Relationship of epidermal growth factor receptor activating mutations with histologic subtyping according to International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society 2011 adenocarcinoma classification and their impact on overall survival

Non-Small Cell Lung Cancer: Targetable Variants in Concurrent Tissue and Liquid Biopsy Testing in a North Indian Cohort

OBJECTIVES

Testing for EGFR, ALK, ROS1 and MET alterations in paired tissue and plasma samples of treatment-naïve patients of NSCLC and correlating their status with overall survival.

MATERIALS AND METHODS

One hundred treatment-naïve patients were recruited after obtaining informed consent. Ten ml of blood was collected within a period of two weeks from histological diagnosis, prior to the start of any treatment. DNA & RNA extraction was done from formalin-fixed paraffin embedded (FFPE) tissue and total cell-free nucleic acid extraction was done from plasma samples. EGFR mutation, ALK, ROS1 and MET rearrangements were tested by ARMS (Amplification Refractory Mutation System) PCR. All statistical analyses were conducted in R version 4.1.1.

RESULTS

A total of 61 cases showed molecular alterations in tissue samples which included EGFR mutations (47), ALK rearrangements (12), ROS1 fusion (2). MET alteration was not detected. Forty-three cases showed EGFR mutations in plasma, 26 of which were concurrently positive in tissue. Concordance observed was 62%. ALK-EML4 rearrangement, ROS1 fusion and MET were not detected in plasma samples. Sensitivity and specificity for detection of EGFR mutation in plasma were 55.3% and 67.9% respectively. Univariate Cox regression analysis showed a positive association between EGFR mutation in tissue and overall survival (HR = 0.4; 95% CI: 0.2-0.7; p = 0.003) and improved overall survival in those who received targeted therapy (HR = 0.29; 95% CI: 0.1-0.8; p = 0.02).

CONCLUSION

Concurrent testing in tissue and liquid biopsy in NSCLC increased the detection of EGFR mutations (47% to 64%). This has substantial implications in deciding treatment and administration targeted therapy and the consequent overall survival.

Detection of ALK Gene Rearrangements in Non-Small Cell Lung Cancer by Immunocytochemistry and Fluorescence in Situ Hybridization on Cytologic Samples

OBJECTIVE

Determination of the molecular status is mandatory for personalized treatment of patients with non-small cell lung carcinoma. The present study was performed to detect anaplastic lymphoma kinase (ALK) rearrangements in pulmonary adenocarcinoma on cytology samples, using immunocytochemistry (ICC) and fluorescence in situ hybridization (FISH) on cell-blocks to assess the diagnostic reliability of these two techniques.

MATERIAL AND METHOD

A total of 50 confirmed lung adenocarcinoma cases were included. In all the 50 cases, ICC was performed for ALK protein expression by using the D5F3 clone on Ventana platform. On the basis of ALK protein expression on ICC, the cases were categorized as ALK positive (2+ or 3+ strong cytoplasmic granular positivity) or negative (negative or 1+ cytoplasmic granular positivity). FISH for detection of ALK gene rearrangement was performed in 7 ALK ICC positive cases and 7 ALK ICC negative cases using the Vysis ALK break apart FISH probe kit.

RESULTS

Based on ICC, 7(14%) cases were ALK positive and 43(86%) were ALK negative. ALK gene rearrangements in lung adenocarcinoma were more commonly seen in non-smokers (31.25%) as compared to smokers (6.25%). Among the ALK-ICC positive cases, FISH demonstrated break apart signal in 5 cases (ALK- ICC positive); however, no break-apart signals were seen in 2 ALK-ICC positive and all the seven ALK-ICC negative cases.

CONCLUSION

Immunocytochemistry on cell- blocks using DF53 clone is a highly sensitive and specific method for the detection of ALK gene rearrangements in lung adenocarcinoma with a greater number of ALK positive cases being detected on ICC as compared to the ALK-FISH.

Correlation of Epidermal Growth Factor Receptor Mutation With Major Histologic Subtype of Lung Adenocarcinoma According to IASLC/ATS/ERS Classification

OBJECTIVE

Our prospective study aims to define the correlation of EGFR(epidermal growth factor receptor) mutations with major histological subtypes of lung adenocarcinoma from resected and non-resected specimens, according to the WHO 2015 classification, in Moroccan North East Population.

METHODS

Epidermal growth factor receptor mutations of 150 primary lung adenocarcinoma were performed using Real-Time PCR or SANGER sequencing. SPSS 21 was used to assess the relationship between histological subtypes of lung adenocarcinoma and EGFR mutation status.

