PDL-1 expression in lung carcinoma and its correlation with clinicopathological and prognostic characteristics

Targeting PD-1/PD-L1 in tumor immunotherapy: Mechanisms and interactions with host growth regulatory pathways

Tumor immunotherapy has garnered considerable attention, emerging as a new standard of care in cancer treatment. The conventional targets, such as VEGF and EGFR, have been extended to others including BRAF and PD-1/PD-L1, which have shown significant potential in recent cancer treatments. This review aims to succinctly overview the impact and mechanisms of therapies that modulate PD-1/PD-L1 expression by targeting VEGF, EGFR, LAG-3, CTLA-4 and BRAF. We investigated how modulation of PD-1/PD-L1 expression impacts growth factor signaling, shedding light on the interplay between immunomodulatory pathways and growth factor networks within the tumor microenvironment. By elucidating these interactions, we aim to provide insights into novel potential synergistic therapeutic strategies for cancer immunotherapy.

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.

Correlation Between Pretreatment Neutrophil-to-Lymphocyte Ratio and Programmed Death-Ligand 1 Expression as Prognostic Markers in Non-Small Cell Lung Cancer

Background

The neutrophil-to-lymphocyte ratio (NLR) at baseline treatment is an important marker of systemic inflammation, which is correlated with survival benefits in lung, breast, ovarian, bladder, and colorectal cancer. Programmed death-ligand 1 (PD-L1) expression is a biomarker with discording results regarding survival benefits in lung cancer. In our research, we studied the relationship between these two markers in patients with lung cancer.

Methods

Patients with stage I, II, III, and IV lung cancer (n = 80) were included in this retrospective study. The NLR baseline was recorded before the initiation of treatment. The NLR cut-off value was 4. PD-L1 expression was determined by immunohistochemical staining. Univariate and multivariate survival analyses were conducted to test their prognostic value.

Results

NLR proved to be a significant prognostic factor for progression-free survival (PFS) (p=0.002, Log Rank) with a mean PFS of 27.7 months for low NLR patients and 12.8 months for high NLR patients. It was also significant for overall survival (OS) (p=0.007, Log Rank) with a mean OS of 52 months for low NLR patients and 41.6 months for high NLR patients. The prognostic impact of PD-L1 expression on PFS and OS was not statistically significant with a mean PFS of 23.1 months for PD-L1-negative patients and 15.8 months for PD-L1-positive patients (p=0.422, Log Rank). Mean OS was 49 months for PD-L1-negative patients while for PD-L1-positive patients, it was 43.3 months (p=0.550 Log Rank). Regarding the correlation between PD-L1 expression and NLR value, PFS mean survival times were 13.1 months for PD-L1(+)/NLR>4, 15.1 months for PD-L1(-)/NLR>4, 16.4 months for PD-L1(+)/NLR<4 and 27.8 months for PD-L1(-)/NLR<4. This correlation between PFS and the combined PD-L1 and NLR prognostic factor was statistically relevant (p=0.04). For OS, the PD-L1/NLR combined prognostic factor was not statistically relevant (p=0.055). A mean PFS time of 27.8 months was reported for PD-L1(-)/NLR<4 group patients while for the other groups, the mean PFS was 14.9 months (p=0.045). In univariate analysis, the elevated NLR was significantly associated with a decreased PFS time (HR=2.31, 95% CI =1.323- 4.051, p=0.03) as well as OS (HR=3.555, 95% CI=1.310- 9.652, p=0.013). In multivariate analysis, NLR remained statistically significant for PFS (HR=2.160, 95% CI=1.148- 4.062, p=0.013) and OS (HR=4.364, 95% CI=1.474- 12.921, p=0.008) after adjusting for the factors of age, gender, tumor stage, lymph node stage, clinical stage, histology, and PD-L1 expression. PD-L1 expression was not a valid prognostic factor for progression or death in either univariate or multivariate analysis. We also stratified the disease control rate (DCR) depending on PD-L1/NLR combined factor expression. In the PD-L1(-)/NLR<4 group, we had the highest number of partial responses (PRs) and only one complete response (CR) compared to the other groups (p=0.006).

