Colorectal Cancer (CRC) in Afrikan Americans
March is National Colorectal Cancer Awareness Month. As a gastroenterologist who focuses on this disease, I feel it necessary to share information about this frequently preventable disease. First of all, the word colon is another name for the large intestine so colorectal cancer (CRC) refers to cancer in the large intestine and the rectum. The colon is approximately five feet long.
Colorectal cancer (CRC) is a serious problem in the black community. Afrikans from the United States of America (AUSA) have the highest rate of CRC among all racial groups in America, especially AUSA men but AUSA women are at increased risk as well. In fact, AUSA men and women tend to have CRC at earlier ages and at more advanced stages. Rates are declining among adults 50 years of age and older but increasing among those younger than 50 years old. The good news is that CRC tends to develop slowly, over a period of 10-20 years and is 80-90% and can be frequently cured.
First, let’s discuss cancer. Cancer occurs when cells in the body grow and replace themselves at an abnormally fast rate. These cancer cells replace normal cells and cause body systems to shut down or function abnormally. These cancerous cells can spread to other parts of the body (this is called metastasis) and cause similar problems. While we don’t know exactly what causes cancer, we do know that there are certain things that predispose to developing cancer. Most cases of CRC occur in the cells of the inner lining of the colon. Cancer is staged according to the degree of spread and the total numbers of different areas of the body that are affected. Stage I is the least serious and Stage IV is most serious.
AUSA die from CRC 15-20% more frequently than White Americans and have worse survival rates even when found early.
The reasons why AUSA are at greater risk varies. One reason is the fact that AUSA are not screened at the same rate as others. While this is frequently related to less access to care, another explanation is that AUSA have poor knowledge of CRC and other health care concerns resulting in them not taking care of their health in an optimal way. There is also a genetic factor to be considered. While most cases of CRC are not genetic, many are and if there is a relative with CRC, families should plan to undergo regular screening.
Interestingly, in “developing” countries, the CRC rate is much lower than in so-called “developed” countries. Afrikans in Afrika have a much lower rate of CRC than Afrikans who have immigrated to America and AUSA. As people become more “Westernized” in diet and lifestyle, cancers of the digestive tract, especially CRC become much more common. In fact, CRC is 20 times more common in “developed” countries than in “developing” or “undeveloped” countries.
Most cases of CRC start out as benign (non-cancerous) growths on the inner lining of the colon called polyps. Although polyps can grow anywhere in the body, in this article, we are concerned with those that grow in the colon. The most common type of polyps are adenomatous and hyperplastic. Hyperplastic polyps rarely become cancer. Even though all adenomas can potentially turn to cancer, fewer than 10% become invasive cancer. Polyps occur in approximately 20% of people over 60 years of age in the western world. Rural people in Afrika, India and Latin America rarely develop polyps or CRC.
There are several risk factors for CRC:
1. Age. The incidence and death rates increase with age.
2. Sex. The incidence and death rate are greater in men, especially AUSA.
3. Family history of CRC.
4. Personal history of other types of cancer.
5. Personal history of polyps.
6. Heavy alcohol consumption (vs. nondrinker) and tobacco use.
7. Physical inactivity.
8. Being overweight or obese.
9. People who have had CRC have a higher risk of developing another CRC.
10.Inflammatory Bowel Disease such as Ulcerative Colitis or Crohn’s Disease.
11.Hereditary conditions such as Gardner’s Syndrome, Familial Adenomatous Polyposis and Lynch Syndrome.
12.Poor diet with high fat and low fiber foods.
There are frequently no symptoms early in the disease. Later symptoms are feeling tired or weak from slowly losing blood (not visible to the eyes) and being anemic. Also, poor appetite, weight loss, alteration in bowel habits (diarrhea and constipation), rectal bleeding and change in the appearance of the stools such as them becoming narrow are symptoms of CRC. Abdominal pain is a late symptom.
There are two main ways of prevention. The first is diet. We should eat much less red meat and much less processed foods such as bacon, sausage, hot dogs and lunch meat. We should eat at least 25-40 grams of fiber (while drinking about 4 liters of water) daily. We should eat more fruits, more salads, more raw or steamed vegetables and fewer fried foods and dairy products. There is a strong correlation between high dietary fat content and the development of CRC.
The second way of prevention is screening. The two main methods of screening are Fecal Immunochemical Tests (FIT) and colonoscopy. FIT tests such as Cologuard, Everlywell, Pixel by Labcorp, Pinnacle Biolabs and LetsGetChecked are available. These tests check the stool for traces of immune substances found in cancer. The advantages of these tests are that they are non-invasive and do not require cleansing preparation of the colon. One of the main disadvantages is that there is a 10% false negative rate. This means that 10% of people tested who have CRC will have a negative result causing delayed diagnosis and a false sense of security. Another disadvantage is that if the FIT test is positive, a colonoscopy should be done as soon as possible.
The gold standard for screening is a test called colonoscopy. A colonoscopy is a test in which the inner lining of the colon is examined with a lighted tube. This is an out-patient test and admission to the hospital is not required. It is a very safe test with a complication rate of less that 2%. The advantages are that if polyps are found, they can be removed right then and large abnormalities can be biopsied. The false negative rate for colonoscopy is 3.5% and that frequently depends on the skill and experience of the doctor performing the colonoscopy.
The treatment of CRC is usually surgery. Occasionally, in early cases, cancer cells will exist on the tip of a polyp and removing the polyp is curative. Usually, however the standard treatment is surgery. Radiation therapy and chemotherapy are occasionally used as well as newer therapies that target the molecules that make tumors grow. Overall, more than 72% of patients with all stages of CRC were alive five years after surgery. It should be noted that many of those patients who transitioned did not die from the CRC but from other causes.
As my mother used to say, “A hint to the wise is sufficient”. Please get screened and explode these negative statistics. Food for thought.