Interaction between age and race alters predicted survival in colorectal cancer

The Prediction of Survival Outcome and Prognosis Factor in Association with Comorbidity Status in Patients with Colorectal Cancer: A Research-Based Study

Colorectal carcinoma (CRC) is rising exponentially in Asia, representing 11% of cancer worldwide. This study analysed the influence of CRC on patients’ life expectancy (survival and prognosis factors) via clinicopathology data and comorbidity status of CRC patients. Methodology: A retrospective study performed in HUSM using clinical data from the Surgery unit from 2015 to 2020. The demographic and pertinent clinical data were retrieved for preliminary analyses (data cleansing and exploration). Demographics and pathological characteristics were illustrated using descriptive analysis; 5-year survival rates were calculated using Kaplan−Meier methods; potential prognostic variables were analysed using simple and multivariate logistic regression analysis conducted via the Cox proportional hazards model, while the Charlson Comorbidity Scale was used to categorize patients’ disease status. Results: Of a total of 114 CRC patients, two-thirds (89.5%) were from Malay tribes, while Indian and Chinese had 5.3% each. The 50−69.9 years were the most affected group (45.6%). Overall, 40.4% were smokers (majorly male (95.7%)), 14.0% ex-smokers, and 45.6% non-smokers (p-value = 0.001). The Kaplan−Meier overall 5-year median survival time was 62.5%. From the outcomes, patients who were male and >70 years had metastasis present, who presented with per rectal bleeding and were classified as Duke C; and who has tumour in the rectum had the lowest survival rate. Regarding the prognosis factors investigated, “Gender” (adjusted hazard ratio (HR): 2.62; 95% CI: 1.56−7.81, p-value = 0.040), “Presence of metastases” (HR: 3.76; 95% CI: 1.89−7.32, p-value = 0.010), “Metastasis site: Liver” (HR: 5.04; 95% CI: 1.71−19.05, p-value = 0.039), “Lymphovascular permeation” (HR: 2.94; 95% CI: 1.99−5.92, p-value = 0.021), and “CEA-level” (HR: 2.43; 95% CI: 1.49−5.80, p-value = 0.001) remained significant in the final model for multiple Cox proportional hazard regression analyses. There was a significant mean association between tumour grades and the patient’s comorbidity status. Conclusions: Histopathological factors (gender, metastases presence, site of metastases, CEA level, and lymphovascular permeation) showed the best prognosis-predicting factors in CRC.

Pan-cancer analysis of the prevalence and associated factors of lung metastasis and the construction of the lung metastatic classification system

This study first presents an analysis of the prevalence and associated factors of the lung metastasis (LM) database and then uses this analysis to construct an LM classification system. Using cancer patient data gathered from the surveillance, epidemiology, and end results (SEER) database, this study shows that the prevalence of LM is not consistent among different cancers; that is, the prevalence of LM ranges from 0.0013 [brain; 95% confidence interval (95% CI); 0.0010–0.0018] to 0.234 (“other digestive organs”; 95% CI; 0.221–0.249). This study finds that advanced age, poor grade, higher tumor or node stage, and metastases including bone, brain, and liver are positively related to LM occurrence, while female gender, income, marital status, and insured status are negatively related. Then, this study generates four categories from 58 cancer types based on prevalence and influence factors and satisfactorily validates these. This classification system reflects the LM risk of different cancers. It can guide individualized treatment and the management of these synchronous metastatic cancer patients and help clinicians better distribute medical resources.

Distant Metastasis Pattern and Prognostic Prediction Model of Colorectal Cancer Patients Based on Big Data Mining

Aims

This study aimed to investigate the distant metastasis pattern from newly diagnosed colorectal cancer (CRC) and also construct and validate a prognostic nomogram to predict both overall survival (OS) and cancer-specific survival (CSS) of CRC patients with distant metastases.

Methods

Primary CRC patients who were initially diagnosed from 2010 to 2016 in the SEER database were included in the analysis. The independent risk factors affecting the OS, CSS, all-cause mortality, and CRC-specific mortality of the patients were screened by the Cox regression and Fine–Gray competitive risk model. The nomogram models were constructed to predict the OS and CSS of the patients. The reliability and accuracy of the prediction model were evaluated by consistency index (C-index) and calibration curve. The gene chip GSE41258 was downloaded from the GEO database, and differentially expressed genes (DEGs) were screened by the GEO2R online tool (p < 0.05, |logFC|>1.5). The Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway and Gene Ontology (GO) annotation and String website were used for enrichment analysis and protein–protein interaction (PPI) analysis of DEGs, respectively, and Cytoscape software was used to construct PPI network and screen function modules and hub genes.