RESULTS

25 mutations were detected in the series of 150 lung adenocarcinomas, most of which were found in cases with papillary, acinar, patterns than without these patterns and more frequently occurred in the cases without solid pattern than with this pattern. A significant correlation was observed between EGFR mutation and acinar (P = 0,024), papillary pattern (P = 0,003) and, negative association with a solid pattern (P < 0,001). In females, EGFR mutations were significantly correlated with the acinar pattern (P = 0,02), whereas in males with the papillary pattern (P = 0,01). Association between the histologic component and exon 19 deletions and exon 21 mutations were also evaluated and, we found a significant correlation between the papillary major pattern with exon 19 mutations (P = 0,004) and, ex21 with the acinar component (P = 0,03).

CONCLUSION

An analysis of resected and non-resected lung ADC specimens in 150 Moroccan Northeast patients, revealed that acinar and papillary patterns may predict the presence of a mutation in the EGFR gene. While the solid major pattern may indicate a low mutation rate of the EGFR gene.

Pathological cytomorphologic features and the percentage of ALK FISH-positive cells predict pulmonary adenocarcinoma prognosis: a prospective cohort study

Background

We conducted a study to explore the relationship between pathological cytomorphologic features and the percentage of anaplastic lymphoma kinase (ALK)-positive cells to better predict pulmonary adenocarcinoma prognosis with crizotinib treatment.

Patients and methods

We investigated 60 cases of patients with ALK-positive advanced or metastatic non-small cell lung cancer (NSCLC). Immunohistochemistry was performed to screen for ALK rearrangement. Fluorescence in situ hybridization (FISH) was used to detect the percentage of ALK-positive cells. The primary objectives of the study were the progression-free survival (PFS), the 3-year overall survival, and the 3-year overall survival (OS) rates. The secondary objectives of the study were the disease control rate (DCR) and the overall response rate (ORR).

Results

We compared the pathological cytomorphologic features of 60 cases of ALK-positive pulmonary adenocarcinoma, of which 21 cases were ALK-positive with signet ring cell cytomorphologic characteristics. There were statistical differences in the ORR (p = 0.019), DCR (p = 0.032), and PFS (p = 0.047) between the signet ring cell group and group without signet ring cells. Of these, 37 cases were ALK-positive with EML4 (echinoderm microtubule associated protein like 4)-ALK high percentage of positivity group. These cases benefited more from crizotinib treatment in the ORR (p = 0.046) and achieved a longer PFS (p = 0.036) compared to those with EML4-ALK low percentage of positivity group.

Conclusions

Signet ring cell cytomorphologic characteristics of pulmonary adenocarcinoma are associated with the percentage of ALK-positive cells. Signet ring cell cytomorphologic characteristics and the percentage of ALK-positive cells might predict the prognosis of pulmonary adenocarcinoma with crizotinib treatment.

Trial registration

The study was approved by the Institutional Review Board (Medical Ethics Committee of Yantai Yuhuangding Hospital). The registration number is NO.2016[193].

Driver and novel genes correlated with metastasis of non-small cell lung cancer: A comprehensive analysis

Although mutations of genes are crucial events in tumorigenesis and development, the association between gene mutations and lung cancer metastasis is still largely unknown. The goal of this study is to identify driver and novel genes associated with non-small cell lung cancer (NSCLC) metastasis. Candidate genes were identified using a novel comprehensive analysis, which was based on bioinformatics technology and meta-analysis. Firstly, EGFR, KRAS, ALK, TP53, BRAF and PIK3CA were identified as candidate driver genes. Further meta-analysis identified that EGFR (Pooled OR 1.33, 95% CI 1.19, 1.50; P < .001) and ALK (Pooled OR 1.52, 95% CI 1.22, 1.89; P < .001) mutations were associated with distant metastasis of NSCLC. Besides, ALK (Pooled OR 2.40, 95% CI 1.71, 3.38; P < .001) mutation was associated with lymph node metastasis of NSCLC. In addition, thirteen novel gene mutations were identified to be correlated with NSCLC metastasis, including SMARCA1, GGCX, KIF24, LRRK1, LILRA4, OR2T10, EDNRB, NR1H4, ARID4A, PRKCI, PABPC5, ACAN and TLN1. Furthermore, elevated mRNA expression level of SMARCA1 and EDNRB was associated with poor overall survival in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), respectively. Additionally, pathway and protein-protein interactions network analyses found the two genes were correlated with epithelial-mesenchymal transition process. In conclusion, mutations of EGFR and ALK were significantly correlated with NSCLC metastasis. In addition, thirteen novel genes were identified to be associated with NSCLC metastasis, especially SMARCA1 in LUAD and EDNRB in LUSC.

