A study of therapy targeted EGFR/ALK mutations in Indian patients with lung adenocarcinoma: A clinical and epidemiological study

PD-L1 and molecular biomarker expression in non-small cell lung cancer in Tunisian patients

In cancer treatment, PD-1 and PD-L1 inhibitors are thriving. Activated T lymphocytes express PD-1; it works with its ligand PD-L1 to limit T lymphocyte activation and prevent autoimmune disease. The expression of molecular biomarkers and PD-L1 in lung cancer determines the appropriate treatment strategy for patients with lung cancer. The purpose of this study was to look at the prevalence of molecular biomarkers and PD-L1 expression in a large group of Tunisian patients with advanced non-small cell lung cancer. We conducted an observational retrospective study in which medical/treatment history data were extracted retrospectively from medical records and archived tissue samples between January 1, 2019, and December 31, 2021. We gathered 157 patients who had recently been diagnosed with non-small cell lung carcinoma. In 36.9% of the cases, there was no molecular genotyping. EGFR (28.6%), KRAS (5.73%), and ALK gene rearrangement were the most common genotyping mutations (3.8%). ROS1 rearrangement was not present. There was a link between EGFR and gender, HER and age, and KRAS and biopsy tissue origin. Six of the tested cases with PD-L1 met the cut-off (350%). PD-L1 positivity was more common in solid-type adenocarcinoma (1.9%) than in acinar or papillary adenocarcinoma. There were no significant differences in PD-L1 expression across clinical and demographic parameters. High PD-L1 expression and molecular abnormalities were found in one case of EGFR, one case of BRAF, and one case of KRAS (three cases). All of the other specimens with abnormalities had a PD-L1<50%. ALK, ROS1, BRAF, KRAS, and MET were found to be significantly associated with PD-L1 expression. Our study is one of the country's largest, describing a large panel of biomarkers and their clinicopathologic/histopathologic associations in Tunisian lung cancer patients. We have the same molecular profile as European patients with an EGFR mutation, which is not the most common genotype abnormality in Tunisian patients. There is only one mutation at any given time. The expression of PD-L1 is determined by the histologic type and the origin of the biopsy tissue.

Comprehensive molecular analysis of driver mutations in non-small cell lung carcinomas and its correlation with PD-L1 expression, An Indian perspective

BACKGROUND

The understanding of molecular mechanisms involved in non-small cell lung carcinoma (NSCLC) has revolutionized significantly in the recent years. These have helped to develop personalized management strategies by identifying specific molecular alterations such as mutations in EGFR, ROS1, BRAF, ERBB2, MET, ALK, and KRAS genes. These mutations are targetable ensuring a better clinical outcome. Next-generation sequencing (NGS) methodology is the recommended technique for the identification of driver mutations in the five hot-spot genes (EGFR, ALK, ROS1, MET, and BRAF) involved in the NSCLC. NGS has numerous advantages including multiplexing, tissue conservation, identification of rare and novel variants, and reduced cost over the sequential single gene testing. Herein, we sought to demonstrate the mutational profile in NSCLC and their clinicopathologic correlation in a contemporary cohort of Indian NSCLC patients. Additionally, we studied the correlation of oncogenic driver mutations with PD-L1 status in these patients.

MATERIALS AND METHODS

Five fifty-two stage IV NSCLC patients (adenocarcinoma=490; squamous cell carcinoma=51; adenosquamous carcinoma=5; large cell carcinoma=2; sarcomatoid carcinoma=3; spindle cell carcinoma=1) underwent broad molecular profiling by a custom-made, targeted DNA- and RNA-based five hot-spot genes lung cancer panel (EGFR, ALK, ROS1, BRAF, and MET), compatible with the NGS Ion S5 system. The mutations were correlated with the clinicopathologic characteristics. Additionally, PD-L1 expression status, available on 252 tumors, was correlated with the oncogenic drivers.

