Reducing colorectal cancer risk among African Americans

Factors Affecting the Rate of Colonoscopy Among African Americans Aged Over 45 Years

African Americans continue to have a low rate of colonoscopy screening despite the U.S. Preventive Services Taskforce's (USPSTF) recommendations and its proven benefits. Colonoscopy has proven to be an effective screening and therapeutic procedure. Understanding the root cause of the problem is a crucial step toward achieving the desired colonoscopy rate among this population. This paper evaluates factors that contribute to the underutilization of colonoscopy. The paper also analyzes strategies that could be maximized to increase colonoscopy rates, minimize colorectal cancer inequalities, and promote optimal colorectal health among African Americans.

Commencing colorectal cancer screening at age 45 years in U.S. racial groups

Screening for colorectal cancer (CRC) is cost-effective for reducing its mortality among the average-risk population. In the US, CRC incidence and mortality differ among racial/ethnic groups, with non-Hispanic Blacks (NHB) and American Indian/Alaska Natives showing highest incidence and mortality and earlier presentation. Since 2005, some professional societies have recommended CRC screening for NHB to commence at 45 years or earlier; this was not implemented due to lack of recommendation from key groups that influence insurance payment coverage. In 2017 the highly influential U.S. Multi-Society Task Force for Colorectal Cancer recommended screening to commence at 45 years for NHB; this recommendation was supplanted by data showing an increase in early-onset CRCs in non-Hispanic Whites approaching the under-50-year rates observed for NHB. Subsequently the American Cancer Society and the USPSTF recommended that the entire average-risk population move to commence CRC screening at 45 years. Implementing screening in 45–49-year-olds has its challenges as younger groups compared with older groups participate less in preventive care. The US had made extensive progress pre-COVID-19 in closing the disparity gap for CRC screening in NHB above age 50 years; implementing screening at younger ages will take ingenuity, foresight, and creative strategy to reach a broader-aged population while preventing widening the screening disparity gap. Approaches such as navigation for non-invasive and minimally invasive CRC screening tests, removal of financial barriers such as co-pays, and complete follow up to abnormal non-invasive screening tests will need to become the norm for broad implementation and success across all racial/ethnic groups.

Epidemiology and biology of early onset colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related mortality in men or women in the United States. Average-risk screening that begins at age 50 years has reduced incidence and mortality of CRC in those over 50 years of age, whereas CRC incidence in those under age 50 years (early onset colorectal cancer (eoCRC)) has recently and dramatically increased. In this review, we summarize the recent literature including risk factors for eoCRC, differences in clinicopathologic presentation and outcomes in eoCRC, and emerging evidence regarding the molecular pathways that are altered in eoCRC compared to later onset CRC (loCRC). Epidemiologic studies of eoCRC show predominance in distal colon and rectum, and association with several modifiable risk factors, including diabetes, obesity, diet, sedentary time, alcohol consumption and smoking. Data regarding potential risk factors of prior antibiotic exposure and microbiome alterations or direct carcinogen exposure are still emerging. Aggressive clinicopathologic features of eoCRC at presentation may be due to delay in diagnosis or more aggressive tumor biology. EoCRC outcomes are similar to loCRC when matched for stage, but overall mortality is greater due to higher frequency of advanced disease at a younger presentation, with more life-years lost. There are only few molecular evaluations of eoCRC to date, with findings of potential increase in TP53 and CTNNB1 somatic mutation and decrease in APC, KRAS and BRAF somatic mutation, compared to loCRC. Other findings include LINE-1 hypomethylation, absence of microsatellite instability (MSI-H), presence of chromosomal instability (CIN) or microsatellite and chromosomal stability (MACS). These studies are only now emerging and have not yet identified a specific molecular signature defining eoCRC. Further research evaluating genetic and molecular differences as well as environmental triggers for eoCRCs should provide a clearer understanding to inform targeted screening for pre-symptomatic at-risk younger individuals.

Impact of Race and Socioeconomics Disparities on Survival in Young-Onset Colorectal Adenocarcinoma-A SEER Registry Analysis

Simple Summary

The results of this study show the effects of socio-economic determinants, such as higher income levels, high school education, private insurance, and married marital status, have favorable survival in patients with young-onset colorectal cancer (YoCRC). Moreover, most of the positive social factors are often interrelated. The inclusion of these factors could further prognosticate and help with healthcare resource allocation for successful interventions through public health measures. Colorectal cancer awareness, knowledge, and even utilization of medical services would differ with the education and health literacy.