Comparison of epidermal growth factor receptor mutation detection turnaround times and concordance among real-time polymerase chain reaction, high-throughput next-generation sequencing and the Biocartis Idylla™ platforms in non-small cell lung carcinomas

OBJECTIVES

Activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene of non-small cell lung carcinomas (NSCLC) can be targeted by the tyrosine kinase inhibitors. A number of molecular diagnostic platforms are used to detect actionable targets in the exon(s) 18, 19, 20, and 21 of the EGFR gene. The Idylla™ system (Biocartis, Mechelen, Belgium) is a relatively novel technique and is unique in integrating both sample processing and real-time polymerase chain reaction (RT-PCR) in a single cartridge. We sought to conduct this study to compare the turnaround time (TAT) and concordance of Idylla™ system with the conventional RT-PCR and next-generation sequencing (NGS) for EGFR mutation detection.

METHODS

In this retrospective analysis, 38 formalin-fixed, paraffin-embedded NSCLC tissue blocks with known NGS results by Ion Torrent™ S5 NGS platform were retested by the RT-PCR and Idylla™ platforms.

RESULTS

A total of 15 of 38 (39.4 %) tumors that showed various EGFR mutations by NGS and conventional RT-PCR techniques were subjected to the Idylla™testing. These cases satisfied the specimen adequacy criteria of at least 10 % tumor cells for the testing. The mutations detected by the NGS were also detected by the Idylla™ testing. However, NGS identified additional 3 mutations in 3 cases, involving T709 V (exon 18, n = 1) and V774 M (exon 20, n = 2). The tumors with wild type EGFR on NGS did not have any actionable mutation detected by the Idylla™. Average EGFR testing TAT by Idylla™ was only 7.2 h (4-12 hours), as compared to conventional RT-PCR taking 54 h (31-79 hours) and NGS requiring 10.7 days (7.1-14 days). The actual procedure time by conventional RT-PCR was 24 h, NGS was 6.5 days, and Idylla™ was only 3 h.

CONCLUSIONS

In summary, the Idylla™EGFR testing is an efficient, rapid, and fairly simple tool that can be used in the routine molecular laboratory with limited expertise and infrastructure and using the lowest amount of tissue material.

Thyroid dysfunction in non-small cell lung cancer patients treated with epidermal growth factor receptor and anaplastic lymphoma kinase inhibitors: Results of a prospective cohort

OBJECTIVES

Epidermal Growth Factor Receptor (EGFR) and Anaplastic Lymphoma Kinase (ALK) Tyrosine Kinase Inhibitors (TKIs) are the preferred treatment option for patients with advanced/metastatic non-small cell lung cancer (NSCLC) harboring EGFR mutations and ALK rearrangements respectively. TKIs can theoretically induce thyroid dysfunction via actions on many levels of the hypothalamic-pituitary-thyroid axis. However, there are no published studies on occurrence of thyroid dysfunction related to use of EGFR/ALK TKIs in lung cancer. The current study aimed to prospectively and comprehensively evaluate incidence of thyroid dysfunction in NSCLC patients treated with EGFR and ALK inhibitors.

METHODS

This prospective observational study at a tertiary care referral hospital included histologically/cytologically proven advanced/metastatic NSCLC patients treated with EGFR and ALK inhibitors over a period of 15 months. Thyroid function tests (including anti-TPO antibody) were done at baseline and repeated every month for first three months and then every three monthly for 12 months.

RESULTS

Six different drugs (EGFR and ALK inhibitors) were used for treatment of 50 NSCLC patients enrolled. Of these, four drugs caused thyroid dysfunction (EGFR inhibitors erlotinib, gefitinib and ALK inhibitors ceritinib, crizotinib). Thyroid dysfunction typically occurred at 1 month following start of TKI treatment. Prevalence of thyroid dysfunction was 8%. Distribution of subclinical (not requiring treatment) and overt thyroid dysfunction (requiring specific treatment) was 4% each. All patients were asymptomatic. Both patients with overt thyroid dysfunction had hypothyroidism while subclinical dysfunction was equally distributed between hypo- and hyper- thyroidism. All patients who developed thyroid dysfunction derived expected clinical benefit and none required TKI dose interruption or stoppage.

