What is the Difference Between Colon and Rectal Cancer

The key difference between colon and rectal cancer is that colon cancer is a type of colorectal cancer that starts anywhere in the colon, while rectal cancer is a type of colorectal cancer that starts in the rectum.

Colon and rectal cancer are two types of colorectal cancers. Cancers such as bowel cancer, colon cancer, and rectal cancer are all categorized under this group. Normally, colorectal cancer is the development of cancer from the colon or rectum. These types of cancer often show similar symptoms, which may include blood in the stool, a change in bowel movement, weight loss, and fatigue. Moreover, most colorectal cancers are due to old age and lifestyle factors. Only a small number of cases are due to underlying genetic disorders.

CONTENTS

1. Overview and Key Difference
2. What is Colon Cancer
3. What is Rectal Cancer
4. Similarities – Colon and Rectal Cancer
5. Colon vs Rectal Cancer in Tabular Form
6. Summary – Colon vs Rectal Cancer

What is a Colon Cancer?

Colon cancer is a type of cancer that begins in the part of the large intestine called the colon. The colon is the final part of the digestive tract. Normally, colon cancer affects old adults though it can be seen at any age. In the beginning, colon cancer starts as small, noncancerous clumps of cells called polyps. Polyps typically form on the inside of the colon. With time, these polyps can become colon cancers. The symptoms of colon cancer may include a persistent change in bowel habits (diarrhea and constipation), blood in the stool, persistent abdominal discomfort, the feeling that the bowel doesn’t empty completely, weakness, and unexplained weight loss.

The risk factors for colon cancer include old age, African-American race, personal history of polyps, inflammatory intestinal conditions, inherited conditions that increase colon cancer risk, family history of colon cancer, low fiber and high-fat diet, diabetes, sedentary lifestyle, obesity, smoking, alcohol, radiation therapy for previous cancers. Furthermore, the diagnosis of this medical condition is made through colonoscopy, blood test, and CT scan. The treatment options may include chemotherapy (capecitabine (Xeloda), radiation therapy with powerful energy sources such as X-ray and protons, and surgeries such as polypectomy, endoscopic mucosal resection, laparoscopic surgery for polyps, partial colectomy, surgery to create a way for waste to leave the body, and lymph node removal.

What is a Rectal Cancer?

Rectal cancer is a type of colorectal cancer that starts in the rectum. The rectum is the last six inches of the large intestine. It is the chamber located between the colon and anus. Rectal cancer is seen more in men than women. In most cases, people diagnosed with this condition are over the age of 50. However, rectal cancer can occur in teens and young adults, as well.

The symptoms of rectal cancer include rectal bleeding, blood in the stool, diarrhea, constipation, narrow stool, a sudden change in bowel habits, tiredness, weakness, abdominal pain, and unexplained weight loss. The risk factors include age (more than 50), gender (men affected more, race (black affected more), family history, certain diseases such as inflammatory bowel diseases, smoking, eating processed meat, and obesity. Moreover, rectal cancer can be diagnosed through colonoscopy, biopsy, CT scan, MRI, and PET scan. Furthermore, the treatment options may include chemotherapy (oxaliplatin, 5-FU, and leucovorin), radiation therapy with strong energy beams, immunotherapy, and surgeries such as transanal endoscopic microsurgery, low anterior resection, and abdominoperineal resection.

What are the Similarities Between Colon and Rectal Cancer?

• Colon and rectal cancer are two types of colorectal cancers.
• Both cancers arise in the large intestine.
• People over 50 have a higher risk for both cancer types.
• People of African American descent have a higher risk for both cancer types.
• Both cancer types may show similar symptoms.
• They are treatable with respective surgeries.

What is the Difference Between Colon and Rectal Cancer?

Colon cancer starts anywhere in the colon, while rectal cancer starts in the rectum. Thus, this is the key difference between colon and rectal cancer. Furthermore, colon cancer affects men and women equally. But, rectal cancer affects more men than women.

The below infographic presents the differences between colon and rectal cancer in tabular form for side by side comparison.

Summary – Colon vs Rectal Cancer

Colorectal cancer starts in the colon or the rectum. Colon cancer is a type of colorectal cancer that starts anywhere in the colon, while rectal cancer is a type of colorectal cancer that starts in the rectum. Both cancers exhibit similar symptoms, and they arise in two different parts of the large intestine. So, this is the summary of the difference between colon and rectal cancer.

Reference:

1. “Colon Cancer.” Mayo Clinic, Mayo Foundation for Medical Education and Research.
2. “Rectal Cancer: What Is It, Signs, Stages & Treatment.” Cleveland Clinic.

Image Courtesy:

1. “Diagram showing a local resection of an early stage bowel cancer CRUK 068” By Cancer Research UK – Original email from CRUK (CC BY-SA 4.0) via Commons Wikimedia
2. “Diagram showing trans anal endoscopic microsurgery for early stage rectal cancer CRUK 377” By Cancer Research UK – Original email from CRUK (CC BY-SA 4.0) via Commons Wikimedia