The frequency of high PD-L1 expression is low in lung adenocarcinoma patients from Northeast Brazil

Clinicopathological Features and Status of Programmed Death Ligand-1 (PD-L1) Expression in Lung Cancer: A Single Centre Study From North India

Introduction Programmed death ligand-1 (PD-L1) is an immunological checkpoint that supports the inhibition of the anti-tumor immune system. A higher level of PD-L1 expression was also discovered on the cell surfaces of several cancer cells, including non-small cell lung carcinoma (NSCLC). Identifying individuals who would benefit from PD-1/PD-L1 antibody immunotherapy is crucial in the era of precision medicine. The study's objective was to assess the distribution and degree of PD-L1 ligand expression in various forms of lung cancer and examine its link to clinicopathological variables. Methods This prospective, observational, cross-sectional study was done in a tertiary care hospital in North India over 2 years from 2019 to 2021. A total of 100 patients diagnosed with lung cancer through either endobronchial or image-guided biopsies were enrolled. The biopsy specimens of lung cancer patients have been subjected to immunohistochemistry (IHC) staining. PD-L1 expression was positive when at least 1% of tumor cells were stained. In our study, we used the rabbit monoclonal Anti-PD-L1 antibody (CAL10) (ab237726) (Abcam Plc, UK).  Results  Of the 100 patients, Squamous cell carcinoma (SQCC) was the predominant histological pattern. The mean age of the study group was 57.26 ± 10.53 years. High PDL-1 positivity (>50% ) is seen in a total of 10 patients, while low PD-L1 positivity (1-50%) is seen in 24 patients. Of all patients with high PD-L1 positivity (n=10), 80% had stage IV at the time of diagnosis. However, on similar lines, 71 % of patients with low PD-L1 positivity presented with stage IV at the time of diagnosis. (p value=0.09). Among 10 patients with epidermal growth factor receptor (EGFR) positive status, high PD-L1 positivity is seen in 20%. Among 3 patients with anaplastic lymphoma kinase (ALK) positive status, only one patient showed high PD-L1 positivity, whereas negative PDL-1 was seen in 2 patients, which was not statistically significant. Conclusion  The management of lung cancer is driven by precision medicine, including PDL-1 expression, which correlates with immune checkpoint inhibitor response. In our cohort, PD-L1 expression appears to be mostly linked to the squamous cell subtype of lung cancer, with elevated tumor stage and mediastinal lymphadenopathy in Kashmiri people. Other oncogenic driver mutations are not connected to PD-L1 expression. The function of PD-L1 expression in lung tumors requires more study.

Distribution and Expression of Programmed Death Ligand -1 (PD-L1) in Non-Small Cell Carcinomas of the Lung in a Tertiary Care Centre in South India

OBJECTIVE

Non-small cell lung carcinomas often present at an advanced stage with a grim prognosis. Immune checkpoint (ICP) inhibitors have drastically changed the scenario, and the response to ICP inhibitors is determined by analyzing the expression of PD-L1 by immunohistochemistry. PD-L1 immunohistochemistry helps in optimizing the treatment, and avoiding unnecessary exposure of patients to the toxic effects of the drugs that are ineffective and expensive in non-expressing tumors. This study was conducted to assess the prevalence of the expression of PD-L1 in non-small cell carcinomas of the lung diagnosed at our institution, which is a tertiary care center in South India.

MATERIAL AND METHOD

The PD-L1 immunohistochemistry of 77 cases of non-small cell carcinomas of the lung diagnosed over a period of two years were reviewed and analyzed (2018-2020). All tissues were fixed in 10% neutral buffered formalin and processed by standard methods, and the Ventana SP263 clone was used.

RESULTS

Seventy-seven cases of non-small cell lung carcinomas were reviewed and studied for (PD-L1) expression. 35/77 (45%) of the cases had PD-L1 expression (≥ 1%) and 14 (18 %) had high (PD-L1) expression. Also there was a male preponderance of 2.3:1. High PD-L1 expression was seen mostly in patients above 60 years of age and was usually associated with high tumor grade.

