Evaluating Effective Biomarker Testing for Advanced Non–Small Cell Lung Cancer in US Community Oncology Practices

PURPOSE Biomarker testing, including immunohistochemistry (IHC) and next-generation sequencing, is the standard of care in advanced non–small cell lung cancer (NSCLC) for identifying actionable mutations such as EGFR , ALK , and KRAS . However, the rate of effective testing, defined as the availability of actionable results before treatment initiation, has not been examined in a US community oncology setting in a more contemporary patient sample. This study quantified effective testing rates and patient factors associated with testing. METHODS This retrospective study included patients with stage IIIB/IIIC/IV NSCLC treated within ONCare Alliance, a network of 30 US community oncology practices. Data collection consisted of patient demographics, disease characteristics, biomarker testing details (order date, test type, assays), and result availability at diagnosis and at the start of systemic therapy. RESULTS Among 306 patients (median age 69 years; 51% female; 69.3% adenocarcinoma), 239 (78.1%) received systemic therapy. Overall biomarker testing rates were 93.1% (95% CI, 89.7 to 95.7) for all patients and 95.8% (95% CI, 92.4 to 98.0) for those treated systemically. Effective testing was significantly lower at 72.0% (95% CI, 65.8 to 77.6). Patients with adenocarcinoma (odds ratio OR, 3.66 95% CI, 1.41 to 9.5; P = .008) or those scheduled to receive systemic therapy (OR, 4.00 95% CI, 1.58 to 10.2; P = .003) were more likely to undergo biomarker testing. Only 39.5% (95% CI, 34.0 to 45.3) was tested for all 13 National Comprehensive Cancer Network–recommended biomarkers. CONCLUSION Although overall testing rates were high, more than 20% of patients lacked timely results to guide initial therapy. This critical gap may limit access to biomarker-directed treatment and highlights the need for streamlined diagnostic workflows and faster turnaround times to ensure optimal, evidence-based care in community oncology.