Local treatment of oligometastatic recurrence in patients with resected non-small cell lung cancer

Complex situations in lung cancer: multifocal disease, oligoprogression and oligorecurrence

With the emergence of lung cancer screening programmes and newly detected localised and multifocal disease, novel treatment compounds and multimodal treatment approaches, the treatment landscape of non-small cell lung cancer is becoming increasingly complex. In parallel, in-depth molecular analyses and clonality studies are revealing more information about tumorigenesis, potential therapeutical targets and the origin of lesions. All can play an important role in cases with multifocal disease, oligoprogression and oligorecurrence. In multifocal disease, it is essential to understand the relatedness of separate lesions for treatment decisions, because this information distinguishes separate early-stage tumours from locally advanced or metastatic cancer. Clonality studies suggest that a majority of same-histology lesions represent multiple primary tumours. With the current standard of systemic treatment, oligoprogression after an initial treatment response is a common scenario. In this state of induced oligoprogressive disease, local ablative therapy by either surgery or radiotherapy is becoming increasingly important. Another scenario involves the emergence of a limited number of metastases after radical treatment of the primary tumour, referred to as oligorecurrence, for which the use of local ablative therapy holds promise in improving survival. Our review addresses these complex situations in lung cancer by discussing current evidence, knowledge gaps and treatment recommendations.

Unravelling oligometastatic disease from the perspective of radiation and medical oncology. Part I: non-small cell lung cancer and breast cancer

Oligometastatic disease (OMD) defines a cancer status that is intermediate between localized and widely spread metastatic disease, and can be treated with curative intent. While diagnostic imaging tools have considerably improved in recent years, unidentified micrometastases can still evade current detection techniques, allowing the disease to progress. The various OMD scenarios are mainly defined by the number of metastases, the biological and molecular tumour profiles, and the timing of the development of metastases. Increasing knowledge has contributed to the earlier and improved detection of OMD, underlining the importance of early disease control. In view of increasing OMD detection rates in current real-world clinical practice and the lack of standardized evidence-based guidelines to treat this cancer status, a board of experts from the Spanish Societies of Radiation Oncology (SEOR) and Medical Oncology (SEOM) organized a series of sessions to update the current state-of-the-art on OMD from a multidisciplinary perspective, and to discuss how results from clinical studies might translate into promising treatment options. This expert review series summarizes what is known and what it is pending clarification in the context of OMD in the scenarios of non-small cell lung cancer and breast cancer (Part I), and prostate cancer and colorectal cancer (Part II), aiming to offer specialists a pragmatic framework to help improve patient management.

Will Patients With Liver Metastasis From Aggressives Cancers Benefit From Surgical Resection?

Background

We aimed to evaluate the outcomes of resections for liver metastases (LMs) originating from pancreatic ductal adenocarcinoma (PDAC), non-small cell lung cancer (NSCLC), and esophagus/gastric cancers (EGCs), which we label as major killers (MKs; overall survival (OS) under 10%). We hypothesized that LM resection must provide the patient with almost a year of OS postoperatively that is considered beneficial.

Methods

From January 2005 to December 2020, 23 patients underwent resection for isolated LM from MKs. These patients underwent surgery after a multidisciplinary discussion about their performance status, disease evolution during prolonged medical treatment, and the existence or absence of extrahepatic metastases.

Results

LM originated from an PDAC, EGC, or NSCLC in 10 patients (43%), nine patients (39%), and four patients (18%), respectively. The median delay between primary cancer and LM diagnoses was 12 months, and the median delay between LM diagnosis and liver resection was 10 months. Most patients, who had objectively responded to medical treatment (57%), had a solitary (61%) and unilobar (70%) LM. Severe morbidity and 90-day mortality rates were 13% and 4.3%, respectively. Margin-free resection was achieved in 16 patients (70%). After liver resection, the median OS was 24 months without a statistical difference when considering the primary tumor site; 1, 3-, and 5-year OS were 70%, 23%, and 23%, respectively.

Conclusion

Selection based on criteria such as good clinical condition, response to treatment, and long observation period helped identify patients with LM of MKs who seemed to benefit from resection.

Definitive local therapy for extracranial single-organ oligorecurrent non-small-cell lung cancer: A single institutional retrospective study

Oligometastatic non-small-cell lung cancer (NSCLC) is potentially curable. Oligo-recurrence occurs with oligometastatic disease characterized by well-controlled primary lesion. The purpose of the present study was to explore the value of definitive local therapy (DLT) for extracranial single-organ oligorecurrent NSCLC. A total of 81 patients with NSCLC who had extracranial single-organ oligorecurrence after receiving radical treatment at the Cancer Hospital of the University of Chinese Academy of Sciences from January 2010 to December 2017 were analyzed. The primary endpoint was progression-free survival (PFS), and the secondary endpoint was overall survival (OS). The median follow-up time of the 81 patients was 65.8 months. A total of 39 patients received DLT. A large proportion of patients who did not accept DLTs received specific tyrosine kinase inhibitors (TKIs). The results of multivariate analysis showed that DLT and specific TKI therapy were favorable prognostic factors significantly related to PFS. Further analysis showed that for patients without specific TKI therapy, DLT significantly improved PFS and the 5-year PFS rate. The 5-year OS rate also improved, but the improvement was not significant. For extracranial single-organ oligorecurrent NSCLC, PFS was significantly superior in patients receiving DLT. Among them, for the subgroup of patients who did not receive specific TKI therapy, DLT is expected to improve long-term prognostic outcomes.

Survival after recurrence following surgical resected non-small cell lung cancer: A multicenter, prospective cohort study

Objectives

The optimal treatment for recurrent non–small cell lung cancer (NSCLC) has not been standardized. In this prospective cohort study, we evaluated post-recurrence survival (PRS) after treatment of recurrent NSCLC and identified prognostic factors after recurrence.

Methods

This multicenter prospective cohort study was conducted in 14 hospitals. The inclusion criteria for this study were patients with recurrence after radical resection for NSCLC. Information about the patient characteristics at recurrence, tumor-related variables, primary surgery, and treatment for recurrence was collected. After registration, follow-up data, such as treatment and survival outcomes, were obtained every 3 months.

Results

From 2010 to 2015, 505 cases were enrolled, and 495 cases were analyzed. As initial treatment for recurrence, 263 patients (53%) received chemotherapy, 46 (9%) received chemoradiotherapy, 98 (20%) had definitive radiotherapy, 14 (3%) received palliative radiotherapy, and 31 (6%) underwent surgical resection. The remaining 43 patients (9%) received supportive care. The median PRS and 5-year survival rates for all cases were 30 months and 31.9%, respectively. The median PRS according to the initial treatment was as follows: supportive care, 8 months; palliative radiotherapy, 16 months; definitive radiotherapy, 30 months; chemotherapy, 31 months; chemoradiotherapy, 35 months; and surgery, not reached. A multivariate analysis showed that the age, gender, performance status, histology presence of symptoms, duration from primary surgery to recurrence, and number of recurrent foci were independent prognostic factors for PRS.

Conclusions

The PRS of patients with recurrent NSCLC was different depending on the patient's background characteristics and initial treatment for recurrence.

Oligometastatic Disease in Non-Small-Cell Lung Cancer: An Update

Simple Summary

Approximately 7–50% of patients with non-small-cell lung cancer (NSCLC) develop oligometastases, which are new tumors found in another part of the body, arising from cancer cells of the original tumor that have travelled through the body. In recent years, these patients have been increasingly regarded as a distinct group that could benefit from treatment that intends to cure the disease, rather than palliative care, to achieve a better clinical outcome. Various treatment procedures have been developed for treating NSCLC patients with different oligometastatic sites. In addition, the newly proposed uniform definition for oligometastases as well as ongoing trials may lead to increased appropriate patient selection and evaluation of treatment effectiveness. The aim of this review article is to summarize the latest evidence regarding optimal management strategies for NSCLC patients with oligometastases.

