Time dependent ethnic convergence in colorectal cancer survival in Hawaii

Disaggregating Data on Pacific Islander Gastric Cancer Patients Reveals Survival Disparity

PURPOSE

The incidence and prognosis of Pacific Islanders with gastric cancer is not well documented as previous studies have often aggregated this population with Asians. The purpose of our study was to describe patient and tumor characteristics, as well as prognostic factors of Pacific Islanders with gastric cancer.

METHODS

Patients diagnosed with gastroesophageal junction or gastric adenocarcinoma between 2000 and 2014 were identified in the tumor registry of the largest hospital in Hawaii. Overall survival of Asians, Whites, and Pacific Islanders were calculated using the Kaplan-Meier method and log-rank test. Cox proportional hazards regression models were constructed to assess predictors of survival adjusting for clinical and pathological factors.

RESULTS

A total of 615 patients were included in the final analysis. Pacific Islanders were found to present at a younger age, were more often uninsured or had Medicaid insurance, and were diagnosed with a higher stage of cancer compared to their Asian and White counterparts. Pacific Islanders were less likely to undergo surgery even after adjusting for stage. Race was a prognostic factor and survival was lowest among Pacific Islanders, but only if the model was unadjusted for treatment.

CONCLUSIONS

We present an analysis of the largest cohort of Pacific Islander gastric cancer patients. Pacific Islanders have different sociodemographic characteristics and inferior survival compared to Asian patients and should be independently studied.

Colorectal Cancer Screening Compliance among Asian and Pacific Islander Americans

Colorectal cancer (CRC) screening prevalence remains low among Asians and Pacific Islanders. This study examined disparities and predictors of CRC screening compliance in adults age 50-75 years in Asians and Pacific Islanders in Hawai'i. Hawai'i Behavioral Risk Factor Surveillance System (BRFSS) data for 2011-2014 were analyzed. CRC screening status was dichotomized. Logistic regression was used to examine ethnic differences in and predictors of CRC screening status. Filipinos (OR 0.56), Chinese (OR 0.70), and Hawaiians (OR 0.75) were significantly less likely than whites to be CRC compliant. Higher education and income, employment, regular health provider, and routine checkups were important predictors of CRC compliance. Findings confirm lower CRC screening compliance in three of the four largest Asian and Pacific Islander groups in Hawai'i and that CRC screening compliance is influenced by several factors. Culturally tailored education and navigation services may be effective in reducing these disparities.

Colonoscopy Screening among Native Hawaiians at Queen's Medical Center between August 2011 and January 2013

A retrospective chart review in the Endoscopy Department at Queen's Medical Center identified 358 Native Hawaiian patients who had completed a colonoscopy screening procedure between August 2011 and January 2013, through either the Direct Referral Colonoscopy program or its Traditional Referral program. The differences in the characteristics of Native Hawaiian patients were summarized and compared between the two referral programs to identify potential barriers for future interventions and increase colorectal cancer screening. The combined colonoscopy screening rate among Native Hawaiians was 13%. Younger patients and those with private insurance were found to be undergoing colonoscopy screening through the Direct Referral program. The findings of this study underscore the need to reduce disparities in colonoscopy screening among Native Hawaiians.

Australia's national bowel cancer screening program: does it work for indigenous Australians?

BACKGROUND

Despite a lower incidence of bowel cancer overall, Indigenous Australians are more likely to be diagnosed at an advanced stage when prognosis is poor. Bowel cancer screening is an effective means of reducing incidence and mortality from bowel cancer through early identification and prompt treatment. In 2006, Australia began rolling out a population-based National Bowel Cancer Screening Program (NBCSP) using the Faecal Occult Blood Test. Initial evaluation of the program revealed substantial disparities in bowel cancer screening uptake with Indigenous Australians significantly less likely to participate in screening than the non-Indigenous population.This paper critically reviews characteristics of the program which may contribute to the discrepancy in screening uptake, and includes an analysis of organisational, structural, and socio-cultural barriers that play a part in the poorer participation of Indigenous and other disadvantaged and minority groups.

METHODS

A search was undertaken of peer-reviewed journal articles, government reports, and other grey literature using electronic databases and citation snowballing. Articles were critically evaluated for relevance to themes that addressed the research questions.

