Colorectal cancer (CRC) is the most commonly diagnosed cancer in both males and females across the world. Majority of the cancers occur in individuals 40-69 years age, a peak age for economic productivity. Breast, cervical & colorectal cancers account for over 40% of the incidence of cancer cases in India. These cancers have highest cure rates if diagnosed in the early stages through screening. Let us learn how screening is beneficial to detect colorectal cancer in the beginning itself.
What is colorectal cancer?
The colon and rectum are part of the large intestine. Colorectal cancer is a term for cancer that develops in the colon & rectum (Abnormal growths in the colon or rectum). It initially starts as a polyp (a growth in the inner lining of colon or rectum), which in most of the cases is not cancer. Only a few polyps, called adenomas can develop as cancer (adenocarcinoma). However, if a polyp is taken early, when small, it may not become cancer. Over 95% of colon and rectal cancers are adenocarcinomas.
Why the mortality rate is high in cancer, particularly in India?
Lower rates of colorectal cancer screening contribute to increase the risk of CRC. Majority of cancers can be effectively treated with curative intent if diagnosed early and treated appropriately. However, in India, delayed diagnosis, poorly equipped hospitals coupled with sub-optimal therapy accounts for high cancer mortality compared to the Western and European countries.
Why screening is important?
Certain cancers like colorectal cancer has a pre-cancer stage called colon polyp, which is a small overgrowth of tissue in the form of a small grape like swelling – when these lesions are found and treated early, it is possible to prevent future cancer in an individual. Screening is the process of looking for cancer or pre-cancers (colon polyps) in people and finding them early. The polyps can be removed before they have the chance to turn into cancer.
Furthermore, you are more likely to get colorectal cancer, if you have colorectal polyps, a family history of colorectal cancer, ulcerative colitis or Crohn’s disease, and if you eat a diet high in fat, or smoke. In view of the above facts, cancer screening is recommended to detect colorectal cancer early. Many people do not experience symptoms in the early stages of cancer. And thus, in the absence of any symptoms, screening helps detect cancer early when it is most treatable. When symptoms appear, they’ll likely vary, depending on the cancer’s size and location in your large intestine.
How is Colorectal Cancer screening done?
If your doctor suspects that you could have colon cancer, they may examine your colon using a scope: colonoscopy, wherein a long flexible tube attached with a camera & surgical tools is passed inside your colon to take tissue samples (biopsies) for analysis. Polyps can also be removed completely during a colonoscopy. The tissue samples are sent to the lab for further analysis. Even though other tests might suggest colorectal cancer, a biopsy is the only way to know for sure. Furthermore, your doctor may do blood test including liver function test to know whether the cancer has spread to the liver.
Next, your doctor will order tests to determine the stage of the cancer, which will help determine the most appropriate treatment for you. The staging tests include Computed tomography (CT or CAT scans) to know the extent of cancer spread to liver, lungs or other organs of the body. CT scans can also be used to guide a biopsy needle into a tumor. Other tests include Ultrasound, MRI scans, chest X-ray, and PET scans.
What is the treatment?
The type of treatment your doctor recommends will largely depend on the stage of your cancer. The treatment includes surgery, chemotherapy, radiation or a combination of all. Surgery can usually cure it when it is found early. With early detection, by surgery, radiation, and/or chemotherapy colorectal cancer can be effectively treated. Therefore, gastroenterologists and cancer specialists recommend colon cancer screening (colonoscopy) for everyone over age 50. Tests to detect blood in stool are also recommended. If you have any familial history, you may need frequent screening programs. If you’re concerned about your family’s history of colon cancer, talk to your doctor about whether your family history suggests you have a risk of these conditions.