Real-world study of upfront genomic testing utilization in newly diagnosed non–small cell lung cancer.

Abstract

221 Background: Comprehensive genomic profiling via tissue DNA next generation sequencing (NGS) is crucial for guiding precision medicine in both metastatic and early-stage non-small cell lung cancer (NSCLC). Complementary tests including liquid biopsy (LB) and tissue RNA sequencing may improve detection of actionable alterations. PDL1 is essential for predicting response to immunotherapy. Disparity data of real-world use of upfront NGS is lacking. Methods: We conducted a retrospective study of adults with biopsy-confirmed stage IB-IV NSCLC diagnosed between 4/2020 - 9/2024 in the MaineHealth Cancer Center Network (MHCCN). NGS closest to diagnosis were obtained from Tempus (Chicago, IL) and demographic and clinical data from our tumor registry and EMR. Zip codes were used to determine rurality. Utilization was compared across subgroups using Wilcoxon rank-sum, Chi-square tests, and multivariable logistic regression (MVLR). Results: Among 1,022 patients with newly diagnosed NSCLC, 433 (42.4%) underwent any upfront NGS. Compared to patients without NGS, patients with NGS were more likely to be younger (69 vs. 72 years), women (53.1 vs. 48.9%), former (69.3 vs. 63.3%) or never smokers (10.9 vs. 5.4%), have adenocarcinoma (70.9 vs. 45.7%), stage IV disease (63.7 vs. 58.2%), ECOG 0-1 (56.1 vs. 15.3%), and Charlson Comorbidity Index (CCI) 8+ (51.5 vs. 24.6%). MVLR with confounders adjusting for age, sex, smoking, histology, diagnosis year, stage, and CCI showed that treating center was not significantly associated with receiving upfront NGS, but rurality was associated with a lower likelihood to receive NGS (OR = 0.621, 95% CI [0.449, 0.854], p=0.004) compared to urban residency. Of the 433 patients who underwent upfront testing, 419 had adequate sample for testing and remained within the MH system. Among them, 372 (88.8%) had tissue-based testing and 48 (11.5%) had LB alone. Among those with tissue-based DNA NGS testing, 127 (34.1%) had LB, 270 (72.6%) had RNA sequencing, and 193 (51.9%) had PDL1 complementary testing. RNA sequencing was more commonly ordered in academic than community treating centers in early-stage disease (67.6 vs. 32.4%, p=0.039). Conclusions: The use of upfront NGS is suboptimal in stage IB-IV NSCLC across a statewide network. Additionally, rural patients were less likely to receive upfront NGS, regardless of their treating center. Complementary LB, RNA sequencing, and PDL1 testing were not consistent, potentially limiting the identification of actionable alterations and treatment options. Our findings highlight gaps in access to precision oncology, particularly related to rurality.