Colo-Rectal cancer is cancer arising from the colon or rectum, more common after the age of 50 years, and among the Chinese. It is one of the easily prevented cancers because it can develop from polyps that can be removed before they become cancerous.
If you answer “yes” to any of the following questions, talk to your colorectal surgeon about getting screened for colorectal cancer.
Are you aged 50 or older?
Are you having blood in stool?
Is there any recent change in your bowel habit?
Has your first degree relative had colorectal cancer?
Has your first degree relative had colon polyps?
Do you have a chronic inflammatory bowel disease such as ulcerative colitis or Crohn’s disease?
The majority of colorectal cancers arise from adenomatous polyps which are largely asymptomatic and it takes 5-10 years for transformation to occur.
Thus, screening asymptomatic individuals for the presence of adenomas and early cancers has good chance of cure.
Screening should begin at ages 50, which are at average risk for colorectal cancer. People with high risk should be screened earlier.
Average Risk Group– Asymptomatic and no family history
Screening starts at 50 years of age
Digital rectal examination, and Stool occult blood testing – Every year
Flexible sigmoidoscopy- every 5 years
Colonoscopy – every 10 years
Barium enema – every 5-10 years
High Risk Group
Family history of colorectal cancer- colonoscopy 10 years prior to youngest case in family
Personal history of colorectal polyp- Colonoscopy one year after polypectomy if polyp was more than 1 cm, multiple and villous or three years after polypectomy for solitary tubular polyp.
Personal history of colorectal cancer/endometrial/ovarian cancer
Very High Risk Group
Family history of familial adenomatous polyposis
Family history of non polyposis colorectal cancer- Colonoscopy 10 years prior to youngest family member
People with inflammatory bowel disease- after15th year of diagnosis
Fecal occult blood testing (FOBT) is the only screening modality that has been shown to be effective thus it should be routine test for individuals age 50 and above. But it detects only those cancers or polyps which are bleeding
Flexible sigmoidoscopy allows examination of lining of the lower one third of the colon and rectum (Portion of the intestine where most polyps and cancers occur). If combined with testing the stool for hidden blood, many cancers and polyps can be detected.
Colonoscopy is gold standard for complete large bowel evaluation. When a polyp or cancer is detected by flexible sigmoidoscopy, or if a person is at high risk to develop colon and rectal cancer, colonoscopy provides a safe, effective means of examining the full lining of colon and rectum. Colonoscopy is used to diagnose colon and rectal problems and to perform biopsies and remove colon polyps. Most colonoscopies are done on an outpatient basis.
Other screening tests i.e. barium enema, and CT colography (virtual colonoscopy) may not be as effective and reliable as FOBT or colonoscopy
Exact cause is not known, it is a combination of genetic and environmental causes.
About 15% of colorectal cancers have a strong genetic basis.
Dietary causes account for about 90% of environmental causes. High calorie intake, red meat consumption, longer cooking times produce a higher concentration of carcinogens, baking, broiling, and steaming are best.
Other factors are obesity (association between excess weight and cancer is very clear-but the reason behind it isn’t), high caloric intake, alcohol intake and tobacco smoking.
Presence of warning symptoms or a mass in your belly or rectum is suspective. Sometimes barium enema, CT colonography or CT scan findings may provide the clue.
Diagnosis is confirmed by colonoscopy (when the tumor is visualized) and biopsy.
Warning symptoms for colorectal cancer.
Blood in the stools
Change in bowel habits
Unexplained abdominal pain
Colorectal cancer can be a silent disease and not have any symptoms at all.
The best way is colorectal screening.
Get screened regularly beginning at age 40.
Exercise and maintain a normal body weight.
Eat plenty of vegetables, fruits and high-fiber foods.
Avoid foods that are high in fat.
Moderate carbohydrate intake and reducing refined suger
Don’t smoke and drink alcohol only in moderation.
Role of ‘antioxidants’, colonic irrigation or herbal remedies is not evidenced.