RESULTS

The NBCSP is not reaching many Indigenous Australians in the target group, with factors contributing to sub-optimal participation including how participants are selected, the way the screening kit is distributed, the nature of the test and comprehensiveness of its contents, cultural perceptions of cancer and prevailing low levels of knowledge and awareness of bowel cancer and the importance of screening.

CONCLUSIONS

Our findings suggest that the population-based approach to implementing bowel cancer screening to the Australian population unintentionally excludes vulnerable minorities, particularly Indigenous and other culturally and linguistically diverse groups. This potentially contributes to exacerbating the already widening disparities in cancer outcomes that exist among Indigenous Australians. Modifications to the program are recommended to facilitate access and participation by Indigenous and other minority populations. Further research is also needed to understand the needs and social and cultural sensitivities of these groups around cancer screening and inform alternative approaches to bowel cancer screening.

Geographic disparities in colorectal cancer survival

BACKGROUND

Examining geographic variation in cancer patient survival can help identify important prognostic factors that are linked by geography and generate hypotheses about the underlying causes of survival disparities. In this study, we apply a recently developed spatial scan statistic method, designed for time-to-event data, to determine whether colorectal cancer (CRC) patient survival varies by place of residence after adjusting survival times for several prognostic factors.

METHODS

Using data from a population-based, statewide cancer registry, we examined a cohort of 25,040 men and women from New Jersey who were newly diagnosed with local or regional stage colorectal cancer from 1996 through 2003 and followed to the end of 2006. Survival times were adjusted for significant prognostic factors (sex, age, stage at diagnosis, race/ethnicity and census tract socioeconomic deprivation) and evaluated using a spatial scan statistic to identify places where CRC survival was significantly longer or shorter than the statewide experience.

RESULTS

Age, sex and stage adjusted survival times revealed several areas in the northern part of the state where CRC survival was significantly different than expected. The shortest and longest survival areas had an adjusted 5-year survival rate of 73.1% (95% CI 71.5, 74.9) and 88.3% (95% CI 85.4, 91.3) respectively, compared with the state average of 80.0% (95% CI 79.4, 80.5). Analysis of survival times adjusted for age, sex and stage as well as race/ethnicity and area socioeconomic deprivation attenuated the risk of death from CRC in several areas, but survival disparities persisted.

CONCLUSION

The results suggest that in areas where additional adjustments for race/ethnicity and area socioeconomic deprivation changed the geographic survival patterns and reduced the risk of death from CRC, the adjustment factors may be contributing causes of the disparities. Further studies should focus on specific and modifiable individual and neighborhood factors in the high risk areas that may affect a person's chance of surviving cancer.

Cancer survival discrepancies in developed and developing countries: comparisons between the Philippines and the United States

Despite the availability of population-based cancer survival data from the developed and developing countries, comparisons remain very few. Such comparisons are important to assess the magnitude of survival discrepancies and to disentangle the impact of ethnic background and health care access on cancer survival. Using the SEER 13 database and databases from the Manila and Rizal Cancer Registries in the Philippines, a 5-year relative survival for 9 common cancers in 1998–2002 of Filipino-American cancer patients were compared with both cancer patients from the Philippines, having the same ethnicity, and Caucasians in the United States, being exposed to a similar societal environment and the same health care system. Survival estimates were much higher for the Filipino-Americans than the Philippine resident population, with particularly large differences (more than 20–30% units) for cancers with good prognosis if diagnosed and treated early (colorectal, breast and cervix), or those with expensive treatment regimens (leukaemias). Filipino-Americans and Caucasians showed very similar survival for all cancer sites except stomach cancer (30.7 vs 23.2%) and leukaemias (37.8 vs 48.4%). The very large differences in the survival estimates of Filipino-Americans and the Philippine resident population highlight the importance of the access to and utilisation of diagnostic and therapeutic facilities in developing countries. Survival differences in stomach cancer and leukaemia between Filipino-Americans and Caucasians in the United States most likely reflect biological factors rather than the differences in access to health care.