Results

A total of 57,835 CRC patients, including 47,823 without distant metastases and 10,012 (17.31%) with metastases, were identified. Older age, unmarried status, poorly differentiated or undifferentiated grade, right colon site, larger tumor size, N2 stage, more metastatic sites, and elevated carcinoembryonic antigen (CEA) might lead to poorer prognosis (all p < 0.01). The independent risk factors of OS and CSS were included to construct a prognosis prediction model for predicting OS and CSS in CRC patients with distant metastasis. C-index and calibration curve of the training group and validation group showed that the models had acceptable predictive performance and high calibration degree. Furthermore, by comparing CRC tissues with and without liver metastasis, 158 DEGs and top 10 hub genes were screened. Hub genes were mainly concentrated in liver function and coagulation function.

Conclusion

The big data in the public database were counted and transformed into a prognostic evaluation tool that could be applied to the clinic, which has certain clinical significance for the formulation of the treatment plan and prognostic evaluation of CRC patients with distant metastasis.

Does adjuvant chemotherapy improve outcomes in elderly patients with colorectal cancer? A systematic review and meta-analysis of real-world studies

BACKGROUND

Elderly patients are frequently excluded from randomized trials. It is unclear if adjuvant chemotherapy improves outcomes of colorectal cancer in such patients. The current study aimed to review evidence on the impact of adjuvant chemotherapy on overall survival (OS) and disease-free survival (DFS) in elderly patients with stage II/III colorectal cancer by pooling data from real-world studies.

METHODS

PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar databases were searched for observational studies reporting adjusted data on OS and DFS in elderly (≥70 years) colorectal cancer patients based on receipt of adjuvant chemotherapy.

RESULTS

Thirteen studies included. The meta-analysis demonstrated statistically significant improved OS in elderly patients receiving adjuvant chemotherapy (p < 0.00001). Results were similar for sub-group analysis based on cancer stage and definition of elderly. Improvement in OS was noted in only Western population studies with no difference in Asian patients. The meta-analysis also revealed no statistically significant difference in DFS in elderly patients receiving adjuvant chemotherapy vs surgery alone (p = 0.14).

CONCLUSION

Real-world evidence indicates that adjuvant chemotherapy significantly improved OS but not DFS in elderly colorectal cancer patients. Scarce evidence suggests a limited role of adjuvant chemotherapy in Asian patients which needs confirmation by further studies.

The impact of hospital volume on racial disparities in resected rectal cancer

BACKGROUND

Although high volume centers (HVC) equate to improved outcomes in rectal cancer, the impact of surgical volume related to race is less defined.

METHODS

Patients who underwent surgical resection for stage I-III rectal adenocarcinoma were divided into cohorts based on race and hospital surgical volume. Outcomes were analyzed following 1:1 propensity-score matching using logistic, Poisson, and Cox regression analyses with marginal effects.

RESULTS

Fifty-four thousand one hundred and eighty-four (91.5%) non-Black and 5043 (8.5%) Black patients underwent resection of rectal cancer. Following 1:1 matching of non-Black (N = 5026) and Black patients, 5-year overall survival (OS) of Black patients was worse (72% vs. 74.4%, average marginal effects [AME] 0.66, p = 0.04) than non-Black patients. When compared to non-Black patients managed at HVCs, Black patients had worse OS (70.1% vs. 74.7%, AME 1.55, p = 0.03), but this difference was not significant when comparing OS between non-Black and Black patients managed at HVCs (72.3% vs. 74.7%, AME 0.62, p = 0.06). Length of stay was longer among Black and HVC patients across all cohorts. There was no difference across cohorts in 90-day mortality.

CONCLUSIONS

Although racial disparities exist in rectal cancer, this disparity appears to be ameliorated when patients are managed at HVCs.

Race, Income, and Survival in Stage III Colon Cancer: CALGB 89803 (Alliance)

Background

Disparities in colon cancer outcomes have been reported across race and socioeconomic status, which may reflect, in part, access to care. We sought to assess the influences of race and median household income (MHI) on outcomes among colon cancer patients with similar access to care.

Methods

We conducted a prospective, observational study of 1206 stage III colon cancer patients enrolled in the CALGB 89803 randomized adjuvant chemotherapy trial. Race was self-reported by 1116 White and 90 Black patients at study enrollment; MHI was determined by matching 973 patients’ home zip codes with publicly available US Census 2000 data. Multivariate analyses were adjusted for baseline sociodemographic, clinical, dietary, and lifestyle factors. All statistical tests were 2-sided.

