Approaches to developing de novo cancer population models to examine questions about cancer and race in bladder, gastric, and endometrial cancer and multiple myeloma: the Cancer Intervention and Surveillance Modeling Network incubator program.

BACKGROUND: We are developing 10 de novo population-level mathematical models in 4 malignancies (multiple myeloma and bladder, gastric, and uterine cancers). Each of these sites has documented disparities in outcome that are believed to be downstream effects of systemic racism. METHODS: Ten models are being independently developed as part of the Cancer Intervention and Surveillance Modeling Network incubator program. These models simulate trends in cancer incidence, early diagnosis, treatment, and mortality for the general population and are stratified by racial subgroup. Model inputs are based on large population datasets, clinical trials, and observational studies. Some core parameters are shared, and other parameters are model specific. All models are microsimulation models that use self-reported race to stratify model inputs. They can simulate the distribution of relevant risk factors (eg, smoking, obesity) and insurance status (for multiple myeloma and uterine cancer) in US birth cohorts and population. DISCUSSION: The models aim to refine approaches in prevention, detection, and management of 4 cancers given uncertainties and constraints. They will help explore whether the observed racial disparities are explainable by inequities, assess the effects of existing and potential cancer prevention and control policies on health equity and disparities, and identify policies that balance efficiency and fairness in decreasing cancer mortality.

A metabolomic investigation of serum perfluorooctane sulfonate and perfluorooctanoate.

BACKGROUND: Exposures to perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), environmentally persistent chemicals detectable in the blood of most Americans, have been associated with several health outcomes. To offer insight into their possible biologic effects, we evaluated the metabolomic correlates of circulating PFOS and PFOA among 3,647 participants in eight nested case-control serum metabolomic profiling studies from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. METHODS: Metabolomic profiling was conducted by Metabolon Inc., using ultra high-performance liquid chromatography/tandem accurate mass spectrometry. We conducted study-specific multivariable linear regression analyses estimating the associations of metabolite levels with levels of PFOS or PFOA. For metabolites measured in at least 3 of 8 nested case-control studies, random effects meta-analysis was used to summarize study-specific results (1,038 metabolites in PFOS analyses and 1,100 in PFOA analyses). RESULTS: The meta-analysis identified 51 and 38 metabolites associated with PFOS and PFOA, respectively, at a Bonferroni-corrected significance level (4.8x10-5 and 4.6x10-5, respectively). For both PFOS and PFOA, the most common types of associated metabolites were lipids (sphingolipids, fatty acid metabolites) and xenobiotics (xanthine metabolites, chemicals). Positive associations were commonly observed with lipid metabolites sphingomyelin (d18:1/18:0) (P = 2.0x10-10 and 2.0x10-8, respectively), 3-carboxy-4-methyl-5-pentyl-2-furanpropionate (P = 2.7x10-15, 1.1x10-17), and lignoceroylcarnitine (C24) (P = 2.6x10-8, 6.2x10-6). The strongest positive associations were observed for chemicals 3,5-dichloro-2,6-dihydroxybenzoic acid (P = 3.0x10-112 and 6.8x10-13, respectively) and 3-bromo-5-chloro-2,6-dihydroxybenzoic acid (P = 1.6x10-14, 2.3x10-6). Other metabolites positively associated with PFOS included D-glucose (carbohydrate), carotene diol (vitamin A metabolism), and L-alpha-aminobutyric acid (glutathione metabolism), while uric acid (purine metabolite) was positively associated with PFOA. PFOS associations were consistent even after adjusting for PFOA as a covariate, while PFOA associations were greatly attenuated with PFOS adjustment. CONCLUSIONS: In this large metabolomic study, we observed robust positive associations with PFOS for several molecules. Further investigation of these metabolites may offer insight into PFOS-related biologic effects.

Cancer beliefs and screening behaviors: The impact of neighborhood and other social determinants of health.