Abstract

Oligometastatic non-small-cell lung cancer (NSCLC) is a distinct entity that is different from localized and disseminated diseases. The definition of oligometastatic NSCLC varies across studies in past decades owing to the use of different imaging modalities; however, a uniform definition of oligometastatic NSCLC has been proposed, and this may facilitate trial design and evaluation of certain interventions. Patients with oligometastatic NSCLC are candidates for curative-intent management, in which local ablative treatment, such as surgery or stereotactic radiosurgery, should be instituted to improve clinical outcomes. Although current guidelines recommend that local therapy for thoracic and metastatic lesions should be considered for patients with oligometastatic NSCLC with stable disease after systemic therapy, optimal management strategies for different oligometastatic sites have not been established. Additionally, the development of personalized therapies for individual patients with oligometastatic NSCLC to improve their quality of life and overall survival should also be addressed. Here, we review relevant articles on the management of patients with oligometastatic NSCLC and categorize the disease according to the site of metastases. Ongoing trials are also summarized to determine future directions and expectations for new treatment modalities to improve patient management.

[Mediastinal Staging]

Thorough mediastinal staging is pivotal for prognostic assessment and treatment planning in patients with non-small-cell lung cancer (NSCLC) without distant metastasis. It aims to answer the question of whether a technically and functionally feasible operation also makes sense from an oncological point of view. In case of a nodal-free mediastinum, primary surgical therapy can be considered. If the ipsilateral mediastinal lymph nodes are affected, multimodal therapy should be sought. Operating is usually no longer the first step, especially with extensive lymph node infestation. Surgery is recommended, if neoadjuvant (radio-)chemotherapy has achieved downstaging or major response. If the contralateral mediastinal lymph nodes are involved, curative surgery is no longer part of the therapeutic concept. The therapy of choice in this situation is definitive chemo-radiotherapy.Guidelines for mediastinal staging consistently require to combine radiological, nuclear medicine and minimally invasive methods. Imaging with CT and PET allows an initial assessment of the mediastinal status. In most cases it has to be complemented with tissue confirmation. Echoendoscopic assessment of the mediastinum with needle biopsy is the minimally invasive method of first choice ("needle first"). Surgical staging methods are reserved for situations, that cannot be satisfactorily clarified by echoendoscopy.Technique and outcome of the different methods are described and algorithms are presented for different oncological situations.

Mediastinales Staging

Thorough mediastinal staging is pivotal for prognostic assessment and treatment planning in patients with non-small-cell lung cancer (NSCLC) without distant metastasis. It aims to answer the question of whether a technically and functionally feasible operation also makes sense from an oncological point of view. In case of a nodal-free mediastinum, primary surgical therapy can be considered. If the ipsilateral mediastinal lymph nodes are affected, multimodal therapy should be sought. Operating is usually no longer the first step, especially with extensive lymph node infestation. Surgery is recommended, if neoadjuvant (radio-)chemotherapy has achieved downstaging or major response. If the contralateral mediastinal lymph nodes are involved, curative surgery is no longer part of the therapeutic concept. The therapy of choice in this situation is definitive chemo-radiotherapy.Guidelines for mediastinal staging consistently require to combine radiological, nuclear medicine and minimally invasive methods. Imaging with CT and PET allows an initial assessment of the mediastinal status. In most cases it has to be complemented with tissue confirmation. Echoendoscopic assessment of the mediastinum with needle biopsy is the minimally invasive method of first choice ("needle first"). Surgical staging methods are reserved for situations, that cannot be satisfactorily clarified by echoendoscopy.Technique and outcome of the different methods are described and algorithms are presented for different oncological situations.

Epidemiology of oligometastatic non-small cell lung cancer: results from a systematic review and pooled analysis

Background

To describe the incidence and the clinical characteristics of oligometastatic non-small cell lung cancer (NSCLC) patients. Oligometastatic NSCLC is gaining recognition as a clinical condition with a different prognosis compared to multi metastatic disease. Usually, four different scenarios of oligometastatic disease can be described but not epidemiological data are available. To date, it is difficult to delineate an exhaustive epidemiological scenario because no uniform or shared definition of oligometastatic status exists, even though a recent consensus defined synchronous oligometastatic disease as having a maximum of 5 metastases in 3 different organs.

Methods

A systematic review and a pooled analysis of literature were performed. Article selection was based on the following characteristics: focus on lung cancers; dealing with oligometastatic settings and providing a definition of oligometastatic disease; number of metastatic lesions with or without the number of organs involved; providing some incidence or clinical characteristics of oligometastatic NSCLC patients. Series focusing on a specific single metastatic organ were excluded. The research was launched in MEDLINE (OvidSP) in March 2020. Full articles were individually and collectively read by the authors according to the previous criteria. Each author inspected the reference list included in the eligible articles. If the selection criteria were recognized, the article was reviewed by all authors and then included. Data on patient clinical features were pooled together from 31 articles selected.

Results

A total number of 31 articles have been selected for the analysis. The following variables were extracted from the publications: (I) number of metastases, (II) number of organs involved, (III) number of patients, (IV) number and percentage of males and females, (V) number and percentage of squamous and non-squamous histology, (VI) T and N status and/or stage of primary disease for oligometastatic setting. The data collected have been analyzed according to the oligometastatic setting.

Conclusions

Oligometastatic status is globally identified as a different clinical condition from multi metastatic NSCLC, although the clinical characteristics were consistent in the general metastatic population, even with a lower-than-expected TN status. The brain and bones were the most frequent organs involved. Lacking consensus definition, these results must be interpreted cautiously and a prospective evaluation is urgently needed.

Local ablative therapies in oligometastatic NSCLC-upfront or outback?-a narrative review

Patients with oligometastatic (OM) non-small cell lung cancer (NSCLC) have favorable outcomes compared to patients presenting with diffuse metastatic disease. Recent randomized trials have demonstrated safety and efficacy signals for local ablative therapies with radiotherapy, surgery, or radiofrequency ablation for OM-NSCLC patients alongside systemic therapies. However, it remains unclear whether local ablative therapy (LAT) should be offered either upfront preceding systemic therapies or following initial systemic therapies as local consolidative therapy (LCT). Establishing optimal timing of RT and systemic therapy combinations is essential to maximize efficacy while maintaining safety. Most published randomized trial evidence surrounding the benefits of LAT and systemic therapies were generated from OM-NSCLC patients receiving cytotoxic chemotherapy agents. With increasing use of novel agents such as targeted therapies (i.e., tyrosine kinase inhibitors) and immune checkpoint inhibitors in management of metastatic NSCLC patients, LAT timing may need to be modulated based on the use of specific agents. This narrative review will discuss the current evidence on either upfront LAT or LCT for OM-NSCLC based on published trials and cohort studies. We briefly explored the possible biological mechanisms of the potential clinical advantages of either approach. This review also summarized the ongoing trials incorporating both upfront LAT and LCT, and considerations for future LAT strategies.

Local Ablative Therapies for Oligometastatic and Oligoprogressive Non-Small Cell Lung Cancer

More than half of all patients with non-small cell lung cancer (NSCLC) have metastatic disease at the time of diagnosis. A subset of these patients has oligometastatic disease, which exists in an intermediary state between locoregional and disseminated metastatic disease. In addition, some metastatic patients on systemic therapy may have limited disease progression, or oligoprogression. Historically, treatment of metastatic NSCLC was palliative in nature, with little expectation of long-term survival. However, an accumulation of evidence over the past 3 decades now demonstrates that local ablative therapy to sites of limited metastases or progression can improve patient outcomes for this complex disease. This review examines the evidence behind local ablative therapy in oligometastatic and oligoprogressive NSCLC, with a focus on surgery, stereotactic radiotherapy, and radiofrequency ablation.

