171P Systematic review-based treatment algorithm for multidisciplinary treatment of lung cancer bone metastases

The clinical manifestations of lung cancer bone metastasis are diverse, and various treatment methods can be used. Disease-specific guidelines are absent, and existing bone metastasis guidelines focus on mechanical bone stability, making them insufficient to be used in multidisciplinary treatment decisions. We conducted a systematic review following the methodologies outlined in the PRISMA and Cochrane Handbook. Inclusion criteria encompassed studies with ≥10 patients, offering multivariate analysis data on survival, and published after 2000. Clinical factors were categorized based on their characteristics, and the pooled hazard ratios (HRs) for each category were calculated using a random effects model. Subsequently, we proposed a treatment algorithm, taking into consideration both clinical importance and the pooled HRs. Fifteen studies with 3759 patients were included. The median survival period across studies ranged from 1.8 to 28 months (median: 12.4). Several clinical categories consistently emerged as significant in multiple studies, including ECOG (9 studies, pooled HR [95% CI]: 2.01 [1.54-2.62]), systemic treatment (6, 1.70 [1.41-2.04]), antiabsorbant (5, 1.60 [1.08-2.37]), smoking (4, 1.53 [1.31-1.79]), gender (4, 1.48 [1.27-1.73]), EGFR+ (4, 2.11 [1.35-3.33]), metastatic character (4, 1.91 [1.44-2.53]), body weight loss (4, 1.61 [1.20-2.16]), visceral metastases (3, 1.53 [1.31-1.79]), skeletal events (3, 1.62 [1.06-2.46]), and histology (3, 1.45 [1.19-1.77]). An algorithm was devised, prioritizing the identification of oncologic emergencies and subsequently exploring clinical factors consistently reported across studies with high pooled hazard ratios (Table). Table: 171PTabulated treatment algorithm based on key clinical questionsCQClinical considerationTreatment strategyQ1Emergency? (cord compression, severe pain, weight bearing bone fx.)Surgical Fixation, and consider Q2Q2Decompensated performance? (i.e. ECOG >3, weight loss)Systemic Tx. +/- palliative RTQ3Oligometastases? (i.e. limited number, non-visceral metastases)Systemic Tx. +/- radical RT* or surgeryQ4Multidisciplinary treatment considering 1) use of TKI, PDL1 inhibitor, antiabsorbant 2) Surgery or RT for pending fx. or pain 3) Radio or chemosensitivity of tumor 4) Patient characteristics (female, smoking.)*SBRT or hypofractionated RT > EQD2 ∼50 Gy Open table in a new tab *SBRT or hypofractionated RT > EQD2 ∼50 Gy In the absence of guidelines for the multidisciplinary treatment of lung cancer bone metastases, our algorithm offers clinical utility. It can be further evolved to guidelines with treatment detail with future studies and experts' opinions.