Background: Beliefs about cancer influence breast and colorectal cancer (CRC) screening behavior. Screening rates for these cancers differ in the contiguous neighborhoods of East Harlem (EH), Central Harlem (CH), and the Upper East Side (UES), which have distinct socio-demographic compositions. We assessed the belief-screening behavior relationship in these neighborhoods. Methods: The 2019 Community Cancer Needs Survey included adults eligible for breast and/or colorectal cancer screening. Raking was used to generate neighborhood-specific distribution estimates. Categorical variables were compared using Chi-square tests. Stepwise logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) for the association between cancer beliefs and screening. Results: Our weighted sample included 147,726 respondents. Screening was 75% in CH, 81% in EH, and 90% in the UES for breast cancer, and 71%, 76%, and 92% for CRC, respectively. The fatalistic belief "There's not much you can do to lower your chances of getting cancer" differed by neighborhood with screening more likely in CH respondents (breast OR =1.45 and colorectal OR =1.11), but less likely in EH (OR= 0.77 and 0.37, respectively). UES ORs were not generated due to too few unscreened respondents. Conclusions: Cancer beliefs were inconsistently associated with breast and CRC screening across three NYC neighborhoods. This suggests that a given belief may either motivate or deter screening, depending upon context or interpretation. Once access is addressed, efforts seeking to enhance screening rates should consider implications of communities' varying beliefs.

Undue burden: Black faculty, COVID-19, and the racial justice movement.

A crucial reckoning was initiated when the COVID-19 pandemic began to expose and intensify long-standing racial/ethnic health inequities, all while various sectors of society pursued racial justice reform. As a result, there has been a contextual shift towards broader recognition of systemic racism, and not race, as the shared foundational driver of both societal maladies. This confluence of issues is of particular relevance to Black populations disproportionately affected by the pandemic and racial injustice. In response, institutions have initiated diversity, equity, and inclusion (DEI) efforts as a way forward. This article considers how the dual pandemic climate of COVID-19-related health inequities and the racial justice movement could exacerbate the "time and effort tax" on Black faculty to engage in DEI efforts in academia and biomedicine. We discuss the impact of this "tax" on career advancement and well-being, and introduce an operational framework for considering the interconnected influence of systemic racism, the dual pandemics, and DEI work on the experience of Black faculty. If not meaningfully addressed, the "time and effort tax" could contribute to Black and other underrepresented minority faculty leaving academia and biomedicine - consequently, the very diversity, equity, and inclusion work meant to increase representation could decrease it.

The influence of racial-ethnic discrimination on women's health care outcomes: A mixed methods systematic review.

BACKGROUND: In the U.S, a wide body of evidence has documented significant racial-ethnic disparities in women's health, and growing attention has focused on discrimination in health care as an underlying cause. Yet, there are knowledge gaps on how experiences of racial-ethnic health care discrimination across the life course influence the health of women of color. Our objective was to summarize existing literature on the impact of racial-ethnic health care discrimination on health care outcomes for women of color to examine multiple health care areas encountered across the life course. METHODS: We systematically searched three databases and conducted study screening, data extraction, and quality assessment. We included quantitative and qualitative peer-reviewed literature on racial-ethnic health care discrimination towards women of color, focusing on studies that measured patient-perceived discrimination or differential treatment resulting from implicit provider bias. Results were summarized through narrative synthesis. RESULTS: In total, 84 articles were included spanning different health care domains, such as perinatal and cancer care. Qualitative studies demonstrated the existence of racial-ethnic discrimination across care domains. Most quantitative studies reported a mix of positive and null associations between discrimination and adverse health care outcomes, with variation by the type of health care outcome. For instance, over three-quarters of the studies exploring associations between discrimination/bias and health care-related behaviors or beliefs found significant associations, whereas around two-thirds of the studies on clinical interventions found no significant associations. CONCLUSIONS: This review shows substantial evidence on the existence of racial-ethnic discrimination in health care and its impact on women of color in the U.S. However, the evidence on how this phenomenon influences health care outcomes varies in strength by the type of outcome investigated. High-quality, targeted research using validated measures that is grounded in theoretical frameworks on racism is needed. This systematic review was registered [PROSPERO ID: CRD42018105448].

Prediagnostic Serum Vitamin D, Vitamin D Binding Protein Isoforms, and Cancer Survival.

