72P Association of receptor activator of nuclear factor kappa-B ligand (RANKL) and epidermal growth factor receptor (EGFR) gene expression with bone metastases (mets) in patients (pts) with metastatic non-small cell lung cancer (mNSCLC)

Bone mets are frequent in NSCLC. The receptor activator of Nuclear Factor κB (RANK)/ RANKL/osteoprotegerin (OPG) pathway is important bone development. EGFR signaling promotes osteoclast formation and stimulation. Understanding the biological mechanism development might have implications for treatment strategies. We studied association EGFR, RANKL, RANK, OPG gene expression tumor presence mNSCLC. Retrospective multicenter study (2008–2017), included: mutated (EGFR+), Kirsten rat sarcoma (KRAS+), EGFR/KRAS wildtype Ribonucleic Acid was isolated from samples expressions were determined via quantitative Polymerase Chain Reaction. Data on demographics, molecular subtyping, origin pathology sample, presence/progression mets, SREs collected. Primary endpoint: relation between expression, RANKL:OPG ratio mets. n 169/335 (50%) pts available, 73 (43%) analysis could be performed. 46/73 (63%) had at diagnosis/developed (table). EGFR+ NSCLC significantly higher compared to other tumors. Pts with a RANKL those without, but not different. An increased resulted 1.65x risk develop especially first 450 days after diagnosis Table 72PBaseline characteristicsCharacteristicsTotal = 73Female (%)46 (63)Never smoker (%)8 (11)Mean age metastatic NSCLC, years (range)62.8 (32–84)Molecular subgroup (%)EGFR+23 (32)KRAS+36 (49)EGFR/KRAS wildtype14 (19)Origin sample (%)Lung (primary tumor)29 (40)Bone9 (12)Other metastasis35 (48)Metastatic disease (%)47 (64)Bone stage IV (%)27 (37)Bone or during course of46 (63)disease (%)SRE (% all mets)26 (57)Type SRE SREs)Radiotherapy25 (96)Pathologic fracture4 (15)Surgery6 (23)Spinal cord compression2 (8)BTA use (%)9 (12)Denosumab1 (1)Bisphosphonate8 (11) Open table new tab Increased ratio, associated incidence