Both rectal and colon cancers impact the large intestine, which is in the lower part of the digestive system. However, most individuals do not understand the differences between them since the rectum and the colon are located close to each other. Both of them are categorized alike in the medical world and come under the purview of colorectal cancer.
This article will help you understand the difference between colon and rectal cancer. The colon absorbs water from the stool, and colon cancer can start anywhere in its length of 5 feet. The last 12 cms of the colon is called the rectum, where stools are stored till bowel movement. The name “Colorectal cancer” is given only because they both occur in the same digestive organ, but they have many similarities and dissimilarities.
Diagnosis and shared symptoms
A colonoscopy is used to diagnose both rectal and colon cancers. With the help of a thin, long and flexible tube, the doctor sees the insides of your colon and rectum. In case the doctor suspects cancerous growth, he or she would remove small samples for test, known as biopsies.
Both cancers are likely to have common symptoms. These include:
- Diarrhea or constipation
- Feeling fatigued
- Red, dark or black stools which indicate presence of blood
- Abdominal pains (possibly due to gas)
Note: A 20% chance of local recurrence is likely in the case of rectal cancer. On the other hand, this risk is down to 2% for colon cancer.
Other common factors include:
- Risk factors– Red meats lead to cancer in both the rectum and the colon, though the association is a bit stronger for rectal cancer.
- Genetic similarities– The genetic mutations causing cancerous growth are almost the same in the colon and the rectum, with only a few variations.
Differences
- Gender- While cancer in the colon can be found in almost the same numbers across both genders, its rectal form is more common amongst males than females.
- Effects of nearby tissues– The rectum is an area crowded with other organs, while the colon has more area around it. As a result, there are greater chances of cancerous cells from the rectum spreading to other body parts.
- Difference in anatomy– The network of lymph drainage, nerve supply and blood supply in the colon and rectum are different from each other. This is an important aspect since cancerous cells metastasize (spread) to other areas of the body through lymph and blood.
- Difficulties during surgery– Surgery for the colon here is simpler in comparison to rectal surgery. This is because of the rectum’s anatomy and the organs surrounding it.
Treatment strategies vary
A case of rectal cancer is said to be “locally advanced” when an MRI or Ultrasound confirms growth of the tumor from the bowel wall into the tissues surrounding the rectum, or if lymph involvement is detected. In such a case, targeted radiation or chemotherapy is used to reduce the tumor’s size. An expert surgeon would be able to extricate the radiated portion of the rectum and then reconnect bowel components. Sometimes chemotherapy may be necessary to kill leftover cancerous cells.
Rectal cancer tumors may need to be treated by urologic, liver, spine and gynecologic specialists. This is in the case of highly advanced cases, where a multi-disciplinary team would be helpful in preserving organ functions. In normal cases, it would involve radiotherapy and chemotherapy.
Reference: https://www.voiceofcancerpatients.com/articles/colorectal-cancer-how-colon-and-rectal-cancer-differ
