Differences In Colorectal Cancer Mortality Research Articles

Abstract 3456: The role of particulate matter exposure in racial differences in colorectal cancer mortality in metropolitan Detroit

Abstract Colorectal cancer (CRC) is the third most diagnosed cancer in the United States and the third leading cause of cancer-related deaths. Non-Hispanic Black (NHB) individuals have the highest rates of CRC incidence and mortality in the United States. These disparities are highly influenced by social determinants of health (SDOH). Neighborhood quality, a well-established SDOH, has been shown to influence cancer outcomes, oftentimes more heavily in minorities. Additionally, neighborhood quality is known to influence an individual’s risk of exposure to harmful environmental contaminants including ambient air pollution as a result of systemic racism such as segregation and historic redlining, leading to environmental injustices. Fine particulate matter (PM2.5) exposure has been shown to increase the risk of CRC mortality, however, its effects by race have not yet been examined. We sought to understand whether higher rates of exposure to PM2.5 played a role in racial differences in CRC survival in metropolitan Detroit. Patient data including census tract at diagnosis, demographics, and clinical features were obtained from the metropolitan Detroit cancer surveillance system registry. Ambient PM2.5 concentration data at the census tract were obtained from the Environmental Protection Agency (EPA) Remote Sensing Information Gateway (RSIG) and converted to annual averages to use in an interval-censored Cox proportional hazards regression model. We found that PM2.5 exposure partly attenuated the effect of race on overall mortality in all patients (NHB vs NHW: Hazard Ratio (HR) = 1.24, 95% Confidence Interval (CI) 1.20 - 1.27, p < 0.0001, NHB vs NHW after accounting for PM2.5: HR = 1.19, 95% CI = 1.16 - 1.23 p < 0.0001) and the effect was stronger among patients under 50 than over 50, though still significant in both models. Additionally, the effect of PM2.5 on mortality was much stronger among NHB patients than NHW patients (NHB HR = 1.30, 95% CI = 1.17 - 1.45, p < 0.0001; NHW HR = 1.06, 95% CI = 1.02 - 1.11 p = 0.008) and especially strong among NHB patients under 50 (HR = 2.51, 95% CI = 2.38 - 3.38, p < 0.0001) compared to any other group. We conclude that ambient air pollution, particularly PM2.5, disproportionately affects mortality risk in NHB CRC patients. These results highlight the importance of environmental justice research in biomedical research, and the need for a better understanding of environmental impact on tumor biology to prevent tumor progression and mortality among all patients. Citation Format: Natalie Gail Snider, Theresa Hastert, Gregory Dyson, Carina Gronlund, Elena M. Stoffel, Ed Peters, Laura Rozek, Ann Schwartz, Kristen Purrington. The role of particulate matter exposure in racial differences in colorectal cancer mortality in metropolitan Detroit [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3456.

Differences between men and women with respect to colorectal cancer mortality despite screening colonoscopy

Background and study aimsWomen aged 55 to 59 years have a similar prevalence rate and number needed to screen for colorectal adenomas as men at a ten years younger age.The aim of this study was to determine sex specific differences in colorectal cancer mortality and estimate the association with adenomas at screening colonoscopy. MethodsThis retrospective study analyzed 323,139 individuals who underwent colonoscopy within a national colorectal cancer screening program in Austria between 01/2007 and 12/2020. ResultsMedian age was (60 years [IQR 54-67]) and sex distribution in all age groups was nearly identical. Men had significantly higher odds to have an adenoma or serrated polyp, low risk polyps, high-risk polyps, or colorectal cancer detected at colonoscopy than women (OR 1.83 [1.80-1.86], OR 1.46 [1.44-1.49], OR 1.74 [1.69-1.80], and OR 1.87 [1.70-2.05] respectively). Strikingly, male sex, when compared to female sex, was associated with an almost 2-fold (HR 1.67 [1.05-2.67]) increased risk to die from colorectal cancer when an adenoma or serrated polyp, and a 4-fold (HR 4.14 [2.72-6.3]) increased risk when a high-risk polyp was found at the screening colonoscopy. The cumulative incidence for death of colorectal cancer for 60-year-old individuals was 8.5-fold higher in men as compared to women. Markedly, this gender gap narrowed with increasing age while the difference in deaths of other causes remained similar in all age groups. ConclusionOur findings strengthen the necessity of sex specific screening recommendations.Importantly, further prospective studies should focus on sex difference in tumor biology to propose personalized surveillance guidelines.

