Commentary: Race and Ethnicity in Biomedical Research - Classifications, Challenges, and Future Directions

The use of race and ethnicity in biomedical research has been a subject of debate for the past three decades. Initially the two major race categories were: White and Black, leaving other minorities uncounted or inappropriately misclassified. As the science of health disparities evolves, more sophisticated and detailed information has been added to large databases. Despite the addition of new racial classifications, including multi-racial denominations, the quality of the data is limited to the data collection process and other social misconceptions. Although race is viewed as an imposed or ascribed status, ethnicity is an achieved status, making it a more challenging variable to include in biomedical research. Ambiguity between race and ethnicity often exists, ultimately affecting the value of both variables. To better understand specific health outcomes or disparities of groups, it is necessary to collect subgroup-specific data. Cultural perceptions and practices, health experiences, and susceptibility to disease vary greatly among broad racial-ethnic groups and requires the collection of nuanced data to understand. Here, we provide an overview of the classification of race and ethnicity in the United States over time, the existing challenges in using race and ethnicity in biomedical research and future research directions.

Serum free light chain measurements to reduce 24-h urine monitoring in patients with multiple myeloma with measurable urine monoclonal protein

Detection of myeloma progression (PD) relies on serial 24-h urinary M protein measurements in patients without measurable serum M spike. We examined whether serial difference free light chain (dFLC) levels could be used as a surrogate for serial 24-h urine M protein measurements in monitoring for PD in patients with baseline measurable urine M protein. We studied 122 patients who had serial measurement of urine M protein and serum FLC and had demonstrated PD. The median increase in dFLC with progression as defined by urine M spike was 110% (IQR: 55-312) and median absolute increase was 74 mg/dL; while 89% of patients had dFLC increase ≥ 25%, 94% had absolute increase in dFLC > 10 mg/dL, and 98% met at least 1 of these 2 criteria at PD. In patients with baseline measurable serum FLC (n = 118), 89% had increase in dFLC ≥ 25%, 97% had dFLC increase of > 10 mg/dL, and 98% had 1 of the 2. We conclude that serial dFLC assessments can be used in place of serial 24-h urine protein assessments during myeloma surveillance to monitor for PD. Once patients have an absolute increase in dFLC of >10 mg/dL from the nadir, a 24-h urine collection can then be assessed to document PD as per the International Myeloma Working Group criteria.

Abstract A27: Diversity in multiple myeloma clinical trials

Background: Multiple myeloma (MM) accounts for approximately 1% of all cancers and 10% of hematologic malignancies in the United States (U.S.). MM occurs in all races, but the incidence in African Americans is two to three times higher than in non-Hispanic whites. MM is also slightly more frequent in men than women (1.4:1). Many clinical trials lack appropriate representation of specific patient populations, limiting the generalizability of the evidence obtained. Therefore, we determined the representation of ethnic minorities, the elderly, and women in MM clinical trials.

Methods: Enrollment data from all therapeutic trials reported as completed in clinicaltrial.gov from 2000 to 2016 were analyzed. Clinical trials including other hematologic malignancies and with recruitment outside of the U.S. were excluded. Enrollment fraction (EF) was defined as the number of enrollees divided by the 2013 SEER database MM complete prevalence. Chi-square test was used to estimate differences in categorical data.

Results: Out of 177 MM clinical trials (CT), 78 (44%) reported ethnicity with a total of 12,055 enrollees. Regarding enrollees' ethnic composition, 84% were non-Hispanic White (NHW), 8.6% African American (AA), 2.8% Asian, 1.8% Hispanic, and 0.1% Native American/Alaskan Indian. Out of those 78 CT, 52 (66%) were phase II, 15 (19%) phase III, and 11 (14%) phase I. Most of the results were published from 2012 to 2016 (74%). Forty-six (59%) trials were sponsored by industry, 7 (9%) by NCI, and 25 (32%) were investigator initiated. Participation in CT varied significantly across ethnic groups, NHW were more likely to be enrolled in CT (EF of 0.23) than AA (EF of 0.08, p < 0.0001) and Hispanics (EF of 0.05, p< 0.0001). Males had a higher recruitment rate than females (58% vs. 42%), but this could be explained by the higher incidence of MM in males. Enrollees' median age was 62 years. Younger patients (< 65 years) were more likely to be enrolled in CT than the elderly (66% vs. 34%, p<0.0001). Industry-sponsored trials were less likely to recruit AA compared with investigator-initiated trials (7.6% vs. 12%, p<0.01).

