A Large-scale Retrospective Study on ROS1 Fusion in Lung Carcinoma in Chinese Population.

Date 24 November 2018
Event ESMO Asia 2018 Congress
Session Poster display - Cocktail
Topics Cancer Biology
Thoracic Malignancies
Pathology/Molecular Biology
Presenter Qing Zhang
Citation Annals of Oncology (2018) 29 (suppl_9): ix143-ix149. 10.1093/annonc/mdy446
Authors Q. Zhang, Y. Han, J. Zhang, J. Shao, L. Zhu, R. Zhao
  • Pathology, Shanghai Chest Hospital, 200030 - Shanghai/CN

Abstract

Background

Crizotinib has been approved by FDA for patients with advanced ROS1 fusion NSCLC since 2016. It is critical to distinguish the target population quickly, but the clinicopathological characteristics are not clear.

Methods

In this retrospective study, we enrolled 3345 Chinese patients with lung carcinoma to investigate ROS1 fusion status by qRT-PCR, Sanger sequencing and immunohistochemistry. The positive samples were also checked for EGFR and ALK status. Follow-up data of patients with different fusion variants were collected to observe the relevant responses to crizotinib.

Results

Ninety samples were detected ROS1 positive (90/3345, 2.69%). Eighty-seven ROS1 positive samples were invasive adenocarcinomas (IA) (87/2811, 3.09%). One ROS1 fusion sample was sarcomatoid carcinoma (SC), and others were NSCLC-NOS. The expression of TTF-1 in both of SC and NSCLC-NOS suggested ROS1 fusion was associated with adenocarcinoma or adenoid differentiation. There was no ROS1 fusion in squamous cell carcinoma, small cell lung carcinoma, adenocarcinoma in situ and minimally invasive adenocarcinoma. Only age had statistical difference between ROS1+ and ROS1- samples [P (0.000, 95% CI (0.938-0.973)]. CD74-E6;ROS1-E34 (M8) was the most frequent fusion variant. ROS1 rarely overlapped with EGFR mutation (5.62%), and we didn’t find ROS/ALK double-positive. All of ROS1/EGFR double-positive samples were ROS1 immunostaining negative and their fusion variants were M8s. Patients with ROS1/EGFR changes benefitted from crizotinib and gefitinib.

Conclusions

All the IA and ILCCA patients should not give up the chance to detect the status of ROS1 fusion. There is no difference of anti-ROS1 immunostaining and response to crizotinib for different fusion variants.

Editorial acknowledgement

Clinical trial identification

Legal entity responsible for the study

Shanghai Chest Hospital.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.