African-American and Caucasian disparities in colorectal cancer mortality and survival by data source: an epidemiologic review

Over the past four decades in the United States, there has been a divergent trend in mortality rates between African-Americans and Caucasians with colorectal cancer (CRC). Rates among Caucasians have been steadily declining, whereas rates among African-Americans have only started a gradual decline in recent years. We reviewed epidemiologic studies of CRC racial disparities between African-Americans and Caucasians, including studies from SEER and population-based cancer registries, Veterans Affairs (VA) databases, healthcare coverage databases, and university and other medical center data sources. Elevated overall and stage-specific risks of CRC mortality and shorter survival for African-Americans compared with Caucasians were reported across all data sources. The magnitude of racial disparities varied across study groups, with the strongest associations observed in university and non-VA hospital-based medical center studies, while an attenuated discrepancy was found in VA database studies. An advanced stage of disease at the time of diagnosis among African-Americans is a major contributing factor to the racial disparity in survival. Several studies, however, have shown that an increased risk of CRC death among African-Americans remains even after controlling for tumor stage at diagnosis, socioeconomic factors, and co-morbidity. Despite advances in treatment, improvements in the standard of care, and increased screening options, racial differences persist in CRC mortality and survival. Therefore, continued research efforts are necessary to disentangle the clinical, social, biological, and environmental factors that constitute the racial disparity. In addition, results across data sources should be considered when evaluating racial differences in cancer outcomes.

Poor survival for US Pacific Islander cancer patients: evidence from the Surveillance, Epidemiology, and End Results database: 1991 to 2004

PURPOSE

Although racial and ethnic differences in cancer survival in the United States have been studied extensively, little is known about cancer survival in US Pacific Islanders (PIs), a fast-growing and economically disadvantaged minority group.

METHODS

Using data from the US National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) registries, we compared cause-specific and all-cause survival for female breast, prostate, lung, colorectal, stomach and liver cancer for Native Hawaiians, Samoans, other PIs (including Tongans, Guamanians, and others), African Americans, and Native Americans with non-Hispanic whites using Cox proportional hazards models. Separate models were fitted adjusting for demographic factors only and demographic and disease severity variables.

RESULTS

Among all groups, Samoans were the most likely to present with advanced disease and had the worst cause-specific survival for all sites considered. Samoans had particularly poor results (adjusted for demographic variables only) for female breast (relative risk [RR] = 3.05; 95% CI, 2.31 to 4.02), colorectal (RR = 1.82; 95% CI, 1.37 to 2.41) and prostate (RR = 4.82; 95% CI, 3.38 to 6.88) cancers. Native Hawaiians and other PIs also had significantly worse cause-specific survival than did non-Hispanic whites for most sites, but generally had better survival than African Americans or Native Americans.

CONCLUSION

Much of the survival disadvantage for PI groups appears to be a result of late diagnosis, and thus targeted interventions have much potential to reduce cancer mortality in this group. More research is needed to find explanations for the particularly poor cancer survival for Samoans in the United States.

Longitudinal, population-based study of racial/ethnic differences in colorectal cancer survival: impact of neighborhood socioeconomic status, treatment and comorbidity

Background

Colorectal cancer, if detected early, has greater than 90% 5-year survival. However, survival has been shown to vary across racial/ethnic groups in the United States, despite the availability of early detection methods.

Methods

This study evaluated the joint effects of sociodemographic factors, tumor characteristics, census-based socioeconomic status (SES), treatment, and comorbidities on survival after colorectal cancer among and within racial/ethnic groups, using the SEER-Medicare database for patients diagnosed in 1992–1996, and followed through 1999.

Results

Unadjusted colorectal cancer-specific mortality rates were higher among Blacks and Hispanic males than whites (relative rates (95% confidence intervals) = 1.34 (1.26–1.42) and 1.16 (1.04–1.29), respectively), and lower among Japanese (0.78 (0.70–0.88)). These patterns were evident for all-cause mortality, although the magnitude of the disparity was larger for colorectal cancer mortality. Adjustment for stage accounted for the higher rate among Hispanic males and most of the lower rate among Japanese. Among Blacks, stage and SES accounted for about half of the higher rate relative to Whites, and within stage III colon and stages II/III rectal cancer, SES completely accounted for the small differentials in survival between Blacks and Whites. Comorbidity did not appear to explain the Black-White differentials in colorectal-specific nor all-cause mortality, beyond stage, and treatment (surgery, radiation, chemotherapy) explained a very small proportion of the Black-White difference. The fully-adjusted relative mortality rates comparing Blacks to Whites was 1.14 (1.09–1.20) for all-cause mortality and 1.21 (1.14–1.29) for colorectal cancer specific mortality. The sociodemographic, tumor, and treatment characteristics also had different impacts on mortality within racial/ethnic groups.