Results

Over a median follow-up of 7.7 years, the adjusted hazard ratios for Blacks (compared with Whites) were 0.94 (95% confidence interval [CI] = 0.66 to 1.35, P = .75) for disease-free survival, 0.91 (95% CI = 0.62 to 1.35, P = .65) for recurrence-free survival, and 1.07 (95% CI = 0.73 to 1.57, P = .73) for overall survival. Relative to patients in the highest MHI quartile, the adjusted hazard ratios for patients in the lowest quartile were 0.90 (95% CI = 0.67 to 1.19, P_trend = .18) for disease-free survival, 0.89 (95% CI = 0.66 to 1.22, P_trend = .14) for recurrence-free survival, and 0.87 (95% CI = 0.63 to 1.19, P_trend = .23) for overall survival.

Conclusions

In this study of patients with similar health-care access, no statistically significant differences in outcomes were found by race or MHI. The substantial gaps in outcomes previously observed by race and MHI may not be rooted in differences in tumor biology but rather in access to quality care.

Racial disparity in survival of patients diagnosed with early-onset colorectal cancer

Background: Survival is reduced in African–Americans (AAs) diagnosed with colorectal cancer (CRC), especially in those <50 years old, when compared with Caucasian Americans (CAs). Yet, the role of clinicopathologic features of CRCs on racial differences in survival needs further study. Materials & methods: Over 1000 individuals (CA 709, AA 320) diagnosed with CRC were studied for survival via the Cox proportional hazards regression analysis based on race and risk of death in two age groups (<50 or 50+). Results: Risk of death for younger AAs (<50) was elevated compared with younger CAs (hazard ratio [HR] 1.98 [1.26–3.09]). Yet no racial differences in survival was observed in older cohort (50+ years), HR 1.07 (0.88–1.31); p for interaction = 0.01. In younger AAs versus CAs only, colonic location attenuated the risk of death. Conclusion: The tumor location and histology influence the poorer survival observed in younger AAs suggesting these may also influence treatment responses.

Effect of adjuvant chemotherapy on survival benefit in stage III colon cancer patients stratified by age: a Japanese real-world cohort study

Background

Adjuvant chemotherapy is relatively underused in older patients with colon cancer in Japan, and its age-specific effects on clinical outcomes remain unclear. This study aimed to assess the effect of adjuvant chemotherapy on survival benefit in stage III colon cancer patients stratified by age in a Japanese real-world setting.

Methods

In this multi-center retrospective cohort study, we analyzed patient-level information through a record linkage of population-based cancer registry data and administrative claims data. The study population comprised patients aged ≥18 years who received a pathological diagnosis of stage III colon cancer and underwent curative resection between 2010 and 2014 at 36 cancer care hospitals in Osaka Prefecture, Japan. Patients were divided into two groups based on age at diagnosis (< 75 and ≥ 75 years). The effect of adjuvant chemotherapy was analyzed using Cox proportional hazards regression models for all-cause mortality with inverse probability weighting of propensity scores. Adjusted hazard ratios were estimated for both age groups.

Results

A total of 783 patients were analyzed; 476 (60.8%) were aged < 75 years and 307 (39.2%) were aged ≥75 years. The proportion of older patients who received adjuvant chemotherapy (36.8%) was substantially lower than that of younger patients (73.3%). In addition, the effect of adjuvant chemotherapy was different between the age groups: the adjusted hazard ratio was 0.56 (95% confidence interval: 0.33–0.94, P = 0.027) in younger patients and 1.07 (0.66–1.74, P = 0.78) in older patients.

Conclusions

The clinical effectiveness of adjuvant chemotherapy in older patients with stage III colon cancer appears limited under current utilization practices.

Survival Rate of Colorectal Cancer in Eastern Mediterranean Region Countries: A Systematic Review and Meta-Analysis

