PD-L1 Expression in Non-Small Cell Lung Cancer: Data from a Referral Center in Spain

Variations in Patterns of Prescribing Durvalumab in Stage III Lung Cancer: A Survey of Australian Medical Oncologists

INTRODUCTION

Local Australian guidelines for the optimal management of stage III unresectable non-small cell lung cancer (NSCLC) are lacking. The American Society of Clinical Oncology (ASCO) guidelines recommend consolidation durvalumab for all patients with unresectable stage III NSCLC, irrespective of their PD-L1 expression or driver mutation status. The European Society of Medical Oncology (ESMO) differs, with consolidation durvalumab only recommended in those patients whose tumours express PD-L1.

METHODS

Due to differing global guidelines, we conducted an Australia and New Zealand wide survey of medical oncologists specialising in thoracic cancer to determine the variations in patterns of prescribing durvalumab in stage III unresectable NSCLC. This survey was done electronically and sponsored by the Thoracic Oncology Group of Australia (TOGA).

RESULTS

Thirty-two medical oncologists completed the survey. In patients with EGFR-mutated stage III unresectable NSCLC, 6% of respondents stated that they prescribed durvalumab for all patients, while an additional 6% strongly recommended treatment. Forty-four percent suggested little benefit of consolidation durvalumab in this cohort, with an additional 19% advocating for observation only. In patients with PD-L1 negative (0%) stage III unresectable NSCLC, 13% of respondents prescribed durvalumab for all patients, while an additional 56% strongly recommended treatment. Interestingly, 18%, 10%, and 10% of prescribers discussed self-funded oral tyrosine kinase inhibitor therapy in patients with EGFR, ALK, or ROS-1-mutated NSCLC respectively as a substitute for consolidation durvalumab.

CONCLUSION

Overall, the clinical practice of Australian and New Zealand Medical Oncologists is variable, but remains consistent with either the ASCO or ESMO guidelines. Local practice guidelines are required to ensure consistency in prescribing patterns across Australia, as well as providing evidence for self-funded treatments outside standard of care.

Surgical Treatment Outcomes of Patients with Non-Small Cell Lung Cancer and Lymph Node Metastases

This study aimed to investigate the appropriate subgroups for surgery and adjuvant chemotherapy in patients with non-small-cell lung cancer (NSCLC) and nodal metastases. We retrospectively reviewed 210 patients with NSCLC and nodal metastases who underwent surgery and examined the risk factors for poor overall survival (OS) and recurrence-free probability (RFP) using multivariate Cox proportional hazards analysis. Pathological N1 and N2 were observed in 114 (52.4%) and 96 (47.6%) patients, respectively. A single positive node was identified in 102 patients (48.6%), and multiple nodes were identified in 108 (51.4%). Multivariate analysis revealed that vital capacity < 80% (hazard ratio [HR]: 2.678, 95% confidence interval [CI]: 1.483-4.837), radiological usual interstitial pneumonia pattern (HR: 2.321, 95% CI: 1.506-3.576), tumor size > 4.0 cm (HR: 1.534, 95% CI: 1.035-2.133), and multiple-node metastases (HR: 2.283, 95% CI: 1.517-3.955) were significant independent risk factors for poor OS. Tumor size > 4.0 cm (HR: 1.780, 95% CI: 1.237-2.562), lymphatic permeation (HR: 1.525, 95% CI: 1.053-2.207), and multiple lymph node metastases (HR: 2.858, 95% CI: 1.933-4.226) were significant independent risk factors for recurrence. In patients with squamous cell carcinoma (n = 93), there were no significant differences in OS or RFP between those who received platinum-based adjuvant chemotherapy (n = 25) and those who did not (n = 68), at p = 0.690 and p = 0.292, respectively. Multiple-node metastases were independent predictors of poor OS and recurrence. Patients with NSCLC and single-node metastases should be considered for surgery despite N2 disease. Additional treatment with platinum-based adjuvant chemotherapy may be expected, especially in patients with squamous cell carcinoma.

Comparison of PD-L1 tumor cell expression with 22C3, 28-8, and SP142 IHC assays across multiple tumor types

BACKGROUND

Multiple PD-L1 immunohistochemistry (IHC) assays, including DAKO 22C3, DAKO 28-8, and Ventana SP142 PD-L1 IHC assays, have been approved by the Food and Drug Administration as a companion diagnostic (CDx) for various antiprogrammed death-1 and antiprogrammed death ligand 1 (PD-L1) based cancer immunotherapies. Here we present 22C3, 28-8, and SP142 analysis of 418 tumor specimens encountered in routine clinical practice.

