|LETTER TO EDITOR
|Year : 2019 | Volume
| Issue : 2 | Page : 259-260
Reviewing ROS1 immunohistochemistry vis-á-vis fluorescence in situ hybridization in NSCLC
Kirti G Chadha, Shaikhali M Barodawala, Ashwini J PatkarKirti
Department of Integrated Oncopathology, Global Reference Laboratory, Metropolis Healthcare Ltd., Mumbai, Maharashtra, India
|Date of Web Publication||20-Dec-2019|
Kirti G Chadha
Kohinoor Commercial Complex, 4th Floor, A Wing, Kurla (w), Mumbai, Maharashtra
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Chadha KG, Barodawala SM, PatkarKirti AJ. Reviewing ROS1 immunohistochemistry vis-á-vis fluorescence in situ hybridization in NSCLC. Cancer Res Stat Treat 2019;2:259-60
|How to cite this URL:|
Chadha KG, Barodawala SM, PatkarKirti AJ. Reviewing ROS1 immunohistochemistry vis-á-vis fluorescence in situ hybridization in NSCLC. Cancer Res Stat Treat [serial online] 2019 [cited 2020 Feb 28];2:259-60. Available from: http://www.crstonline.com/text.asp?2019/2/2/259/273695
Review of the article 'Determination of ROS1 positivity by immunohistochemistry (IHC) in a multicentric cohort of 426 non-small cell lung cancer (NSCLC) cases in India' by Jain et al. and the editorial 'ROS1 rearrangement testing: Is IHC changing the horizon?' by Choughule and D'Souza when coupled with the recent NCCN guidelines and relative percentages of the NSCLC driver mutations has lent a practical roadmap for testing. So far, based on the current NCCN guidelines for NSCLC recommending testing for epidermal growth factor receptor, anaplastic lymphoma kinase (ALK), and ROS1, the technology of choice has been fluorescence in situ hybridization (FISH) for ROS1. Statistics published so far indicate that ROS1-positive results are infrequent with positivity of <1% in most Indian studies., Most of these have been performed by FISH which is expensive, labor-intensive needing high man hours and expertise, reducing scalability of setup apart from select referral centers. This limitation does not apply to IHC, which the authors have tried to establish. We concur with this thought based on literature and our own experience submitted for publication wherein in >5000 NSCLC patients, 130 cases were studied for ROS1 by FISH, but only 1 case was positive (0.7%). Hence, we allude to NCCN suggestion and current editorial that IHC could be used as a valuable alternative to screen NSCLC patients as it has a high negative predictive value and can be easily performed on automated IHC platforms achieving lower turn-around time and cost. Standardization and reproducibility are also feasible. Review of literature comparing IHC method with FISH for ROS1 detection with a concordance of well above 90% recommends cell signaling technology, ROS antibody (ROS1 clone D4D6 rabbit mAb). A fully automated procedure using Ventana Benchmark XT automated stainer was carried out. However, due to the lack of specificity,, cases positive by IHC must be confirmed by FISH. We have been successfully utilizing a similar algorithm for ALK-positive cases. The authors have shared good concordance rates between IHC and FISH. An improvisation needed by the authors is to carry out a direct comparison of a subset for a stronger recommendation. Preanalytical and analytical mandates must be strictly adhered to as for all predictive and theranostic IHC. ROS1-positive tumors are very sensitive to treatment with crizotinib; hence, detecting this rare genetic alteration is an important step in the diagnostic workup of the NSCLC patient.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Jain J, Chinta D, Jayaraman UB, Pathak N, Kaur M, Chatterjee S, et al
. Determination of ROS1 positivity by immunohistochemistry in a multicentric cohort of 426 non-small-cell lung cancer cases in India. Cancer Res Stat Treat 2019;2:16-20. [Full text]
Choughule A, D'Souza H. ROS1 rearrangement testing: Is immunohistochemistry changing the horizon? Cancer Res Stat Treat 2019;2:66-8. [Full text]
Ettinger DS, Aisner DL, Wood DE, Akerley W, Bauman J, Chang JY, et al
. NCCN Guidelines Insights: Non-Small Cell Lung Cancer, Version 5.2018. J Natl Compr Canc Netw 2018;16:807-21. doi: 10.6004/jnccn.2018.0062.
Mino-Kenudson M. Immunohistochemistry for predictive biomarkers in non-small cell lung cancer. Transl Lung Cancer Res 2017;6:570-87.