Rectal cancer

Overview

The rectum is the last part of the intestinal tract which starts from the end part of the colon down to the anus. Rectal cancer begins at the rectum. When cancer occurs inside the colon it is called colon cancer. When both rectal and colon cancer occur together, it is called “colorectal cancer”. Rectal and colon cancer may have a lot of similarities but they have different treatments. The reason is because the rectum is quite attached to the other organs which makes it difficult to surgically remove rectal cancer. 

Symptoms 

Rectal cancer may manifest with many signs and symptoms such as: 

• Changes in bowel movement such as diarrhea or constipation or bowel movement that has become more frequent. 
• Feeling of being unable to empty the large bowel
• Abdominal pain or cramping 
• Maroon-colored or black-colored stool  
• Narrow stool
• Rectal bleeding
• Unexplained weight loss
• Fatigue 

If these symptoms persist, consult your doctor.

Causes

Rectal cancer starts when the DNA of the healthy cells mutate causing uncontrolled duplication, resulting in forming a mass of cells also known as a tumor. This tumor then starts to invade and destroy the healthy cell and could metastasize (spread to other parts of the body).

Inherited gene mutations that increase the risk of colon and rectal cancer 

There are two common syndromes of colorectal abnormalities which relates to higher risk of developing colorectal cancer:  

• Hereditary Nonpolyposis Colorectal Cancer (HNPCC) or Lynch syndrome. May have higher risk to acquire colon cancer and other types of cancers in people, even those who are less than 50 years old.
• Familial Adenomatous Polyposis (FAP). This is a rare condition which causes colon and rectum to have multiple polyps and has a higher chance of developing colon or rectal cancer before 40 years old.  

If you have a family history of colorectal cancer, consult your doctor to perform proper genetic tests or other diagnostic tests. 

Risk factors