Local consolidative therapy for synchronous oligometastatic non‐small cell lung cancer treated with first‐line pembrolizumab: A retrospective observational study

Local Ablative Therapy Combined With Pembrolizumab in Patients With Synchronous Oligometastatic Non-Small Cell Lung Cancer: A Recursive Partitioning Analysis

PURPOSE

This study aimed to evaluate the efficacy of local ablative therapy (LAT) combined with pembrolizumab in patients with synchronous oligometastatic non-small cell lung cancer (NSCLC) and to identify patients who would most benefit from LAT.

METHODS AND MATERIALS

We retrospectively identified patients who received diagnosis of synchronous oligometastatic NSCLC (≤5 metastatic lesions and ≤3 organs involved) and were treated with first-line pembrolizumab between January 2017 and December 2022. Patients who underwent LAT, including surgery or radiation therapy at all disease sites, were compared with those who did not undergo LAT. A recursive partitioning analysis (RPA) model was developed using prognostic factors for progression-free survival (PFS).

RESULTS

Among the 258 patients included, 78 received LAT with pembrolizumab, and 180 received pembrolizumab alone. The median follow-up duration was 15.5 months (range, 3.0-71.2 months). In the entire cohort, LAT was independently associated with significantly improved PFS (hazard ratio [HR], 0.64; P = .015) and overall survival (OS) (HR, 0.61; P = .020). In the propensity score-matched cohort (N = 74 in each group), the median PFS was 19.9 months and 9.6 months, respectively (P = .003), and the median OS was 42.2 months and 20.5 months, respectively (P = .045), for the LAT and non-LAT groups. Based on the RPA model, incorporating the number of metastatic lesions, performance status, and programmed cell death-ligand 1 expression level, patients were stratified into 3 risk groups with distinct PFS. LAT significantly improved PFS and OS in the low- and intermediate-risk groups; however, no difference was observed in the high-risk group. LAT was more effective as a consolidative treatment after pembrolizumab initiation than as an upfront therapy.

CONCLUSIONS

LAT combined with pembrolizumab was associated with higher PFS and OS compared with pembrolizumab alone in selected patients with synchronous oligometastatic NSCLC. The RPA model could serve as a valuable clinical tool for identifying appropriate patients for LAT.

Oligometastatic non-small cell lung cancer: Impact of local and contemporary systemic treatment approaches on clinical outcome

Oligometastatic (OMD) non-small cell lung cancer (NSCLC) is a distinct but heterogeneous entity. Current guidelines recommend systemic therapy and consolidation with local ablative therapy (LAT). However, evidence regarding the optimal choice of multimodal treatment approaches is lacking, in particular with respect to the integration of immunotherapy. This real-world study identified 218 patients with OMD NSCLC (2004-2023, prespecified criteria: ≤5 metastases in ≤2 organ systems) from three major German comprehensive cancer centers. Most patients had one (72.5%) or two (17.4%) metastatic lesions in a single (89.9%) organ system. Overall survival (OS) was significantly longer with a single metastatic lesion (HR 0.54, p = .003), and female gender (HR 0.4, p < .001). Median OS of the full cohort was 27.8 months, with 29% survival at 5 years. Patients who had completed LAT to all NSCLC sites, typically excluding patients with early progression, had a median OS of 34.4 months (37.7% 5-year OS rate) with a median recurrence-free survival (RFS) of 10.9 months (13.3% at 5 years). In those patients, systemic treatment as part of first-line therapy was associated with doubling of RFS (12.3 vs. 6.4 months, p < .001). Despite limited follow-up of patients receiving chemo-immunotherapy (EU approval 2018/2019), RFS was greatly improved by adding checkpoint inhibitors to chemotherapy (HR 0.44, p = .008, 2-year RFS 51.4% vs. 15.1%). In conclusion, patients with OMD NSCLC benefitted from multimodality approaches integrating systemic therapy and local ablation of all cancer sites. A substantial proportion of patients achieved extended OS, suggesting a potential for cure that can be further augmented with the addition of immunotherapy.