Colorectal cancer (CRC) is the second most common cause of cancer-related deaths worldwide. Survival rates are among the most important factors in quality control and assessment of treatment protocols. This study was aimed to assess the survival rate of colorectal cancer in Eastern Mediterranean Region Countries. In the present study we comprehensively searched 6 international databases including PubMed/Medline, ProQuest, Scopus, Embase, Web of Knowledge and Google Scholar for published articles until November 2018. The Newcastle-Ottawa Quality Assessment Form for Cohort Studies was applied to evaluate the quality of included studies. The heterogeneity of papers was assessed with the Cochran Test and I-Square statistics. Meta-regression test was performed based on publication year, sample size and Human Development Index (HDI) of each study. Among the total of 1023 titles found in the systematic search, 43 studies were eligible to be included in the present meta-analysis. According to the results, the 1-year, 3-year and 5-year survival rate of patients with Colorectal Cancer was 88.07% (95% CI, 83.22-92.92), 70.67% (95% CI, 66.40-74.93) and, 57.26% (95% CI, 50.43-64.10); respectively. Furthermore, Meta-regressions did not show significant correlations between survival rate and year, sample size or Human Development Index. Survival rates, especially the 5-year survival rate in the EMRO were less than European countries and the USA. Documented and comprehensive evidence-based findings of the present meta-analysis can be used to enhance policies and outcomes of different medical areas including prophylaxis, treatment and health related objectives in colorectal cancer.

Analysis of racial disparities in the treatment and outcomes of colorectal cancer in young adults

BACKGROUND

The incidence of colorectal cancer (CRC) in young adults is increasing. Minority populations with CRC are known to have worse survival outcomes. The aim of this study is to evaluate adults under age 50 years with CRC by race and ethnicity.

METHODS

Data were obtained from all US hospitals that contributed to the National Cancer Database (NCDB) between 2004 and 2013. Univariate and multivariable testing was done to identify factors associated with patient outcome. Kaplan-Meier analysis and Cox proportional hazards models were used for association between patient characteristics and survival.

RESULTS

A total of 83,449 patients between 18 and 50 years of age were identified. Median age was 45 years (SD ± 6), with male preponderance (53.9%). 72% were non-Hispanic Whites (NHW), Blacks (AA) were 15.1% and Hispanics (who did not identify as Blacks) were 8.3% of the study population. Distribution across stages IIV was 15.6%, 22.4%, 33.9% and 27% consecutively. 41.8% of NHW and 28.4% of AA had rectal cancers (p < 0.001). Despite equally receiving standard of care (SOC) as per national guidelines, AA had significantly lower 5-year survival rates (58.8%) compared to Hispanics (64.8%) and NHW (66.9%; HR 1.42; 1.38-1.46; p < 0.001). Furthermore, NHW (HR 0.85; 0.81-0.88; p < 0.001) and Hispanics (HR 0.75; 0.70-0.79; p < 0.001) were more likely to benefit from chemotherapy compared to AA. SOC utilization was associated with improved survival across all racial groups, especially in AA (HR 0.64; 0.60-0.69; p < 0.001).

CONCLUSION

Despite comparable rates of SOC utilization, AA young adults had worse survival outcomes compared to other races. More colon (compared to rectal) cancers in AA may have contributed to their worse outcomes.

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.

Evaluation of the transferability of survival calculators for stage II/III colon cancer across healthcare systems

Adjuvant! Online Inc (A!O), the Memorial Sloan Kettering Cancer Center (MSKCC), MD Anderson (MDA) and Mayo Clinic (MC) provide calculators to predict survival probabilities for patients with resected early-stage colon cancer, trained on data from United States (US) patient cohorts or patients enrolled in international clinical trials. Limited data exist on the transferability of calculators across healthcare systems. Calculator transferability to Australian community practice was evaluated for 1,401 stage II/III patients. Calibration and discrimination were assessed for overall (OS), cancer-specific (CSS) or recurrence-free survival (RFS). The US patient cohort-based calculators, A!O, MSKCC and MDA, significantly overestimated risks of recurrence and death in Australian patients, with 5-year OS, CSS and RFS prediction differences of -6.5% to -9.9%, -9.1% to -14.4% and - 3.8% to -6.8%, respectively (p < 0.001). Significant heterogeneity in calibration was observed for subgroups by tumor stage and treatment, age, gender, tumor location, ECOG and ASA score. Calibration appeared acceptable for the clinical trial patient-based MC calculator, but restricted tool applicability (stage III patients, ≥12 examined lymph nodes, receiving adjuvant treatment) limited the sample size. Compared to AJCC 7th edition tumor staging, calculators showed improved discrimination for OS, but no improvement for CSS and RFS. In conclusion, deficiencies in calibration limited transferability of US patient cohort-based survival calculators for early-stage colon cancer to the setting of Australian community practice. Our results demonstrate the utility for multi-feature survival calculators to improve OS predictions but highlight the importance for performance assessment of tools prior to implementation in an external health care setting.

