Background: Advanced non-small cell lung cancer (NSCLC) has a high mortality rate and poor prognosis. However, outcomes have gradually improved after the introduction of novel immunotherapies, including immune checkpoint inhibitors (ICIs). Although programmed death-ligand 1 (PD-L1) expression in tumor tissues is a known biomarker for guiding ICI treatment of NSCLC, challenges such as difficulty of liquid biopsy and heterogeneous results during treatment persist. This study evaluated the potential of miR200b as a surrogate biomarker for PD-L1 expression. Methods: We used the human lung cancer cell lines H226, H460, H520, A549, and H1975. miR200b expression in blood and bronchoscopy specimens of NSCLC patients was evaluated using reverse-transcription-quantitative PCR. Using flow cytometry, PD-L1 expression in vitro, as well as in tumor tissues, was evaluated after transfection with a mimic miR200b or siRNA. Results: miR200b expression negatively correlated with PD-L1 expression in all cell lines. The induction or knockdown of miR200b also altered PD-L1 expression in vitro. The patient group with a PD-L1 tumor proportion score ≥ 50% had significantly lower miR200b expression in the bronchoscopy specimens (P = 0.025) and serum-derived exosomes (P = 0.022) than that with PD-L1 tumor proportion score < 50%. Conclusions: miR200b can regulate PD-L1 expression in lung cancer cells, and miR200b expression in clinical specimens negatively correlated with PD-L1 expression. Thus, miR200b may be a useful surrogate biomarker for PD-L1 expression in lung cancer patients.
Background
Differences in the resistance mechanisms of epidermal growth factor receptor tyrosine kinase inhibitors in patients with non‐small cell lung cancer (NSCLC) harboring epidermal growth factor receptor mutations are unknown. This meta‐analysis aimed to clarify the differences in resistance mechanisms after treatment with various epidermal growth factor receptor tyrosine kinase inhibitors.
Methods
We systematically searched PubMed, Cochrane, and Web of Science on July 29, 2020, for relevant studies on acquired resistance mechanisms against epidermal growth factor receptor tyrosine kinase inhibitors. The primary outcome measure was differences in the resistance mechanism between individual or generations of epidermal growth factor receptor tyrosine kinase inhibitors.
Results
In total, 33 trials involving 2418 individuals were included and analyzed. T790M was significantly less frequent after afatinib treatment (40.2%, 95% confidence interval [CI]: 31.7%–48.7%) than after gefitinib and erlotinib treatments (52.5%, 95% CI: 48.7%–56.3%, p = 0.005). There were no significant differences between Asian and non‐Asian patients in the incidence of T790M after gefitinib, erlotinib, and afatinib treatments. Regarding epidermal growth factor receptor pathway‐independent resistant mechanisms, the incidences of small cell lung cancer transformation (osimertinib: 7.9%, 95% CI: 3.6%–12.2%, others: 2.3%, 95% CI: 0.8%–3.8%) and Kirsten rat sarcoma (KRAS) viral oncogene homolog mutation (osimertinib: 4.6%, 95% CI: 1.5%–7.7%, others: 0.2%, 95% CI: 0.0%–1.7%) were significantly higher following osimertinib treatment than with others.
Conclusions
Significant differences in the incidence of resistance mechanisms among epidermal growth factor receptor tyrosine kinase inhibitors exist, which should be taken into consideration when choosing the treatment strategy.
In this multi-center prospective test-negative case-control study in Japan, the effectiveness of both BA.1-containing and BA.4/BA.5-containing bivalent COVID-19 mRNA vaccines against symptomatic infection during the BA.5-dominant period was high compared to no vaccination (65% and 76%) and moderate compared to monovalent vaccines administered over half a year before (46% combined).
Background: Pembrolizumab alone or in combination with chemotherapy is a standard treatment for patients with non-small-cell lung cancer (NSCLC) with high programmed death-ligand 1 (PD-L1) expression. However, no study has compared the efficacies of these two regimens. Therefore, we aimed to compare the efficacy of pembrolizumab alone and in combination with chemotherapy in NSCLC patients with high PD-L1 expression. Methods: We conducted a multicenter retrospective trial involving patients with diagnosed unresectable or recurrent NSCLCs who had received pembrolizumab with or without chemotherapy in the first-line setting. Patients were divided into monotherapy and combination therapy groups. The progression-free survival (PFS), overall survival (OS), and response rate (RR) were analyzed and compared between the groups. Clinical characteristics of patients were analyzed to assess their possible relationship with treatment outcomes. Results: We enrolled 96 patients from five hospitals. Of these, 47 and 49 patients received monotherapy and combination therapy, respectively. The median PFS was 343 and 328 days in the monotherapy and combination therapy groups, respectively (hazard ratio 1.003, p = 0.99). No statistically significant differences were observed in the OS and RR between the two groups. However, in patients with metastases to the liver, lung, adrenal glands, bone, or lymph nodes, the PFS was longer in the monotherapy group than in the combination therapy group. Conclusion: Although the PFS, OS, and RR were not significantly different between patients treated with pembrolizumab alone and or with pembrolizumab in combination with chemotherapy, patients with NSCLC having metastases to specific sites may benefit more from monotherapy.
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