ROS1 is now recognised as a definite molecular target in NSCLC.1 Studies showed that ROS1 positive patients are significantly younger & more likely to be non-smokers.2 Previous studies found epidermal growth factor receptor (EGFR) mutation in NSCLC was significantly higher in Asian population compared to non-Asian.3 Objective of the study is to evaluate difference between epidemiological parameters of ROS1 rearrangements in Asian & non-Asian patients by performing meta-analysis.
We systematically searched databases like PubMed & e-journals since 2011. Statistical analysis for this study was done on 20 studies (11,665 patients) conducted globally & open source software R (version 3.3.2) was used for meta-analysis.
Global prevalence of ROS1 rearrangement was 2% (95% CI: 0.016- 0.026) & it was higher in Asian [2.2% (95% CI: 0.016- 0.029)] than non-Asian [1.9% (95% CI: 0.012- 0.027)] (p=0.92). Mean age of Asian & non-Asian was 54.5 yrs & 59 yrs respectively. The prevalence rate in non-Asian females, was significantly higher [3.8% (95% CI: 0.011-0.078)] than non-Asian males [0.7% (0.003- 0.012)] (p=0.003). Similarly, prevalence rate in Asian females [2.8% (95% CI: 0.019-0.038)] was higher than Asian males [2.1% (95% CI: 0.012-0.033)] (p=0.88).
Smokers in Asia were more likely to have ROS1 rearrangement [1.8% (95% CI: 0.005-0.037)] compared to non-smokers [0.6% (95% CI: 0.0004-0.0152)] (p=0.93). Whereas, prevalence rate amongst non-smokers in non-Asia [7.1% (95% CI: 0.039-0.110)] was significantly higher than smokers [0.7% (95% CI: 0.002-0.007)] (p=0.008). Clinical stage IV was more common in both population than other stages. In 5 out of 20 studies, ROS1 positivity was higher (3-12.5%) in enriched (EGFR-ve/ALK-ve) population [non-smokers 6.5% (95% CI: 0.046-0.083)] compared to overall population.
Our meta-analysis showed that ROS1 gene rearrangement was more prevalent in NSCLC, females, non-smokers & patients with clinical stage IV while there is no significant difference in Asians vs non-Asians.
1] Bubendorf et al. Virchows Arch. 2016; 469:489–503. 2] Bergethon et al. JCO. 2012; 30(8): 863-870. 3] Expert Opin Pharmacother. 2015 Jun;16(8):1167-76.