An integrated biomarker of PD-L1 expression and intraepithelial CD8+ T cell infiltration was associated with the prognosis of lung cancer patients after intracranial resection of brain metastases

Background

Brain metastases (BM) are common in lung cancer. However, data on the status of immune biomarkers in BM lesions remain limited.

Methods

We retrospectively analyzed PD‐L1 expression and infiltration levels of CD3⁺, CD4⁺, CD8⁺ T cells as biomarkers by immunohistochemistry in both BM lesions and primary lung cancer (PL) lesions of 29 lung cancer (LC) patients. In addition, the correlations between these biomarkers and the clinical outcome were analyzed using log‐rank test.

Results

Intratumoral heterogeneous expression of PD‐L1 was observed on tumor cells (TCs) in 11 cases and on immune cells (ICs) in 10 cases with BM samples from multiple regions. There was a disagreement in PD‐L1 expression on TCs between paired BM and PL lesions in 15 cases and on ICs in seven cases. Intraepithelial CD3⁺ and CD8⁺ T cell infiltration levels in BM samples were lower than those in the paired PL samples. PD‐L1 positivity on both TCs and ICs was associated with a better post‐BM‐surgery prognosis (p = 0.010; p = 0.041). Notably, PD‐L1 positivity on TCs and a high level of intraepithelial CD8⁺ T cell infiltration could serve as an integrated biomarker that indicates longer survival time (p = 0.004) in LC patients.

Conclusion

The heterogeneity in PD‐L1 expression was common in both stromal and intraepithelial regions in BM lesions of LC patients, suggesting the need for multiregional PD‐L1 testing in clinical practice. More importantly, a combination of PD‐L1 expression on TCs with intraepithelial CD8⁺ T cell infiltration might predict better post‐BM‐surgery outcomes.

High SHP2 expression determines the efficacy of PD-1/PD-L1 inhibitors in advanced KRAS mutant non-small cell lung cancer

BACKGROUND

Src homology region 2 domain-containing phosphatase 2 (SHP2) is a novel target for Kirsten rat sarcoma oncogene (KRAS) mutant cancer. We retrospectively studied the significance of SHP2 in KRAS mutant non-small cell lung cancer (NSCLC) treated with immunotherapy and its relationship with tumor microenvironment (TME).

METHODS

Sixty-one advanced KRAS mutant NSCLC patients who underwent immunotherapy were enrolled. Next-generation sequencing (NGS) was used to profile mutation status. The expression of SHP2, phospho-SHP2 (pSHP2), and programmed death ligand 1 (PD-L1) were analyzed by immunohistochemistry (IHC). Quantitative multiplexed immunofluorescence cytochemistry (mIFC) analysis was conducted to describe the TME.

RESULTS

SHP2 was heterogeneously expressed in 32 samples in both tumor cells and immune cells and highly expressed (H-score >10) in 25 (78.1%) samples. The expression levels of SHP2 and pSHP2 were positively correlated. Stromal SHP2 (s-SHP2) was higher in tumors with PD-L1 ≥50% versus PD-L1 <50% (p = 0.039). By quantitative mIFC analysis, the expression of s-SHP2 had positive correlation with CD8, CD4, CD68, and PD-L1 levels in stromal area. Patients with high SHP2 expression made up 100.0% of the partial respond (PR) and 80.0% of the stable disease (SD), whereas 50.0% of the progress disease (PD). High SHP2 expression was associated with longer progression-free survival (PFS) and overall survival (OS) (p < 0.001, p = 0.013). Patients with high expression of both SHP2 and PD-L1 had longer PFS (p < 0.001).

CONCLUSION

High SHP2 expression could predict the efficacy of immunotherapy and better survival in advanced KRAS mutant NSCLC. SHP2 may function in both tumor cells and immune cells, warranting further study on the potential diverse effects of SHP2 inhibition in TME.

Low frequency of mutation of epidermal growth factor receptor (EGFR) and arrangement of anaplastic lymphoma kinase (ALK) in primary pulmonary lymphoepithelioma-like carcinoma

Background

Primary pulmonary lymphoepithelioma‐like carcinoma (PLELC) is a rare and unique subtype of lung cancer. However, the prevalence of driver alterations, such as epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements, and the response of tyrosine kinase inhibitor (TKIs) in PLELC has not been thoroughly investigated.

Method

We retrospectively reviewed the genetic profiles and treatment course of 330 PLELC patients at the Guangdong Lung Cancer Institute (GLCI) from 1st January, 2008 to 30th December, 2018. We searched and analyzed related literature published in PubMed and Web of Science from 1st January, 2000 and 31th August, 2019 based on their mention of “driver mutations” and “the response of TKIs to mutant PLELC”.

Results

Genetic alterations of EGFR/ALK were tested in 203 patients (203/330, 61.5%). Five patients (5/175, 2.9%) had EGFR mutation and three patients (3/140, 2.1%) had ALK alteration. From the total of 15 articles identified from electronic searches, 1071 PLELC cases mentioned the driver mutations. EGFR mutation and ALK rearrangement were detected in 15 patients and one patient, respectively. In total, there were four EGFR/ALK mutant PLELC patients who received targeted therapy as palliative treatment at the GLCI and in the literature. However, there was disease progression in all cases one month after use of TKIs.

Conclusion

The mutation rates of EGFR and ALK were low in PLELC. EGFR and ALK TKIs showed limited response in EGFR/ALK mutant PLELC. Further studies are needed to explore other molecular targets to optimize the therapeutic strategy for PLELC.