Abstract PO-223: Examining racial differences in metastatic site and mortality among de novo stage IV colorectal cancer

Abstract Background: Racial disparities persist in colorectal cancer (CRC) incidence and survival despite advances in screening and therapeutic options. While the liver and lung are often described as common sites for CRC metastasis, the effect of race and ethnicity on the presentation of metastases remains largely unexplored. In this study, we investigate the racial differences in metastatic patterns of de novo stage IV CRC and associate these patterns with racial differences in CRC mortality. Methods: This retrospective cohort study used 18 Surveillance, Epidemiology and End Results (SEER) registries with data from 2010-2017 to identify 49,654 patients diagnosed with de novo metastatic, stage IV CRC. We evaluated the pattern of bone, lung, liver and brain metastases by race and ethnicity. Using multi-variate logistic regression, we obtained adjusted odds ratios (aOR) to estimate the association between metastatic pattern and race and ethnicity. We assessed the adjusted hazard ratios (aHR) for CRC-specific mortality and all-cause mortality by race and ethnicity using Cox proportional hazards regression models. Results: Of 49,654 patients, 63.5% were non-Hispanic White (NHW), 14.81% were NHB, and 12.6% were Hispanic. Majority of metastases were within the liver (72.3%) and lung (24.7%). The odds of metastasis to the liver was 1.13 times higher (95% CI, 1.06-1.20) and the odds of metastasis to lung was 1.19 times higher (95% CI, 1.09-1.23) in NHB than NHW patients. The odds of metastasis at any site was 1.19 times higher in NHB than NHW patients (95% CI, 1.10-1.28). The odds of metastasis to multiple sites was 1.16 times higher than to a single site for a NHB patient (95% CI, 1.09- 1.24). NHB patients had a higher adjusted hazard ratio of CRC-specific mortality when compared to NHW patients, overall (aHR 1.15, 95% CI 1.12-1.19); and when looking specifically at metastasis to the lung (aHR 1.10, 95% CI 1.04-1.16) and the liver (aHR 1.17, 95% CI 1.13-1.21). NHB had a 14% increased risk of mortality with metastases to multiple sites (aHR 1.14, 95% CI 1.07-1.121). Conclusion: In this retrospective cohort study, NHB patients presented more frequently with metastases at diagnosis and had higher odds of multiple metastases at diagnosis than their NHW counterparts, placing these patients at a higher risk of mortality. This study quantifies the ongoing severity of racial disparity that persists despite advances in CRC diagnostics and therapeutics. Targeted effort is needed at the prevention, screening and therapy levels, to create equity and improve CRC outcomes for the NHB patient population. Citation Format: Sakshi M. Dhar, Yunan Han, Adetunji Toriola. Examining racial differences in metastatic site and mortality among de novo stage IV colorectal cancer [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-223.

Regional Differences in Colorectal Cancer Mortality Between 2000 and 2013 in Republic of Korea.

ObjectiveColorectal cancer (CRC) is the fourth most common site for cancer death in the Republic of Korea. The aim of this study was to describe the trends of colorectal cancer mortality by region.MethodsCRC mortality trends in Republic of Korea were described by region using a Joinpoint regression model in both sexes. The annual percent changes (APCs) were calculated for each segment. Visualization of the changes in mortality rate of colorectal cancer death rates by 16 geographic areas in both sexes between 2000–2004 and 2009–2013 were also conducted.ResultsCRC mortality rates of men showed decreasing trend after increase in Daegu, Gyeongsangnam-do, and Chungcheongbuk-do between 2000 and 2013 based on the joinpoint model, while Gwangju, Jeollabuk-do, Jeollanam-do, and Gyeongsangbuk-do showed increase in CRC mortality during the same period. For women, CRC mortality of Seoul, Incheon, Daejeon, and Gyeongsangnam-do started to decrease in 2005, 2003, 2007, and 2006, respectively. The mortality rate for CRC in the eastern regions, which had relatively low rates of CRC among men in 2000 through 2004, reached a level similar to that in the northwestern regions of 2009 through 2013, while the highest CRC mortality rates in women was observed in Chungcheongbuk-do.ConclusionsReduction in CRC mortality varied across 16 metropolitan cities and provinces in men, and the visualization pattern showed that the east side of South Korea had the least progress in mortality reduction.