Conclusion

In this comprehensive analysis, race/ethnic-specific models revealed differential effects of covariates on survival after colorectal cancer within each group, suggesting that different strategies may be necessary to improve survival in each group. Among Blacks, half of the differential in survival after colorectal cancer was primarily attributable to stage and SES, but differences in survival between Blacks and Whites remain unexplained with the data available in this comprehensive, population-based, analysis.

Comparison of characteristics and survival of colorectal cancer between Japanese-Americans in Hawaii and native Japanese in Japan

PURPOSE

This study was designed to investigate whether characteristics, prognostic risk factors, and survival of colorectal cancer of Japanese-Americans in Hawaii are different from those of native Japanese in Japan.

METHODS

A retrospective review of patients with colorectal cancer surgically resected in single institutions in Hawaii and Japan from 1996 to 2002.

RESULTS

A total of 410 Japanese-American patients (218 males; median age, 73 years) and 621 native Japanese patients (382 males; median age, 65 years) were included. There were significant differences in age (P < 0.001), age distribution (P < 0.001), gender (P = 0.008), preoperative carcinoembryonic antigen (P < 0.001), and anatomic site distribution (P < 0.001). The tumor characteristics of Japanese-American patients were close to the general American population compared with the Surveillance, Epidemiology, and End Results data. There were no differences in tumor size, histologic grade, each of T, N, M status and TNM stage between the two groups. The overall five-year survival rates (Japanese-Americans, 75.5 percent; native Japanese, 76.2 percent; P = 0.55) and survival rates in each of four stratified stages were similar. Risk factors associated with survival were not different, except for carcinoembryonic antigen (P = 0.036).

CONCLUSIONS

In patients with colorectal cancer in Japanese-Americans in Hawaii, some of tumor characteristics have changed from those of native Japanese in Japan. However, there are no remarkable differences in prognostic factors and survival between the two groups. The present study suggests that certain changes of colorectal cancer characteristics that were seen in Japanese-American may occur in native Japanese in Japan in the near future, although the survival outcome of colorectal cancer may remain the same.

The MTHFR C677T polymorphism and colorectal cancer: the multiethnic cohort study

Methylenetetrahydrofolate reductase (MTHFR) is a key regulatory enzyme in the metabolism of folate, a nutrient that has been inversely related to colorectal cancer risk. The common C677T variant in the MTHFR gene results in a reduced activity of this enzyme, thereby increasing the availability of folate for the production of thymidylate and purine for DNA synthesis and repair. We investigated the association of the 677TT genotype with colorectal cancer in a case-control study of 822 cases and 2,021 controls nested within the Multiethnic Cohort Study. The Multiethnic Cohort Study is a large prospective study of men and women of Japanese, White, African American, Latino, and Native Hawaiian origin, residing in Hawaii and Los Angeles. After adjusting for covariates, we found an inverse association between colorectal cancer risk and the TT genotype, with odds ratios (OR; and 95% confidence intervals) for the CC, CT, and TT genotypes of 1.00, 1.01 (0.84-1.21), and 0.77 (0.58-1.03), respectively. This association was similar in both sexes, stronger at high levels of folate intake, and limited to light and nondrinkers (P for interaction with ethanol = 0.02). An analysis by subsite (rectum versus colon) and stage (regional/distant versus in situ/localized) showed that the inverse association with the TT genotype was limited to colon tumors, especially those diagnosed at an advanced stage. The OR for the TT versus CC genotype for early- and late-stage colon cancer was 0.88 (0.58-1.33) and 0.52 (0.32-0.85), respectively (P for difference in OR = 0.04). The frequency of the T allele was relatively low in African Americans (0.13) and Native Hawaiians (0.22), consistent with their greater likelihood of presenting at a late stage when diagnosed with colorectal cancer. This study corroborates previous findings of an inverse association of the MTHFR 677TT genotype with colorectal cancer, especially at high levels of folate and low levels of ethanol intake. It also suggests that this effect may be specific to advanced colon cancer.