Outcomes of local thoracic surgery in patients with stage IV non-small-cell lung cancer: A SEER-based analysis

BACKGROUND

The outcomes of thoracic surgery for patients with stage IV non-small-cell lung cancer (NSCLC) are controversial and uncertain.

PATIENTS AND METHODS

The National Cancer Institute's Surveillance, Epidemiology, and End Results was queried for patients with stage IV NSCLC, including those treated with surgery-participated therapy modalities. Overall survival (OS) was evaluated using a variety of statistical analyses.

RESULTS

The analysis was carried out for 90,982 patients from 1975 to 2016 who had been diagnosed as stage IV NSCLC. Propensity score-matched (PSM) analyses that were well-balanced with all the important confounding covariates revealed improved OS (median survival time [MST]) with patients receiving surgery versus non-surgery (MST: 15 versus 8 months, P < 0.001); undergoing surgery plus chemotherapy versus chemotherapy (MST: 19 versus 11 months, P < 0.001); and having surgery plus chemoradiation versus chemoradiation (MST: 18 versus 11 months, P < 0.001). Sequential landmark analyses for long-term survivors of ≥1 and ≥3 years all indicated improved OS (P < 0.001) on univariate and multivariate analyses for the patients receiving the three surgery-related treatment patterns listed earlier, relative to the corresponding surgery-absent treatment modalities. For synchronous presentations of varied treatment paradigms, surgical intervention significantly led to increased OS (MST, months) benefits following treatment paradigms: surgery plus chemotherapy (22), surgery plus chemoradiation (18), chemotherapy (10), surgery only (9), chemoradiation (9), surgery plus radiation (6) and radiation alone (2). The subgroup analysis demonstrated that the elevated OS associated with local thoracic surgery in addition to chemotherapy (versus chemotherapy) or chemoradiation (versus chemoradiation) fell in the subcategories of T0-3, N0-2 and 0-1 (metastatic sites) tumours. The comparison of the aforementioned two types of treatment patterns indicated that the optimal patients for the surgery were those with any combination of T1-4, N0-3, Msite0-1 and adeno- or squamous carcinoma.

CONCLUSIONS

The patients with T1-4, N0-3, Msite0-1 and adeno- or squamous carcinoma of stage IV NSCLC had a longer OS with local thoracic surgery in combination with chemotherapy or chemoradiation.

Multidisciplinary team care in advanced lung cancer

Lung cancer is the most common cause of cancer mortality globally. A vast majority of lung cancer cases are diagnosed at advanced stages. Management of advanced lung cancer requires several diagnostic and therapeutic procedures provided by various specialists. To optimise the entire diagnostic and therapeutic process, a concept of care provided simultaneously by a multidisciplinary team (MDT) has been developed and implemented in specialised centres worldwide. Observational studies suggest that integrated and coordinated care increases adherence to clinical guidelines, significantly shortens the interval from diagnosis to treatment, and may increase survival and quality of life (QoL). Prospective studies are warranted to assess the real impact of MDT on treatment outcomes and to further refine this approach.

Definitive Local Therapy for Oligo-recurrence in Patients With Completely Resected Non-small Cell Lung Cancer

BACKGROUND

The aim of this study was to elucidate a curable subgroup among patients with non-small cell lung cancer (NSCLC) who developed postoperative recurrence.

PATIENTS AND METHODS

Between 1986 and 2012, among the 1408 patients who underwent complete anatomic lung resection for NSCLC at our institution, 420 developed recurrence. After excluding 14 patients with insufficient information about recurrence, 406 were included in this retrospective study. We investigated the association between several clinicopathologic factors and postrecurrence overall survival (PR-OS) and postrecurrence progression-free survival (PR-PFS).

RESULTS

The 5-year PR-OS and PR-PFS rates were 14.0% and 5.9%, respectively. By multivariate analysis, female sex, longer disease-free interval, specific targeted therapy, recent recurrence, oligo-recurrence, and definitive local therapy (DLT) were found to be independent favorable prognostic factors for both PR-OS and PR-PFS. Among these 6 prognostic factors, although female sex, longer disease-free interval, and specific targeted therapy were associated with a prolonged median PR-PFS time, they were not associated with an improved 5-year PR-PFS rate. In contrast, recent recurrence, oligo-recurrence, and DLT were associated with improvement in both the median PR-PFS time and 5-year PR-PFS rate.

CONCLUSIONS

We found that recent recurrence, oligo-recurrence, and DLT were associated with an improved median PR-PFS time and long-term PR-PFS rate in patients with postoperative recurrence after complete resection of NSCLC. On the basis of these results, we believe that DLT should be considered first for patients with oligo-recurrence before applying noncurative treatment.

Clinical Features and Prognostic Factor of Thoracic Postoperative Oligo-Recurrence of Non-Small-Cell Lung Cancer

Objective

The study aimed to clarify clinical features and prognostic factors of thoracic oligo-postoperative recurrences that underwent local therapy of non-small-cell lung cancer (NSCLC).

Methods

From 2332 patients of resected pathological stage I–IIIA NSCLC between 2008 and 2015, a total of 542 patients in follow developed recurrence. Thoracic oligo-recurrence was defined as 1–3 loco-regional confined to lung lobe, hilar/mediastinal lymph nodes, bronchial stump, or chest wall. This study included 56 thoracic oligo-recurrences. Local therapy included secondary surgery, stereotactic radiotherapy, radiotherapy with a 45 Gy or higher dose, and proton radiation therapy, performed with radical intent. We retrospectively reviewed the postoperative data and performed the univariate and multivariate analysis by Kaplan-Meier methods and Cox regression models, respectively.

Results

Thoracic Oligo-recurrence was identified in 56(542,10.3%) patients, mainly in lung lobe(n=22,39%) and regional lymph nodes(n=19,34%). Compared with distant oligo-recurrences, more of the thoracic oligo-recurrences were II–III in pathological stage at initial surgery(p=0.002) and less were adenocarcinoma(p=0.005). The 5-year postoperative survival rate and postoperative progression-free survival rate of thoracic oligo-recurrence were 10.8% and 6.7%, respectively. Median post-recurrence survival (PRS) was 31 months, and the median postoperative progression-free survival (PR-PFS) was 17 months. Multivariate analyses revealed that time to recurrence ≥ 12 months was associated with improved PRS [odds ratio (OR) 0.74, confidence interval (CI) 0.65–0.85], and regional lymph node oligo-recurrence was associated with poor PRS [OR 1.48, CI 1.38–1.60]. All the five long-term (≥5-year) progression-free survivors were with a solitary pulmonary recurrence.

Conclusion

Thoracic postoperative oligo-recurrence of non-small-cell lung cancer is a limited but highly heterogeneous population, with different prognosis at different recurrence sites. Local therapy for thoracic oligo-recurrence of NSCLC achieved favourable PRS in a selected population. Pulmonary solitary oligo-recurrence may achieve a long survival time.

Radiosurgery and fractionated stereotactic radiotherapy in oligometastatic/oligoprogressive non-small cell lung cancer patients: Results of a multi-institutional series of 198 patients treated with "curative" intent

OBJECTIVES

stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) are a therapeutic option for Oligometastatic/Oligoprogressive (OM/OP) NSCLC. This retrospective multicentre analysis aims to analyse clinical outcomes and treatment related toxicity of patients treated to all sites of know disease with SRS and/or FSRT for OM/OP NSCLC in 8 Italian radiation oncology centres.

