1437P Clinical and economic burden of tissue re-biopsy (TRB) vs. tissue followed by liquid biopsy (TFLB) in metastatic non-small cell lung cancer (mNSCLC) patients

Tissue biopsy (TIB) is the gold standard for biomarker testing in mNSCLC patients. Although TIB is common, it is associated with potential invasive procedure-related complications. Liquid biopsies are used when tissue is unavailable or insufficient for testing. Studies suggest that TFLB has comparable diagnostic accuracy to TIB for detecting genetic alterations in mNSCLC patients. Liquid biopsies are increasingly used to genotype a tumor in a less invasive manner. This study compared TIB-related complications and healthcare costs with TRB vs. TFLB in mNSCLC patients. US administrative claims were assessed retrospectively for patients diagnosed with mNSCLC between July 2016 to June 2021 to identify adult Medicare Advantage or commercially insured patients with ≥2 biopsy claims, and whose first biopsy was tissue-based. The second biopsy defined the cohorts: TRB or TFLB. To control for possible confounding factors, study cohorts were matched 1:1 using propensity-scores (PSM). The study comprised 470 patients post-PSM, each group had 235 patients. TFLB had a lower TIB-related complication rate and associated healthcare costs compared with TRB (Table). Furthermore, mean number of complication-related healthcare visits were lower for TFLB than TRB group; outpatient visits (0.51 v 1.12, p=0.002), inpatient stays (0.45 v 0.67, p<0.001) and inpatient days (3.49 v 6.60, p=0.002).Table: 1437PComparison of outcomes between study cohortsTFLB (N = 235)TRB (N = 235)TIB-related complications (%)*65.184.7Pneumothorax*17.546.0Prolonged air leak >5 days*1.311.9Hemorrhage14.018.3Infection*23.031.9Thrombotic complications13.28.5Cardiovascular complications38.742.1Death0.42.6Mean [SD] TB complication-related healthcare costs - US$Medical costs*8,494 [15,706]19,741 [30,641]Office visits*20 [71]51 [219]Outpatient visits251 [1,672]336 [1,562]Emergency room visits119 [590]85 [358]Inpatient stays*8,076 [15,338]18,918 [30,012]Other medical costs29 [148]352 [3622]∗P-value <0.05 Open table in a new tab ∗P-value <0.05 The analysis suggests that TFLB, compared with traditional TRB, is a method that carries less economic burden and fewer TIB-related complications to detect actionable genetic mutations during mNSCLC diagnostic work-up.