Clinical Determinants of Durable Clinical Benefit of Pembrolizumab in Veterans With Advanced Non–Small-Cell Lung Cancer

Background

Because of the prevalence of smoking in the veteran population, non–small-cell lung cancer (NSCLC) remains a significant cause of morbidity and mortality. The objectives of our study were to evaluate the extent of durable clinical benefit (DCB) to pembrolizumab in veterans with metastatic NSCLC and to identify clinical determinants of DCB.

Brain Metastases in Non–Small-Cell Lung Cancer

Up to 50% of patients with advanced non-small-cell lung cancer will develop brain metastases at some point during their illness. These metastases cause a substantial burden in morbidity and mortality, which has motivated research and technological innovation over the past 2 decades. Surgery, radiotherapy, and systemic therapies have each played a role in management, with the greatest changes associated with the popularization of stereotactic radiosurgery. In this review, the evidence behind each modality used in the management of brain metastases for non–small-cell lung cancer patients is examined, and recommendations regarding the current standards of care and areas of future research focus are provided.     

Non–small-cell Lung Cancer With Brain Metastasis at Presentation

Background

Data on the prevalence of brain metastases at presentation in patients with non–small-cell lung cancer (NSCLC) are limited. We queried the National Cancer Data Base to determine prevalence, clinical risk factors, and outcomes of patients with NSCLC presenting with brain metastases.

Isolated Brain Metastases as the First Relapse After the Curative Surgical Resection in Non–Small-Cell Lung Cancer Patients With an EGFR Mutation

Introduction

The aim of this study was to clarify the incidence and disease behavior of brain metastases (BM) without extracranial disease (ie, isolated BM) as the first relapse after curative surgery in non–small-cell lung cancer (NSCLC) patients, analyzed according to epidermal growth factor receptor (EGFR) mutation status.

Management and Prognosis in Synchronous Solitary Resected Brain Metastasis from Non–Small-Cell Lung Cancer

BackgroundReports in the medical literature have described cases of extended survival of patients with non–small-cell lung cancer (NSCLC) with solitary metastatic disease who have received aggressive treatment both to the brain metastasis and to the local/regional disease. The objective of this research is to analyze prognostic factors that predict for outcome in this unique patient population.Patients and MethodsA single-institution, retrospective chart review was performed on 35 patients with NSCLC and a synchronous solitary brain metastasis (SSBM) treated with craniotomy and whole-brain radiation therapy. Eight patients (22.9%) had chest surgery, 24 (68.6%) had chemotherapy, and 14 (40%) had thoracic radiation as part of their local management. Fourteen had stage I/II disease (42.9%), and 20 had stage III disease (57.1%). Mean age at diagnosis was 58.5 years. Eighteen patients (56.25%) had a brain metastasis < 3 cm, and 14 patients (43.75%) had a metastasis > 3 cm.ResultsMedian survival was 7.8 months, and at last follow-up, 3 patients (8.6%) were alive and well, 6 patients (17.1%) were alive and with disease, 24 patients (68.6%) had died of disease, and 2 patients (5.7%) had died of other causes. Univariate analysis demonstrated that lung surgery (P = .0033), primary lung treatment > 8 weeks after brain surgery (P = .0128), and stage I/II disease (P = .0467) were predictive of overall survival.ConclusionSurvival remains poor for patients with NSCLC with an SSBM. However, patients with thoracic disease amenable to local resection should be considered for such therapy because a survival advantage could exist compared with patients with more locally advanced disease.     