Cancer Surveillance Research: a Vital Subdiscipline of Cancer Epidemiology

Public health surveillance systems relevant to cancer, centered around population-based cancer registration, have produced extensive, high-quality data for evaluating the cancer burden. However, these resources are underutilized by the epidemiology community due, we postulate, to under-appreciation of their scope and of the methods and software for using them. To remedy these misperceptions, this paper defines cancer surveillance research, reviews selected prior contributions, describes current resources, and presents challenges to and recommendations for advancing the field. Cancer surveillance research, in which systematically collected patient and population data are analyzed to examine and test hypotheses about cancer predictors, incidence, and outcomes in geographically defined populations over time, has produced not only cancer statistics and etiologic hypotheses but also information for public health education and for cancer prevention and control. Data on cancer patients are now available for all US states and, within SEER, since 1973, and have been enhanced by linkage to other population-based resources. Appropriate statistical methods and sophisticated interactive analytic software are readily available. Yet, publication of papers, funding opportunities, and professional training for cancer surveillance research remain inadequate. Improvement is necessary in these realms to permit cancer surveillance research to realize its potential in resolving the growing cancer burden.

Differences in colorectal carcinoma stage and survival by race and ethnicity

BACKGROUND

In the United States, blacks with colorectal carcinoma (CRC) presented with more advanced-stage disease and had higher mortality rates compared with non-Hispanic whites. Data regarding other races/ethnicities were limited, especially for Asian/Pacific Islander and Hispanic white subgroups.

METHODS

Using data from 11 population-based cancer registries that participate in the Surveillance, Epidemiology and End Results program, the authors evaluated the relation among 18 different races/ethnicities and disease stage and mortality rates among 154,103 subjects diagnosed with CRC from 1988 to 2000.

RESULTS

Compared with non-Hispanic whites, blacks, American Indians, Chinese, Filipinos, Koreans, Hawaiians, Mexicans, South/Central Americans, and Puerto Ricans were 10-60% more likely to be diagnosed with Stage III or IV CRC. Alternatively, Japanese had a 20% lower risk of advanced-stage CRC. With respect to mortality rates, blacks, American Indians, Hawaiians, and Mexicans had a 20-30% greater risk of mortality, whereas Chinese, Japanese, and Indians/Pakistanis had a 10-40 % lower risk.

CONCLUSIONS

The authors observed numerous racial/ethnic disparities in the risks of advanced-stage cancer and mortality among patients with CRC, and there was considerable variation in these risks across Asian/Pacific Islander and Hispanic white subgroups. Although the etiology of these disparities was multifactorial, developing screening and treatment programs that target racial/ethnic populations with elevated risks of poor CRC outcomes may be an important means of reducing these disparities.

Hepatitis B and alcohol affect survival of hepatocellular carcinoma patients

AIM: In the USA, Hawaii has the highest incidence of hepatocellular carcinoma (HCC) and a diverse population. It is an ideal place to characterize HCC in the context of ethnicity/risk factors.

METHODS: A total of 262 cases of HCC (1992-2003) were retrospectively reviewed for demographics, ethnicity, birthplace, viral hepatitis, alcohol use, diabetes, smoking and risk factors for viral hepatitis such as intravenous drug abuse (IVDA), transfusions, tattoos and vertical transmission. Tumor stage, Child’s class, Cancer of the Liver Italian Program (CLIP) score, α-fetoprotein level, treatment and survival were recorded.

RESULTS: Gender, age, viral hepatitis, alcohol, IVDA, and diabetes differed significantly in Asians, non-Asians and Pacific Islanders. There were also specific differences within Asian subgroups. Alpha-fetoprotein, smoking, transfusions, stage and resectability did not differ between groups. Asians were more likely to have hepatitis B, while non-Asians were more likely to have hepatitis C. Factors that decreased survival included hepatitis B, alcohol, elevated alpha-fetoprotein, CLIP >2 and increased Child’s class. When Asians were combined with Pacific Islanders, median survival (1.52 years vs 3.54 years), 1- and 3-year survival was significantly worse than those for non-Asians. After Cox regression analysis for hepatitis B and alcohol, there was no difference in survival by ethnicity.

CONCLUSION: Various ethnicities have different risk factors for HCC. Hepatitis B, alcohol, and α-fetoprotein are more important factors for survival than ethnicity.