Colorectal Cancer in Blacks: Incidence & Prevention

Sunny Okosun, a legendary musician, succumbed to colon cancer at the age of 61 at Howard University Hospital, DC, USA, in May of 2008. The newspaper report also rumored that Alhaja (Mrs) Simbiat Atinuke Abiola, the wife of the Philanthropist, Chief MKO Abiola, also lost her life to the same malignancy at the age of 54 in 1992. A very gifted actor, Chadwick Boseman, a hero in the Black Panther movie, died from colon cancer at 43. These prominent people shared one thing in common, the “black race” What is it about the black race and the incidence of colorectal cancer (CRC), including high mortality compared to other races? Like most solid tumors, CRC is classified from stage I-IV (IV is the most advanced and signifies spreading (metastatic) of the disease outside the colon). When an individual is diagnosed with stage IV CRC, the treatment intent is no longer curative but palliative.

Colorectal cancer (CRC) is the third most common cancer in the United States (US), and it is the second most common cause of cancer-related deaths. About 53,000 people will die from colon cancer and its related complications this year, with a median age of death of 72 years. Blacks represent about 13% Of the US population, and CRC incidence is about 20% higher for blacks than whites. Why is this the case? Interestingly, there has been an increase in CRC incidence in people under 50 (a rate of 2% per year for the past two decades, when all races are considered). Most cancers tend to occur in the elderly, but in CRC, there is a decline in the incidence in people over the age of 50.

Blacks are often diagnosed at an earlier age and often with aggressive disease. Pieces of literature have shown that African Americans (AA) are 20% more likely to be diagnosed with CRC and likely to succumb than other racial groups. Is it something about the genetics, cultural, environmental factors, or governmental policies that disproportionately affect the black race?

A study in Northern Nigeria, from the Ahmadu Bello University, compared the incidence of CRC amongst Nigerians with African Americans (AA) utilizing the SEERS (Surveillance Epidemiology, End Results) data for the latter group (1989-2017). This study showed that about one-third of blacks were diagnosed with rectal tumors (distal part of the colon or large intestine), and Nigerians are eight-fold more likely to be diagnosed with rectal tumors and more likely to be diagnosed at an earlier age. Is there a difference in the pattern of distribution of colon cancer amongst Nigerians as compared to African Americans (34.8 years vs 42.3 years)? It is distressing to note that more than half of patients diagnosed with CRC in Nigeria have early-onset CRC. Therefore, the health policymakers in Nigeria need to consider this when setting guidelines for detecting CRC.

Another critical issue that requires consideration is risk factors (RF) for CRC development. RFs can be categorized as modifiable versus non-modifiable RFs. The latter includes a history of CRC in first-degree relatives, race, and gender. The former include hyperlipidemia, obesity, unhealthy dietary intake, use of NSAIDs, red meat intake, and alcohol use. Many of the modifiable factors remain debatable.

CRC has been more frequently diagnosed at an earlier age than ever before. What is the significance of this observation? The central issue is how do we prevent CRC, especially in blacks.
Most CRC arises from adenomatous polyps (a benign tumor of the epithelium) that eventually progress to carcinoma, and they occur in about 30% of men and about 20% of women. The progression from an adenoma to carcinoma takes an average of at least ten years (see the recommendation regarding colonoscopy). Commonly, we categorize the risk of developing CRC into average versus high (note most CRC are still sporadic).

It is imperative to be aware of the family history (medical), which is very difficult amongst Nigerians because of inadequate diagnosis techniques and many deaths outside healthcare institutions. On many occasions, the cause of death is unknown; illness is still considered an unacceptable human predicament shrouded in secrecy in Nigerian culture. It is essential to know if any family member has CRC or adenomas, age at diagnosis because the individual may be classified as high risk and require enhanced screening techniques. Conditions that increase the incidence of CRC includes a family history of specific genetic syndromes (Lynch, etc.), individuals with a history of inflammatory bowel disease (Crohn disease or Ulcerative colitis), prior abdominal radiation, HIV infection in men, and race.