Abstract

Introduction: We aimed to assess the impact of socio-economic determinants of health (SEDH) on survival disparities within and between the ethnic groups of young-onset (<50 years age) colorectal adenocarcinoma patients. Patients and Methods: Surveillance, epidemiology, and end results (SEER) registry was used to identify colorectal adenocarcinoma patients aged between 25–49 years from 2012 and 2016. Survival analysis was performed using the Kaplan–Meir method. Cox proportional hazards model was used to determine the hazard effect of SEDH. American community survey (ACS) data 2012–2016 were used to analyze the impact of high school education, immigration status, poverty, household income, employment, marital status, and insurance type. Results: A total of 17,145 young-onset colorectal adenocarcinoma patients were studied. Hispanic (H) = 2874, Non-Hispanic American Indian/Alaskan Native (NHAIAN) = 164, Non-Hispanic Asian Pacific Islander (NHAPI) = 1676, Non-Hispanic black (NHB) = 2305, Non-Hispanic white (NHW) = 10,126. Overall cancer-specific survival was, at 5 years, 69 m. NHB (65.58 m) and NHAIAN (65.67 m) experienced worse survival compared with NHW (70.11 m), NHAPI (68.7), and H (68.31). High school education conferred improved cancer-specific survival significantly with NHAPI, NHB, and NHW but not with H and NHAIAN. Poverty lowered and high school education improved cancer-specific survival (CSS) in NHB, NHW, and NHAPI. Unemployment was associated with lowered CSS in H and NAPI. Lower income below the median negatively impacted survival among H, NHAPI NHB, and NHW. Recent immigration within the last 12 months lowered CSS survival in NHW. Commercial health insurance compared with government insurance conferred improved CSS in all groups. Conclusions: Survival disparities were found among all races with young-onset colorectal adenocarcinoma. The pattern of SEDH influencing survival was unique to each race. Overall higher income levels, high school education, private insurance, and marital status appeared to be independent factors conferring favorable survival found on multivariate analysis.

Racial and ethnic disparities in colorectal cancer incidence and mortality

The occurrence of colorectal cancer (CRC) shows a large disparity among recognized races and ethnicities in the U.S., with Black Americans demonstrating the highest incidence and mortality from this disease. Contributors for the observed CRC disparity appear to be multifactorial and consequential that may be initiated by structured societal issues (e.g., low socioeconomic status and lack of adequate health insurance) that facilitate abnormal environmental factors (through use of tobacco and alcohol, and poor diet composition that modifies one's metabolism, microbiome and local immune microenvironment) and trigger cancer-specific immune and genetic changes (e.g., localized inflammation and somatic driver gene mutations). Mitigating the disparity by prevention through CRC screening has been demonstrated; this has not been adequately shown once CRC has developed. Acquiring additional knowledge into the science behind the observed disparity will inform approaches towards abating both the incidence and mortality of CRC between U.S. racial and ethnic groups.

Disparities in Early-Onset Colorectal Cancer

The incidence and mortality of early-onset colorectal cancer (CRC) are increasing in the United States (US) and worldwide. In the US, there are notable disparities in early-onset CRC burden by race/ethnicity and geography. African Americans, Hispanic/Latinos, and populations residing in specific regions of the Southern U.S. are disproportionately affected with CRC diagnosed at younger ages, while less is known about disparities in other countries. Reasons for these disparities are likely multi-factorial and potentially implicate differences in health determinants including biology/genetics, diet/environment, individual health behaviors, and access to high-quality health services, as well as social and policy factors. This review summarizes current understanding of early-onset CRC disparities and identifies specific research areas that will inform evidence-based interventions at individual, practice, and policy levels to reduce the global burden of this disease.

Cancer health disparities in racial/ethnic minorities in the United States

There are well-established disparities in cancer incidence and outcomes by race/ethnicity that result from the interplay between structural, socioeconomic, socio-environmental, behavioural and biological factors. However, large research studies designed to investigate factors contributing to cancer aetiology and progression have mainly focused on populations of European origin. The limitations in clinicopathological and genetic data, as well as the reduced availability of biospecimens from diverse populations, contribute to the knowledge gap and have the potential to widen cancer health disparities. In this review, we summarise reported disparities and associated factors in the United States of America (USA) for the most common cancers (breast, prostate, lung and colon), and for a subset of other cancers that highlight the complexity of disparities (gastric, liver, pancreas and leukaemia). We focus on populations commonly identified and referred to as racial/ethnic minorities in the USA-African Americans/Blacks, American Indians and Alaska Natives, Asians, Native Hawaiians/other Pacific Islanders and Hispanics/Latinos. We conclude that even though substantial progress has been made in understanding the factors underlying cancer health disparities, marked inequities persist. Additional efforts are needed to include participants from diverse populations in the research of cancer aetiology, biology and treatment. Furthermore, to eliminate cancer health disparities, it will be necessary to facilitate access to, and utilisation of, health services to all individuals, and to address structural inequities, including racism, that disproportionally affect racial/ethnic minorities in the USA.