Use of Cetuximab After Failure of Gefitinib in Patients With Advanced Non–Small-Cell Lung Cancer

BackgroundGefitinib and cetuximab are both epidermal growth factor receptor (EGFR) target therapies used to treat patients with non–small-cell lung cancer (NSCLC) with different mechanisms. To clarify the effectiveness of cetuximab after failure of gefitinib treatment, we investigated the clinical features of patients with NSCLC who received cetuximab-containing chemotherapy after failure of gefitinib.Patients and MethodsWe analyzed the clinical data and mutational studies of patients with NSCLC in the National Taiwan University Hospital who had received gefitinib and, after failure of gefitinib, cetuximab-containing chemotherapy.ResultsFifteen patients who received cetuximab-containing chemotherapy after failure of gefitinib were identified. Four were responders to gefitinib therapy, and 3 were responders to cetuximab-containing chemotherapy. Ten were sequenced for EGFR and KRAS mutations. Six of the 10 patients had EGFR mutations, and all 10 patients had wild-type (WT) KRAS. In the 4 patients who had the gefitinib-resistant EGFR T790M mutation, 2 were responders to cetuximab-containing chemotherapy. The other cetuximab responder had WT EGFR.ConclusionCetuximab might add benefit in treatment after failure of gefitinib, regardless of EGFR mutational status. Treatment with cetuximab should be further explored, even in patients who have previously received gefitinib treatment.     

Metastasis Dynamics for Non–Small-Cell Lung Cancer: Effect of Patient and Tumor-Related Factors

BackgroundWe studied event dynamics (probability of an event occurring over a specific time interval) in patients undergoing surgery for early-stage non–small-cell lung cancer (NSCLC) according to patient and tumor characteristics.MethodsBy using a database of 1506 patients who underwent initial surgery for NSCLC, event dynamics, based on a time-specific hazard rate, were evaluated. The event of interest was the development of distant metastases, with or without a local recurrence. The effect of sex, tumor size, nodal involvement, histology, lymphovascular space invasion, pleural invasion, age, and race were studied.ResultsThe hazard rate for developing distant metastases was not constant over time but was characterized by specific peaks, the first being approximately 9 months after surgery and the second at 18 to 20 months for men and 24 to 26 months for women. For women, the hazard rate peaked considerably in the first year. For men, the hazard rate peaks were smaller but lasted for a longer duration. Pathologic factors associated with a higher risk of recurrence (eg, size, lymph node involvement, pleural invasion) all increased the sex-specific hazard rates.ConclusionsThe probability of developing distant metastases after surgery for NSCLC peaks at specific and consistent time intervals after surgery, with specific differences between men and women. A factor-specific modulation of peak heights that ranged from no impact (eg, race) to relevant effects for primary tumor size, nodal involvement, and pleural invasion, possibly related to sex, was also observed. The bimodal distant metastases dynamics may be an intrinsic feature of metastatic progression in NSCLC.     

Association of Immune-Related Adverse Events and Efficacy Outcomes With Consolidation Pembrolizumab After Chemoradiation in Patients With Inoperable Stage III Non–Small-Cell Lung Cancer

BackgroundMany patients with non–small-cell lung cancer (NSCLC) treated with immunotherapy experience immune-related adverse events (irAEs). Patients with metastatic NSCLC who receive checkpoint inhibitors (CPI) and experience irAEs generally receive fewer cycles of CPI without decreased efficacy. However, the association between irAEs and efficacy outcomes in patients with locally advanced NSCLC treated with curative intent with CPI after chemoradiation has never been reported. Here we report a retrospective analysis of the association between irAEs and efficacy outcomes from the Hoosier Cancer Research Network (HCRN) LUN 14-179 single-arm phase 2 trial of consolidation pembrolizumab after chemoradiation in patients with stage III NSCLC.Patients and MethodsA total of 92 eligible patients were enrolled from March 2015 to November 2016. Demographics, disease characteristics, and number of pembrolizumab cycles received were reported in patients with and without irAEs. Chi-square test was used for comparisons for categorical variables and Wilcoxon test for continuous variables. The Kaplan-Meier method was used to analyze time to metastatic disease or death (TMDD), progression-free survival (PFS), and overall survival (OS). A log-rank test was used to compare groups.ResultsAny grade irAEs occurred in 55.4% of patients. There was no significant difference in number of pembrolizumab cycles received, TMDD, OS, or PFS in patients with and without irAEs. Patients who discontinued pembrolizumab early because of irAEs received significantly fewer cycles of pembrolizumab (5 vs 15, P = .0016) without a significant difference in TMDD, PFS, or OS. Similarly, patients who received immunosuppressive therapy received fewer numbers of cycles of pembrolizumab (4 vs 16, P < .001) without significantly reduced TMDD, PFS, or OS.ConclusionirAEs due to pembrolizumab, regardless of grade or number of irAEs, were not associated with decreased efficacy outcomes. Furthermore, early discontinuation of pembrolizumab because of irAEs and/or treatment of irAEs with immunosuppressive therapy was not associated with a decrease in treatment efficacy.     