RESULTS

Validation of the 5 gene panel yielded the following results: a) specificity of 99.74%; b) sensitivity of 100% for single nucleotide variants (SNVs) (>5% variant allele frequency, VAF), indels (>10% VAF) and fusions; c) 100% intra- and inter-run reproducibility; d) 88% inter-laboratory agreement. Validated panel was then used to analyze clinical samples. Sixty percentage tumors harbored either one (54.71%) or multiple (3.26%) mutations. EGFR and BRAF V600E mutations, ALK and ROS1 rearrangements, and MET exon 14 skipping mutation were observed in 38.41% (n = 212) and 2.72% (n = 15) patients, 12.14% (n = 67) and 3.62% (n = 20) patients, and 1.09% (n = 6) patients, respectively. EGFR exon 19 deletion accounted for 52.83% of all mutations, followed by L858R (35.85%), T790M (5.19%), exon 20 insertions (6.6%), and other rare mutations (G719X, L861Q, S768I) (9.91%). Concurrent EGFR with ALK, EGFR with ROS1, EGFR with MET, and EGFR with BRAF were observed in 10, 4, 1, and 3 patients, respectively. PD-L1 was expressed in 134 patients (53.2%). Exon 19 deletion was more prevalent in PD-L1 negative tumors whereas exon 21 substitution (L858R) was seen more in PD-L1 positive tumors.

CONCLUSIONS

This is one of the largest cohorts of NSCLC for comprehensive targeted mutational profiling and correlation with the PD-L1 expression. The mutations are more prevalent in non-smoker females for all genes, except ALK (non-smoker males). MET and BRAF mutations are more common in elderly population whereas EGFR mutations, and ALK and ROS1 genes rearrangements are more prevalent in younger population. The most common histopathologic subtype/feature associated with various mutations was as follows: acinar with EGFR, solid with ALK, macronucleoli with ROS1, signet ring with MET, and micropapillary with BRAF.

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.

Prevalence of highly actionable mutations among Indian patients with advanced non-small cell lung cancer: A systematic review and meta-analysis

BACKGROUND

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-related mortality in India. To clarify rates of actionable mutations, and thereby identify opportunities to improve the delivery of best available care for a large volume of patients, a comprehensive review of available data is warranted.

METHODS

Studies that reported prevalence of any actionable gene variant among adult Indian patients with advanced NSCLC were selected from three databases (PubMed, EMBASE, and Cochrane Library). Ranges in actionable variant prevalence were reported. Meta-analysis of proportions was completed among studies specifically evaluating mutational prevalence within ALK or EGFR. Sensitivity analyses were undertaken among populations sharing high heterogeneity.

RESULTS

Twenty-six studies were selected. Ranges in actionable mutational prevalence among NSCLC patients were as follows: ALK: 4.1-21.4%, BRAF: 1.5-3.5%, EGFR: 11.9-51.8%, HER2: 0-1.5%, KRAS: 4.5-6.4%, NTRK: 0-.7%, and ROS-1: 3.5-4.1%. Following sensitivity analysis, pooled ALK mutational prevalence rates were 8.3% (95% CIs: 6.6-10.4%) and 4.01% (95% CIs: 2.3-7.0) for adenocarcinoma and NSCLC patients, respectively. Pooled EGFR mutational prevalence rates were 28.7% (95% CIs: 23.5-34.6%) and 24.2% (95% CIs: 19.9-29.1%) for adenocarcinoma and NSCLC patients, respectively.

CONCLUSIONS

Nearly 40% of Indian patients with advanced adenocarcinoma and 30% with NSCLC share an actionable mutation in ALK or EGFR. Approximately one-half of adenocarcinoma patients have an actionable variant. Efforts should be directed toward efficiently identifying candidates for targeted agents and delivering such treatments.