Association between Race and Cancer-Related Mortality among Patients with Colorectal Cancer in the United States: A Retrospective Cohort Study.

Colorectal cancer (CRC) is the third most common cause of mortality in the United States (US). Differences in CRC mortality according to race have been extensively studied; however, much more understanding with regard to tumor characteristics’ effect on mortality is needed. The objective was to investigate the association between race and mortality among CRC patients in the US during 2007–2014. A retrospective cohort study using data from the Surveillance, Epidemiology, and End Results (SEER) Program, which collects cancer statistics through selected population-based cancer registries during in the US, was conducted. The outcome variable was CRC-related mortality in adult patients (≥18 years old) during 2007–2014. The independent variable was race of white, black, Asian/Pacific Islander (API), and American Indian/Alaska Native (others). The covariates were, age, sex, marital status, health insurance, tumor stage at diagnosis, and tumor size and grade. Bivariate analysis was performed to identify possible confounders (chi-square tests). Unadjusted and adjusted logistic regression models were used to study the association between race and CRC-specific mortality. The final number of participants consisted of 70,392 patients. Blacks had a 32% higher risk of death compared to whites (adjusted odds ratio (OR) 1.32; 95% confidence interval (CI) 1.22–1.43). Corresponding OR for others were 1.41 (95% CI 1.10–1.84). API had nonsignificant adjusted odds of mortality compared to whites (0.95; 95% CI 0.87–1.03). In conclusion, we observed a significant increased risk of mortality in black and American Indian/Alaska Native patients with CRC compared to white patients.

Assessing disparities in colorectal cancer mortality by socioeconomic status using new tools: health disparities calculator and socioeconomic quintiles

PurposeColorectal cancer mortality rates dropped by half in the past three decades, but these gains were accompanied by striking differences in colorectal cancer mortality by socioeconomic status (SES). Our research objective is to examine disparities in colorectal cancer mortality by SES, using a scientifically rigorous and reproducible approach with publicly available online tools, HD*Calc and NCI SES Quintiles.MethodsAll reported colorectal cancer deaths in the United States from 1980 to 2010 were categorized into NCI SES quintiles and assessed at the county level. Joinpoint was used to test for significant changes in trends. Absolute and relative concentration indices (CI) were computed with HD*Calc to graph change in disparity over time.ResultsDisparities by SES significantly declined until 1993–1995, and then increased until 2010, due to a mortality drop in populations living in high SES areas that exceeded the mortality drop in lower SES areas. HD*Calc results were consistent for both absolute and relative concentration indices. Inequality aversion parameter weights of 2, 4, 6 and 8 were compared to explore how much colorectal cancer mortality was concentrated in the poorest quintile compared to the richest quintile. Weights larger than 4 did not increase the slope of the disparities trend.ConclusionsThere is consistent evidence for a significant crossover in colorectal cancer disparity from 1980 to 2010. Trends in disparity can be accurately and readily summarized using the HD*Calc tool. The disparity trend, combined with published information on the timing of screening and treatment uptake, is concordant with the idea that introduction of medical screening and treatment leads to lower uptake in lower compared to higher SES populations and that differential uptake yields disparity in population mortality.

Correlation between County-Level Surgeon Density and Mortality from Colorectal Cancer.

We aimed to explore the effect of county-level general surgeon (GS) and colorectal surgeon (CS) density on colorectal cancer (CRC) mortality and to identify additional county characteristics associated with outcomes. Using data from the Area Resource File, US Census, and National Cancer Institute, we developed multivariate regression models to determine the effect of density of GS and CS on CRC death between 2005 and 2009 while controlling for CRC incidence, county demographics, and other socioeconomic factors. In total, we included 1767 counties: Mean CRC incidence and death rates were 64.9 and 19.9%, respectively. In this cohort, 45% were metropolitan areas. Mean GS and CS densities were 7.2 and 0.15 per 100,000 people, respectively. Counties with at least 1 GS had a statistically significant decrease in CRC-specific mortality (beta coefficient -0.18, p < 0.001). Increasing GS density beyond 8 per 100,000 people did not result in any further meaningful reductions in mortality. The presence of at least 1 CS at the county-level was not associated with differences in CRC mortality (beta coefficient -0.021, p = 0.37). Metropolitan counties and a larger percentage of individuals who were <65years old were associated with decreased CRC mortality. Conversely, a higher proportion below the poverty line was correlated with a significant increase in CRC mortality. Unlike CS, the presence of GS at the county-level was associated with lower CRC mortality. However, increasing GS density beyond a certain point did not result in further meaningful reductions in mortality. A balanced strategy of distributing the surgical workforce across all counties can result in population-based improvements in CRC outcomes.