Co-morbid risk factors and NSAID use among white and black Americans that predicts overall survival from diagnosed colon cancer

Black Americans (BA) have higher incidence and higher mortality rates for colorectal cancers (CRC) as compared to White Americans (WA). While there are several identified risk factors associated with the development of CRC and evidence that high levels of adequate screening can reduce differences in incidence for CRC between BA and WA, there remains little data regarding patient co-morbid contributions towards survival once an individual has CRC. Here we set out to identify patient risk factors that influenced overall survival in a cohort of 293 BA and 348 WA with colon cancer. Amid our cohort, we found that patients’ age, tobacco usage, and pre-diagnosed medical conditions such as hypertension and diabetes were associated with shorter overall survival (OS) from colon cancer. We identified pre-diagnosed hypertension and diabetes among BA were responsible for one-third of the colon cancer mortality disparity compared with WA. We also identified long-term regular use of non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin, was associated with shorter OS from colon cancer among WA >65 years of age, but not younger WA patients or any aged BA patients. Our results raise the importance of not only treating the colon cancer itself, but also taking into consideration co-morbid medical conditions and NSAID usage to enhance patient OS. Further evaluation regarding adequate treatment of co-morbidities and timing of NSAID continuance after cancer therapy will need to be studied.

Disparities in Cancer Prevention in the COVID-19 Era

Screening for cancer is a proven and recommended approach to prevent deaths from cancer; screening can locate precursor lesions and/or cancer at early stages when it is potentially curable. Racial and ethnic minorities and other medically underserved populations exhibit lower uptake of cancer screening than nonminorities in the United States. The COVID-19 pandemic, which disproportionately affected minority communities, has curtailed preventive services including cancer screening to preserve personal protective equipment and prevent spread of infection. While there is evidence for a rebound from the pandemic-driven reduction in cancer screening nationally, the return may not be even across all populations, with minority population screening that was already behind becoming further behind as a result of the community ravages from COVID-19. Fear of contracting COVID-19, limited access to safety-net clinics, and personal factors like, financial, employment, and transportation issues are concerns that are intensified in medically underserved communities. Prolonged delays in cancer screening will increase cancer in the overall population from pre-COVID-19 trajectories, and elevate the cancer disparity in minority populations. Knowing the overall benefit of cancer screening versus the risk of acquiring COVID-19, utilizing at-home screening tests and keeping the COVID-19-induced delay in screening to a minimum might slow the growth of disparity.

Causes of Socioeconomic Disparities in Colorectal Cancer and Intervention Framework and Strategies

Colorectal cancer (CRC) disproportionately affects people from low socioeconomic backgrounds and some racial minorities. Disparities in CRC incidence and outcomes might result from differences in exposure to risk factors such as unhealthy diet and sedentary lifestyle; limited access to risk-reducing behaviors such as chemoprevention, screening, and follow-up of abnormal test results; or lack of access to high-quality treatment resources. These factors operate at the individual, provider, health system, community, and policy levels to perpetuate CRC disparities. However, CRC disparities can be eliminated. Addressing the complex factors that contribute to development and progression of CRC with multicomponent, adaptive interventions, at multiple levels of the care continuum, can reduce gaps in mortality. These might be addressed with a combination of health care and community-based interventions and policy changes that promote healthy behaviors and ensure access to high-quality and effective measures for CRC prevention, diagnosis, and treatment. Improving resources and coordinating efforts in communities where people of low socioeconomic status live and work would increase access to evidence-based interventions. Research is also needed to understand the role and potential mechanisms by which factors in diet, intestinal microbiome, and/or inflammation contribute to differences in colorectal carcinogenesis. Studies of large cohorts with diverse populations are needed to identify epidemiologic and molecular factors that contribute to CRC development in different populations.

Racial Disparities and Trends in Pancreatic Cancer Incidence and Mortality in the United States

BACKGROUND & AIMS

Pancreatic cancer is one of the few cancers in the United States that is increasing in incidence. Little is known about racial disparities in incidence and mortality. We characterized racial disparities in pancreatic cancer incidence and mortality in different locations, time periods, age groups, and disease stages.