Early onset sporadic colorectal cancer: Worrisome trends and oncogenic features

Early onset colorectal cancers, defined as arising before 50 years of age, are a growing health hazard in western and eastern countries alike. The incidence of colon and rectal cancers in young individuals is projected to increase by as much as 90% and 140%, respectively, by 2030. Although several known cancer risk factors (e.g. smoking, alcohol, dietary habits) have been investigated, there is no single compelling explanation for this epidemiological trend. While some early onset colorectal cancers have been associated with germline mutations in cancer predisposition genes, genetic syndromes are implicated in only a fraction of these cancers (20%) and do not explain the rising incidence. Colorectal neoplasms develop through microsatellite instability or chromosomal instability pathways, with most of the early onset colorectal cancers exhibiting microsatellite stable phenotypes. Genome-wide hypomethylation is a feature of a subgroup of early onset cancers, which appears to be correlated with chromosomal instability and poor prognosis.

Factors That Contribute to Differences in Survival of Black vs White Patients With Colorectal Cancer

BACKGROUND & AIMS

Previous studies reported that black vs white disparities in survival among elderly patients with colorectal cancer (CRC) were because of differences in tumor characteristics (tumor stage, grade, nodal status, and comorbidity) rather than differences in treatment. We sought to determine the contribution of differences in insurance, comorbidities, tumor characteristics, and treatment receipt to disparities in black vs white patients with CRC 18-64 years old.

METHODS

We used data from the National Cancer Database, a hospital-based cancer registry database sponsored by the American College of Surgeons and the American Cancer Society, on non-Hispanic black (black) and non-Hispanic white (white) patients, 18-64 years old, diagnosed from 2004 through 2012 with single or first primary invasive stage I-IV CRC. Each black patient was matched, based on demographic, insurance, comorbidity, tumor, and treatment features, with 5 white patients, from partially overlapping subgroups, using propensity score and greedy matching algorithms. We used the Kaplan-Meier method to estimate 5-year survival and Cox proportional hazards models to generate hazard ratios.

RESULTS

The absolute 5-year survival difference between black and white unmatched patients with CRC was 9.2% (57.3% for black patients vs 66.5% for white patients; P < .0001). The absolute difference in survival did not change after patient groups were matched for demographics, but decreased to 4.9% (47% relative decrease [4.3% of 9.2%]) when they were matched for insurance and to 2.3% when they were matched for tumor characteristics (26% relative decrease [2.4% of 9.2%]). Further matching by treatment did not reduce the difference in 5-year survival between black and white patients. In proportional hazards model, insurance and tumor characteristics matching accounted for the 54% and 27% excess risk of death in black patients, respectively.

CONCLUSIONS

In an analysis of data from the National Cancer Database, we found that insurance coverage differences accounted for approximately one half of the disparity in survival rate of black vs white patients with CRC, 18-64 years old; tumor characteristics accounted for a quarter of the disparity. Affordable health insurance coverage for all populations could substantially reduce differences in survival times of black vs white patients with CRC.

Social disparities in survival after diagnosis with colorectal cancer: Contribution of race and insurance status

BACKGROUND

Both minority race and lack of health insurance are risk factors for lower survival in colorectal cancer (CRC) but the interaction between the two factors has not been explored in detail.

METHODS

One to 5-year survival by race/ethnic group and insurance type for patients with CRC diagnosed in 2007-13 and registered in the Surveillance Epidemiology, and End RESULTS: database were explored. Shared frailty models were computed to further explore the association between CRC specific survival and insurance status after adjustment for demographic and treatment variables.

RESULTS

Age-adjusted 5-year survival estimates were 70.4% for non-Hispanic whites (nHW), 62.7% for non-Hispanic blacks (nHB), 70.2% for Hispanics, 64.7% for Native Americans, and 73.1% for Asian/Pacific Islanders (API). Survival was greater for patients with insurance other than Medicaid for all races, but the differential in survival varied with race, with the greatest difference being seen for nHW at +25.0% and +20.2%, respectively, for Medicaid and uninsured versus other insurance. Similar results were observed for stage- and age-specific analyses, with survival being consistently higher for nHW and API compared to other groups. After confounder adjustment, hazard ratios of 1.53 and 1.50 for CRC-specific survival were observed for Medicaid and uninsured. Racial/ethnic differences remained significant only for nHB compared to nHW.

CONCLUSIONS

Race/ethnic group and insurance type are partially independent factors affecting survival expectations for patients diagnosed with CRC. NHB had lower than expected survival for all insurance types.