A brief report on the mutational landscape in non-small cell lung cancer of South Asian patients: Comparison at a US and an Indian Institution

Background

Various molecular underpinnings of lung cancer have been noted in Asian populations, especially with targetable oncogenic drivers such as EGFR mutations and ALK rearrangements, although they have been lesser described in South Asian/Indian patients.

Methods

Tumour molecular testing results from non-small cell lung cancer (NSCLC) patients with a name of South Asian origin and diagnosed from 2005 to 2019 at the Stanford Cancer Center in the United States were retrospectively reviewed and compared to the results of molecular testing from PGIMER in Chandigarh, India, from the patients diagnosed from 2011 to 2019.

Results

We identified 72 patients of South Asian (largely Indian) origin, of whom 64 patients (51% female) had mutational testing at Stanford. Of the tested patients, 33% of cases harboured either an EGFR exon 19 deletion or exon 21 L858R mutation, and 12.5% had ALK rearrangements. At PGIMER, a larger sample of 1,264 patients was identified (33% female), with 22.5% of patients having two main EGFR activating mutations, and 9.5% harbouring an ALK rearrangement.

Conclusions

South Asian, largely Indian, patients with NSCLC appear to have a higher chance of harbouring EGFR mutations and ALK translocation as compared to Caucasians. The percentage of South Asian patients with these molecular abnormalities was largely similar in two different geographical locations. These findings corroborate prior single-institution findings and emphasise the importance of molecular testing.

Real world experience of treatment and outcome in ALK-rearranged metastatic nonsmall cell lung cancer: A multicenter study from India

BACKGROUND

Anaplastic lymphoma kinase (ALK) rearranged metastatic non-small cell lung cancer (NSCLC) comprises 5%-7% of all lung cancer and carries a good prognosis with available ALK-inhibitors. Majority of registration trials in ALK-inhibitors did not include Indian patients. Hence, this study was planned to analyze the outcome of Indian patients treated with ALK-inhibitors and associated challenges.

METHODS

This is a multi-center study in 5 major tertiary care cancer centers across India treating ALK-rearranged NSCLC patients from April 2013 to April 2019. ALK rearrangement was determined by Ventana immunohistochemistry with D5F3 clone and/or by break-apart FISH. Patients treated with ALK-inhibitors in any lines of treatment were included in this study. Patients were evaluated for clinicopathologic features, patterns of ALK-inhibitors use and outcome. Progression free-survival (PFS) and overall survival (OS) were calculated and data were censored on April 30, 2019.

RESULTS

A total of 274 patients were studied, out of which 250 patients received ALK inhibitor and were analyzed further for outcome. The median age was 50 years (range: 24-82) and male to female ratio of 1.17:1. ALK was evaluated by immunohistochemistry in majority of patients (97%), 3 patients by FISH and 3 more patients were evaluated by both methods. Sixty-five percent (n = 162) of the patients received ALK-inhibitor as first line therapy, 51 patients received ALK-inhibitor as switch maintenance therapy after initial chemotherapy. Crizotinib and Ceritinib were used in 88% and 12%, respectively. One patient received Alectinib. Forty-one percent of patients had CNS progression. After median follow up of 27 months (1-72 months), the median OS was 24.7 months with OS rate of 72%, 51%, and 18% at 1, 2, and 4-years respectively. Median OS was 21.2, 26, and 38 months in the first line ALK-inhibitors use (n = 162), switch maintenance group (n = 51) and second line ALK-inhibitors use (postchemotherapy progression) (n = 33), respectively. No baseline variable predicted PFS. Presence of brain metastasis (P = 0.039) and first line ALK-inhibitors use (P = 0.032) emerged as poor prognostic factor for OS on multivariate analysis. PFS rate was 70%, 47%, and 31% at 6, 12, and 18 months respectively.

CONCLUSION

This is one of the largest real-world data on outcome of ALK inhibitors in ALK-rearranged NSCLC from Asia. In absence of second line ALK inhibitor, initial chemotherapy followed by ALK-inhibitors (switch maintenance) had better outcome. This fact may be studied in individual patient data meta-analysis. Poor performance status and brain metastases at presentation are poor prognostic factors for overall survival. Second-line ALK inhibitor use crucial for better outcome and access to clinical trials are much needed in Indian patients.

