Race and prognosis of brain tumor patients entering multicenter clinical trials. A report from the Radiation Therapy Oncology Group

Systematic Review of Racial, Socioeconomic, and Insurance Status Disparities in Neurosurgical Care for Intracranial Tumors

BACKGROUND

The impact of race, socioeconomic status (SES), insurance status, and other social metrics on the outcomes of patients with intracranial tumors has been reported in several studies. However, these findings have not been comprehensively summarized.

METHODS

We conducted a PRISMA systematic review of all published articles between 1990 and 2020 that analyzed intracranial tumor disparities, including race, SES, insurance status, and safety-net hospital status. Outcomes measured include access, standards of care, receipt of surgery, extent of resection, mortality, complications, length of stay (LOS), discharge disposition, readmission rate, and hospital charges.

RESULTS

Fifty-five studies were included. Disparities in mortality were reported in 27 studies (47%), showing minority status and lower SES associated with poorer survival outcomes in 14 studies (52%). Twenty-seven studies showed that African American patients had worse outcomes across all included metrics including mortality, rates of surgical intervention, extent of resection, LOS, discharge disposition, and complication rates. Thirty studies showed that privately insured patients and patients with higher SES had better outcomes, including lower mortality, complication, and readmission rates. Six studies showed that worse outcomes were associated with treatment at safety-net and/or low-volume hospitals. The influence of Medicare or Medicaid status, or inequities affecting other minorities, was less clearly delineated. Ten studies (18%) were negative for evidence of disparities.

CONCLUSIONS

Significant disparities exist among patients with intracranial tumors, particularly affecting patients of African American race and lower SES. Efforts at the hospital, state, and national level must be undertaken to identify root causes of these issues.

Missing diversity in brain tumor trials

Background

Clinical trials for brain tumors represent a significant opportunity for both patients and providers to understand and combat a disease with substantial morbidity. The aim of this study was to quantify and map ethnic and racial representation in brain tumor trials and examine the potential gaps in trial recruitment. We also show that these representation gaps persist even in large multicultural cities like New York City.

Methods

We analyzed brain tumor clinical trials registered on www.clinicaltrials.gov between July 1, 2005 and completed on or before November 11, 2017. We used a combination of PubMed/MEDLINE and Google Scholar to find associated publications and obtained trial information as well as patient demographic information (when available) including race or ancestry.

Results

Out of 471 trials, 27% had no published results. Only 28.4% of trials with results reported race or ethnicity of trial participants, with no observed upward trend by year. Whites were significantly overrepresented in trials for metastatic brain tumors (P < .001) and high-grade trials (P < .001). Blacks/African Americans (AAs), Hispanics, and Asians were significantly underrepresented (P < .001) in high-grade trials, while only Blacks/AAs were underrepresented in trials for metastatic brain tumors (P < .001). Representation gaps were not observed in pediatric trials. Despite being a multicultural hub, New York City displayed similar gaps in trial representation.

Conclusions

Despite increasing representation in the American population, minorities are underrepresented in brain tumor trials. In addition, despite numerous legal requirements and ethical mandates, published results including race-based information are remarkably absent from 70% of brain tumor trials.

The association between race and survival in glioblastoma patients in the US: A retrospective cohort study

Background

Glioblastoma is the most common primary brain cancer in adults with an incidence of 3.4 per 100,000, making up about 15% of all brain tumors. Inconsistent results have been published in regard differences in survival between white and black glioblastoma patients. The objective of this to study the association between race and in Glioblastoma patients in the USA during 2010–2014.

