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K. Jangra
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P3.04 - Poster Session/ Biology, Pathology, and Molecular Testing (ID 235)
- Event: WCLC 2015
- Type: Poster
- Track: Biology, Pathology, and Molecular Testing
- Presentations: 1
- Moderators:
- Coordinates: 9/09/2015, 09:30 - 17:00, Exhibit Hall (Hall B+C)
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P3.04-006 - ALK Immunohistochemistry in NSCLC: Evaluation of Performance of D5F3-IHC without Using Automated Ventana System (ID 2377)
09:30 - 09:30 | Author(s): K. Jangra
- Abstract
Background:
Since the advent of targeted therapy, molecular testing for common mutations has become vital in the diagnostic algorithm of non- small cell lung cancer (NSCLCs). ALK-EML4 fusion is a rare abnormality detected in 3–13% patients of adenocarcinomas (ADC). Although Fluorescent In-Situ Hybridization (FISH) is a gold standard technique for detection of ALK rearrangement, it is expensive, time-consuming and requires specialized equipment and expertise for interpretation. Immunohistochemistry (IHC) with ALK rearrangement-specific antibodies is considered as a more economical method for routine diagnostic practice. Ultrasensitive automated Ventana D5F3-IHC revealed a very high correlation with FISH and approved by China FDA for targeted therapy; however, the automated IHC apparatus are not widely used in most general laboratories. In this study, we evaluated performance of ALK IHC using manual semiquantitative method in a cohort of 133 adenocarcinomas, to achieve the frequency of ALK positivity in Indian patients and correlation with automated Ventana D5F3-IHC.
Methods:
We tested 133 cases of primary lung ADCs, which were negative for EGFR mutation, for ALK rearrangement by D5F3-IHC.Thirty three of them were tested by both automated Ventana (D5F3) and manual methods (Cell Signaling Technology, Danvers, MA, USA). The intensity of cytoplasmic staining was classified as 0 (negative) or 1+/2+/3+ (weak/medium/strong). Binary score of positive (strong granular cytoplasmic staining in any percentage of tumor cells) and negative (absence of strong granular cytoplasmic staining) was used for Ventana IHC which was taken as gold standard. A comparison analysis and clinicopathological features were recorded.
Results:
Male to female ratio of the patient population was 2.3:1. ALK rearrangement was positive in 10 (7.5%) cases, out of which 7 were men and 50% were non- smokers. Median age for all ADCs was 55 years and for ALK rearrangement positive cases was 47 years. Three of 10 ALK IHC positive cases showed signet ring cell morphology. On comparison, all cases positive by Ventana (10 cases) (Figure 1A) showed positive results by manual method. Six cases showed 3+ (Figure1B) whereas 2+ (Three cases) and 1+ (one case) staining intensity was observed. The latter 4 cases were positive by FISH. All negative cases by Ventana system were negative by manual method. Figure 1
Conclusion:
Mutation specific IHC serves as a rapid tool for detection of ALK rearrangement in low resource settings. Manual IHC is equally effective in detection of ALK rearranged cases as automated methods. IHC positive cases may subsequently be analyzed by FISH thus reducing the cost of automated systems.