BACKGROUND: Higher circulating vitamin D has been associated with improved overall cancer survival, but data for organ-specific cancers are mixed. METHODS: We examined the association between prediagnostic serum 25-hydroxyvitamin D [25(OH)D], the recognized biomarker of vitamin D status, and cancer survival in 4038 men and women diagnosed with 1 of 11 malignancies during 22 years of follow-up (median = 15.6 years) within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Multivariable-adjusted proportional hazards regression estimated hazard ratios (HR) and 95% confidence intervals (CI) for associations between baseline 25(OH)D concentration and subsequent cancer survival; we also stratified on the common vitamin D binding protein isoforms (Gc1f, Gc1s, and Gc2) defined by two single-nucleotide polymorphisms (rs7041 and rs4588) in the vitamin D binding protein gene GC. All P values were 2-sided. RESULTS: Higher 25(OH)D concentrations were associated with greater overall cancer survival (HR for cancer mortality = 0.83, 95% CI = 0.70 to 0.98 for highest vs lowest quintile; Ptrend = .05) and lung cancer survival (HR = 0.63, 95% CI = 0.44 to 0.90; Ptrend = .03). These associations were limited to cases expressing the Gc2 isoform (HR = 0.38 for Gc2-2, 95% CI = 0.14 to 1.05 for highest vs lowest quintile; Ptrend = .02; and HR = 0.30 for Gc1-2/Gc2-2 combined, 95% CI = 0.16 to 0.56; Ptrend < .001 for overall and lung cancer, respectively). CONCLUSIONS: Higher circulating 25(OH)D was associated with improved overall and lung cancer survival. As this was especially evident among cases with the genetically determined Gc2 isoform of vitamin D binding protein, such individuals may gain a cancer survival advantage by maintaining higher 25(OH)D blood concentrations.

The associations of anthropometric, behavioural and sociodemographic factors with circulating concentrations of IGF-I, IGF-II, IGFBP-1, IGFBP-2 and IGFBP-3 in a pooled analysis of 16,024 men from 22 studies.

Insulin-like growth factors (IGFs) and insulin-like growth factor binding proteins (IGFBPs) have been implicated in the aetiology of several cancers. To better understand whether anthropometric, behavioural and sociodemographic factors may play a role in cancer risk via IGF signalling, we examined the cross-sectional associations of these exposures with circulating concentrations of IGFs (IGF-I and IGF-II) and IGFBPs (IGFBP-1, IGFBP-2 and IGFBP-3). The Endogenous Hormones, Nutritional Biomarkers and Prostate Cancer Collaborative Group dataset includes individual participant data from 16,024 male controls (i.e. without prostate cancer) aged 22-89 years from 22 prospective studies. Geometric means of protein concentrations were estimated using analysis of variance, adjusted for relevant covariates. Older age was associated with higher concentrations of IGFBP-1 and IGFBP-2 and lower concentrations of IGF-I, IGF-II and IGFBP-3. Higher body mass index was associated with lower concentrations of IGFBP-1 and IGFBP-2. Taller height was associated with higher concentrations of IGF-I and IGFBP-3 and lower concentrations of IGFBP-1. Smokers had higher concentrations of IGFBP-1 and IGFBP-2 and lower concentrations of IGFBP-3 than nonsmokers. Higher alcohol consumption was associated with higher concentrations of IGF-II and lower concentrations of IGF-I and IGFBP-2. African Americans had lower concentrations of IGF-II, IGFBP-1, IGFBP-2 and IGFBP-3 and Hispanics had lower IGF-I, IGF-II and IGFBP-3 than non-Hispanic whites. These findings indicate that a range of anthropometric, behavioural and sociodemographic factors are associated with circulating concentrations of IGFs and IGFBPs in men, which will lead to a greater understanding of the mechanisms through which these factors influence cancer risk.

Concordance of cancer registry and self-reported race, ethnicity, and cancer type: a report from the American Cancer Society's studies of cancer survivors.