MATERIALS AND METHODS

From January 2016 to January 2017 198 OM/OP NSCLC patients (pts) were treated in 8 Centres. Inclusion criteria were as follows: 1-5 lesions at onset or after previous systemic treatment; Pts must have all metastatic lesions treated. Endpoints analysed were local progression free survival (LPFS); out-of-field recurrence free survival (OFPS); progression free survival (PFS); overall survival (OS). Time to New systemic Therapy free survival (TNT) and toxicity were also analysed.

RESULTS

At the time of radiotherapy, 119 pts (60 %) were treated for a single lesion, 49 (25 %) for 2 lesions, 30 (15 %) for 3-5 metastases. Total number of lesions treated was 333: 204 brain, 68 lung, 24 bone, 16 nodal, 12 adrenal, 8 liver and 1 soft tissue. 83/198 pts (41.8 %) had the primary tumour controlled at the time of the SRT. After a median follow-up of 18 months, median OS and PFS were 29.6 months and 10.6 months, respectively. One year LPFS and OPFS were 90 % and 47 %, respectively. Median TNT was 10 months. At univariate analysis factors associated with better OS were PS 0-1; controlled primary tumour, 1-2 lesions; extracranial metastasis. Multivariate analysis confirmed number of lesions <3 and extracranial metastasis to be related with better survival (Relative Risk 0.4 and 0.41, respectively). Two cases of death possibly related to brain radionecrosis were observed.

CONCLUSION

OM/OP NSCLC pts treated with an ablative SRT to all metastatic sites have fair outcomes with acceptable toxicity. Better results might be achieved in case of low disease burden and extracranial possibly when primary tumour is controlled.

Stereotactic Ablative Radiation Therapy for Pulmonary Recurrence-Based Oligometastatic Non-Small Cell Lung Cancer: Survival and Prognostic Value of Regulatory T Cells

PURPOSE

We evaluated survival of patients with pulmonary recurrence-based oligometastatic non-small cell lung cancer (NSCLC) whose lesions were all treated with stereotactic ablative radiation therapy (SABR) and the prognostic value of peripheral immune cells.

METHODS AND MATERIALS

In this prospective observational cohort study, we prospectively enrolled 63 patients with oligometastatic NSCLC, for whom all metastases were treated with SABR. Peripheral blood samples were collected 3 days before treatment began, and flow cytometry was used to identify proportions of regulatory T cells (Tregs; CD4+CD25+CD127^low), B cells, NK cells, γδT cells, CD8+CD28+ T cells, and CD8+CD28- T cells. Overall survival (OS) and progression-free survival (PFS) was estimated by the Kaplan-Meier method, and the potential prognostic value of clinicopathologic factors was evaluated by Cox proportional hazards regression.

RESULTS

At a median follow-up time of 19.1 months, estimated OS rates were 84.3% at 1 year, 63.4% at 2 years, and 44.0% at 3 years; corresponding PFS rates were 55.2%, 30.9%, and 25.7%. Estimated local control rates were 96.7% at 1 year and 92.7% at both 2 years and 3 years. Patients with high numbers of Tregs had poorer OS and PFS than did those with low numbers of Tregs (OS: 16.1 months vs not reached, P = .006; PFS: 11.0 vs 21.7 months, P = .013). Treg level was found to be an independent predictor of both OS and PFS in multivariate analyses (OS: hazard ratio 2.68, P = .038; PFS: hazard ratio 2.35, P = .011).

CONCLUSIONS

Our results revealed the independent prognostic value of Tregs in patients treated with SABR for pulmonary recurrence-based oligometastatic NSCLC. Additional treatments may be needed for patients with oligometastatic NSCLC and poor outcomes.

Managing Patients With Oligometastatic Non-Small-Cell Lung Cancer

Metastatic lung cancer has long been considered incurable, with the goal of treatment being palliation. However, a clinically meaningful number of these patients with limited metastases (approximately 25%) are living long term after definitive treatment to all sites of active disease. These patients with so-called oligometastatic disease likely represent a distinct clinical group who may possess a more indolent biology compared with their more widely metastatic counterparts. Hellman and Weichselbaum proposed the existence of the oligometastatic state, on the basis of the spectrum theory of cancer spread. The literature suggests that an oligometastatic state exists in patients with non-small-cell lung cancer (NSCLC). This observation in the setting of rapidly evolving systemic therapies, including immune checkpoint inhibitors and an increasing number of targeted therapies, represents a unique clinical opportunity. Metastasis-directed therapies to address sites of disease include surgery (metastasectomy) and/or radiation therapy. Available evidence suggests that treating patients with limited or oligometastases may improve outcomes in a meaningful way; however, the majority of the randomized data includes patients with intracranial metastatic disease, and there are limited robust, randomized data available in the setting of NSCLC with only extracranial sites of metastatic disease. Ongoing randomized trials, including NRG-LU002 and the UK Conventional Care Versus Radioablation (Stereotactic Body Radiotherapy) for Extracranial Oligometastases trial, are aimed at evaluating this question further. One of the current limitations of aggressive treatment of oligometastatic NSCLC is the inability to accurately identify these patients before therapy, yet molecular markers, including microRNA profiles, are being investigated as a promising way to identify these patients.

Local therapy combined with chemotherapy versus chemotherapy for postoperative oligometastatic non-small-cell lung cancer

Aim: To compare the efficacy and toxicity of local therapy plus chemotherapy versus chemotherapy in non-small-cell lung cancer (NSCLC) patients with oligometastases after surgery. Patients & methods: A total of 152 patients with oligometastases after surgery were enrolled. Data of patient survival, treatment response and toxicities were compared between the groups receiving local ablative therapy plus chemotherapy and chemotherapy alone. Results: Compared with chemotherapy, the combination treatment conferred better progression-free survival, objective response rate and disease control rate (10 vs 7 months; 66.7 vs 31.9%; 94.3 vs 80.9%, respectively), but with more grade ≥3 adverse events. Besides, the overall survival was not significantly different (19 vs 20 months). Conclusion: The addition of local therapy to chemotherapy improved progression-free survival, objective response rate and disease control rate, but not overall survival in postoperative oligometastatic non-small-cell lung cancer.

Concomitant radiotherapy and TKI in metastatic EGFR- or ALK-mutated non-small cell lung cancer: a multicentric analysis on behalf of AIRO lung cancer study group

PURPOSE

To investigate the role of radiotherapy (RT) in the management of EGFR- or ALK-mutated metastatic non-small cell lung cancer (NSCLC) treated with TKI.

MATERIALS AND METHODS

Clinical data of 106 patients (pts) from five Institutions treated with RT concomitant to TKI were retrospectively revised. Overall survival (OS) and toxicities were analyzed as endpoints of the study.

RESULTS

Median age of pts was 65 years. TKIs were given for EGFR (81%)- or ALK (19%)-mutated metastatic NSCLC. Stereotactic RT (SRT) was delivered to 49 pts (46%). Patients with four or less metastasis were defined as oligometastatic/oligoprogressive (OM/OP); sites of RT were brain, bone, lung or others in 46%, 27%, 14% and 13%, respectively. Median OS was 23 months. At univariate analysis SRT, ECOG PS 0-1, OM/OP disease, lung sites and a TKI duration longer than median favorably affected OS (all p < 0.001). Multivariate analysis confirmed SRT (HR 0.355, CI 95% 0.212-0.595; p < 0.001) and median duration of TKI > 14 months (HR 0.17, 95% CI 0.10-0.30; p < 0.001) as independent factors related to better OS. Toxicities were rare.

CONCLUSIONS

SRT seems to positively affect OS with limited toxicity in selected patients.