Pattern of distant metastases in colorectal cancer: a SEER based study

More and more evidences suggest that primary colon and rectum tumors should not be considered as a single disease entity. In this manuscript, we evaluate the metastatic patterns of colon and rectum cancers and analyze the potential distribution of metastatic disease in these two malignancies. Data queried for this analysis include colorectal adenocarcinoma (2010-2011) from the Surveillance, Epidemiology, and End Results Program (SEER) database. Metastatic distribution information was provided for liver, lung, bone and brain. All of statistical analyses were performed using the Intercooled Stata 13.0 (Stata Corporation, College Station, TX). All statistical tests were two-sided. Totally, there were 46,027 eligible patients for analysis. We found that colon cancer had a higher incident rate of liver metastasis than rectum cancer (13.8% vs 12.3%), while rectum cancer had a higher incident rate of lung (5.6% vs 3.7%) and bone (1.2% vs 0.8%) metastasis than colon cancer, P<0.001. Colorectal cancer patients with lung metastasis had a higher risk of bone (10.0% vs 4.5%) or brain metastasis (3.1% vs 0.1%) than patients without lung metastases. The 1-year cause-specific survival was not significant different for bone or brain metastasis patients with and without lung metastasis (32.9% vs 38.7%, P=0.3834 for bone, 25.8% vs 36.9%, P=0.6819 for brain). Knowledge of these differences in metastatic patterns may help to better guide pre-treatment evaluation of colorectal cancer patients, especially in making determinations regarding curative-intent interventions.

Colorectal Cancer Survival Disparities among Puerto Rican Hispanics: A Comparison to Racial/Ethnic Groups in the United States

PURPOSE

Ethnic/racial disparities in colorectal cancer (CRC) survival have been well documented. However, there is limited information regarding CRC survival among Hispanic subgroups. This study reports the 5-year relative survival of Puerto Rican Hispanic (PRH) CRC patients and the relative risk of death compared to other racial/ethnic groups in the US.

METHODS

CRC incidence data from subjects ≥50 years was obtained from the Puerto Rico Central Cancer Registry and the Surveillance, Epidemiology and End Results (SEER) database from January 1, 2001 to December 31, 2003. Relative survival rates were calculated using the life tables from the population of PR and SEER. A Poisson regression model was used to assess relative risk of death by stage, sex, and age.

RESULTS

A total of 76,444 subjects with incident CRC were analyzed (non-Hispanic White (NHW) n=59,686; non-Hispanic black (NHB) n=7,700; US Hispanics (USH) n=5,699; PRH n=3,359). Overall and stage-specific five-year survival rates differed by race/ethnicity. When comparing PRH to the other racial/ethnic groups, PRH had the lowest survival rates in regional cancers and were the only racial/ethnic group where a marked 5-year survival advantage was observed among females (66.0%) compared to males (60.3%). A comparable and significantly higher relative risk of death of CRC was observed for PRH and NHB compared to NHW.

CONCLUSIONS

Our findings establish baseline CRC survival data for PRH living in Puerto Rico. The gender and racial/ethnic disparities observed in PRH compared to US mainland racial/ethnic groups warrant further investigation of the risk factors affecting this Hispanic subgroup.

Racial/Ethnic Disparities in Survival Among Patients With Young-Onset Colorectal Cancer

PURPOSE

Racial disparities in colorectal cancer (CRC) persist, despite overall reductions in morbidity and mortality. In addition, incidence is rising among individuals younger than 50 years of age. We compared the survival of young-onset CRC among non-Hispanic black (NHB), non-Hispanic white (NHW), and Hispanic individuals.

PATIENTS AND METHODS

Using the National Cancer Institute's Surveillance, Epidemiology, and End Results program data, we identified individuals between the ages of 20 and 49 years, diagnosed with CRC between 2000 and 2009. Survival rates and Cox proportional hazards models were used to compare stage-specific 5-year survival among NHBs, NHWs, and Hispanics.

RESULTS

We identified 28,145 patients with young-onset CRC (19,497 NHW; 4,384 NHB; 4,264 Hispanic) during the 10-year study period. Overall survival at 5 years after CRC diagnosis was 54.9% among NHB, 68.1% among NHW, and 62.9% among Hispanic individuals (P < .001). NHB individuals had a significantly higher hazard of cancer-specific death compared with NHWs after adjusting for age, sex, race, stage, county-level poverty, and treatment history in cases of colon (hazard ratio [HR], 1.35; 95% CI 1.26 to 1.45) and rectum/rectosigmoid junction (HR, 1.51; 95% CI, 1.37 to 1.68) cancers, whereas there was no significant difference in survival between NHWs and Hispanics. The greatest racial disparities in cancer-specific survival were observed among NHB and NHW patients diagnosed with stage II cancers of the colon (HR, 1.69; 95% CI, 1.33 to 2.14) and stage III cancers of the rectum (HR, 1.98; 95% CI, 1.63 to 2.40).