PURPOSE: To examine the concordance between cancer registry and self-reported data for race, Hispanic ethnicity, and cancer type in the American Cancer Society's Studies of Cancer Survivors (SCS) I and II. METHODS: We calculated sensitivity, specificity, positive predictive value, and Kappa statistics for SCS-I and II. The gold standard for cancer type was registry data and for race and ethnicity was self-reported questionnaire data. RESULTS: Among 6,306 survivors in SCS-I and 9,170 in SCS-II, overall agreement (Kappa) for cancer type was 0.98 and 0.99, respectively. Concordance was strongest for breast and prostate cancer (Sensitivity ≥ 0.98 in SCS-I and II). For race, Kappa was 0.85 (SCS-I) and 0.93 (SCS-II), with strong concordance for white (Sensitivity = 0.95 in SCS-I and 0.99 in SCS-II) and black survivors (Sensitivity = 0.94 in SCS-I and 0.99 in SCS-II), but weak concordance for American Indian/Alaska Native (Sensitivity = 0.23 in SCS-I and 0.19 in SCS-II) and Asian/Pacific Islander survivors (Sensitivity = 0.43 in SCS-I and 0.87 in SCS-II). Agreement was moderate for Hispanic ethnicity (Kappa = 0.73 and 0.71; Sensitivity = 0.74 and 0.76, in SCS-I and SCS-II, respectively). CONCLUSIONS: We observed strong concordance between cancer registry data and self-report for cancer type in this national sample. For race and ethnicity, however, concordance varied significantly, with the poorest concordances observed for American Indian/Alaska Native and Asian/Pacific Islander survivors. Ensuring accurate recording of race/ethnicity data in registries is crucial for monitoring cancer trends and addressing cancer disparities among cancer survivors.

A Collaborative Analysis of Individual Participant Data from 19 Prospective Studies Assesses Circulating Vitamin D and Prostate Cancer Risk.

Previous prospective studies assessing the relationship between circulating concentrations of vitamin D and prostate cancer risk have shown inconclusive results, particularly for risk of aggressive disease. In this study, we examine the association between prediagnostic concentrations of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D] and the risk of prostate cancer overall and by tumor characteristics. Principal investigators of 19 prospective studies provided individual participant data on circulating 25(OH)D and 1,25(OH)2D for up to 13,462 men with incident prostate cancer and 20,261 control participants. ORs for prostate cancer by study-specific fifths of season-standardized vitamin D concentration were estimated using multivariable-adjusted conditional logistic regression. 25(OH)D concentration was positively associated with risk for total prostate cancer (multivariable-adjusted OR comparing highest vs. lowest study-specific fifth was 1.22; 95% confidence interval, 1.13-1.31; P trend < 0.001). However, this association varied by disease aggressiveness (P heterogeneity = 0.014); higher circulating 25(OH)D was associated with a higher risk of nonaggressive disease (OR per 80 percentile increase = 1.24, 1.13-1.36) but not with aggressive disease (defined as stage 4, metastases, or prostate cancer death, 0.95, 0.78-1.15). 1,25(OH)2D concentration was not associated with risk for prostate cancer overall or by tumor characteristics. The absence of an association of vitamin D with aggressive disease does not support the hypothesis that vitamin D deficiency increases prostate cancer risk. Rather, the association of high circulating 25(OH)D concentration with a higher risk of nonaggressive prostate cancer may be influenced by detection bias. SIGNIFICANCE: This international collaboration comprises the largest prospective study on blood vitamin D and prostate cancer risk and shows no association with aggressive disease but some evidence of a higher risk of nonaggressive disease.

Prostate cancer risk factors in black and white men in the NIH-AARP Diet and Health Study.

BACKGROUND: There are few prospective studies comparing race-specific associations between diet, nutrients, and health-related parameters, and prostate cancer risk. METHODS: Race-specific prostate cancer risk associations were examined among men in the National Institutes of Health (NIH)-AARP Diet and Health Study. We identified 1417 cases among black men (209 advanced), and 28,845 among white men (3898 advanced). Cox proportional hazards regression models estimated hazard ratios (HRs) and 95% confidence intervals (CIs). We also evaluated the cumulative change in the HR for black race following adjustment for each factor. RESULTS: Race-specific prostate cancer associations were similar in black and white men across disease subtypes only for history of diabetes (overall : HR = 0.77, 95% CI: 0.65-0.90 and HR = 0.72, 95% CI: 0.69-0.76, respectively; Pinteraction = 0.66). By contrast, there was a positive risk association with height for white men  and  inverse for black men (Pinteraction: non-advanced = 0.01; advanced = 0.04). This difference remained among men with at least 2 years of follow-up for non-advanced (Pinteraction = 0.01), but not advanced disease (Pinteraction = 0.24); or after adjustment for prostate cancer screening (non-advanced Pinteraction = 0.53, advanced Pinteraction = 0.31). The only other evidence of interaction with race was observed for dietary vitamin D intake and non-advanced disease, but only after adjustment for screening (Pinteraction = 0.02). Cumulative adjustment for each factor increased the HR for black race by 32.9% for overall cancer and 12.4% for advanced disease. CONCLUSIONS: Our data suggest few of the dietary, nutrient, and health-related factors associated with prostate cancer risk in predominantly non-Hispanic white men were associated with risk in black men, and adjustment for these factors widen the black-white difference in risk. Larger studies of black men, particularly with prospective data, are needed to help identify risk factors relevant to this population.