Palliative Thoracic Radiotherapy in the Era of Modern Cancer Care for NSCLC

Palliative thoracic radiotherapy provides rapid and effective symptom relief in approximately two-thirds of NSCLC patients treated. In patients with poor performance status, the degree of palliation appears unrelated to the radiation dose or fractionation schedule. Conversely, in patients with good performance status, higher radiation doses administered over longer periods have shown modest survival benefits. These findings stem from studies conducted before the advent of immunotherapy and targeted therapy in clinical practice. Currently, there are no large prospective studies specifically dedicated to palliative radiotherapy conducted in this new treatment era. Modern radiotherapy technologies are now widely available and are increasingly used for palliative purposes in selected patients, reflecting the expanded array of therapeutic options for disseminated NSCLC and improved prognosis. Some traditional tenets of palliative thoracic radiotherapy, such as the improvement of overall survival with a protracted radiation schedule and the use of simple, cost-effective radiation techniques for palliative purposes, may no longer hold true for patients receiving immunotherapy or targeted therapy. The application of IMRT or SBRT in the context of palliative radiotherapy for NSCLC is not yet sufficiently explored, and this is addressed in this review. Moreover, new risks associated with combining palliative radiotherapy with these systemic treatments are being explored and are discussed within the context of palliative care. The optimal timing, doses, fractionation schedules, and treatment volumes for radiotherapy combined with immunotherapy or targeted therapy are currently subjects of investigation. In emergencies, radiotherapy should be used as a life-saving measure without delay. However, for other indications of palliative thoracic radiotherapy, decisions regarding doses, timing relative to systemic treatments, and treatment volumes should be made in a multidisciplinary context, considering the patient's prognosis, anticipated outcomes, and access to potentially effective treatments. We still lack robust data from prospective studies on this matter. This review examines and discusses available evidence on the use of palliative thoracic radiotherapy within the framework of modern treatment strategies for NSCLC.

Oligometastasis: Expansion of Curative Treatments in the Field of Oncology

Oligometastasis is defined as the presence of several limited metastatic lesions and is generally limited to three or fewer than five metastatic lesions. Previously, the treatment of metastatic cancer aimed to alleviate symptoms rather than cure them; however, the use of immunotherapy or targeted therapy has greatly improved patient life expectancy. Additionally, the effectiveness and safety of local treatment have recently been proven for oligometastatic cancers and have significantly improved patient survival and decreased recurrence rates. A few metastatic studies on lung cancer have demonstrated the usefulness of combining radiation therapy and immunotherapy. Recently, local and targeted therapy combinations have shown promising results in treating non-small cell lung cancer, predominantly caused by the epidermal growth factor receptor and anaplastic lymphoma kinase gene mutations, suggesting the potential of these new treatment strategies. It is well known that oligometastasis has better clinical results than polymetastasis; however, research on the biological profile of oligometastasis is still lacking. Studies using circulating tumor DNA and circulating tumor cells are at the initial stages of providing a better understanding of oligometastatic cancers, and the biological characteristics of these cancers may be revealed based on more diverse studies. With the development of these treatments, the prognosis for patients with oligometastatic cancers is steadily improving, and if the biological profile is revealed, customized treatment may be provided.

Radiation and immune checkpoint inhibitors in the treatment of oligometastatic non-small-cell lung cancer: a practical review of rationale, recent data, and research questions

The combined use of stereotactic ablative radiotherapy (SABR) and immune checkpoint inhibitors (ICIs) is an emerging treatment paradigm for oligometastatic non-small-cell lung cancer (NSCLC). Recent phase I and II trial data suggest that SABR to multiple metastases in addition to ICI use is safe and effective with promising progression-free survival and overall survival signals. There is great interest in capitalizing on combined immunomodulation from these two modalities for the treatment of oligometastatic NSCLC. Ongoing trials seek to validate the safety, efficacy, and preferred sequencing of SABR and ICI. This narrative review of the role of SABR when combined with ICI in oligometastatic NSCLC discusses the rationale for this bimodality treatment, summarizes recent clinical trial evidence, and proposes key principles of management based on the available evidence.

Oligometastatic Non-Small Cell Lung Cancer: A Practical Review of Prospective Trials

Simple Summary

A significant number of patients diagnosed with non-small cell lung cancer (NSCLC) will have a metastatic Stage IV disease at presentation. Among those, patients with limited number of metastases are referred to as oligometastatic, and their treatment will combine systemic and possible local therapy. The aim of this article is to review the current definition of oligometastatic cancer, a historic perspective of lung cancer leading to modern oligometastatic disease and to present available prospective evidence for treatment of oligometastatic NSCLC. We describe trials exploring role of local therapy in oligometastatic NSCLC with actionable mutation in combination with TKI or without any actionable mutation and in combination with chemo-immunotherapy. We also discuss general treatment approaches adopted based on limited data. Finally, we discuss the on-going clinical trials for oligometastatic and oligoprogressive NSCLC.

Abstract

Oligometastatic non-small cell lung cancer (NSCLC) is an intermediate state between localized and widely metastatic NSCLC, where systemic therapy in combination with aggressive local therapy when feasible can yield a favorable outcome. While different societies have adopted different definitions for oligometastatic NSCLC, the feasibility of curative intent treatment remains a major determinant of the oligometastatic state. The management involves a multidisciplinary approach to identify such patients with oligometastatic stage, including the presence of symptomatic or potentially symptomatic brain metastasis, the presence of targetable mutations, and programmed death-ligand (PD-L1) expression. Treatment requires a personalized approach with the use of novel systemic agents such as tyrosine kinase inhibitors and immune checkpoint inhibitors with or without chemotherapy, and addition of local ablative therapy via surgery or stereotactic radiation therapy when appropriate.