Initiating screening at age 50 years for average-risk individuals was initially adopted, but this has changed to age 45 because of the early stage of the onset of CRC. Therefore, if you are an average-risk individual, you should be screened for CRC by age 45, and it is covered under preventive medical insurance. The Canadian Task Force on Preventive Health Care (CTFPHC) equally recommended age 50 to initiate screening, and this recommendation has not been altered like their American counterpart. The individual with average risk may discontinue screening for CRC at age 75 as long as their life expectancy is ten years or greater. Most guidelines recommend screening at least to age 75 of these patients.

Various medical societies in North America recommend screening programs for the population. These are often similar, except the initial recommendation for CRC screening by CTFPHC for CRC. The United States Preventive Services Task Force (USPSFT) is tasked with recommending preventive care for people in the US. In a recent article by JAMA (December 2021), the agency developed strategies to mitigate the influence of systemic racism in its recommendations because there is a notion that systemic racism may play a role in its recommendations.

The procedures for screening include colonoscopy, which is recommended every ten years (it takes an adenomatous polyp ten years to develop into cancer). This procedure has the highest sensitivity for adenomas and CRC, and polyps can be removed during this procedure. Many medical groups recommend this method. However, the CTFPHC does not recommend using colonoscopy as a screening test. Others include Fecal immunochemical testing (FIT): this is done annually on a single sample for patients unable or unwilling to have a colonoscopy. If this test is positive, the individual must undergo colonoscopy. The FIT test is not affected by drugs or food and therefore has fewer false positives. If ordered by your physician, the kit will be mailed to you at home, and you will return the specimen per instruction. Results are usually available within two weeks. Many societies recommend it as a screening option. A related test is the FIT-DNA multitargeted stool DNA testing (or COLOGUARD (the little caricature on TV advertisement). The COLOGUARD combines the FIT with another sensitive test that detects abnormal DNA in the stool. The test is performed every three years on ONE stool collection sample. It has a higher single application sensitivity.

Another option is the Guacic-based fecal occult blood test (gFOBT). This test is done annually on three samples as a take-home test that the individual mails back to the laboratory for evaluation. There are dietary restrictions, including cutting out all red meats, broccoli, carrots, cucumbers, mushrooms, grapefruits. This test has low sensitivity for polyps and needs to be repeated yearly if negative. It’s recommended by most societies in the US to be done annually but every two years by the CTHPHC

There are still many unanswered questions: are blacks more likely to develop CRC at an earlier age than other races because of genetic factors, cultural issues, lack of access to adequate health care, distrust of the system (i.e., Tuskegee experiment)? Why is the distribution pattern different amongst blacks in the US and those of Northern Nigeria patients? Is the study’s finding in northern Nigeria (ABU) an anomaly? Can the analysis be generalized to the entire Nigerian populace? Another interesting question is whether Nigerians living in North America have a similar pattern of CRC incidence and distribution like the study of Northern Nigeria?

In summary, blacks, including Nigerians, are diagnosed with CRC earlier than any other race, and the mortality rate is higher. CRC is a preventive morbid condition, and if CRC is diagnosed at an early stage, there is a higher probability of a cure. An individual should be familiar with their family history so that individual risk can be ascertained. Discuss with older family members regarding the cause of death, especially among first-degree relatives.

Get screened! It’s the best thing you can do to prevent colon cancer

Ayodele G. Ayoola, PT, MD, FACP
Assistant Professor of Medicine
College of Medicine, Penn State University
Department of Medicine
Division of Hematology/Oncology
Penn State Health/Hershey Medical Center
Hershey, PA

Please send correspondence to office@ianpt.org

References

  1. Actions to Transform US Preventive Services Task Force Methods to Mitigate Systemic Racism in Clinical Preventive Services. JAMA. December 21, vol 326 (23), 2405-2420
  2. Augustus GJ & Ellis NA. Colorectal Cancer Disparity in African Americans. Risk factors and Carcinogenic Mechanisms. Am J Pathol 2018 Feb; 188 (2): 291-303
  3. Holowatyl et al. Patterns of Early-Onset Colorectal Cancer Among Nigerians and Africans Americans. JCO Glob Oncol 2020; 6. Published online 2020 Nov 3. doi: 10.1200/GO.20.00272
  4. https://canadiantaskforce.ca/guidelines/published-guidelines/colorectal-cancer. Accessed January 02, 2022
  5. https://www.uptodate.com/contents/screening-for-colorectal-cancer – accessed December 24, 2021
  6. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/colorectal-cancer-screening
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