Colon Cancer

Overview and Facts about Colon Cancer

Colon cancer occurs with the presence of cancer cells in the colon or large intestine of the digestive system. Your colon makes up the first five to six feet of your large intestine, thus making your colon the longest part of your large intestine. The remaining six inches of your large intestine include your rectum and anal canal.

Your colon consists of four sections that lead to the final section of the gastrointestinal duct or the rectum:

• Cecum/ascending colon: the beginning of your large intestine from the small intestine, which is located on the right side of your abdomen
• Transverse colon: the following section of your colon, located across the top of your abdomen
• Descending colon: the section of your colon that descends the left side of your abdomen
• Sigmoid colon: the final section of your colon that carries waste down into your rectum

The term “colon cancer” is often blended with the term “rectal cancer” to form the hybrid term colorectal cancer. Cancer cells within the colon or rectum are called adenocarcinoma. Colon cancer, however, is distinct from colorectal cancer; colon cancer begins specifically in the colon while rectal cancer begins in the rectum.  

Symptoms and Signs of Colon Cancer

Signs and symptoms of colon cancer are very similar to symptoms of inflammatory bowel disease and other gastrointestinal illnesses. It is important to monitor your digestive health and consult with your doctor if you experience a combination of any signs or symptoms of colon cancer.

Some signs and symptoms of colon cancer include:

• Changes in the frequency of bowel movements
• Bloody or very dark stool color
• Constipation, diarrhea, vomiting or a prolonged sense of fullness in the bowel  
• Anemia or a low blood cell count
• Unexplained weight loss
• Narrow or thin stools
• Prolonged gas or bloating accompanied by pain
• Prolonged or persistent tiredness or fatigue

Causes and Risk Factors of Colon Cancer

Colon cancer risk is influenced by many factors, including age, weight, gender, and family medical history. For instance, obese males over the age of 50 are at a higher risk of developing colon cancer. Lifestyle factors such as smoking, exercise, and nutrition also influence an individual’s risk of developing colon cancer. Bowel inflammation, which often occurs in inflammatory bowel disease, also increases the risk of developing colon cancer.

Risk factors for developing colon cancer include:

• Age
• Gender
• Ethnicity
• Diet
• Exercise levels and obesity
• Excessive smoking or alcohol use
• The presence of polyps or growths in the colon, called adenomas, which can develop into tumors
• Personal history of cancer in the colon, rectum, uterus or ovary
• An identified genetic risk of colon cancer

Tests and Diagnosis of Colon Cancer

Colonoscopy, or an examination of the entire rectum and colon using a scoping tool, is the most common method used to identify the presence of cancer cells or tumors in the colon. If tumors or suspected cancer tissue is found, a sample of that tissue is removed using a small tool for further examination by a pathologist under a microscope (biopsy).

Blood tests may also be performed to screen for the presence of tumor-related molecules circulating in the blood stream. Other imaging techniques used to test or diagnose colon cancer include specialized stool tests, magnetic resonance imaging (MRI), computed tomography (CT or CAT) scans, tiny cameras implanted in swallowable pills (capsule endoscopy), and positron emission tomography (PET) or PET-CT scans.

Treatment and Care for Colon Cancer

Colon cancer treatment depends on several factors:

• The size and location of the tumor
• The patient’s age, health status, and nutrition
• The patient’s level of social support
• The presence of any accompanying illnesses in the patient
• The number of medications the patient currently takes
• The stage of the colon cancer

In some cases, surgical treatment, such as laparoscopic surgery, is recommended to remove the cancer tissue. Colon cancer surgery at Loyola University Medical Center is rated as a high-performing speciality by U.S. News & World Report's Best Hospitals list.