CONCLUSION

Survival after CRC diagnosis at a young age is significantly worse among NHBs compared with NHWs, even among patients with early-stage disease. Further study is needed to determine whether differences in tumor biology and/or treatment are associated with racial disparities in outcomes, which would have implications for CRC treatment and prevention.

Metastatic Colorectal Cancer in Hispanics: Treatment Outcomes in a Treated Population

BACKGROUND

In United States Hispanics have disparities in the presentation and outcome of colorectal cancer (CRC) largely attributed to their late presentation and lower socioeconomic status. Impact of treatment, especially in the metastatic setting, in the observed outcome is an unexplored area. We explored the role of treatment in the outcome of metastatic CRC we performed a retrospective analysis to assess the contribution of demographics, tumor characteristics, and health care setting on survival differences.

PATIENTS AND METHODS

We conducted a retrospective study of patients who were treated with metastatic CRC at Los Angeles County Hospital-University of Southern California (LAC-USC, a public hospital) and Norris Comprehensive Cancer Center (NCCC, private hospital) between 2002 and 2012. Both these institutions are staffed by the same providers and therefore treatment algorithms and access to drugs were similar. We identified metastatic CRC patients who received chemotherapy from administrative records. Demographics, tumor, and treatment related factors were collected. The primary end point was time to progression (TTP: time from the first day of chemotherapy to the date of progression). Overall survival (OS) was measured from the first day of chemotherapy to death or last follow-up. Descriptive statistics were used to describe the population and chi-square, Wilcoxon, and log-rank tests were used for comparison between the groups.

RESULTS

A total of 242 patients, 44% Hispanic, 26% non-Hispanic whites (NHWs), 21% Asian and 9% black were included. Median TTP was 9.2 months (95% confidence interval [CI], 7.6-11.6) in Hispanics, and 20.7 months (95% CI, 9.6-27.5; P < .05) in NHWs. Median OS in Hispanics was 16.3 months (95% CI, 13.3-18.5), and in NHWs was 33.5 months (95% CI, 22.1-63.6; P < .001). Hispanics who were treated at LAC-USC had longer TTP in comparison to Hispanics at NCCC (P = .04).

CONCLUSION

Hispanics with metastatic CRC have shorter TTP and OS on first line therapy when adjusted for health care setting, demographics, disease characteristics, and treatment factors.

Racial Differences in BRAF/KRAS Mutation Rates and Survival in Stage III Colon Cancer Patients

BACKGROUND

It is unknown if, after controlling for clinicopathologic variables and treatment, racial disparities in colon cancer outcomes persist. Molecular marker analysis in North American patients comparing Asians with other races has not been reported.

METHODS

BRAF (V600E) and KRAS mutations were analyzed in node-positive colon cancer patients (n = 3305) treated with FOLFOX-based chemotherapy in an adjuvant trial (Alliance N0147). Race categories included Asian, black, or white. Cox models were used to estimate disease-free survival (DFS) and time to recurrence (TTR). All statistical tests were two-sided.

RESULTS

BRAF mutation frequency in tumors from whites (13.9%) was twice that of tumors from Asians or blacks. KRAS mutation rates were highest in tumors from blacks (44.1%). KRAS/BRAF wild-type tumors were most common among Asians (66.7%) (P overall < .001). The prognostic impact of race differed by age and N stage (both P interaction < .02). Compared with whites, blacks had shorter DFS among patients younger than age 50 years (hazard ratio [HR] = 2.84, 95% confidence interval [CI] = 1.73 to 4.66) or with N1 disease (HR = 1.54, 95% CI = 1.04 to 2.29), independent of BRAF, KRAS, and other covariates. Findings were consistent using TTR as the outcome. Asians had longer DFS among N2 tumors that was partly mediated by less frequent BRAF mutation.

CONCLUSIONS

Colon cancers from Asians have a lower rate of BRAF and KRAS mutations than blacks or whites. We report a novel interaction of race with age and N stage in node-positive disease, indicating that racial disparities in survival persist despite uniform stage and treatment in a phase III trial.

Provider-based research networks may improve early access to innovative colon cancer treatment for African Americans treated in the community

BACKGROUND

African American (AA) patients with colon cancer (CC) experience worse outcomes than whites partly due to differential treatment. The National Cancer Institute's Community Clinical Oncology Program (CCOP), a provider-based research network, adopts and diffuses innovative CC treatments quickly. The authors hypothesized that CCOP participation would lessen racial differences in the receipt of oxaliplatin, an innovative treatment for CC, among patients with stage III CC in the community.