Conclusions

As the number of patients is limited in the present analysis, it is hypothesized that these two markers can be useful in dividing patients into two prognostic groups: the good prognostic group reunites PD-L1(+)/NLR<4 and PD-L1(-)/NLR<4 and the poor prognostic group reunites PD-L1(+)/NLR>4 and PD-L1(-)/NLR>4.

An immune-related nomogram model that predicts the overall survival of patients with lung adenocarcinoma

Background

Lung adenocarcinoma accounts for approximately 40% of all primary lung cancers; however, the mortality rates remain high. Successfully predicting progression and overall (OS) time will provide clinicians with more options to manage this disease.

Methods

We analyzed RNA sequencing data from 510 cases of lung adenocarcinoma from The Cancer Genome Atlas database using CIBERSORT, ImmuCellAI, and ESTIMATE algorithms. Through these data we constructed 6 immune subtypes and then compared the difference of OS, immune infiltration level and gene expression between these immune subtypes. Also, all the subtypes and immune cells infiltration level were used to evaluate the relationship with prognosis and we introduced lasso-cox method to constructe an immune-related prognosis model. Finally we validated this model in another independent cohort.

Results

The C3 immune subtype of lung adenocarcinoma exhibited longer survival, whereas the C1 subtype was associated with a higher mutation rate of MUC17 and FLG genes compared with other subtypes. A multifactorial correlation analysis revealed that immune cell infiltration was closely associated with overall survival. Using data from 510 cases, we constructed a nomogram prediction model composed of clinicopathologic factors and immune signatures. This model produced a C-index of 0.73 and achieved a C-index of 0.844 using a validation set.

Conclusions

Through this study we constructed an immune related prognosis model to instruct lung adenocarcinoma’s OS and validated its value in another independent cohost. These results will be useful in guiding treatment for lung adenocarcinoma based on tumor immune profiles.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01902-6.

Evaluation of the programmed death-ligand 1 mRNA expression and immunopositivity and their correlation with survival outcomes in Indian lung cancer patients

The presence of membranous immunopositivity of programmed death-ligand 1 (PD-L1) in tumors serves as a key determinant of response to immune checkpoint inhibitors. However, there are very limited studies on the evaluation of the PD-L1 mRNA expression and immunopositivity and their correlation with therapeutic response and survival outcomes, especially in Indian lung cancer patients. In this prospective study, conducted between 2017 and 2020, we collected biopsies and surgically resected tumors from 173 lung cancer patients. PD-L1 immunopositivity and mRNA expression were determined by immunohistochemistry using SP263 assay and qRT-PCR, respectively. PD-L1 expression was correlated with various clinicopathological variables, response to therapy, and survival outcomes using appropriate statistical methods. The median age was 60 years (range 33-81 years) with the majority of patients being male (86.5%) and smokers (83%). Histologically, the majority of patients were non-small cell lung cancer (89.4%) and of squamous cell carcinoma histology (64.3%). PD-L1 immunopositivity in tumor cells (tumor proportion score (TPS) ≥ 1%) was detected in 37.6%, while high immunopositivity (TPS ≥ 50%) was detected in 16.8% of lung cancer patients. Almost 76% of lung cancer patients with PD-L1 TPS ≥ 50% belonged to PD-L1 mRNA high-expression group. PD-L1 mRNA expression and immunopositivity did not correlate with response to therapy and survival outcomes. We conclude that PD-L1 immunopositivity and mRNA expression do not seem to serve as a prognostic biomarker for lung cancer patients treated with chemotherapy. More prospective studies should be planned to evaluate the predictive and prognostic relevance of PD-L1 expression in Indian lung cancer patients being treated with immune checkpoint inhibitors.