March is designated as colorectal cancer (CRC) month. We lost two of our brothers to CRC and a third to liver cancer; hence, I have a deep personal commitment to any cancer awareness program.
CRC and other cancers in the breast, liver, lungs and kidneys are potentially curable if detected early enough and properly treated. Screening laboratory tests are very helpful in diagnosing early cancer, which may not present any symptom yet. This is especially important in those with risk factors, like a strong family history for cancer.
Dr. Jun Ruiz, our contributing editor in H&L (Health and Lifestyle) and head of the Colorectal Screening Task Force of The Medical City, gives up-to-date screening recommendations for CRC in his article in the magazine.
He writes that in the Philippines, CRC is the third most common cancer among Filipinos, next to breast and lung cancers. Screening for CRC can cut cancer risk by as much as 70 percent. That means it could potentially save seven out of 10 people afflicted with it.
Cancers like CRC don’t develop overnight, or in a few weeks. Almost all of these slowly grow over a long period. For example, colonic polyps, abnormal growths in the lining of the large intestine are the precursors of CRC, take around 10 years to develop into cancer.
Given the long process, these polyps can literally be nipped and permanently removed during colonoscopy, one of the recommended screening tests.
Polyps and very early cancer usually do not yield symptoms, like blood in the stools, abdominal pain, change in bowel habits or weight loss.
Dr. Ruiz explains that the five-year survival rate of persons affected with this cancer is 90 percent when diagnosed early, but is markedly reduced to 11 percent when diagnosed at Stage 4. Again, that highlights the importance of screening and early detection.
The known risk factors that predispose an individual to develop CRC include age (older than 50), personal history of adenoma or prior CRC, family history of CRC, and pre-existing diseases, like inflammatory bowel disease.
Around 90 percent of CRCs occur after the age of 50; hence, screening is recommended at this age. But if one has a family history of a first-degree relative with sporadic CRC, the risk increases two- to three-fold.
The risk increases further when the CRC occurred before age 60, or when two relatives have CRC. There are even cases of CRC in young adults in their 20s or 30s because of this increased risk. Screening should be initiated at an earlier age in these high-risk cases.
Acquired environment factors or unhealthy lifestyle practices may contribute to the development of CRC, and these include cigarette smoking, alcohol consumption and obesity due to bad diet and lack of physical activity.
CRC is strongly associated with a diet rich in saturated fat, low fiber and high red meat consumption. Fiber reduces fecal transit time, dilutes carcinogens, adsorbs potentially carcinogenic substances such as heterocyclic amines, and maintains cell integrity of the intestinal lining.
With no symptoms, CRC patients may already have occult bleeding detected in the stools. “Occult” means it cannot be seen by the naked eye, but can be detected through special tests such as the fecal immunochemical test (FIT).
During later stages, they can already have bleeding in the stools (hematochezia) and anemia, leading to easy fatigability, shortness of breath, and weight loss. Cancers of the right colon tend to grow larger than those of the left colon before symptoms occur.
When the tumor is big, it can obstruct the colon, causing colicky abdominal pain, vague abdominal discomfort, change in bowel habits or diminished stool caliber (like goat stool), and constipation. Change in bowel habits, like alternating diarrhea and constipation, can be a symptom of CRC.
For screening and when CRC is suspected, an endoscopic examination of the colon should be done by a gastroenterologist, a specialist in intestinal and other abdominal problems. Colonoscopy is the procedure of choice, in which a small, flexible hose-like device is inserted through the anus and rectum and carefully advanced to visualize the entire length of the colon under mild anesthesia.
Abnormal growths, like polyps and cancers, and other inflammatory conditions can be easily diagnosed. Polyps can be immediately excised during the procedure.
If the tumor has gone beyond the polyp stage, as diagnosed by colonoscopy, the patient is referred for surgery, which may still be curative. Concurrent chemotherapy is recommended for patients with more advanced disease, especially with lymph node involvement and distant metastases or spread of the cancer cells.
Radiation therapy is an adjunctive treatment in those with rectal cancer.
For those with advanced CRC, surgery may no longer be advisable, and these patients are treated with chemotherapy for palliation—to slow down the spread of the CRC.
So for everyone 50 years and older, it would be a good idea to see your gastroenterologist for a colonoscopy. First-degree relatives of patients with sporadic CRC should undergo screening at age 40, or 10 years before the age the CRC was detected in the first-degree relative, whichever comes first.
If it’s normal, the next one can be done 10 years later, for so long as an annual stool test—fecal immunochemical test or FIT—is negative.
Alternative screening tests include CT (computerized tomography) colonography every five years, plus the FIT stool test every three years.
Colonoscopy is the procedure of choice, but the cost may not be within the means of many. Dr. Ruiz recommends the FIT stool test, and colonoscopy only if this test turns out positive. It can detect eight out of 10 cases of CRC, and if negative it can accurately rule out nine out of 10 cases. Persons with a positive FIT are 12 to 40 times more likely to already have CRC than those with a negative test.
“I advocate an extensive discussion with the patient on these two options, considering the patient as a unique individual, and to weigh the benefits and risks. The best screening for that patient is based on his preferences, and the availability of resources would influence which test he eventually chooses,” explains Dr. Ruiz.
Early detection is best, but better late than never—so have yourselves screened for colorectal cancer.