Impact of ethnicity and insurance on colorectal cancer outcomes.

3598 Background: Previous studies have demonstrated ethnic disparities in mortality rates among colorectal cancer patients. The following analysis was performed to quantify disparities in a diverse ethnic population and explore reasons for the demonstrated differences. Methods: Data from 4,232 consecutive colorectal cancer patients were collected from hospital tumor registries between 1990 and 2007. Measures of association (chi-square, Cox regression) were used to analyze differences in colorectal cancer mortality and ethnicity as well as factors hypothesized to contribute to cancer mortality including age at diagnosis, sex, area of residence, place of birth, insurance, site of disease, histologic grade, stage, and initial treatment. Results: Filipino and native Hawaiian patients were significantly younger than white patients at the time of diagnosis (p < 0.0005) and Native Hawaiians were more likely than other groups to be uninsured or covered by Medicaid (p < 0.0005). Although there were no differences in stage at diagnosis among the ethnic groups, Filipinos and Native Hawaiians more often received chemotherapy (p < 0.0005). Multivariate Cox regression revealed that Filipino [HR 1.7 (1.3-2.3, 95% CI), p < 0.0005] and Native Hawaiian [HR 1.6 (1.2-2.0, 95% CI), p = 0.001] ethnicity adversely impacted survival even after adjusting for age, stage, histologic grade, treatment and insurance status. Conclusions: Among colorectal cancer patients, ethnic disparities exist that cannot be solely explained by differences in clinical tumor characteristics, treatment or insurance status. Further study into molecular characteristics of tumors and utilization of healthcare services is warranted. No significant financial relationships to disclose.

Racial differences in colorectal cancer mortality: The importance of stage and socioeconomic status

This investigation studies racial and socioeconomic differences in mortality from colorectal cancer, and how they vary by stage and age at diagnosis. Cox proportional hazards models were used to estimate the hazard ratio of dying from colorectal cancer, controlling for tumor characteristics and sociodemographic factors. Black adults had a greater risk of death from colorectal cancer, especially in early stages. The gender gap in mortality is wider among blacks than whites. Differences in tumor characteristics and socioeconomic factors each accounted for approximately one third of the excess risk of death among blacks. Effects of socioeconomic factors and race varied significantly by age. Higher stage-specific mortality rates and more advanced stage at diagnosis both contribute to the higher case-fatality rates from colorectal cancer among black adults, only some of which is due to socioeconomic differences. Socioeconomic and racial factors have their most significant effects in different age groups.

Sex differences in colorectal cancer mortality in Europe, 1955-1996.

Colorectal cancer is the leading cancer in non-smokers in Western countries, and over the last decades its trends have been generally more favourable for women than for men. Possible explanations of the sex differentials in colorectal cancer relate to different exposure to exogenous hormones and to other risk factors including diet, physical activity and alcohol drinking. The objective of this investigation was to systematically analyse the trends in colorectal cancer mortality sex ratios in major European countries over the last four decades. Trends in death certification rates from colorectal cancer over the period 1955-1996 were analysed for 20 European countries (excluding the former Soviet Union and a few of the smaller countries). In all countries, the mortality sex ratios (M/F) were around or slightly above unity in the 1950s, and systematically increased to approach 1.5 in the 1990s. The extent of the rises varied across countries, ranging between + 0.8% in Germany, + 9.7% in Sweden, and + 12.1% in Denmark (the lowest increases) to + 65.3% in Spain, + 56.2% in Portugal, and + 50.4% in Hungary (the highest ones). Mortality sex ratios in Europe show more favourable trends for females, which may be attributable, in part, to the introduction of exogenous hormones in the late 1950s and 1960s, and, in part, to differential sex exposure to major environmental risk factors.