Methods and findings

The National Cancer Institute’s Surveillance Epidemiology and End Results (SEER) database were used to evaluate race/ethnicity (White non-Hispanic, Black non-Hispanic, Asian/Pacific Islanders non-Hispanic (API)) and Hispanic) adults patients with first-time diagnosis of glioblastoma (International Classification of Diseases for Oncology, 3rd Edition [ICD-O-3], codes C711-C714, and histology type 9440/3) from 2010–2014. The primary outcome was 3-year overall survival which was defined as months from diagnosis to death due to any cause and cancer, Kaplan-Meier (KM) and log-rank test were used to compare overall survival times across race groups. Cox proportional hazard models were used to determine the independent effect of race on 3-year survival. Age, gender, health insurance coverage, primary site, tumor size, extent of surgery and year of diagnosis were included in the adjusted model. The 3-year overall survival for API-non Hispanic (NH) patients decreased by 25% compared with White NH glioblastoma patients (hazard ratio (HR) 0.75; 95% confidence interval (CI) 0.62–0.90)) after adjusting for age, gender, health insurance, primary site, tumor size, and extent of the surgery. Black NH (HR 0.95; 95% CI 0.80–1.13) and Hispanic (HR 1.01, 95% CI 0.84–1.21) exhibited similar mortality risks compared with White NH patients.

Conclusion

Compared with White NH, API NH with glioblastoma have a better survival. The findings from this study can help increase the accuracy of the prognostic outlook for white, black and API patients with GBM.

Pediatric neuro-oncology survival disparities in California

The objective of this study was to investigate racial/ethnic differences in survival for pediatric high-grade glioma (HGG) and medulloblastoma in the state of California. We obtained data from the California Cancer Registry on 552 high-grade glioma patients (110 brainstem, 442 non-brainstem) and 648 medulloblastoma patients ages 0-19 years from 1988 to 2012. Using multivariate Cox proportional hazards regression, we examined the impact of individual and neighborhood characteristics on survival. Socioeconomic quintile and insurance status differed significantly by race for both diagnoses. Hispanic children with non-brainstem HGG had worse survival than non-Hispanic white children: hazard ratio (HR) 1.62; 95% confidence interval (CI) 1.24-2.11, but the difference was mitigated some by accounting for socioeconomic status (HR 1.48, CI 1.10-1.99). Racial/ethnic differences in survival exist for children with high-grade glioma, particularly Hispanic children with non-brainstem high-grade glioma, and are likely related to sociologic factors.

Socioeconomic status does not affect prognosis in patients with glioblastoma multiforme

Background:

Glioblastoma multiforme (GBM) is an aggressive malignancy, but there is marked heterogeneity in survival time. Health care disparities have demonstrated significance in oncologic outcomes but have not been clearly examined in this patient population. We investigated the role of sociodemographic variables in the prognosis of adult patients diagnosed with GBM.

Methods:

This retrospective analysis included patients with a histologically confirmed diagnosis of GBM, who underwent resection or biopsy at a single institution from 2000 to 2014. Socioeconomic status (SES) was determined by household income according to the US Census zip code tabulation areas and the US national poverty level. Multivariate Cox proportional hazards analysis calculated effects on patient survival.

Results:

Thirty percent of 218 subjects were of low SES, 57% mid, and 13% high. Low SES patients tended to be male (62%), Caucasian (92%), unmarried (91%), have dependents (100%), and limited to high school education (55%). SES did not predict insurance or employment status. SES was associated with marital status and number of cohabitants (P < 0.0001) but not clinical trial enrollment. Multivariate analysis demonstrated no relationship between SES and survival. Shorter prognosis was associated with history of military service (hazard ratio [HR] 2.06, P = 0.0125), elderly patients (HR 1.70, P = 0.0158), and multifocal disease (HR 1.75, P = 0.0119). Longer prognosis was associated with gross total resection (HR 0.49, P = 0.0009), radiation therapy (HR 0.12, P < 0.0001), and temozolomide (HR 0.28, P < 0.0001).

Conclusions:

SES alone does not predict prognosis in patients with newly diagnosed GBM. Sociodemographic variables such as old age, military service record, and insurance type may have a prognostication role.