Conclusions: Despite the higher incidence of MM in African Americans and the elderly, the former only represented 8.6% of the study participants and 66% of these were less than 65 years of age; therefore, we are lacking data in the tolerability of these new agents in our aging MM population. We also observed that industry studies were less likely to recruit AA patients. Collaborations between investigators, sponsors, and the community are necessary to increase our minority and elderly patients' access to clinical trials.

Citation Format: Narjust Duma, Miguel Gonzalez Velez, Jesus Vera-Aguilera, Richardo Parrondo, Veronica Mariotti, Jonas Paludo, Yucai Wang, Ronald Go, Alex Adjei. Diversity in multiple myeloma clinical trials [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr A27.

Abstract 4230: Influence of sociodemographic factors on treatment decisions in lung cancer

Background: In stage IV non-small cell lung cancer (NSCLC), survival has significantly improved with the use of novel therapies and better supportive care. Despite such trends, it has been noted that patients (pts) frequently refuse cancer treatment. Therefore, we explored the factors associated with treatment refusal in pts with stage IV NSCLC.

Methods: Utilizing the National Cancer Database (NCDB), we identified all incident cases with stage IV NSCLC from 2004 to 2014. Patients who received cancer treatment outside of the reporting facility or died before receiving treatment were excluded. Multivariable logistic regression models were used to determine associations with treatment refusal.

Results: A total of 341,993 pts were identified. On average, 5.4% of pts refused radiation therapy and 10.3% refused chemotherapy despite provider recommendations. The proportion of pts refusing radiation and chemotherapy increased over the study period from 4.2% to 7.3% and 7.9% to 15%, respectively (p<0.001 for both). In multivariable analysis, men were less likely to refuse radiation or chemotherapy compared to women (OR: 0.82, 95%CI: 0.76-0.83, p<0.001; OR: 0.84, 95%CI: 0.81-0.86, p<0.001, respectively). Factors associated with radiation therapy refusal included: Medicaid or Medicare as primary insurance (OR: 1.95, 95%CI: 1.76-2.15, p<0.001; OR: 1.25, 95%CI: 1.17-1.34, p<0.001, respectively) or a >2 Charlson Comorbidity Index (OR: 1.97, 95%CI: 1.85-2.10, p<0.001). Moreover, receiving care at an academic center (OR: 0.57, 95%CI: 0.53-0.62, p<0.001) was associated with less likelihood of refusing radiation. Regarding chemotherapy, uninsured pts (OR: 2.45, 95%CI: 2.26-2.66, p<0.001), pts with Medicaid as primary insurance (OR: 2.17, 95%CI: 2.03-2.32, p<0.001) or with a high comorbidity index (OR: 1.76, 95%CI: 1.68-1.84, p<0.001) were more likely to refuse chemotherapy. Contrary to findings from previous studies, Non-Hispanic Blacks and Hispanics were less likely to refuse chemotherapy compared to non-Hispanic whites (OR: 0.86, 95%CI: 0.82-0.91, p<0.001; OR: 0.78, 95%CI: 0.72-0.89, p<0.001). Patients receiving care at an academic center and residing in high income neighborhoods were less likely to refuse chemotherapy (OR: 0.76, 95%CI: 0.72-0.80, p<0.001; OR: 0.76, 95%CI: 0.71-0.81, p<0.001, respectively). Distance from residence to treating facility and living in a rural county did not affect treatment refusal.