Aggressive Treatment of Primary Tumor in Patients With Non–Small-Cell Lung Cancer and Exclusively Brain Metastases

Between 30% and 50% of patients with non–small-cell lung cancer (NSCLC) will develop cerebral metastases in the course of their illness. As improvements are made in the local brain treatment, the question arises on how to manage patients with NSCLC who have solely stable brain metastatic disease and if treatment should be considered for the primary lung lesion. The present article will review published series of patients with NSCLC and with brain metastases treated with aggressive thoracic management, with either lung tumor resection or thoracic radiation with or without chemotherapy as definitive treatment. We will also assess which prognostic factors may be useful in the identification of the subset of patients who could benefit from this more aggressive approach. For patients treated with surgical resection for the primary lung tumor, median survival ranged from 19 to 27 months, and the 1-, 2-, and 5-year survival reached 56%-69%, 28%-54%, and 11%-24%, respectively. Patients treated with aggressive radiotherapy with or without chemotherapy, achieved a median survival of 15.5-31.8 months, with a 1-year survival of 50%-71%, and a 2-year survival of 16%-60%. Well-selected patients with NSCLC and with exclusively oligometastatic cerebral disease represent a subgroup of patients with stage IV NSCLC that might achieve long-term survival after treatment directed to the brain and lung tumor lesions. Patients with N0 or N1 disease may be selected for surgical thoracic treatment, whereas those with N2 or N3 disease may benefit from combined chemoradiotherapy in the absence of progression after induction chemotherapy.     

Gefitinib-Related Interstitial Lung Disease in Taiwanese Patients With Non–Small-Cell Lung Cancer

BackgroundGefitinib (Iressa; AstreZeneca, Wilmington, DE) is effective in the treatment of NSCLC, especially in the Asian population. However, ILD is usually a serious pulmonary adverse effect and almost leads to cessation of gefitinib treatment. In this study, we investigated the incidence, clinical features, and prognosis of gefitinib-related ILD in Taiwanese patients with NSCLC.Patients and MethodsThis was a retrospective observational study conducted in 2 medical centers and a local teaching hospital.ResultsA total of 1080 patients with NSCLC, who received at least 1 dose (250 mg per day) of gefitinib treatment, were enrolled. Of these, 42 patients were diagnosed with ILD. Twenty-five of the 42 patients were diagnosed with gefitinib-related ILD (incidence, 2.3%). The main manifestations of ILD included dyspnea, cough, and hypoxemia. Six of the 25 patients (24%) with gefitinib-related ILD required invasive mechanical ventilation and all patients were treated with steroids. Twenty-two patients (88%) discontinued gefitinib treatment without further rechallenge. Ten (40%) patients died directly from ILD and in-hospital mortality was 52%. Eleven patients received subsequent cytotoxic chemotherapy with a mean of 33.5 days after ILD events. Kaplan-Meier analysis demonstrated that gefitinib nonresponder and gefitinib use rather than first-line treatment were associated with poor prognosis when ILD developed during gefitinib treatment.ConclusionTaiwanese patients with NSCLC had a relatively high incidence of ILD during gefitinib treatment. Gefitinib-related ILD is usually life-threatening, especially in gefitinib nonresponders and gefitinib use rather than first-line treatment.