Objectives: EML4-ALK rearrangement is found in a small group of non-small cell lung cancer (NSCLC). In this patient population, the search of the predictive and prognostic biomarkers have been still continuing. Systemic immune-inflammation index (SII) is a novel marker for reflection of the inflammatory condition of the human body. So, we aimed that evaluated the prognostic value of SII in NSCLC with ALK rearrangement. Methods: The patients who diagnosed advanced NSCLC with ALK rearrangement and received crizotinib at any-line of treatment were enrolled to study. SII was calculated by using formula as follow: (Neutrophil x platelet) / lymphocyte. The cut-off value was accepted as 640 and the patients stratified according to SII level as low and high. The progressionfree survival (PFS), overall survival (OS) and overall response rate (ORR) differences between SII low and high groups have investigated The correlation between SII and PFS was also evaluated. Results: Totally, 50 patients enrolled to study. Twenty-eight of 50 were stratified to SII high group and 22 of 50 to SII low group. Median follow-up time from diagnosis was 25 months. Median PFS was significantly longer in SII low group than SII high group (24.01 vs. 7.8 months; p=0.024). Overall survival was also significantly longer in SII low group compare with SII high group (NR vs. 29.08 months; p=0.001). the significantly negative correlation between PFS and SII was also detected (r=-0.355; p=0.011). Conclusion: SII, a non-invasive, easily accessible - assessable marker, can be used as a prognostic marker in NSCLC with ALK-rearrangement, according to results of our study. Keywords: ALK-rearrangement; inflammation; peripheral blood parameter; prognostic marker
Corresponding Author: Burak B.