Conclusions: Socioeconomic factors rather than race/ethnicity appear to influence refusal of cancer treatment in pts with stage IV NSCLC in the NCDB. Assessing socioeconomic challenges should be an essential part of patients' evaluation when discussing treatment options.

Citation Format: Narjust Duma, Urshila Durani, Ryan Frank, Jonas Paludo, Gustavo Westin, Yanyan Lou, Leventakos Konstantinos, Julian Molina, Ronald Go, Aaron Mansfield, Sikander Ailawadhi, Alex Adjei. Influence of sociodemographic factors on treatment decisions in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4230.

Representation of Minorities and Elderly Patients in Multiple Myeloma Clinical Trials

Multiple myeloma (MM) occurs in all races, but the incidence in non-Hispanic black patients (NHBs) is two to three times higher than in non-Hispanic white patients (NHWs). We determined the representation of minorities and elderly patients in MM clinical trials. Enrollment data from all therapeutic trials reported in ClinicalTrials.gov from 2000 to 2016 were analyzed. Enrollment fraction (EF) was defined as the number of trial enrollees divided by the 2014 MM prevalence. Participation in MM clinical trials varied significantly across racial and ethnic groups; NHWs were more likely to be enrolled in clinical trials (EF 0.18%) than NHBs (EF 0.06%, p < .0001) and Hispanic patients (EF 0.04%, p < .0001). The median age of trial participants was 62 years, with 7,956 participants (66%) being less than 65 years of age. Collaborations between investigators, sponsors, and the community are necessary to increase access to clinical trials to our minority and elderly patients.

Evolving changes in disease biomarkers and risk of early progression in smoldering multiple myeloma

We studied 190 patients with smoldering multiple myeloma (SMM) at our institution between 1973 and 2014. Evolving change in monoclonal protein level (eMP) was defined as ⩾10% increase in serum monoclonal protein (M) and/or immunoglobulin (Ig) (M/Ig) within the first 6 months of diagnosis (only if M-protein ⩾3 g/dl) and/or ⩾25% increase in M/Ig within the first 12 months, with a minimum required increase of 0.5 g/dl in M-protein and/or 500 mg/dl in Ig. Evolving change in hemoglobin (eHb) was defined as ⩾0.5 g/dl decrease within 12 months of diagnosis. A total of 134 patients (70.5%) progressed to MM over a median follow-up of 10.4 years. On multivariable analysis adjusting for factors known to predict for progression to MM, bone marrow plasma cells ⩾20% (odds ratio (OR)=3.37 (1.30-8.77), P=0.013), eMP (OR=8.20 (3.19-21.05), P<0.001) and eHb (OR=5.86 (2.12-16.21), P=0.001) were independent predictors of progression within 2 years of SMM diagnosis. A risk model comprising these variables was constructed, with median time to progression of 12.3, 5.1, 2.0 and 1.0 years among patients with 0-3 risk factors respectively. The 2-year progression risk was 81.5% in individuals who demonstrated both eMP and eHb, and 90.5% in those with all three risk factors.

Acetyl-L-carnitine (ALCAR) for the prevention of chemotherapy-induced peripheral neuropathy in patients with relapsed or refractory multiple myeloma treated with bortezomib, doxorubicin and low-dose dexamethasone: a study from the Wisconsin Oncology Network

Purpose

Retreatment with bortezomib (B) is often considered for patients with relapsed multiple myeloma (MM), but this strategy is hindered by uncertainty of response and emergence of B-induced peripheral neuropathy (PN). We incorporated acetyl-l-carnitine (ALCAR) to prevent PN and allow for adequate dosing. We also investigated the correlation between B-inducible NF-κB activation and response to therapy.

Methods

Nineteen patients with relapsed/refractory MM received up to 8 cycles of intravenous bortezomib, doxorubicin and oral low-dose dexamethasone (BDD) to evaluate response and toxicity. Thirteen additional patients received prophylactic ALCAR (BDD-A). Patients receiving BDD-A were evaluated by FACT-GOG-TX, FACIT-Fatigue, Neuropathic Pain index (NPI) and Grooved Pegboard (GP) testing. Primary MM cells from 11 patients were tested for B-inducible NF-κB activation.