CONCLUSION

It is important to assess PD-L1 expression in non-small cell carcinomas of patients especially with higher tumor grade and older age groups that they may benefit from immune checkpoint inhibitor therapy.

Analysis of Predictive Biomarkers in Patients With Lung Adenocarcinoma From Southern Brazil Reveals a Distinct Profile From Other Regions of the Country

PURPOSE

Adenocarcinoma is the most common histologic subtype of non–small-cell lung cancer, representing 40% of all diagnoses. Several biomarkers are currently used to determine patient eligibility for targeted treatments, including analysis of molecular alterations in EGFR and ALK, as well as programmed death-ligand 1 (PD-L1) protein expression. Epidemiologic data reporting the frequency of these biomarkers in Brazilian patients with lung adenocarcinoma (LUAD) are limited, and existing studies predominantly included patients from the southeast region of the country.

MATERIALS AND METHODS

The goal of this study was to investigate the frequency of somatic mutations in the EGFR, KRAS, NRAS, and BRAF genes, ALK, and PD-L1 expression in a series of Brazilian patients diagnosed with LUAD predominantly recruited from centers in southern Brazil. Molecular analysis of the EGFR, KRAS, NRAS, and BRAF genes was performed by next-generation sequencing using DNA extracted from tumor tissue. Immunohistochemistry was used to detect ALK and PD-L1 expression.

RESULTS

Analysis of 619 tumors identified KRAS mutations in 189 (30.2%), EGFR mutations in 120 (19.16%), and BRAF mutations in 19 (3%). Immunohistochemistry demonstrated ALK and PD-L1 expression in 4% and 35.1% of patients, respectively.

CONCLUSION

To our knowledge, this is the first study investigating the molecular epidemiology of patients with LUAD from southern Brazil and the largest assessing the frequency of multiple predictive biomarkers for this tumor in the country. The study also reveals a distinct mutation profile compared with data originating from other regions of Brazil.

Correlation of programmed death-ligand 1 expression with gene expression and clinicopathological parameters in Indian patients with non-small cell lung cancer

Objectives:

The aim of this study is to evaluate the incidence of programmed cell death-ligand 1 (PD-L1) expression in non-small cell lung cancer (NSCLC) cases and its correlation with gene mutation and clinicopathological parameters.

Methods:

Samples from NSCLCs patients were studied for PD-L1 expression through immunohistochemistry (IHC) using Rabbit anti-human PDL-1/CD274 Monoclonal Antibody. Genetic mutations were studied using IHC/fluorescence in situ hybridization (FISH) methods (for anaplastic lymphoma kinase [ALK]) or polymerase chain reaction/gene sequencing analysis (for epidermal growth factor receptor [EGFR]). Pearson's correlation coefficient (r) was used for correlation analysis. PD-L1 expression was analyzed for association with clinicopathological features.

Results:

Of the 101 NSCLC cases, PD-L1 expression was observed in 33.66% (34/101) cases; tumor proportion score of <50%: 67.65% (23/34) and ≥50%: 32.35% (11/34) cases. PD-L1 positivity was seen in; males: 35.5%, females: 28%, smokers: 37.7%, cases with brain metastasis: 20%, cases with pleural effusion: 20.8%, and histopathological evaluation (well-differentiated: 21.42%, moderately-differentiated: 13.79%, poorly-differentiated: 36.11%, and adenosquamous disease: 40.9%). Genetic mutation studies revealed PD-L1 positivity in 18.1% cases with EGFR mutation, 50% of ALK-IHC positive cases, and 33.3% ALK-FISH positive cases. No or very weak correlation (r < 0.3) in PD-L1 expression with gene mutations or clinicopathological parameters was observed.

Conclusions:

The study demonstrated PD-L1 expression in ~ 1/3^rd cases of NSCLC patients. No or very weak correlation was observed for PD-L1 expression with genetic mutations and other parameters studied. The presence of gene mutations in PD-L1 expressed samples suggests further investigation on PD-L1 inhibitors in such patients for decisive treatments.