Canadian consensus: oligoprogressive, pseudoprogressive, and oligometastatic non-small-cell lung cancer

Background

Little evidence has been generated for how best to manage patients with non-small-cell lung cancer (nsclc) presenting with rarer clinical scenarios, including oligometastases, oligoprogression, and pseudoprogression. In each of those scenarios, oncologists have to consider how best to balance efficacy with quality of life, while maximizing the duration of each line of therapy and ensuring that patients are still eligible for later options, including clinical trial enrolment.

Methods

An expert panel was convened to define the clinical questions. Using case-based presentations, consensus practice recommendations for each clinical scenario were generated through focused, evidence-based discussions.

Results

Treatment strategies and best-practice or consensus recommendations are presented, with areas of consensus and areas of uncertainty identified.

Conclusions

In each situation, treatment has to be tailored to suit the individual patient, but with the intent of extending and maximizing the use of each line of treatment, while keeping treatment options in reserve for later lines of therapy. Patient participation in clinical trials examining these issues should be encouraged.

M1b Disease in the 8th Edition of TNM Staging of Lung Cancer: Pattern of Single Extrathoracic Metastasis and Clinical Outcome

The 8th edition of TNM staging of lung cancer revised M staging and defined M1b disease with single extrathoracic metastasis, to be distinguished from M1c with multiple extrathoracic metastases in one or more organs. This new distinct category of M1b disease consists of patients with a single extrathoracic metastasis, thus consisting of a strictly defined oligometastatic disease. This article reports the prevalence of M1b disease among patients with stage IV non‐small cell lung cancer, focusing on the clinical characteristics and patterns of single extrathoracic metastasis and relationships with overall survival.

Background.

The 8th edition of TNM staging of non‐small cell lung cancer (NSCLC) has revised M classification and defined M1b disease with single extrathoracic metastasis, which is distinguished from M1c with multiple extrathoracic metastases. We investigated the prevalence, characteristics, and overall survival (OS) of M1b disease in patients with stage IV NSCLC.

Methods.

The study reviewed the medical records and imaging studies of 567 patients with stage IV NSCLC to determine M stage using the 8th edition of TNM staging. Clinical characteristics and OS were compared according to M stages.

Results.

Among 567 patients, 57 patients (10%) had M1b disease, whereas 119 patients (21%) had M1a disease and 391 patients (69%) had M1c disease. Squamous histology was more common in M1b (16%) than in M1a (6%) and M1c (6%; p = .03). The median OS of patients with M1b disease was 14.8 months, compared with 22.6 months for patients with M1a and 13.4 months for those with M1c disease (p < .0001). Significant OS differences of M1b compared with single‐organ M1c and multiorgan M1c groups were noted (single‐organ M1c vs. M1b: hazard ratio [HR], 1.49; p = .02; multiorgan M1c vs. M1b: HR, 1.57; p = .01) in multivariable analyses adjusting for smoking and systemic therapy types. Among patients with M1b disease, the brain was the most common site of single metastasis (28/57; 49%), followed by bone (16/57; 28%). Single brain metastasis was more frequently treated with local treatment (p < .0001).

Conclusion.

M1b disease was noted in 10% of patients with stage IV NSCLC. Squamous histology was more common in M1b group than others. The brain was the most common site of single metastasis and was often treated locally.

Implications for Practice.

The newly defined group of M stage consists of a unique subset among patients with stage IV non‐small cell lung cancer that can be studied further to optimize treatment approaches.

Local ablative therapy with or without chemotherapy for non-small-cell lung cancer patients with postoperative oligometastases

Background

The optimal treatment strategy for patients with non-small-cell lung cancer (NSCLC) with postoperative oligometastases is poorly defined. This two-institution analysis sought to retrospectively compare the efficacy and toxicity of local ablative treatment plus chemotherapy vs local treatment alone in patients with NSCLC who developed oligometastases after surgery.

Patients and methods

Among patients who underwent surgery for stage I–III NSCLC, 163 patients with oligometastases were enrolled between 2005 and 2016 in this study. All patients had ≤5 metachronous metastases with a disease-free interval (DFI) of ≥6 months after surgery. Patients with a second primary cancer, local recurrence, or driver mutations were excluded. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), failure patterns, and treatment-related toxicities were compared between groups receiving local ablative treatment plus chemotherapy and local treatment alone.

Results

A total of 105 patients who underwent local ablative therapy combined with chemotherapy and 58 patients who received local ablative therapy alone were included in this study. The median follow-up was 19 (range, 1.5–107) months. The combination therapy group had a higher ORR than the local therapy alone group (66.7% vs 46.5%, P=0.012), while the median PFS was 10 vs 7 months (P=0.006) and the median OS was 19 vs 18.5 months (P=0.498), respectively. By multivariate analysis, combination therapy and DFI ≥24 months were associated with superior PFS. Age was the only independent prognostic factor for OS (P<0.001). The incidences of grade ≥3 adverse events were higher in the combination treatment group.

Conclusion

Local ablative therapy plus chemotherapy conferred higher ORR and prolonged PFS but did not improve OS in NSCLC patients with postoperative oligometastases. Further prospective and randomized trials are urgently needed to validate these findings.

Hepatectomy for oligo-recurrence of non-small cell lung cancer in the liver

BACKGROUND

The prognosis of metastatic recurrent non-small cell lung cancer (NSCLC) is poor, and chemotherapy improves survival by only a few months. The concept of oligo-recurrence, defined as a small number of new lesions at a distant site theoretically curable by local therapy, has recently been proposed for several cancers. To evaluate the possible benefits of surgical resection for oligo-recurrence, we report the outcomes of seven patients who underwent hepatic resection for oligo-recurrence of NSCLC in the liver.

METHODS

Among the 2038 patients who underwent resection for NSCLC between January 1997 and December 2015 at the Department of Chest Surgery, Chiba Cancer Center, 7 (0.34%) with oligo-recurrence in the liver underwent hepatectomy. Perioperative data were retrospectively reviewed, including recurrence-free and overall survival.

RESULTS

Primary tumor histopathological types included five cases of squamous cell carcinoma, one case of adenocarcinoma, and one case of large-cell carcinoma. All patients underwent complete tumor resection without complication. The median survival duration following hepatectomy was 24.0 (range 15.2-30.2) months. Four patients were alive at the end of follow-up (23.4-30.2 months), whereas three died between 15.2 and 24.5 months. There was no evidence of second recurrence in two patients.

CONCLUSIONS

Hepatectomy may be equally effective as multidisciplinary therapy for oligo-recurrence of NSCLC in the liver.

Can urologists introduce the concept of "oligometastasis" for metastatic bladder cancer after total cystectomy?

We investigated whether the concept of oligometastasis may be introduced to the clinical management of metastatic bladder cancer patients. Our study population comprised 128 patients diagnosed with metastatic bladder cancer after total cystectomy at our 6 institutions between 2004 and 2014. We extracted independent predictors for identifying a favorable. Occurrence that fulfilled all 4 criteria which were independently associated with cancer-specific death was defined as oligometastasis: a solitary metastatic organ; number of metastatic lesions of 3 or less; the largest diameter of metastatic foci of 5cm or less; and no liver metastasis. We evaluated differences in clinical outcomes between patients with oligometastasis (oligometastasis group) and those without oligometastasis (non-oligometastasis group). Overall, there were 43 patients in the oligometastasis group. The 2-year cancer-specific survival rate in the oligometastasis group was 53.3%, which was significantly higher than that in the non-oligometastasis group (16.1%, p<0.001). A multivariate analysis revealed that non-oligometastasis (p<0.001), not performing salvage chemotherapy (p<0.001), and not performing metastatectomy (p=0.028) were independent risk factors for cancer-specific death. In the subgroup of 83 patients who received salvage chemotherapy, 30 were in the oligometastasis group. The 2-year cancer-specific survival rate in the oligometastasis group was 55.0%, which was significantly higher than that in the non-oligometastasis group (22.0%, p=0.005). Non-oligometastasis (p=0.009) was the only independent risk factor for cancer-specific death. We presented that urothelial carcinoma with oligometastasis had a favorable prognosis and responded to systemic chemotherapy. Oligometastasis may be treated as a separate entity in the field of metastatic urothelial carcinoma.

