Clinical Analysis Of Lung Adenocarcinoma With ROS1 Fusion

Background and aims:Lung cancer has the highest incidence in recent years and remains the leading cause of the cancer-related death among men and women in worldwide,ROS1 arrangement defined a new kind of lung cancer subtype which has been studied intensively in recent years.In this study we will further carry out the prevalence and special clinical characteristics of ROS1-positive adenocarcinoma(ADC)patients,compare the computed tomography(CT)images between tumors with and without c-ros oncogene 1(ROS1)rearrangement,and investigate the clinical efficacy of crizotinib in real world of China.Methods:In the study we retrospectively enrolled 1482 patients with adenocarcinoma from March 2013 to January 2017 in the first affiliated hospital of Zhejiang University,they were all screened for ROS1 rearrangement by multiplex reverse transcription-polymerase chain reaction(RT-PCR),clinical and imaging features were summarized.We compared the percentages of the solid portion volume(PSV)which was calculated by imaging parameters such as volume and estimated diameter with different ROS1 status.DCRs and ORRs were compared between first-line crizotinib and first-line pemetrexed combined with platinum chemotherapy,between first-line and non-first line crizotinib,as well as between first-line and non-first line pemetrexed combined with platinum chemotherapy.Results:A total of 1482 cases have accepted ROS1 fusion test,54(3.6%)patients was demonstrated with express of ROSI fusion,our results showed that ROS1 rearrangement was prone to be younger(p<0.001),never-smoker(p=0.007),and female(p<0.001)adenocarcinoma subgroup.PSV in ROS1 fusion positive group(81.6±21.3)%was significant higher than ROS1 negative group(62.2±25.3)%,the area under the curve(AUC)of ROC curves of PSV to predict ROS1 rearrangement was 0.736(p<0.0015 95%CI:0.637-0.835);at a cut-off value of 0.849,sensitivity was 0.697 and specificity was 0.702.In patients with ROS1 fusion,first line crizotinib treatment group had a statistical priority in overall response rate(ORR,84.6%)than pemetrexed-based therapy group(ORR,53.3%)(p=0.031),whereas a higher DCR(92.3%)than pemetrexed group DCR(80%)without statistical significance.Non-first line crizotinib treatment group achieved ORR(58%)and DCR(83%),there exists no statistic difference between different lines of crizotinib.And there were also no difference in ORR(20%)(p=0.194)and DCR(40%)(p=0.191)between all lines of pemetrexed-based chemotherapy.Conclusion:This retrospective study indicated that ROS1 fusion usually occurs in younger,never smoke,female adenocarcinoma patients,CT imagining makes no difference in ROS1 fusion positive group with negative group,but it often shows a higher PSV in ROS1 positive group compared with others,it is probable a positive ROS1 fusion when a higher PSV presented in the CT.Crizotinib treatment shows a better ORR and DCR than pemetrexed-based chemotherapy,but there exists no difference between different lines of crizotinib treatment and pemetrexed based chemotherapy.