METHODS

We obtained data on the incidence of pancreatic cancer from the National Program of Cancer Registries and the Surveillance, Epidemiology, and End Results program of cancer registries from 2001 through 2015 on incidence, demographics, tumor characteristics, and population estimates for all 50 states and the District of Columbia. We obtained data on mortality from pancreatic cancer from the National Center for Health Statistics during the same time period. We plotted incidence rates by 10-year age group (30-39 years through 70-79 years and 80 years or older) separately for white and black patients. We calculated incidence and mortality rate ratios with 95% CIs for categories of age and race. To determine racial disparities, we calculated incidence rate ratios (IRR) for black vs white patients and mortality rate ratios by state.

RESULTS

Disparities in pancreatic cancer incidence and mortality in black vs white patients decreased over 5-year time periods from 2001 through 2015. However, among all age groups, from 2001 through 2015, pancreatic cancer incidence and mortality were higher among blacks than whites (incidence, 24.7 vs 19.4 per 100,000; IRR, 1.28; 95% CI, 1.26-1.29; mortality, 23.3 vs 18.4 per 100,000; IRR, 1.27; 95% CI, 1.26-1.28). Black patients had a higher incidence of distant pancreatic cancer (IRR, 1.32; 95% CI, 1.31-1.34) and a lower incidence of local cancer. Incidence increased in whites and blacks of younger age groups and was most prominent among persons 30-39 years old. Incidence increased by 57% among younger whites (IRR, 1.70; 95% CI, 1.43-2.02) and by 44% among blacks (IRR, 1.47; 95% CI, 1.01-2.15) from 2001 through 2015. Mortality remained stable among blacks and slightly increased among whites during this time period.

CONCLUSIONS

In the United States, there are racial disparities in pancreatic incidence and mortality that vary with location, patient age, and cancer stage. Further research is needed to identify factors associated with increasing incidence and persistence of racial disparities in pancreatic cancer.

Racial Disparities in Incidence of Young-Onset Colorectal Cancer and Patient Survival

BACKGROUND & AIMS

Increasing rates of young-onset colorectal cancer (CRC) have attracted substantial research and media attention, but we know little about racial disparities among younger adults with CRC. We examined racial disparities in young-onset CRC by comparing CRC incidence and relative survival among younger (<50-year-old) adults in 2 time periods.

METHODS

Using data from the Surveillance, Epidemiology, and End Results program of cancer registries, we estimated CRC incidence rates (per 100,000 persons 20-49 years old) from 1992 through 2014 for different periods (1992-1996 vs 2010-2014) and races (white vs black). Relative survival was calculated as the ratio of observed survival to expected survival in a comparable cancer-free population.

RESULTS

From 1992-1996 to 2010-2014, CRC incidence increased from 7.5 to 11.0 per 100,000 in white individuals and from 11.7 to 12.7 per 100,000 in black individuals. The increase in rectal cancer was larger in whites (from 2.7 to 4.5 per 100,000) than in blacks (from 3.4 to 4.0 per 100,000); in the 2010-2014 period, blacks and whites had similar rates of rectal cancer. Compared with whites, blacks had smaller increases in relative survival with proximal colon cancer but larger increases in survival with rectal cancer (from 55.3% to 70.8%).

CONCLUSION

In an analysis of the Surveillance, Epidemiology, and End Results database, we found racial disparities in incidence of young-onset CRC and patient survival for cancer of the colon but minimal difference for rectal cancer. Well-documented and recent increases in young-onset CRC have largely been due to increases in rectal cancer, especially in whites.

Clinical and Genetic Factors to Inform Reducing Colorectal Cancer Disparitites in African Americans

Colorectal cancer (CRC) is the third most prevalent and second deadliest cancer in the U.S. with 140,250 cases and 50,630 deaths for 2018. Prevention of CRC through screening is effective. Among categorized races in the U.S., African Americans (AAs) show the highest incidence and death rates per 100,000 when compared to Non-Hispanic Whites (NHWs), American Indian/Alaskan Natives, Hispanics, and Asian/Pacific Islanders, with an overall AA:NHW ratio of 1.13 for incidence and 1.32 for mortality (2010-2014, seer.cancer.gov). The disparity for CRC incidence and worsened mortality among AAs is likely multifactorial and includes environmental (e.g., diet and intestinal microbiome composition, prevalence of obesity, use of aspirin, alcohol, and tobacco use), societal (e.g., socioeconomic status, insurance and access to care, and screening uptake and behaviors), and genetic (e.g., somatic driver mutations, race-specific variants in genes, and inflammation and immunological factors). Some of these parameters have been investigated, and interventions that address specific parameters have proven to be effective in lowering the disparity. For instance, there is strong evidence raising screening utilization rates among AAs to that of NHWs reduces CRC incidence to that of NHWs. Reducing the age to commence CRC screening in AA patients may further address incidence disparity, due to the earlier age onset of CRC. Identified genetic and epigenetic changes such as reduced MLH1 hypermethylation frequency, presence of inflammation-associated microsatellite alterations, and unique driver gene mutations (FLCN and EPHA6) among AA CRCs will afford more precise approaches toward CRC care, including the use of 5-fluorouracil and anti-PD-1.