CONCLUSIONS

NSCLC patients may need to be monitored for occurrence of thyroid dysfunction during treatment with EGFR and ALK TKIs.

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.

Clinicopathologic Significance of Intestinal-type Molecules' Expression and Different EGFR Gene Status in Pulmonary Adenocarcinoma

Variant pulmonary adenocarcinoma with intestinal-type molecules shares similar molecular expression with colorectal carcinoma. However, expression of such molecules and their association with survival time with clinicopathologic parameters, such as epidermal growth factor receptor (EGFR) gene status in other types of pulmonary adenocarcinoma, has been rarely demonstrated. Sixty patients with resected pulmonary adenocarcinoma were divided into the enteric differentiation group (I group, n=30) and the usual group (U group, n=30). Immunohistochemical staining was used to assess the expression of carcinoembryonic antigen (CEA), Villin, CK20, and caudal-related homeobox 2 (CDX2). EGFR gene status was examined by Fluorescence Quantitative polymerase chain reaction. Kaplan-Meier survival curve was drawn by GraphPad Prism 5.0 software. The results showed that there was a significant difference between the 2 groups (P<0.05) in the expression of Villin, CK20, and CDX2, whereas the expression of CEA showed no significant difference (P>0.05). Compared with the U group, patients in the I group were mainly female individuals and in clinical stages III to IV, prone to lymph node metastasis (P<0.05). The patients in the I group with CDX2CK20 phenotype (tumor size>5 cm) had a shorter survival time (P<0.05), and EGFR gene status was not associated with median survival time and the expression of CEA, Villin, CK20, and CDX2 (P>0.05). Thus, our research indicates that patients with enteric differentiation have unique clinical characteristics and different prognosis, which may play important roles in diagnosis and choosing therapeutic strategies for pulmonary adenocarcinoma patients in clinical practice.

Epidermal growth factor receptor (EGFR), KRAS, and BRAF mutations in lung adenocarcinomas: A study from India

Mitogen-Activated Protein (MAP) Kinase pathway involves several oncogenic genes which can serve as potential targets for therapy. Therefore, aim of the present study is to analyze mutations in the MAP Kinase pathway in pulmonary adenocarcinoma (ADCA) of Indian patients along with clinico-pathologic correlation and determination of the survival status in patients receiving therapy. Blocks and slides of 125 pulmonary ADCA of last 5 years were retrieved. Histo-morphology and tumor content were determined. EGFR, KRAS, BRAF and MEK1 genes were analyzed using Sanger sequencing and Real-time polymerase chain reaction (PCR). Clinico-pathologic correlation and survival analysis were performed. Fifty-eight (46.4%) patients harbored genetic mutations of which 49 had single somatic mutations, 5 had multiple exonic and 4 showed coexisting EGFR and KRAS mutations. EGFR mutations were seen in 24.8%, KRAS in 19.2% and BRAF (non-V600E) in 2.4% cases. There was no difference in progression-free survival of wild- type/single mutations when compared with multiple/ coexisting mutations (P = 0.09). However, the P value may indicate borderline correlation. To conclude, EGFR and KRAS mutations may coexist in the same patient in lung ADCA. Multiple exonic mutations of KRAS gene formed substantial percentage of our cohort, requiring further exploration. Lung ADCA harbouring BRAF mutations are commonly non-V600E. Testing of all major genetic driver mutations of lung ADCA irrespective of histology and other demographic characteristics is necessary.

Cytomorphological features as predictors of epidermal growth factor receptor mutation status in lung adenocarcinoma

BACKGROUND

Epidermal growth factor receptor mutation-positive (EGFR-p) lung adenocarcinomas are sensitive to tyrosine kinase inhibitors. Although histopathological subtype is an independent predictor of mutation status, there is a paucity of data on the cytomorphological features correlating with the EGFR mutation status. Therefore, the aim of this study was to determine whether certain cytomorphological features correlate with EGFR mutation in lung adenocarcinoma.

MATERIALS AND METHODS

A retrospective analysis of 48 lung adenocarcinoma cases diagnosed on fine needle aspiration cytology with known EGFR mutation status was conducted. All cytology smears with cellblock sections were reviewed. The cytomorphological features including tumor pattern, stromal features, nuclear and cytoplasmic features, and tumor grade were evaluated. Clinicoradiological features such as age, sex, smoking, tumor size, clinical stage, metastases, and presence of mass, nodule, lymphadenopathy, pleural effusion, and clinical outcome were also assessed.