Results

Seventy-six percent of subjects were refractory to previous treatment, 39 % refractory to bortezomib. Median cycles received were 5. CR + PR for the entire group were 53 % and did not differ between groups. Incidence of ≥3 PN was 32 % in the BDD group versus 15 % in the BDD-A group (p = ns). Patient-reported fatigue and PN measured by FACT-GOG-TX increased throughout the treatment period in the BDD-A group, although time to complete GP testing declined. In a sub-study examining constitutive bortezomib-inducible NF-κB activity in primary subject-specific MM cells, the presence of NF-κB activation correlated with lower likelihood of response.

Conclusions

Addition of ALCAR to BDD did not alter the incidence or severity of PN in relapsed MM patients receiving a B-based regimen. Bortezomib-inducible NF-κB activation in patient-derived primary MM cells may be associated with poorer response.

Long-term disease control in patients with newly diagnosed multiple myeloma after suspension of lenalidomide therapy

There are no systematic data regarding nonmaintained induction for those patients with multiple myeloma (MM) who do not receive consolidative autologous stem cell transplantation. Of 173 patients with newly diagnosed MM treated with lenalidomide and dexamethasone (LenDex) as primary therapy, 31 patients had their lenalidomide discontinued for reasons other than progression or alternate therapy. Median progression free survival (PFS) from the time of discontinuing lenalidomide was longer in patients who received lenalidomide ≥ 1 year (39 vs. 13 months, P < 0.05); there was no difference in PFS for those treated for 1-2 years as compared to ≥ 2 years. Among those taking lenalidomide for ≥ 1 year PFS was superior in patients who were in very good partial response (VGPR) or better as compared to those with partial response (48.4 versus 14.8 months, P < 0.05). All patients who progressed and were rechallenged with LenDex responded. These analyses illustrate that discontinuation of lenalidomide after 1 year among those patients achieving a ≥VGPR can result in long-term disease control.

A new anthraquinone from Morinda citrifolia roots

An investigation of Morinda citrifolia roots afforded a new anthraquinone, 2-ethoxy-1-hydroxyanthraquinone (1), along with five other known anthraquinones: 1-hydroxy-2-methylanthraquinone (2), damnacanthal (3), nordamnacanthal (4), 2-formyl-1-hydroxyanthraquinone (5) and morindone-6-methyl-ether (6). This is the first report on the isolation of morindone-6-methyl-ether (6) from this plant. The structures of these compounds were elucidated based on spectroscopic analyses such as NMR, MS and IR. Biological evaluation of five pure compounds and all the extracts against the larvae of Aedes aegypti indicated 1-hydroxy-2-methylanthraquinone (2) and damnacanthal (3) were the extracts to exhibit promising larvicidal activities.

Cancer in the oldest old population in the United States: Current statistics and projections