Clinical profile of lung cancer in North India: A 10-year analysis of 1862 patients from a tertiary care center

INTRODUCTION

Over the past few years, the demographic profile of lung cancer has changed. However, most reports are limited by small numbers, short follow-up period, and show an inconsistent pattern. A comprehensive evaluation of changing trends over a long period has not been done.

MATERIALS AND METHODS

Consecutive lung cancer patients were studied over a 10-year period from January 2008 to March 2018 at the All India Institute of Medical Sciences, New Delhi, and relevant clinical information, and survival outcomes were analyzed.

RESULTS

A total of 1862 patients were evaluated, with mean (SD) age of 59 (11.1) years, and comprising 82.9% males. Majority were smokers (76.2%) with median smoking index of 500 (interquartile range [IQR]: 300-800). Adenocarcinoma (ADC) was the most common type (34%), followed by squamous cell carcinoma (SCC - 28.6%) and small cell lung cancer (SCLC) (16.1%). Over the 10-year period, ADC increased from 9.5% to 35.9%, SCC from 25.4% to 30.6%, and non-small cell lung cancer -not otherwise specified (NSCLC-NOS) decreased from 49.2% to 21.4%. The proportion of females with lung cancer increased although smoking rates remained similar. Majority of NSCLC (95%) continued to be diagnosed at an advanced stage (3 or 4). Epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements were present in 25.3% and 11.5% ADC patients, respectively. The median overall survival was 8.8 months (IQR 3.7-19) for all patients and 12.57 (IQR 6.2-28.7) months among the 1013 patients who were initiated on specific treatment (chemotherapy, targeted therapy, radiotherapy, or surgery). Never-smokers were younger, more likely to be female and educated, had a higher prevalence of ADC and EGFR/ALK mutations, and had better survival.

CONCLUSION

Among this large cohort, our center seems to follow the global trend with increasing incidence of ADC. EGFR mutation positivity was similar to existing reports, while higher ALK positivity was detected. A characteristic phenotype of never-smokers with lung cancer was elucidated which demonstrated better survival.

Molecularly targeted therapies in non-small cell lung cancer: The evolving role of tyrosine kinase inhibitors

Non-small cell lung cancer (NSCLC) is a major subtype of lung cancer. Patients with NSCLC are diagnosed at a locally advanced or metastatic stage where prognosis with palliative chemotherapy is poor. The discovery of epidermal growth factor receptor (EGFR) mutations has revolutionized cancer treatment for NSCLC by promoting the development of molecularly targeted therapies like tyrosine kinase inhibitors (TKIs). This review summarizes the clinical efficacy and tolerability of EGFR-TKIs, including osimertinib, in EGFR-mutated advanced NSCLC. EGFR-TKIs have demonstrated superior response and overall survival rates compared with chemotherapy in EGFR-mutated NSCLC. However, despite the initial rapid and durable clinical responses, acquired resistance to first- and second-generation TKIs eventually develops in most cases, with disease progression observed mostly within 12 months of treatment initiation. Osimertinib, a potent third-generation TKI, irreversibly inhibits mutated EGFR alleles, including T790M. In addition to longer survival and higher response rate, osimertinib has a favorable safety profile with a lower incidence of grade ≥3 treatment-related adverse events compared with other TKIs. Based on the efficacy and safety results, recently the National Comprehensive Cancer Network (NCCN) has included osimertinib as the "preferred first-line of treatment" in patients with metastatic EGFR mutationpositive NSCLC. Thus, osimertinib as first-line therapy for EGFRpositive patients irrespective of the T790M mutation status could be an ideal choice in the Indian setting where only 50% of patients opt for any second-line therapy after first-line failure.