Post-recurrence survival analysis of stage I non-small-cell lung cancer

Background The aim of this retrospective study was to review recurrence patterns of stage I non-small-cell lung cancer and identify prognostic factors for post-recurrence survival. Methods Among 940 patients with pathological stage I non-small-cell lung cancer who underwent curative resection, 261 experienced a recurrence; of these, 188 had adenocarcinoma and 62 had squamous cell carcinoma. Oligo-recurrence was defined as 1-3 recurrent lesions restricted to a single organ. Potentially curative local treatment included surgery, stereotactic radiotherapy, and photodynamic therapy. Results The median follow-up duration was 65 months (range 4-186 months). The most common site of recurrence was the lung in 145 patients, followed by mediastinal lymph nodes in 49, pleura in 30, and brain in 27. Local treatment for recurrent tumors included surgery in 59 patients, stereotactic radiotherapy in 46, photodynamic therapy in 2, and other radiotherapy in 41. Seventy-eight patients received chemotherapy only, and 35 received conservative treatment. Among 125 patients who were evaluated for an epidermal growth factor receptor gene mutation, 31 were treated with epidermal growth factor receptor-tyrosine kinase inhibitor. The 3- and 5-year post-recurrence survival rates were 49.1% and 33.8%, respectively. Age at recurrence, adenocarcinoma cell type, disease-free interval, epidermal growth factor receptor-tyrosine kinase inhibitor treatment, and potentially curative local treatment were independent prognostic factors for survival in multivariate analysis. Conclusions Local treatment for recurrence should be considered in selected candidates, and use of epidermal growth factor receptor-tyrosine kinase inhibitor I is reasonable if an epidermal growth factor receptor mutation is detected.

Radiotherapy for Oligometastatic Lung Cancer

Non-small cell lung cancer (NSCLC) typically presents at an advanced stage, which is often felt to be incurable, and such patients are usually treated with a palliative approach. Accumulating retrospective and prospective clinical evidence, including a recently completed randomized trial, support the existence of an oligometastatic disease state wherein select individuals with advanced NSCLC may experience historically unprecedented prolonged survival with aggressive local treatments, consisting of radiotherapy and/or surgery, to limited sites of metastatic disease. This is reflected in the most recent AJCC staging subcategorizing metastatic disease into intra-thoracic (M1a), a single extra thoracic site (M1b), and more diffuse metastases (M1c). In the field of radiation oncology, recent technological advances have allowed for the delivery of very high, potentially ablative, doses of radiotherapy to both intra- and extra-cranial disease sites, referred to as stereotactic radiosurgery and stereotactic body radiotherapy (or SABR), in much shorter time periods compared to conventional radiation and with minimal associated toxicity. At the same time, significant improvements in systemic therapy, including platinum-based doublet chemotherapy, molecular agents targeting oncogene-addicted NSCLC, and immunotherapy in the form of checkpoint inhibitors, have led to improved control of micro-metastatic disease and extended survival sparking newfound interest in combining these agents with ablative local therapies to provide additive, and in the case of radiation and immunotherapy, potentially synergistic, effects in order to further improve progression-free and overall survival. Currently, despite the tantalizing potential associated with aggressive local therapy in the setting of oligometastatic NSCLC, well-designed prospective randomized controlled trials sufficiently powered to detect and measure the possible added benefit afforded by this approach are desperately needed.

Surgical treatment in non-small cell lung cancer with pulmonary oligometastasis

BACKGROUND

Previous studies have demonstrated survival benefits for local treatment in solitary metastatic non-small cell lung cancer (NSCLC).This study aimed to investigate the effect of local surgery for NSCLC with pulmonary oligometastasis.

METHODS

This study included 21 patients of NSCLC with pulmonary oligometastasis between January 2003 and December 2013, which were divided into two groups, group A (11 cases) for local surgery and group B (10 cases) for systematic chemotherapy, compared the median survival time (MST) and 5-year survival rate between the two groups, and analyzed the impact of the pathological types, the TNM and pN stage of primary tumor, the site, and the mode and number of oligometastatic nodule on group A.

RESULTS

The MST of group A and B were 37 and 11.6 months respectively, 5-year survival rates were 18.2 and 9.1% respectively (p < 0.05). Patients with single nodule, oligo-recurrence, primary tumor of pN0, TNM stage I or II obtained higher survival rate than those with multiple nodules, sync-oligometastases, pN1-2, stage III or IV in group A (p < 0.05). There was no significant survival time difference among pathological types of primary tumor and oligometastatic site (p > 0.05).

CONCLUSION

Local surgery significantly prolonged the overall survival time and 5-year survival rate of primary NSCLC with pulmonary oligometastasis.

Should aggressive thoracic therapy be performed in patients with synchronous oligometastatic non-small cell lung cancer? A meta-analysis

BACKGROUND

We performed a meta-analysis to compare overall survival (OS) outcomes in patients with synchronous oligometastatic non-small cell lung cancer (NSCLC) who underwent aggressive thoracic therapy (ATT) with those who did not.

METHODS

A systematic review of controlled trials of ATT on survival in synchronous oligometastatic NSCLC was conducted. Hazard ratio (HR) for the main endpoint OS was pooled using a fixed-effects model. Subgroup analysis was performed in patients with single organ metastases, or with different numbers of brain metastases, or with different stages of thoracic disease. Pooled survival curves of OS were constructed.

RESULTS

Seven eligible retrospective observational cohort studies were identified including 668 synchronous oligometastatic NSCLC patients, of whom 227 (34.0%) received ATT. For patients with synchronous oligometastatic NSCLC, ATT was associated with a significant improvement of OS (HR, 0.48; 95% CI, 0.39-0.60; P<0.00001). In subgroup analysis, the association with OS was similar or even strengthened, with a HR of 0.42 (95% CI, 0.31-0.56) in single organ metastases group, 0.49 (95% CI, 0.31-0.75) in solitary brain metastasis group, and 0.38 (95% CI, 0.20-0.73) in thoracic stage I-II group, respectively. The pooled cumulative survival rates for patients received ATT were 74.9% at 1 year, 52.1% at 2 years, 23.0% at 3 years, and 12.6% at 4 years. The corresponding pooled survival for patients who did not receive ATT were 32.3%, 13.7%, 3.7%, and 2.0%, respectively.

CONCLUSIONS

Survival benefit from ATT is common in synchronous oligometastatic patients. Selected patients with synchronous oligometastatic NSCLC could also achieve long-term survival with ATT.

Oligometastatic non-small-cell lung cancer: current treatment strategies

The oligometastatic disease theory was initially described in 1995 by Heilman and Weichselbaum. Since then, much work has been performed to investigate its existence in many solid tumors. This has led to subclassifications of stage IV cancer, which could redefine our treatment approaches and the therapeutic outcomes for this historically “incurable” entity. With a high incidence of stage IV disease, non-small-cell lung cancer (NSCLC) remains a difficult cancer to treat and cure. Recent work has proven the existence of an oligometastatic state in NSCLC in terms of properly selecting patients who may benefit from aggressive therapy and experience long-term overall survival. This review discusses the current treatment approaches used in oligometastatic NSCLC and provides the evidence and rationale for each approach. The prognostic factors of many trials are discussed, which can be used to properly select patients for aggressive treatment regimens. Future advances in both molecular profiling of NSCLC to find targetable mutations and investigating patient selection may increase the number of patients diagnosed with oligometastatic NSCLC. As this disease entity increases, it is of utmost importance for oncologists treating NSCLC to be aware of the current treatment strategies that exist and the potential advantages/disadvantages of each.