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Background: The oldest old, defined as people age ≥ 85 years, in the U.S. is projected to double from 4.3 million in 2000 to 9.6 million in 2030. Since cancer is the number one cause of death, it is critical to assess the current and projected cancer burden in this population. Methods: We obtained data from the Surveillance, Epidemiology and End Results (SEER) program. We included patients who had a previous cancer before age 85, but excluded benign tumors, myeloproliferative, and myelodysplastic neoplasms. Incidence was reported per 100,000 person years and age-adjusted to the 2000 U.S. standard population. For current statistics, we included years 2001–2005. Trend analyses were based on 1973–2005 data. Results: The oldest old represents 7.2% of annual new cancers cases diagnosed and 10.5% of cancer deaths in the U.S. The 10 leading cancers by incidence (both sexes and decreasing order) are colorectal (388.9), lung (287.7), breast (250), prostate (211.5), urinary bladder (162.5), non-Hodgkin lymphoma (110.9), leukemia (85.1), melanoma (65), renal (46.4), and uterine (40.2). The incidences of melanoma, non-Hodgkin lymphoma, renal, and lung cancers are increasing, while those of leukemia, prostate, breast, and colorectal cancers are decreasing. The top 5 causes of cancer deaths are lung and bronchus (21%), colorectal (15%), pancreatic (7.1%), prostate (5.9%), and breast cancers (5.3%). Cancer specific survival (CSS) has been increasing continuously since 1973 for melanoma, non-Hodgkin lymphoma, breast, colorectal, prostate, and urinary bladder cancers but decreasing in recent years for colorectal, breast, prostate, and uterine cancers. CSS for leukemia, lung, renal, and uterine cancers showed no change over time. If the current incidence trends for each cancer continue in a linear fashion, it is projected, using 1973–2005 data, that in 2030, the oldest old will represent 8.8% of annual new cancers cases diagnosed and 13.6% of cancer deaths. Conclusions: Cancer incidence and mortality trends in the oldest old differ from the general population. Because the oldest old are likely to have multiple co-morbid conditions, there is a need to find better ways to diagnose and treat cancers in this unique segment of the population.

No significant financial relationships to disclose.

Compliance to National Comprehensive Cancer Network guidelines in patients with newly diagnosed small cell lung cancer at a community cancer center

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Background: The National Comprehensive Cancer Network (NCCN) provides yearly updated guidelines for the management of patients diagnosed with small cell lung cancer (SCLC). Compliance to clinical guidelines may improve patient care and outcome, but this may vary among institutions. In this study, we determined the compliance of our community cancer center to the NCCN guidelines in patients with SCLC. Methods: We identified patients with newly diagnosed SCLC in 2004 and 2005 using our cancer registry database. Using the NCCN guideline for the corresponding years, we determined the compliance rate for the following phases of cancer care: initial evaluation (pathology review, imaging, smoking cessation counseling, mediastinal staging for T1-T2 limited disease), and treatment (chemotherapy, radiation). Results: There were 39 new patients with SCLC, 14 (35.9%) of which had limited stage disease. The overall compliance rates for initial evaluation and treatment were 33.3%, and 92.3%, respectively. A total of 32 deviations were identified: 21 (65.6%) for neglecting smoking cessation counseling, 7 (21.9%) for not performing recommended imaging, 3 (9.4%) for not giving recommended chemotherapy and/or radiation and 1 (3.1%) for not reviewing outside pathology. In all of the imaging and treatment deviations, there were medically appropriate reasons for doing so: 7 patients with limited disease had PET/CT scan instead of CT/bone scan (PET/CT scan now incorporated into the 2006 guidelines); 2 patients with limited disease did not receive concurrent chemoradiotherapy due to poor performance status and co-morbidity; 1 patient with extensive disease refused chemotherapy. Conclusion: Our compliance with NCCN guidelines for SCLC was poor for initial evaluation, but better for treatment. The primary reasons for this outcome were the lack of a perceived benefit in smoking cessation counseling and the use of PET/CT scanning as the initial imaging modality of choice.

No significant financial relationships to disclose.

Unequal treatment access and malaria risk in a community-based intervention program in the Philippines

This study assesses the influence of several malaria risk factors and volunteer health worker (VHW) accessibility on parasite prevalence and treatment-seeking in a remote area of Mindanao, the Philippines. An anti-malaria program in the area seeks to devolve malaria diagnosis and treatment to the VHWs. Firstly, the relationship between malaria and demographic factors, bednet use, and access to treatment was investigated. Secondly, adults from villages with and without resident VHWs were questioned on historical and proposed treatment-seeking for fever and the capacity of the communities to support more health workers was assessed. Parasite prevalence was significantly higher among patients living in villages lacking a resident VHW (adjusted OR=3.88, p=0.02), where proposed delays in consulting VHWs and the official health service, and the use of alternative medicine, were also significantly higher. Kinship or social closeness to VHWs appears to play a role in accessibility. The educational and economic requirements demanded of VHWs impede potential expansion of the program to non-serviced villages. If the effectiveness and equity of community-based treatment strategies is to be increased, increased flexibility allowing use of local, less-educated, drug dispensers needs to be considered.

