Comparison of molecular testing rates and biomarker positivity by histology among patients (pts) with stage IV non-small cell lung cancer (NSCLC): A quality initiative by Integra Connect PrecisionQ.

582 Background: National Comprehensive Cancer Network guidelines for NSCLC recommend biomarker testing for EGFR, ALK, ROS1, BRAF, NTRK1/2/3, METex14 skipping, KRAS, RET, and ERBB2 (HER2) in advanced or metastatic NSCLC regardless of histology. We sought to understand the testing rates for these markers among pts with a squamous (S) histology compared to pts with a non-squamous (NS) histology, while also assessing positivity rates among pts based on histology by the respective biomarkers for pts with stage IV NSCLC. Methods: We used the Integra Connect PrecisionQ real-world de-identified database of over 2 million cancer pts across 500 sites of care to assess testing rates and biomarker positivity rates based on histology among adult NSCLC patients. We included 3,889 Stage IV NSCLC pts, where we conducted chart reviews, investigating testing rates across each of the biomarkers based on patient histology (group 1). In addition, we evaluated 6,303 stage IV NSCLC pts, regardless of whether we conducted chart reviews, to assess rates of positivity among the respective biomarkers (group 2). Pts included in the analysis were diagnosed on or after 1/1/2019. We assessed rates of biomarker testing in group 1 and biomarker positivity (irrespective of the type of mutation) in group 2 stratified by histology. Descriptive analyses were used and proportions were compared using a two-tailed two-sample z-test. Results: Among the Group 1 stage IV pts in the comparison of tested vs. not-testedbased on histology (N= 3889), the average age was 72.9 (median = 75), 49% were female, 81.6% were NS. We found the testing rates among S pts (N=714) vs. NS (N=3175) as follows: EGFR-S 76% vs. EGFR-NS 92%, ALK-S 77% vs. ALK-NS 92%, BRAF-S 75% vs. BRAF-NS 87%, KRAS-S 71% vs. KRAS-NS 81%, MET-S 72% vs. MET-NS 80%, RET-S 72% vs. RET-NS 79%, ROS1-S 72% vs. ROS1-NS 79%, ERBB2-S 69% vs. ERBB2-NS 76%, and NTRK-S 62% vs. NTRK-NS 68%. All comparisons were statistically significant at P < .01. Among the Group 2 stage IV pts who were tested(N = 6303), the average age was 72.6 (median = 73), 50.8% were female, 86.0% were NS. We found the positivity rates among S pts vs. NS pts as follows: EGFR-S 7.5% (N = 827) vs. EGFR-NS 19.5% (N = 4650), ALK -S 1.3% (N =837) vs. ALK-NS 3.6% (N = 5099), BRAF-S 2.8% (N = 742) vs. BRAF-NS 6.0% (N = 4399), KRAS-S 10.4% (N = 694) vs. KRAS-NS 31.1% (N=3763), MET-S 4.3 (N=645) vs. MET-NS 7.5% (N = 3537), RET-S 0.5% (N = 635) vs. RET-NS 1.4% (N= 3397), ROS1-S 0.6% (N = 629) vs. ROS1-NS 1.4% (N = 3346), ERBB2-S 2.2% (N = 504) vs. ERBB2-NS 3.8% (N = 2510), and NTRK-S 1.0% (N = 486) vs. NTRK-NS 1.5% (N = 2444). Conclusions: Our results indicate a need to increase biomarker testing among pts with S histology to be equivalent to those who were tested with a NS histology, as biomarker positivity rates present in pts with S histology warrant a molecular evaluation regardless of histology.