  • Gastrointestinal stromal tumor – These tumors start in the Interstital cells of the Cajal.
  • Lymphoma – This type of cancer stems from immune cells of the body. The formation of lymphoma in the rectum can be most typical with Non-Hodgkin Lymphoma.
  • Sarcomas – Sarcomas start in the soft and connective tissue of the rectum. This could be the muscle, blood vessels and other connective tissues.

Symptoms

  • Sudden and persistent change in bowel habits. This could include, diarrhea, constipation or any change in the consistency of your stool.
  • Blood in stool (typically very red in color)
  • Abdominal discomfort such as pain, cramps or gas
  • Urge to have a bowel movement even when no need
  • Persistent weakness or fatigue
  • Change in appetite
  • Unexplained weight loss

Diagnosis

  • Colonoscopy – Using a long flexible tube with a tiny camera on the tip, a doctor is able to insert the camera into the colon and view the entire colon and rectum. If any suspect areas are found, the doctor can note them or cut them out immediately for biopsy to test for cancerous cells.
  • Blood Test – Blood tests cannot definitely tell that you have colon cancers, but coupled with a colonoscopy, and other examination techniques the doctor can tell your over all health. Doctors can also test for carcinoembryonic antigen which is a substance that is produced by rectal cancers.

Conclusion

Colorectal cancer 4th most diagnosed cancer in the world behind nonmelanoma skin cancer, lung cancer and breast cancer only. According to the world cancer research Fund globally it is estimated that 1,800,000 colorectal cases are diagnosed each year. This accounts for 10.6% of all cancer if not counting nonmelanoma skin cancer. The survival rate of most colorectal cancer is relatively high if caught early. Diet is extremely important in preventing colorectal cancer, and we believe that in most cases by making good choices about diet and lifestyle, you can mitigate this risk of colorectal cancer drastically.