METHODS

Using Surveillance, Epidemiology, and End Results (SEER)-Medicare data, the authors performed a population-based retrospective cohort study of AA and white individuals aged ≥66 years who were diagnosed with AJCC stage III CC from 2003 through 2005. Generalized estimating equations were used to calculate the odds of receiving an oxaliplatin-containing regimen. Predicted probabilities of oxaliplatin receipt for race-CCOP combinations were calculated. The absolute difference in oxaliplatin receipt between races was estimated using the interaction contrast ratio.

RESULTS

Of 2971 included individuals, 36% received oxaliplatin, 29.5% were CCOP-affiliated, and 7.6% were AA. On multivariate analysis, early diffusion of oxaliplatin was not found to be associated with race or CCOP participation. The probability of receiving oxaliplatin for AAs participating in a CCOP (0.46) was nearly double that of AAs who were not participating in a CCOP (0.25; P <.05). For white individuals, the probabilities of receiving oxaliplatin did not differ by CCOP participation. For oxaliplatin receipt, the joint effects assessment suggested a greater benefit of CCOP participation among AAs (interaction contrast ratio, 1.7).

CONCLUSIONS

Among older patients with stage III CC, there is a differential impact of race on oxaliplatin receipt depending on CCOP participation. AAs treated by CCOPs were more likely to receive oxaliplatin than AAs treated elsewhere. Provider-based research networks may facilitate early access to innovative treatment for AAs with stage III CC.

The association of age and race and the risk of large bowel polyps

BACKGROUND

Blacks have a higher incidence of colorectal cancer and a younger age at diagnosis compared with whites. Few studies have investigated racial differences in risk of metachronous adenomas and serrated polyps and whether this risk differs by polyp characteristics or age of patient.

METHODS

We analyzed data pooled from three placebo-controlled adenoma chemoprevention trials to explore racial differences in the risk of large bowel polyps in patients ≤50 and >50 years of age. Using generalized linear regression, we estimated risk ratios (RR) and 95% confidence intervals (CI) as measures of the association between race and risk of one or more adenomas or serrated polyps after randomization.

RESULTS

Among the 2,605 subjects who completed at least one follow-up exam, blacks ≤50 years of age had a higher risk of any conventional adenoma (RR, 1.70; 95% CI, 0.99-2.92) and advanced neoplasms (RR, 4.05; 95% CI, 1.43-11.46) and a nonsignificantly lower risk of serrated polyps (RR, 0.75; 95% CI, 0.34-1.62) compared with whites. Among patients >50 years, there was no racial difference in risk of adenomas (RR, 1.08; 95% CI, 0.92-1.27) or advanced neoplasms (RR, 1.05; 95% CI, 0.71- 1.56). However, blacks had a significantly lower risk of serrated polyps (RR, 0.65; 95% CI, 0.49-0.87) than whites.

CONCLUSIONS

Our results demonstrate a higher risk of metachronous adenomas in blacks compared with whites at younger ages.

IMPACT

Our results suggest that the racial disparity in colorectal cancer incidence may be due to an excess of neoplasia in younger blacks.

Impact of lymph node ratio and number on survival in patients with rectal adenocarcinoma after preoperative chemo radiation

BACKGROUND

Retrieval of <12 lymph nodes after proctectomy and preoperative chemoradiation (C-XRT) may improve survival in good risk patients. The objective of this study was to determine impact of <12 retrieved lymph nodes and lymph node ratio (LNR) on survival in a population with certain poor prognostic features for rectal cancer.

METHODS

Patients who underwent surgery for rectal adenocarcinoma between 2005 and 2011 were divided them into <12 or >12 lymph node groups. The LNR groups were based on interquartile range. Clinicopathological and treatment outcomes were compared. Expected 5 year disease free and overall survival was calculated. Cox proportional hazard model was used to determine independent predictors.

RESULTS

More patients in <12 lymph nodes removed group had low tumors (<5 cm from anal verge) (75.5% versus 60.7%) (P=0.03) and underwent abdominoperineal resection (59.1% versus 42.9%) (P=0.02). Overall survival (OS) and disease free survival (DFS) was not different [(56% and 52% (P=0.7)] [(50% and 57% (P=0.5)]. LNR<0.15 was independent predictor of DFS while LNR ratio<0.12 for OS on multivariate analysis.

CONCLUSION

LNR and not number of retrieved nodes impacts survival in younger patients with predominance of anorectal tumors after C-XRT. A specific LNR cutoff remains to be defined.