Radiofrequency ablation alone or in combination with cementoplasty for local control and pain palliation of sacral metastases: preliminary results in 11 patients

PURPOSE

To determine the safety and effectiveness of radiofrequency ablation (RFA) to treat sacral metastases for pain palliation and local tumor control (LTC).

MATERIALS AND METHODS

An institutional tumor ablation registry was retrospectively reviewed for sacral RFA procedures performed between January 2012 and December 2015. Clinical history, pre-procedural imaging, and procedural details were reviewed to document indication for treatment, primary tumor histology, tumor volumes, presence of concurrent cementoplasty after RFA, and the occurrence of peri-procedural complications. Pain scores before and 4 weeks after the procedure were recorded. Post-procedure imaging was reviewed for imaging evidence of tumor progression. Long-term complications and duration of clinical follow-up were recorded.

RESULTS

During the study period, 11 RFA procedures were performed to treat 16 sacral metastases. All procedures were for pain palliation. Four procedures (36 %; 4 out of 11) were also performed with the intention of achieving LTC in patients with oligometastatic disease. Concurrent cementoplasty was performed in 63 % of cases (7 out of 11). The median pain score decreased from 8 (interquartile range, 6-9.25) at baseline to 3 (interquartile range, 1.75-6.3) 1 month following RFA (P = 0.004). In the 4 patients with oligometastatic disease, LTC was achieved in 3 patients (75 %; 3 out of 4) after a median follow-up of 7.6 months (range, 3.6-11.9 months). No acute or long-term complications were documented during the overall median clinical follow-up of 4.7 months (range, 0.9-28.7 months).

CONCLUSIONS

Radiofrequency ablation maybe a safe and potentially effective treatment for patients with painful sacral metastases and can achieve LTC in selected patients.

The role of local ablative therapy in oligometastatic non-small-cell lung cancer: hype or hope

In recent years, the emergence of the oligometastatic state has called into question whether patients found to have a limited or low metastatic tumor burden may benefit from locally ablative therapy (LAT). In the past two decades, stereotactic body radiation therapy has been increasingly used to safely deliver LAT and provide high local control in nonoperable non-small-cell lung cancer patients. Mostly retrospective analyses suggest that using LAT for oligometastatic disease in non-small-cell lung cancer offers excellent local control and may provide an improvement in progression-free survival. Any meaningful improvement in cancer-specific survival remains debatable. We examine the role of integrating LAT in this patient population and the rationale behind its use in combination with targeted therapy and immunotherapy.

Patterns of Distant Metastases After Surgical Management of Non-Small-cell Lung Cancer

BACKGROUND

Patients with limited metastases, oligometastases (OMs), might have improved outcomes compared with patients with widespread distant metastases (DMs). The incidence and behavior of OMs from non-small-cell lung cancer (NSCLC) need further characterization.

PATIENTS AND METHODS

The medical records of patients who had undergone surgery for stage I-III NSCLC from 1995 to 2009 were retrospectively reviewed. All information pertaining to development of the first metastatic progression was recorded and analyzed. Patients with DMs were categorized into OMs (1-3 lesions potentially amenable to local therapy) and DM subgroups.

RESULTS

Of 1719 patients reviewed, 368 (21%) developed DMs with a median follow-up period of 39 months. A single lesion was diagnosed in 115 patients (31%) and 69 (19%) had 2 to 3 lesions (50% oligometastatic). The median survival from the DM diagnosis for oligometastatic and diffuse DM was 12.4 and 6.1 months, respectively (hazard ratio, 0.54; 95% confidence interval, 0.42-0.68; P < .001). Patients with a single metastasis had the longest median survival at 14.7 months. Younger age, OM, the use of chemotherapy for the primary tumor, and DM detection by surveillance imaging were independently associated with improved survival.

CONCLUSION

DMs and OMs are common in surgically managed NSCLC. Overall survival appears to be prolonged with OM.

Radiation Therapy for Oligometastatic Non-Small Cell Lung Cancer: Theory and Practice

Management paradigms for metastatic non-small cell lung cancer (mNSCLC) are evolving. Locally ablative therapies are now being increasingly integrated into combined-modality treatment strategies for mNSCLC patients with limited burdens of metastatic foci, termed oligometastases. Concurrently, techniques allowing for precise high-dose radiotherapy delivered over 1 to 5 total treatments, termed stereotactic body radiation therapy (SBRT) or stereotactic ablative radiation therapy (SABR), have emerged as a powerful means of noninvasive tumor ablation with broad patient candidacy. Strong rationale exists for ablative therapy in the setting of oligometastatic NSCLC, including patterns-of-failure analyses and data supporting local ablation of oligoprogressive disease for patients with oncogene-addicted mNSCLC treated with tyrosine kinase inhibitors. In this article, we examine the theoretical basis for ablation of oligometastatic NSCLC and review the growing clinical literature of mNSCLC patients treated with ablative radiation therapy.

Approach for oligometastasis in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) harboring a limited number of distant metastases, referred to as the oligometastatic state, has been indicated for surgery for the past several decades. However, whether the strategy of surgical treatment results in a survival benefit for such patients remains controversial. Experientially, however, thoracic surgeons often encounter long-term survivors among surgically resected oligometastatic NSCLC patients. In this article, the current situation of surgical approach and potential future perspective for oligometastatic NSCLC are reviewed.

The evolving role of radiotherapy in treatment of oligometastatic NSCLC

Non-small cell lung cancer (NSCLC) patients with metastases limited in site and number, termed oligometastases, may represent a unique subpopulation of advanced NSCLC with improved prognosis. The optimal management of these patients remains unclear with the treatment approach currently undergoing a paradigm shift. The potential benefit of aggressive metastasis directed local treatment with surgery and/or radiotherapy (RT) in combination with systemic therapy is bolstered predominantly by retrospective analyses but also by a growing number of non-randomized prospective studies regarding the use of ablative RT techniques including stereotactic body radiotherapy (SBRT), alternatively termed stereotactic ablative radiotherapy (SABR), directed at the primary tumor (if present) and all metastatic sites. Long-term survival is possible in a subset of patients treated aggressively in this manner. The challenge for the clinical oncology community moving forward is appropriately selecting patients for this treatment approach based on clinical, imaging, and molecular features and increasing enrollment of patients to prospective clinical trials to more definitively determine the added benefit and appropriate timing of aggressive metastasis directed therapy in the oligometastatic setting.

Postoperative oligo-recurrence of non-small-cell lung cancer: clinical features and survival†

OBJECTIVES

Postoperative recurrences of non-small-cell lung cancer (NSCLC) are usually disseminated and systemic. Recently, the concept of oligo-recurrence, which is theoretically curable by definitive local therapy (DLT), has been proposed in several cancers. The aim of this study was to clarify clinical features and outcomes of patients with postoperative oligo-recurrence of NSCLC.

METHODS

From 3275 patients with resected pathological stage IA-IIIB NSCLC between 1993 and 2011, a total of 768 patients who developed recurrence were included in this study. Oligo-recurrence was defined as 1-3 loco-regional or distant recurrent lesions restricted to a single organ. Other recurrences were classified as poly-recurrence. Second primary lung cancers and suspected lesions were excluded. DLT included surgery, stereotactic radiotherapy and radiotherapy with a 45 Gy or higher dose, performed with curative intent.