Circulating 25-hydroxyvitamin D up to 3 decades prior to diagnosis in relation to overall and organ-specific cancer survival.

While vitamin D has been associated with improved overall cancer survival in some investigations, few have prospectively evaluated organ-specific survival. We examined the accepted biomarker of vitamin D status, serum 25-hydroxyvitamin D [25(OH)D], and cancer survival in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Of 4616 cancer cases with measured serum 25(OH)D, 2884 died of their cancer during 28 years of follow-up and 1732 survived or died of other causes. Proportional hazards regression estimated hazard ratios (HR) and 95% confidence intervals (CI) for the association between pre-diagnostic 25(OH)D and overall and site-specific survival. Serum 25(OH)D was significantly lower among cases who subsequently died from their malignancy compared with those who did not (medians 34.7 vs. 36.5 nmol/L, respectively; p = 0.01). Higher 25(OH)D was associated with lower overall cancer mortality (HR = 0.76, 95% CI 0.67-0.85 for highest vs. lowest quintile, p-trend < 0.0001). Higher 25(OH)D was related to lower mortality from the following site-specific malignancies: prostate (HR = 0.74, 95% CI 0.55-1.01, p-trend = 0.005), kidney (HR = 0.59, 95% CI 0.35-0.98, p-trend = 0.28), and melanoma (HR = 0.39, 95% CI 0.20-0.78, p-trend = 0.01), but increased mortality from lung cancer (HR = 1.28, 95% CI 1.02-1.61, p-trend = 0.19). Improved survival was also suggested for head and neck, gastric, pancreatic, and liver cancers, though not statistically significantly, and case numbers for the latter two organ sites were small. Higher 25(OH)D status years prior to diagnosis was related to improved survival for overall and some site-specific cancers, associations that should be examined in other prospective populations that include women and other racial-ethnic groups.

Quality Of Breast Cancer Care In The US Territories: Insights From Medicare.

The quality of breast cancer care among Medicare beneficiaries in the US territories-where federal spending for health care is lower than in the continental US-is unknown. We compared female Medicare beneficiaries who were residents of the US territories and had surgical treatment for breast cancer in 2008-14 to those in the continental US in terms of receipt of recommended breast cancer care (diagnostic needle biopsy and adjuvant radiation therapy [RT] following breast-conserving surgery) and the timeliness (time from needle biopsy to surgery and from surgery to adjuvant RT) of that care. Residents of the US territories were less likely to receive recommended care (24 percent lower odds of receiving diagnostic needle biopsy and 34 percent lower odds of receiving adjuvant RT) and to receive timely care (45 percent lower odds of receiving surgery and 82 percent lower odds of receiving adjuvant RT, both within three months). Further research is needed to identify barriers to the provision of adequate and timely breast cancer care in this unique population.

Vitamin D and Cancer Risk and Mortality: State of the Science, Gaps, and Challenges.

There has been substantial enthusiasm recently regarding the potential role of vitamin D in the primary and secondary prevention of cancer. Laboratory studies demonstrate a range of anticarcinogenic effects for vitamin D compounds, but human studies have yielded little consistent evidence supporting a protective association. Higher circulating levels of vitamin D (i.e., 25-hydroxyvitamin D or 25(OH)D) appear to be associated with reduced risk of colorectal and bladder malignancies, but higher risk of prostate and possibly pancreatic cancers, with no clear association for most other organ sites examined. Despite there being no official institutional recommendations regarding the use of vitamin D supplements for cancer prevention, screenings for vitamin D deficiency and vitamin D supplement use have increased substantially over the past decade. These widespread practices demonstrate that population sociobehavioral changes are often adopted before scientifically well-informed policies and recommendations are available. This review critically examines the currently available epidemiologic literature regarding the associations between circulating 25(OH)D, vitamin D supplementation, and vitamin D-related genetic variation and cancer risk and mortality, with a particular emphasis on prospective studies. We identify several important gaps in our scientific knowledge that should be addressed in order to provide sufficient reproducible data to inform evidence-based recommendations related to optimal 25(OH)D concentrations (and any role for vitamin D supplementation) for the primary and secondary prevention of cancer. With few exceptions, such recommendations cannot be made at this time.

