Department of pathology.
Anand Diagnostic Laboratory
Colorectal cancer develops in the colon or the rectum, also known as the large intestine. The digestive system processes food for energy and rids the body of solid waste (fecal matter or stool). Water and mineral nutrients are absorbed from the food matter in the colon. Waste (feces) left from this process passes into the rectum, the final 6 inches of the large intestine, and is then expelled from the anus.
Colorectal cancer is a formidable health problem worldwide. It is the third most common cancer in men and the second most common in women. Almost 60% of cases are encountered in developed countries. The number of colorectal cancers-related deaths is estimated 8% of all cancer deaths and making colorectal cancers the fourth most common cause of death due to cancer. In India, the annual incidence rates for colon cancer and rectal cancer in men are about 4.4 and 3.9 in women per 100000. According to the 2013 report, the highest annual incidence rate of colorectal cancers in men was recorded in Thiruvananthapuram followed by Bangalore and Mumbai.
Risk factors for colorectal cancers can be broadly divided into genetic and environmental or lifestyle-related factors. Most colorectal cancers are sporadic, although genetic factors increase the risk considerably. Most common genetic causes are familial adenomatous polyposis and its variants.
Environmental causes – Older men are at a high risk compared to women, inflammatory bowel disease with prolonged disease activity, people on immunosuppression following organ transplantation, diabetes mellitus, alcohol consumption, obesity, cigarette smoking, decreased dietary fibers and fruit intake and decreased physical activity.
Certain medical conditions such as cholecystectomy, uretero-colic anastomosis, the presence of coronary heart disease, history of radiation therapy for prostate cancer, HIV/AIDS infection, patients treated for Hodgkin lymphoma are more prone to colorectal cancers.
See your doctor if you have any of these warning signs:
- Bleeding from the rectum
- Blood in the stool or in the toilet after having a bowel movement
- Dark or black stools
- Cramping or discomfort in the lower abdomen
- An urge to have a bowel movement when the bowel is empty
- Constipation or diarrhea that lasts for more than a few days
- Decreased appetite
- Unintentional weightloss
- Decrease in stool caliber (thickness)
Investigative facilities that are helpful and that are available at Anand Diagnostic Laboratory
- Complete blood counts,
- Fecal Occult Blood Test (FOBT)/Fecal Immunochemical Test (FIT)
- Carcinoembryonic antigen (CEA) tests, and
- Carbohydrate antigen 19.9 (CA19.9)
- Ultrasound abdomen and CT scan
- Histopathology and cytology studies
Increasing tumour marker level can be an indication for early imaging studies such as abdominal ultrasonography and colonoscopy followed by histopathological confirmation. Tumor marker testing would be a good screening tool in cases with positive family history
Advantages of early detection
- Slow course of growth from precancerous polyp to invasive cancer provides a unique opportunity for the prevention and early detection of colorectal cancer
- Screening can prevent cancer through the detection and removal of precancerous growths, as well as detect cancer at an early stage when treatment is more successful. As a result, screening reduces colorectal cancer mortality both by decreasing the incidence of disease and by increasing the likelihood of survival.
Preventive measures to reduce your risk of colorectal cancer.
- Diagnosis of colorectal cancers includes proper counseling regarding family history and risk assessment.
- Patients with family history of colorectal cancer should undergo digital rectal examination which has a high positive predictive value for the presence of rectal tumours and get screened regularly.
- Options of screening tests are – a) Fecal Occult Blood Test (FOBT)/Fecal Immunochemical Test (FIT) – yearly once, b)Colonoscopy – every 10 years and flexible Sigmoidoscopy- every five years.
- Maintain a healthy weight throughout life.
- Adopt a physically active lifestyle.
- Consume a healthy diet with an emphasis on plant sources; specifically:
- Choose foods and beverages in amounts that help achieve and maintain a healthy weight.
- Limit consumption of red and processed meat.
- Eat at least 21⁄2 cups of vegetables and fruits each day.
- Choose whole grains instead of refined grain products.
- If you drink alcoholic beverages, limit consumption.
- Consume the recommended levels of calcium, primarily through food sources
- Avoid tobacco products.