METHODS

All specimens were tested with 22C3, 28-8, and SP142 assays following the manufacturer's established staining protocols.

RESULTS

The same PD-L1 status (defined as tumor cell expression (TC) scores with all three assays ≥1% or all &lt;1%) was observed in 60.0% (251/418) tumor specimens (45.9% (192/418) were triple negative and 14.1% (59/418) were triple positive). A total of 54.1% (226/418) tumor cases were positive with at least one IHC assay (94.2% (213/226), 77.0% (174/226), and 28.8% (65/226) of these were positive for 22C3, 28-8 and SP142, respectively). Among the 40.0% (167/418) tumor cases that showed a different PD-L1 status, 62.3% (104/167) were 22C3+/28-8+/SP142-, and 28.7% (48/167) were 22C3+/28-8-/SP142-. The same PD-L1 status with all three antibody clones was observed in 48.7% (97/199) of NSCLC cases, and among these, 54.6% (53/97) were triple negative and 45.4% (44/97) triple positive. A total of 73.4% (146/199) NSCLC cases were positive with at least one IHC assay (95.2% (n=139/146), 82.2% (n=120/146), and 32.2% (n=47/146) were positive for 22C3, 28-8, and SP142, respectively). Among the 51.3% (102/199) NSCLC cases that showed a different status among the three IHC assays, 67.6% (69/102) were 22C3+/28-8+/SP142-, and 23.5% (24/102) were 22C3+/28-8-/SP142-. A total of 81.1% (43/53) lung squamous cell carcinoma, 72.1% (88/122) of lung adenocarcinoma, 69.6% (16/23) of non-small cell lung cancer (NSCLC) not otherwise specified (NOS), and 50.0% (4/8) of small cell lung carcinoma cases were positive with at least one IHC assay.

CONCLUSIONS

Our data suggest that 22C3 is the most sensitive PD-L1 IHC assay for tumor cell expression, followed by 28-8 and in turn by SP-142. These findings represent an additional factor for clinical teams to consider when deciding which PD-L1 IHC assay (and in turn which CDx-associated PD-L1 based immunotherapy) is most appropriate for each individual patient.

Distribution and concordance of PD-L1 expression by routine 22C3 assays in East-Asian patients with non-small cell lung cancer

Background

Currently, programmed death ligand-1 (PD-L1) expression has been widely applied in clinical trials and real-world clinical practice as a major biomarker for the efficacy of immune-checkpoint inhibitors. The purpose of this study is to reveal the distribution and concordance of PD-L1 expression in a large-scale consecutive cohort from East-Asian patients with non-small cell lung cancer (NSCLC).

Methods

PD-L1 testing was conducted using 22C3 assays, and cases were categorized into the high, low, and no expression of PD-L1 based on the tumor proportion score (TPS). Target-capture next-generation sequencing was used to identify molecular events.

Results

A total of 4550 patients and 4622 tests of PD-L1 expression were enrolled. There were 3017 (66.3%) patients with no PD-L1 expression (TPS < 1%), 1013 (22.3%) with low PD-L1 expression (TPS 1–49%), 520 (11.4%) with high PD-L1 expression (TPS ≥ 50%). Higher proportions of positive PD-L1 expression (TPS ≥ 1%) were observed in smokers, males, squamous cell carcinoma, and high-grade lung adenocarcinoma. Further analyses revealed fair agreement in primary and metastatic lesions (kappa = 0.533), poor agreement in multi-focal primary tumors (kappa = 0.045), and good agreement in biopsy and resection samples (kappa = 0.662) / two biopsy samples (kappa = 0.711). Mutational analyses revealed association between high PD-L1 expression (TPS ≥ 50%) and EGFR wild-type, KRAS mutation, ALK rearrangement, and TP53 mutation.

Conclusion

The study reveals the unique distribution pattern of PD-L1 expression in a large-scale East-Asian cohort with NSCLC, the concordance of multiple PD-L1 tests, and the association between PD-L1 expression and molecular events. The results shed a light on the optimization of PD-L1 testing in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02201-8.