Serum 25-hydroxyvitamin D, vitamin D binding protein, and prostate cancer risk in black men.

BACKGROUND: Few studies have prospectively examined the relationship between vitamin D status and prostate cancer risk in black men, a group at high risk for both low vitamin D status and prostate cancer. METHODS: Among black men in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, we identified 226 prostate cancer cases and 452 controls matched on age at randomization (±5 years), date of blood draw (±30 days), calendar year of cohort entry, and time since baseline prostate cancer screening (±1 year). Conditional logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between serum 25-hydroxyvitamin D [25(OH)D], vitamin D binding protein (DBP), the 25(OH)D:DBP molar ratio, and prostate cancer risk. RESULTS: Serum 25(OH)D was not associated with overall prostate cancer (Q4 vs Q1: OR, 0.73; 95% CI, 0.40-1.33; P for trend = .25), although there were apparent inverse associations for nonaggressive disease (global P = .03, clinical stage I/II, and Gleason score <7) and among men ≥62 years old (P for interaction = .04) that were restricted to Q3. Interestingly, serum DBP was significantly inversely associated with prostate cancer risk (Q4 vs Q1: OR, 0.45; 95% CI, 0.20-1.00; P for trend = .03), whereas the 25(OH)D:DBP molar ratio was not. Results were similar when we mutually adjusted for 25(OH)D and DBP, and we found no evidence of interaction between the two. CONCLUSION: Our study suggests higher (versus lower) circulating DBP may be independently associated with a decreased prostate cancer risk in black men independent of 25(OH)D status. Cancer 2017;123:2698-704. © 2017 American Cancer Society.

Survivorship care plans in research and practice.

The Institute of Medicine (IOM) recommends the use of survivorship care plans (SCPs) for all cancer survivors. Developing useful SCPs requires understanding what survivors and their providers need and how SCPs can be implemented in practice. Published studies investigating the perspectives of stakeholders (survivors, primary care providers, and oncology providers) were reviewed regarding the content and use of SCPs. All National Cancer Institute (NCI)-designated cancer centers were surveyed concerning the extent to which SCPs for survivors of breast and colorectal cancers are in use, their concordance with the IOM's recommendation, and details about SCP delivery. Survivors and primary care providers typically lack the information the IOM suggested should be included in SCPs. Oncology providers view SCPs favorably but express concerns about the feasibility of their implementation. Fewer than one-half (43%) of NCI-designated cancer centers deliver SCPs to their breast or colorectal cancer survivors. Of those that do, none deliver SCPs that include all components recommended by the IOM. Survivors' and providers' opinions about the use of SCPs are favorable, but there are barriers to implementation. SCPs are not widely used in NCI-designated cancer centers. Variation in practice is substantial, and many components recommended by the IOM framework are rarely included. \

Studying cancer in minorities: a look at the numbers.

BACKGROUND: Inclusion of minorities is an important but challenging aspect of epidemiologic studies in the United States. One aspect of this challenge that has received little attention is the actual number of minorities with specific cancers. The authors aimed to understand how population characteristics affect the numbers of minority cancer cases in Surveillance, Epidemiology, and End Results (SEER) regions. METHODS: By using SEER data, the authors identified 6 cancers with higher incidence rates in racial and ethnic minorities and reviewed the annual number of cases of those cancers in SEER areas where there are large numbers of blacks, Hispanics, and Asians. The authors examined the age characteristics of the populations in SEER areas using data from the US Census. RESULTS: Although there are substantial numbers of cases for the most common cancers with higher incidence in blacks, their numbers are quite small for other cancers, <150 cases, and in many areas, <100 per year. Few registries have substantial numbers of Hispanics or Asians. As expected, the proportion of minority populations is lower in older age groups, whereas the proportion of non-Hispanic whites is larger. CONCLUSIONS: Because of the sharp decline in minority populations associated with age and the high age-specific incidence rates of most cancers, the actual number of minority cases is quite small for several cancers. Thus, the inclusion of minority groups in studies of any but the most common cancers presents a challenge.