EP.13E.04 Racial Disparities in Genomic Subtypes of Small Cell Lung Cancer Patients
Recommended Citation
Godbole MM, Abu Rous F, Ghosh S, Chitale D, Gadgeel SM. EP.13E.04 Racial Disparities in Genomic Subtypes of Small Cell Lung Cancer Patients. J Thorac Oncol 2024; 19(10):S682.
Document Type
Conference Proceeding
Publication Date
10-1-2024
Publication Title
J Thorac Oncol
Abstract
Introduction: Recent studies have identified 4 distinct subtypes of small cell lung cancer (SCLC) defined by the expression of several transcription factors. Immunohistochemistry (IHC) based analysis can help define these genomic subtypes. Previous analyses included very few samples from Black patients with SCLC. We present the initial results of IHC expression of relevant transcription factors in tumor samples from Black and White SCLC patients. Methods: SCLC patients diagnosed between January 2018 and January 2023 at Henry Ford Health were included. Demographics, including self-defined race, clinical characteristics and therapeutic details were retrieved from electronic medical record. A tissue microarray (TMA) was constructed using standard published protocols (1.0 mm cores in triplicate). The constructed TMA and an additional subset of whole sections were used for IHC staining for ASCL1, NEUROD1, POU2F3 and YAP1. IHC scoring was performed using H-score (score ≥10 was considered positive). Chi-square statistics and independent t-test was used for statistical analysis in the SPSS 28 software. Results: Of 258 patients with SCLC, adequate tissue for IHC scoring of all transcriptional factors was obtained for 58 patients (32 on TMA; 26 on whole sections). Of these, 28 were male and 30 female, mean age was 68 years (range: 52-86). 98% of patients were current or former smokers. Nine patients were Black and 49 were White. No statistical differences were observed for demographics, stage at diagnosis and presence of brain metastases between Black and White patients. YAP1 expression was more common in tumors of Black patients compared to tumors of White patients (33% vs 12%, p=0.136), while the expression of POU2F3 (0 vs 13%, p=0.575) and NEUROD1 (22% vs 45%, p=0.282) were more common in White patients. Positivity for more than one marker was noted in 22% of Black vs 8% of White patients (p=0.231). POU2F3 negative patients had significantly better overall survival than positive patients (p=0.034). Other markers did not show a statistically significant difference in survival. Survival analysis stratified by race was not conducted due to limited sample size. Conclusions: The initial results of our study show that the prevalence of genomic subsets of SCLC defined by IHC expression of relevant transcription factors differs between self-defined Black and White patients. We are evaluating more samples to confirm our initial results. If these differences persist with further analysis, this data could suggest differences in SCLC biology among different racial groups and may have therapeutic implications. [Formula presented] Keywords: Small cell lung cancer, Genomic subtypes, IHC
Volume
19
Issue
10
First Page
S682
