Frequency of EGFR mutations in non-small cell lung cancer patients: screening data from West Siberia

Percutaneous core needle biopsy in the diagnosis of lung lesions: An experience on 280 consecutive cases from a university hospital in southern India

Context:

Percutaneous needle biopsy of lung (PCNBL) is advantageous over bronchoscopic biopsies to obtain adequate sample for peripheral lung lesions.

Objective:

The objective was to evaluate the diagnostic yield of image-guided PCNBL in the diagnosis of lung lesions and to classify lung carcinomas as per the recently proposed International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society/European Respiratory Society classification for small biopsies modified and adopted by the World Health Organization, 2015.

Materials and Methods:

A total of 280 image-guided PCNBL were analyzed. The radiological findings and routine hematoxylin and eosin (H&E)-stained sections along with immunohistochemistry (IHC) were analyzed in all the cases. Molecular testing was done depending on tissue diagnosis and availability.

Results:

Majority (81%) were diagnosed as malignant lesions, with adenocarcinoma (ADC) being the most common. More than 70% were diagnosed on H&E morphology alone, with thirty cases requiring IHC to categorize as ADC. Nearly 60% were categorized as squamous cell carcinoma on morphology alone and the rest required IHC. Though TTF1 showed higher sensitivity than napsin A, the latter is more specific. Both p63 and p40 were found to be highly sensitive for squamous cell carcinoma, but p40 was more specific than p63. Epidermal growth factor receptor could be evaluated on 94.4% of ADC samples, indicating good yield for molecular testing.

Conclusion:

PCNBL yields adequate sampling for tissue diagnosis and ancillary testing with minimal complications. The use of IHC markers reduces the number of non-small-cell not otherwise specified cases significantly.

Epidermal Growth Factor Receptor Mutation Frequency in Squamous Cell Carcinoma and Its Diagnostic Performance in Cytological Samples: A Molecular and Immunohistochemical Study

Background

Epidermal growth factor receptor (EGFR) mutation is the most frequent mutation tested in lung cancer for targeted therapy in the era of personalized medicine. Knowledge about EGFR mutation is constantly expanding regarding its frequency, clinicopathological association, advancements in testing methodology and sample requirement. We investigated EGFR mutation frequency in non-small cell lung cancer (NSCLC) in North Indian patients and evaluated its diagnostic performance in cytological samples.

Methods

Molecular EGFR testing was done in 250 cases of NSCLC by both real-time polymerase chain reaction (PCR) (Therascreen) and mutation-specific EGFR immunohistochemistry (IHC). Thirty cases had both cytology samples and biopsy including 20 pleural effusions and 10 fine-needle aspirates. EGFR mutation concordance between pleural effusion and biopsy was studied.

Results

EGFR mutation was overall 31.6% in NSCLC with 36.5% in adenocarcinoma and 15% in squamous cell carcinoma. L858R mutation accounted for 50.7% and DEL19 for 39.3% of total EGFR mutations. Complex mutations were seen in 2% of cases. Sensitivity of mutation-specific EGFR IHC was 48.3% and specificity was 92.3%. L858R showed higher sensitivity (55% vs. 33.3%) but similar specificity (93.2% vs. 91.3%) compared to DEL19. EGFR mutation was successful in 95% of pleural effusion and showed 83.3% concordance with tissue biopsy.

Conclusions

EGFR mutation frequency in North Indian patients was comparable to that of Asia-Pacific region and showed a similar pattern of histological distribution. EGFR mutation in squamous cell carcinomas is increasingly recognized which was 15% in our study. Mutation-specific EGFR IHC shows variable but generally low sensitivity and considering its significant pre- and post-analytical variables, it should be highly discouraged in patient management. Cytological samples may not only serve as suitable alternative but may be complementary to tissue biopsies.

In silico insight into EGFR treatment in patients with lung carcinoma and T790M mutations

The T790M mutational basis of treatment failure, following treatment via alteration of the epidermal growth factor receptor (EGFR) pathway, is a well-known anomaly in patients with non-small cell lung cancer (NSCLC). The T790M mutation activates the kinase domain, causing tyrosine kinase inhibitors, such as gefitinib, to elicit little or no response. To overcome this acquired resistance in NSCLC cells, the present study utilized a structure-based drug designing method to identify a novel lead compound. An in-house traditional Chinese medicinal compound database was used and following initial virtual screening, pre-absorption, distribution, metabolism and excretion/Tox and automated docking analyses, nardosinon was selected as the most appropriate candidate for further analysis. Two NSCLC cell lines, PC9GR4 and H2347, were used to test nardosinon and the results were compared with gefitinib. Results from an initial cell death assay revealed that nardosinon was able to induce cell death in NSCLC cells with and without the T790M mutation. These findings suggest that nardosinon may be an effective pharmacological compound for NSCLC treatment, including T790M EGFR mutant NSCLC cells.