Diagnosis of malaria in a remote area of the Philippines: comparison of techniques and their acceptance by health workers and the community

OBJECTIVE

To compare the efficacies of remote symptom-based diagnosis of malaria, rapid diagnostic tests and microscopy in an area of low endemicity in the Philippines.

METHODS

In Trial I, 350 symptomatic patients were tested within their villages using malaria Plasmodium falciparum (Pf)/Plasmodium vivax (Pv) immunochromatographic tests (ICT tests) and blood films stored and read under local conditions. The slides were later restained and read. In Trial II, unsupervised volunteer barangay health workers prepared ICT tests and slides after brief training. These slides were read at rural health units. Twenty-seven barangay health workers and 72 community members were later questioned about the three diagnostic strategies.

FINDINGS

A history of fever alone was sensitive (95.4%) but poorly specific (16.5%) for predicting parasitaemia. The inclusion of other symptoms reduced the sensitivity to below 85%, while specificity remained low. The axillary temperature was poorly predictive. ICT tests achieved high sensitivity (97.9%) but many cases indicated as positive by ICT tests were negative by microscopy. Further analysis of these cases in Trial I indicated that ICT tests were detecting low-level parasitaemias missed by microscopy, and that local microscopy had poor accuracy. ICT tests were well accepted and accurately performed by barangay health workers.

CONCLUSION

These tests meet a strong desire in the community for blood-based diagnosis and may increase the compliance and treatment-seeking behaviour of patients.

No evidence for genetic association or linkage of the cathepsin D (CTSD) exon 2 polymorphism and Alzheimer disease

Two recent case-control studies have suggested a strong association of a missense polymorphism in exon 2 of the cathepsin D gene (CTSD) and Alzheimer disease (AD). However, these findings were not confirmed in another independent study. We analyzed this polymorphism in two large and independent AD study populations and did not detect an association between CTSD and AD. The first sample was family-based and included 436 subjects from 134 sibships discordant for AD that were analyzed using the sibship disequilibrium test (SDT, p = 0.68) and the sib transmission/disequilibrium test (Sib-TDT, p = 0.81). The second sample of 200 AD cases and 182 cognitively normal controls also failed to show significant differences in the allele or genotype distribution in cases versus controls (chi2, p = 0.91 and p = 0.88, respectively). In addition, two-point linkage analyses in an enlarged family sample (n = 670) did not show evidence for linkage of the chromosomal region around CTSD. Thus, our analyses on more than 800 subjects suggest that if an association between the CTSD exon 2 polymorphism and AD exists, it is likely to be smaller than previously reported.

Candidate genes showing no evidence for association or linkage with Alzheimer's disease using family-based methodologies

Alzheimer's disease (AD) is a genetically complex and heterogeneous disorder. To date, a large number of candidate genes have been associated with the disease, however none of these findings has been consistently replicated in independent datasets. In this study we report the results of family-based analyses for polymorphisms of five such candidates on chromosomes 2 (interleukin-1beta, IL-1B), 3 (butyrylcholinesterase, BCHE), 11 (cathepsin D, CTSD; Fe65, APBB1) and 12 (lipoprotein receptor-related protein-1, LRP1) that were all suggested to be associated with AD in recent case-control studies. To minimize the possibility of spurious findings due to population admixture, we used a family-based design applying the sibship disequilibrium test (SDT) as well as two-point parametric linkage analyses on families from the National Institute of Mental Health (NIMH) Genetics Initiative. Contrary to the initial reports, none of the polymorphisms that were analyzed showed evidence for association or linkage with AD in our families. Our results suggest that the previously reported associations from case-control studies are either (a) false positive results, e.g. due to type I error or population admixture, (b) smaller than initially proposed, or (c) due to linkage disequilibrium with an as yet unidentified polymorphism nearby.