Disparities in Reported Testing for 1p/19q Codeletion in Oligodendroglioma and Oligoastrocytoma Patients: An Analysis of the National Cancer Database.

Jad Zreik,Yagiz U Yolcu,Mohammed Ali Alvi,Panagiotis Kerezoudis,Sani H Kizilbash

doi:10.3389/fonc.2021.746844

Jad Zreik, Yagiz U Yolcu + Show 3 more

Open Access

https://doi.org/10.3389/fonc.2021.746844

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Abstract

PurposeA chromosomal 1p/19q codeletion was included as a required diagnostic component of oligodendrogliomas in the 2016 World Health Organization (WHO) classification of central nervous system tumors. We sought to evaluate disparities in reported testing for 1p/19q codeletion among oligodendroglioma and oligoastrocytoma patients before and after the guidelines.MethodsThe National Cancer Database (NCDB) was queried for patients with histologically-confirmed WHO grade II/III oligodendroglioma or oligoastrocytoma from 2011-2017. Adjusted odds of having a reported 1p/19q codeletion test for patient- and hospital-level factors were calculated before (2011-2015) and after (2017) the guidelines. The adjusted likelihood of receiving adjuvant treatment (chemotherapy and/or radiotherapy) based on reported testing was also evaluated.ResultsOverall, 6,404 patients were identified. The reported 1p/19q codeletion testing rate increased from 45.8% in 2011 to 59.8% in 2017. From 2011-2015, lack of insurance (OR 0.77; 95% CI 0.62-0.97;p=0.025), lower zip code-level educational attainment (OR 0.62; 95% CI 0.49-0.78;p<0.001), and Northeast (OR 0.68; 95% CI 0.57-0.82;p<0.001) or Southern (OR 0.62; 95% CI 0.49-0.79;p<0.001) facility geographic region were negatively associated with reported testing. In 2017, Black race (OR 0.49; 95% CI 0.26-0.91;p=0.024) and Northeast (OR 0.50; 95% CI 0.30-0.84;p=0.009) or Southern (OR 0.42; 95% CI 0.22-0.78;p=0.007) region were negatively associated with reported testing. Patients with a reported test were more likely to receive adjuvant treatment (OR 1.73; 95% CI 1.46-2.04;p<0.001).ConclusionDespite the 2016 WHO guidelines, disparities in reported 1p/19q codeletion testing by geographic region persisted while new disparities in race/ethnicity were identified, which may influence oligodendroglioma and oligoastrocytoma patient management.

Highlights

Chromosomal 1p/19q codeletion status plays an important role in tumor diagnosis for patients with a histological diagnosis of oligodendroglioma or oligoastrocytoma
Unknown facility setting and geographic region were not excluded in order to attenuate potential selection bias given that the National Cancer Database (NCDB) suppresses these variables for patients aged
Significant differences in the rates of reported codeletion tests were identified based on Extent of resection (EOR) (p

Summary

Introduction

Chromosomal 1p/19q codeletion status plays an important role in tumor diagnosis for patients with a histological diagnosis of oligodendroglioma or oligoastrocytoma. An isocitrate dehydrogenase (IDH) mutation has been previously shown to occur in most gliomas harboring a 1p/19q codeletion [5, 6]. As a result of these associations, the 2016 WHO classification of CNS tumors included the presence of an IDH mutation and 1p/19q codeletion as required criteria for diagnosing an oligodendroglioma in WHO grade II and grade III diffuse gliomas [7]. A number of studies have described inequitable access to neuro-oncological care among glioma patients. Factors such as race, socioeconomic status, and geography have been previously shown to influence receipt of treatment, access to high-volume facilities, and overall survival (OS) [8,9,10,11]. We sought to evaluate the trends, disparities, and potential impact of a reported 1p/19q codeletion test among oligodendroglioma and oligoastrocytoma patients before and after implementation of the 2016 WHO guidelines

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