Epidemiologic and molecular prognostic review of glioblastoma

Glioblastoma multiforme (GBM) is the most common and aggressive primary central nervous system malignancy with a median survival of 15 months. The average incidence rate of GBM is 3.19/100,000 population, and the median age of diagnosis is 64 years. Incidence is higher in men and individuals of white race and non-Hispanic ethnicity. Many genetic and environmental factors have been studied in GBM, but the majority are sporadic, and no risk factor accounting for a large proportion of GBMs has been identified. However, several favorable clinical prognostic factors are identified, including younger age at diagnosis, cerebellar location, high performance status, and maximal tumor resection. GBMs comprise of primary and secondary subtypes, which evolve through different genetic pathways, affect patients at different ages, and have differences in outcomes. We report the current epidemiology of GBM with new data from the Central Brain Tumor Registry of the United States 2006 to 2010 as well as demonstrate and discuss trends in incidence and survival. We also provide a concise review on molecular markers in GBM that have helped distinguish biologically similar subtypes of GBM and have prognostic and predictive value.

Racial, ethnic and socioeconomic disparities in the treatment of brain tumors

Disparities in American health care based on socially-defined patient characteristics such as race, ethnicity, and socioeconomic position are well-documented. We review differences and disparities in incidence, pathobiology, processes and outcomes of care, and survival based on social factors for brain tumors of all histologies. In the US, black patients have lower incidences of most brain tumor types and lower-income patients have lower incidences of low grade glioma, meningioma and acoustic neuroma; ascertainment bias may contribute to these findings. Pathogenetic differences between malignant gliomas in patients of different races have been demonstrated, but their clinical significance is unclear. Patients in disadvantaged groups are less often treated by high-volume providers. Mortality and morbidity of initial treatment are higher for brain tumor patients in disadvantaged groups, and they present with markers of more severe disease. Long term survival differences between malignant glioma patients of different races have not yet been shown. Clinical trial enrollment appears to be lower among brain tumor patients from disadvantaged groups. We propose future research both to better define disparities and to alleviate them.

Long-term follow-up in managing anaplastic astrocytoma by multimodality approach with surgery followed by postoperative radiotherapy and PCV-chemotherapy: phase II trial

Overall survival and progression-free survival after 5 and 10 years of 31 patients with malignant glioma treated by a combination of surgery, postoperative radiotherapy, and chemotherapy with a PCV regimen (procarbazine, CCNU [lomustine] and vincristine) is described. Parameters were evaluated by age at diagnosis, gender, ethnic origin, pre- and postsurgery Karnofsky Performance Status (KPS) score, limit and amount of surgical resection, histopathologic type, number of chemotherapy courses, time between surgery and radiotherapy, response to combined therapy, and dosage and type of radiotherapy. Progression-free survival was 29% at 24 months and 22% at 60 and 120 months. Overall survival was 47%, 36%, and 36% after 24, 60, and 120 months, respectively. Favorable prognostic factors for survival in univariate analysis were pre- and postoperative KPS (> or =70; p = 0.015; p = 0.0025, respectively), age of patients (<40; p = 0.01), number of chemotherapy cycles (> or =6; p = 0.02), and radiation dose (> or =60 Gy; p = 0.0015). The only significant prognostic factors for overall survival in a stepwise multivariate analysis were irradiation dose (p = 0.0001), number of chemotherapy cycles (p = 0.001), and preoperative KPS (p = 0.05); for progression-free survival it was number of chemotherapy cycles (p = 0.004). Survival was not affected by excision size, radiation method, histopathologic type of tumor, gender, ethnic origin, or time lapsed between surgery and irradiation.

A phase I-II trial of lovastatin for anaplastic astrocytoma and glioblastoma multiforme

Malignant gliomas are thought to be highly dependent on the mevalonate pathway for cell growth. Lovastatin, a cholesterol-lowering drug, inhibits not only the rate-limiting step in the mevalonate pathway (hepatic hydroxymethyl glutaryl coenzyme A reductase), but also the prenylation of several key regulatory proteins including ras and the small guanosine triphosphate binding proteins. Therefore, from August 1994 through March 1996, 18 patients with either anaplastic glioma or glioblastoma multiforme were entered into a trial testing the safety of high-dose lovastatin with or without radiation. Although the response data is too premature to evaluate activity, the fact that high doses of lovastatin are well tolerated with concurrent radiation suggests that central nervous system toxicity will not be a significant limiting toxicity as more selective farnesyltransferase inhibitors are brought into the clinic as radiation sensitizers.