Establishing a research agenda for early-onset colorectal cancer

In this month's Editorial Caitlin C. Murphy and Amit Singal discuss the increasing incidence of early-onset colorectal cancer in patients under the age of 50.

Racial Disparity in Gastrointestinal Cancer Risk

Cancer from the gastrointestinal tract and its associated excretory organs will occur in more than 300,000 Americans in 2017, with colorectal cancer responsible for >40% of that burden; there will be more than 150,000 deaths from this group of cancers in the same time period. Disparities among subgroups related to the incidence and mortality of these cancers exist. The epidemiology and risk factors associated with each cancer bear out differences for racial groups in the United States. Esophageal adenocarcinoma is more frequent in non-Hispanic whites, whereas esophageal squamous cell carcinoma with risk factors of tobacco and alcohol is more frequent among blacks. Liver cancer has been most frequent among Asian/Pacific Islanders, chiefly due to hepatitis B vertical transmission, but other racial groups show increasing rates due to hepatitis C and emergence of cirrhosis from non-alcoholic fatty liver disease. Gastric cancer incidence remains highest among Asian/Pacific Islanders likely due to gene-environment interaction. In addition to esophageal squamous cell carcinoma, cancers of the small bowel, pancreas, and colorectum show the highest rates among blacks, where the explanations for the disparity are not as obvious and are likely multifactorial, including socioeconomic and health care access, treatment, and prevention (vaccination and screening) differences, dietary and composition of the gut microbiome, as well as biologic and genetic influences. Cognizance of these disparities in gastrointestinal cancer risk, as well as approaches that apply precision medicine methods to populations with the increased risk, may reduce the observed disparities for digestive cancers.

Decrease in Incidence of Colorectal Cancer Among Individuals 50 Years or Older After Recommendations for Population-based Screening

BACKGROUND & AIMS

The incidence of colorectal cancer (CRC) in the United States is increasing among adults younger than 50 years, but incidence has decreased among older populations after population-based screening was recommended in the late 1980s. Blacks have higher incidence than whites. These patterns have prompted suggestions to lower the screening age for average-risk populations or in blacks. At the same time, there has been controversy over whether reductions in CRC incidence can be attributed to screening. We examined age-related and race-related differences in CRC incidence during a 40-year time period.

METHODS

We determined the age-standardized incidence of CRC from 1975 through 2013 by using the population-based Surveillance, Epidemiology, and End Results (SEER) program of cancer registries. We calculated incidence for 5-year age categories (20-24 years through 80-84 years and 85 years or older) for different time periods (1975-1979, 1980-1984, 1985-1989, 1990-1994, 1995-1999, 2000-2004, 2005-2009, and 2010-2013), tumor subsite (proximal colon, descending colon, and rectum), and stages at diagnosis (localized, regional, and distant). Analyses were stratified by race (white vs black).

RESULTS

There were 450,682 incident cases of CRC reported to the SEER registries during the entire period (1975-2013). Overall incidence was 75.5/100,000 white persons and 83.6/100,000 black persons. CRC incidence peaked during 1980 through 1989 and began to decrease in 1990. In whites and blacks, the decreases in incidence between the time periods of 1980-1984 and 2010-2013 were limited to the screening-age population (ages 50 years or older). Between these time periods, there was 40% decrease in incidence among whites compared with 26% decrease in incidence among blacks. Decreases in incidence were greater for cancers of the distal colon and rectum, and reductions in these cancers were greater among whites than blacks. CRC incidence among persons younger than 50 years decreased slightly between 1975-1979 and 1990. However, among persons 20-49 years old, CRC incidence increased from 8.3/100,000 persons in 1990-1994 to 11.4/100,000 persons in 2010-2013; incidence rates in younger adults were similar for whites and blacks.

CONCLUSIONS

On the basis of an analysis of the SEER cancer registries from 1975 through 2013, CRC incidence decreased only among individuals 50 years or older between the time periods of 1980-1984 and 2010-2013. Incidence increased modestly among individuals 20-49 years old between the time periods of 1990-1994 and 2010-2013. The decision of whether to recommend screening for younger populations requires a formal analysis of risks and benefits. Our observed trends provide compelling evidence that screening has had an important role in reducing CRC incidence.