RESULTS

Oligo-recurrence was identified in 162 (21%) patients, mainly as a solitary recurrence (n = 129, 80%) in regional lymph nodes, brain, lung, bone and adrenal gland, and the proportion of patients with oligo-recurrence increased gradually year by year. The patients with oligo-recurrence had more early-staged disease at initial surgery and a longer time to recurrence than those with poly-recurrence. The entire population of oligo-recurrence patients had better post-recurrence survival (PRS) than those with poly-recurrence (5-year PRS: 32.9 vs 9.9%, P < 0.001). For oligo-recurrence, DLT was totally conducted in 105 (65%) patients as initial treatment. Multivariate analyses revealed that the initial DLT was associated with improved PRS [odds ratio (OR) 0.44; 95% confidence interval (CI) 0.29-0.68]. The recurrence location and initial pathological stage did not affect PRS. The 5-year PRS and postoperative progression-free survival rates after DLT were 38.6 and 22.3%, respectively. Of the 10 long-term (≥5-year) progression-free survivors, 9 were those with a solitary recurrence.

CONCLUSIONS

Initial DLT for oligo-recurrence achieved favourable PRS in a selected population. Oligo-recurrence curable by DLT was found in a subset of patients who received DLT, mostly as a solitary recurrence.

The biology and treatment of oligometastatic cancer

Clinical reports of limited and treatable cancer metastases, a disease state that exists in a transitional zone between localized and widespread systemic disease, were noted on occasion historically and are now termed oligometastasis. The ramification of a diagnosis of oligometastasis is a change in treatment paradigm, i.e. if the primary cancer site (if still present) is controlled, or resected, and the metastatic sites are ablated (surgically or with radiation), a prolonged disease-free interval, and perhaps even cure, may be achieved. Contemporary molecular diagnostics are edging closer to being able to determine where an individual metastatic deposit is within the continuum of malignancy. Preclinical models are on the outset of laying the groundwork for understanding the oligometastatic state. Meanwhile, in the clinic, patients are increasingly being designated as having oligometastatic disease and being treated owing to improved diagnostic imaging, novel treatment options with the potential to provide either direct or bridging therapy, and progressively broad definitions of oligometastasis.

Therapeutic strategy for postoperative recurrence in patients with non-small cell lung cancer

Postoperative recurrence occurs in approximately half of patients with non-small cell lung cancer (NSCLC), even after complete resection. Disease recurrence after surgical resection reduces the patient’s life expectancy sharply. The prognosis after postoperative recurrence is considered to largely depend on both the mode of first recurrence (distant, locoregional or combined) and the treatment modality: (1) The majority of cases of postoperative recurrence involve distant metastasis with or without locoregional recurrence. Platinum-based systemic chemotherapy is practically accepted as the treatment for these diseases on the basis of evidence for original stage IV disease. The advent of both pemetrexed and molecular-targeted drugs has improved the survival of nonsquamous NSCLC and changed the chemotherapeutic algorithm for NSCLC; (2) Among patients with distant metastatic recurrence without locoregional recurrence at the primary tumor site, the metastasis is often limited in both organ and number. Such metastases are referred to as oligometastases. Local therapy, such as surgical resection and radiotherapy, has been suggested to be the first-line treatment of choice for oligometastatic recurrence; and (3) While locoregional recurrence is likely to cause troublesome symptoms, it is a potentially limited disease. Therefore, providing local control is important, and radiation is usually beneficial for treating local recurrence. In order to obtain better control of the disease and provide treatment with curative intent in patients with limited disease, the administration of concurrent platinum-based chemoradiotherapy is recommended according to the results of originally nonresectable stage IIIA and IIIB disease.

Evaluating the utility of local therapy for oligometastatic lung cancer

SUMMARY 

In patients with metastatic non-small-cell lung cancer, limited metastases are identified as ‘oligometastases’, and such patients are expected to be long-term progression-free, or possibly curable by local control of those lesions. Especially for oligometastatic recurrence after complete resection of the original primary tumor, local treatment should be taken into consideration as a choice of treatment. Oligoprogression after the administration of EGF receptor tyrosine kinase inhibitors for EGFR-mutated non-small-cell lung cancer might also be indicated for local treatment while continuing the EGF receptor tyrosine kinase inhibitor treatment. Since stereotactic radiotherapy delivery is now available, its potential for local control is nearly comparable to that of surgery. These two major modalities of local therapy should be selected for the treatment of oligometastases after carefully considering both the oligometastatic status (organs, number) and patient status.

[Radiofrequency ablation for lung neoplasms with isolated postsurgical local recurrences or metastases of non-small cell lung cancer]

BACKGROUND

Primary lung cancer is one of the most common malignancies worldwide. Surgical resection remains the first choice for the treatment of early stage non-small cell lung cancer (NSCLC). Relapse after surgery sharply reduces the patient's life expectancy. This relapse is referred to as isolated postsurgical local recurrences or metastases (IPSLROM), which can be treated via local therapy to achieve long-term survival or cure. In recent years, radiofrequency ablation (RFA) has been increasingly used as a non-surgical treatment option for patients with primary and metastatic lung tumors. This study aims to evaluate the efficacy of RFA among patients with IPSLROM of NSCLC.

METHODS

A total of 20 patients underwent computerd tomograghy (CT)-guided RFA for lung neoplasm with IPSLROM of NSCLC (with unresectable disease because of poor lung reserve or multifocality) in our hospital between December 2008 and November 2013. These patients comprised 15 males and 5 females with a mean age of 69.2 years (range: 45-85). All patients exhibited pathological evidence of neoplastic lesion (14 tumors were adenocarcinoma, and six were squamous cell carcinoma). The mean size of the lesions was 3.9 cm (range: 2.0 cm to 8.0 cm). Treatment complications, progression-free survival (PFS), and survival parameters were retrospectively analyzed.

RESULTS

RFA was well tolerated by all patients with an average time of 34.3 min (range: 15 min to 60 min). Intraprocedural complications included eight cases of chest pain (40%). No procedure-related deaths occurred in all of the 20 ablation procedures. The median PFS was 25 months in all of the patients who received RFA. The median overall survival for the entire group of patients was 27.0 months. No differences were observed in the overall survival between patients with IPSLROM. The overall survival rates at 1 and 2 years after RFA were 92.9% and 57.0%, respectively.

CONCLUSIONS

RFA is a safe and effective procedure in unresectable lung tumors with IPSLROM of NSCLC.

Definitive primary therapy in patients presenting with oligometastatic non-small cell lung cancer

PURPOSE

Although palliative chemotherapy is the standard of care for patients with diagnoses of stage IV non-small cell lung cancer (NSCLC), patients with a small metastatic burden, "oligometastatic" disease, may benefit from more aggressive local therapy.

METHODS AND MATERIALS

We identified 186 patients (26% of stage IV patients) prospectively enrolled in our institutional database from 2002 to 2012 with oligometastatic disease, which we defined as 5 or fewer distant metastatic lesions at diagnosis. Univariate and multivariable Cox proportional hazards models were used to identify patient and disease factors associated with improved survival. Using propensity score methods, we investigated the effect of definitive local therapy to the primary tumor on overall survival.

RESULTS

Median age at diagnosis was 61 years of age; 51% of patients were female; 12% had squamous histology; and 33% had N0-1 disease. On multivariable analysis, Eastern Cooperate Oncology Group performance status ≥ 2 (hazard ratio [HR], 2.43), nodal status, N2-3 (HR, 2.16), squamous pathology, and metastases to multiple organs (HR, 2.11) were associated with a greater hazard of death (all P<.01). The number of metastatic lesions and radiologic size of the primary tumor were not significantly associated with overall survival. Definitive local therapy to the primary tumor was associated with prolonged survival (HR, 0.65, P=.043).

CONCLUSIONS

Definitive local therapy to the primary tumor appears to be associated with improved survival in patients with oligometastatic NSCLC. Select patient and tumor characteristics, including good performance status, nonsquamous histology, and limited nodal disease, may predict for improved survival in these patients.