RESULTS

Of 48 cases, 19 were EGFR-p and 29 were negative. EGFR-p cases showed a positive and significant correlation with flat monolayered sheets and acini, mild nuclear atypia, fine chromatin and smooth nuclear margins and these tumors were well differentiated. EGFR-negative tumors were moderate to poorly differentiated with predominance of solid clusters, moderate to marked nuclear atypia, with irregular nuclear margins and coarse chromatin. Clinically, female sex, nonsmoking status, smaller tumor size, and good clinical outcome correlated with EGFR-p status.

CONCLUSION

Certain cytomorphological features correlate with and may suggest EGFR mutation status in advanced lung adenocarcinoma in an appropriate clinical context.

Comparison of Symptom Score and Bronchoscopy-Based Assessment With Conventional Computed Tomography-Based Assessment of Response to Chemotherapy in Lung Cancer

PURPOSE

There is a paucity of literature on symptom score (SS) plus fiberoptic bronchoscopy (FOB) -based response evaluation (RE) to chemotherapy for lung cancer. This study aimed to compare the reliability of RE by SS, chest radiograph (CXR), and FOB with computed tomography (CT) -based assessment (Response Evaluation Criteria in Solid Tumors (RECIST) and WHO criteria) for lung cancer chemotherapy.

METHODS

This was a prospective observational study involving treatment-naïve patients with lung cancer planned for chemotherapy, with one or more lesions on FOB and CT. Patients underwent assessment twice by SS, CXR, FOB, and CT (at baseline and after chemotherapy). Six symptoms (dyspnea, cough, chest pain, hemoptysis, anorexia, and weight loss) were noted on visual analog scale. Respiratory symptom burden (RSB) and total symptom burden (TSB) were calculated from the first four and all six symptoms, respectively, as the mean of individual SS. Bronchoscopic findings were recorded as per European Respiratory Society classification for tracheobronchial stenosis. Responses were classified as complete response (CR), partial response (PR), stable disease (SD), or progressive disease (PD) by each method. For FOB and SS, improvement or worsening by ≥ 20% was taken as PR or PD, respectively, whereas < 20% change was considered SD. Agreements were tested using Cohen's κ statistic.

RESULTS

All individual SS, RSB, and TSB scores, and the number and distribution of FOB lesions improved significantly after chemotherapy. Individually, CXR and SS had no or minimal agreement with FOB-based and CT-based responses. RECIST and WHO criteria had strong agreement overall (Cohen's κ = 0.872) and perfect agreement for PD (Cohen's κ = 1.000). Cohen's κvalues for FOB-based assessment with RECIST and WHO were 0.324 and 0.349, respectively for overall RE, and 0.462 and 0.501 for differentiating responders (CR and PR) from nonresponders (SD and PD), respectively. Cohen's κvalues for PD were 0.629 (FOB alone), 0.672 (FOB and RSB), 0.739 (FOB and TSB), and 0.764 (FOB and CXR).

CONCLUSION

CT-based assessment should remain the reference for objective RE of chemotherapy in lung cancer. A combination of FOB and CXR may be used as a surrogate to diagnose PD if CT is not feasible.

ALK gene rearranged lung adenocarcinomas: molecular genetics and morphology in cohort of patients from North India

ALK gene rearrangement in the lung adenocarcinomas is the second most common (1.6-11.7% of NSCLC) targetable genomic change after EGFR mutations. However, the prevalence and clinicopathological features of ALK-rearranged lung adenocarcinomas from North India are lacking. A total of 240 cases of lung adenocarcinoma were screened for EGFR mutations and for ALK expression. Smoking status, TNM stage, and treatment response were recorded in all cases. Out of 240 cases screened, 37 cases were positive for EGFR mutations and 17 cases (7.08%) showed ALK positivity with immunohistochemistry and break-apart FISH. On excluding 37 EGFR mutation-positive cases, the incidence of ALK-positive adenocarcinoma appears to be higher (17/203 cases, 8.03%). Eight were men and nine were women with mean age of 51.7 years. Majority (62.5%) were non-smokers and had unresectable disease (70.6% stage IV, 17.6% IIIB). The morphological patterns noted were solid (12 cases), papillary (four cases), and micropapillary (one case). Signet ring (two cases) and clear cell change (one cases) were noted. Out of five patients who received crizotinib, three had partial response and two had stable disease. ALK-rearranged lung adenocarcinomas account for a minor proportion of NSCLC with prevalence similar to that reported in literature. However, as contrast to published data in our series, patients were in older age group and had solid and papillary pattern on morphology with an aggressive course.