A call for the aggressive treatment of oligometastatic and oligo-recurrent non-small cell lung cancer

Optimal Treatment Strategy for Oligo-Recurrence Lung Cancer Patients with Driver Mutations

BACKGROUND

The efficacy of local therapies for lung cancer patients with postoperative oligo-recurrence has been reported. However, whether local therapies should be chosen over molecular targeted therapies for oligo-recurrence patients with driver mutations remains controversial. Therefore, we aimed to investigate the optimal initial treatment strategy for oligo-recurrence in lung cancer patients with driver mutations.

METHODS

Among 2152 patients with lung adenocarcinoma who underwent surgical resection at our institute between 2008 and 2020, 66 patients with driver mutations who experienced cancer oligo-recurrence after surgery and were treated with local or molecularly targeted therapy as an initial therapy after recurrence were evaluated. Oligo-recurrence was characterized by the presence of 1 to 3 recurrent lesions. These patients were investigated, focusing on their post-recurrence therapies and prognoses.

RESULTS

The median follow-up period was 71 months. Local and molecular targeted therapies were administered to 41 and 25 patients, respectively. The number of recurrence lesions tended to be lower in the initial local therapy group than in the molecular targeted therapy group. In the initial local therapy group, 23 patients (56%) subsequently received molecular targeted therapies. The time from recurrence to the initiation of molecular targeted therapy was significantly longer in the local therapy group than in the molecular targeted therapy group (p < 0.001). There was no significant difference in post-recurrence overall survival (hazard ratio, 1.429; 95% confidence interval, 0.701-2.912; log-rank, p = 0.324) and post-recurrence progression-free survival (hazard ratio, 0.799; 95% confidence interval, 0.459-1.390; log-rank, p = 0.426) in the initial local ablative therapy group compared with the initial molecular targeted therapy group.

CONCLUSIONS

Local therapies as a first-line treatment did not show statistically significant differences in post-recurrence survival or progression-free survival compared with molecular targeted therapies. However, local therapies as an initial treatment should be considered preferably, as they can cure the recurrence and can delay the start of administration of molecular targeted therapies.

Clinical features and lipid metabolism genes as potential biomarkers in advanced lung cancer

BACKGROUND

Lung cancer is one of the most lethal tumors with a poor survival rate even in those patients receiving new therapies. Metabolism is considered one of the hallmarks in carcinogenesis and lipid metabolism is emerging as a significant contributor to tumor metabolic reprogramming. We previously described a profile of some lipid metabolism related genes with potential prognostic value in advanced lung cancer.

AIM

To analyze clinical and pathological characteristics related to a specific metabolic lipid genomic signature from patients with advanced lung cancer and to define differential outcome.

METHODS

Ninety samples from NSCLC (non-small cell lung cancer) and 61 from SCLC (small cell lung cancer) patients were obtained. We performed a survival analysis based on lipid metabolic genes expression and clinical characteristics. The primary end point of the study was the correlation between gene expression, clinical characteristics and survival.

RESULTS

Clinical variables associated with overall survival (OS) in NSCLC patients were clinical stage, adenocarcinoma histology, Eastern Cooperative Oncology Group (ECOG), number and site of metastasis, plasma albumin levels and first-line treatment with platinum. As for SCLC patients, clinical variables that impacted OS were ECOG, number of metastasis locations, second-line treatment administration and Diabetes Mellitus (DM). None of them was associated with gene expression, indicating that alterations in lipid metabolism are independent molecular variables providing complementary information of lung cancer patient outcome.

CONCLUSIONS

Specific clinical features as well as the expression of lipid metabolism-related genes might be potential biomarkers with differential outcomes.

Results of Radiation Therapy as Local Ablative Therapy for Oligometastatic Non-Small Cell Lung Cancer

Oligometastatic cancer is characterized by a limited number of metastatic deposits. Compared with lung cancer patients who have more widespread disease, oligometastatic lung cancer patients have more favorable survival outcomes. Therefore, it has been hypothesized that local ablative therapy (LAT) directed at the metastatic deposits in addition to standard-of-care systemic therapy may further improve survival outcomes in oligometastatic lung cancer patients. One LAT modality that has been utilized in oligometastatic lung cancer is radiation therapy. In particular, ultra-hypofractionated radiotherapy, also known as stereotactic body radiotherapy (SBRT), has been shown to provide excellent local control with a favorable safety profile. Here, we reviewed the retrospective studies and prospective trials that have deployed radiation therapy as LAT in oligometastatic lung cancer, including randomized studies showing benefits for progression-free survival and overall survival with the addition of LAT. We also discuss the impact of targeted therapies and immunotherapy on radiation as LAT.

Multicentre study of microwave ablation for pulmonary oligorecurrence after radical resection of non-small-cell lung cancer

BACKGROUND

Microwave ablation (MWA) is an effective minimally invasive technique for lung tumours. We aim to evaluate its role for pulmonary oligorecurrence after radical surgery of non-small-cell lung cancer (NSCLC).

METHODS

From June 2012 to Jan 2020, a total of 103 patients with pulmonary oligorecurrence after previous radical surgical resection of NSCLC were retrospectively analysed. The primary endpoint was postoperative progression-free survival (PFS). Secondary endpoints were postoperative overall survival (OS), patterns of failure, complications and predictive factors associated with prognosis.

RESULTS

Of the 103 patients identified, 135 pulmonary oligorecurrences developed at a median interval of 34.8 months. In total, 143 sessions of MWA were performed to ablate all the nodules. The median PFS and OS were 15.1 months and 40.6 months, respectively. After MWA, 15 (14.6%) patients had local recurrence as the first event, while intrathoracic oligorecurrence and distant metastases were observed in 45 (43.7%) and 20 (19.4%) patients, respectively. In the multivariate analysis, local recurrence and intrathoracic oligorecurrence were not significant predictors for OS (P = 0.23 and 0.26, respectively). However, distant metastasis was predictive of OS (HR = 5.37, 95% CI, 1.04-27.84, P = 0.04).

CONCLUSION

MWA should be considered to be an effective and safe treatment option for selected patients with pulmonary oligorecurrence after NSCLC radical surgical resection.

Stereotactic body radiotherapy for adrenal oligometastasis in lung cancer patients

OBJECTIVE

To report our experience on stereotactic body radiotherapy (SBRT) in adrenal metastases from lung cancer.

METHODS

37 oligometastatic lung cancer patients with 38 adrenal metastases submitted to SBRT were retrospectively analyzed. SBRT was delivered by volumetric modulated arc therapy (VMAT) or helical tomotherapy (HT). Primary study end point was local recurrence-free survival (LR-FS) and secondary end points were distant-progression free survival (d-PFS) and overall survival (OS).

RESULTS

Median age was 67 years and primary tumor was non-small-cell lung cancer in 27 (73%) and small-cell lung cancer in 10 (27%) patients. Adrenal metastases were in the left side in 66% cases. Median prescribed dose was 30 Gy in 5 fractions for a median biologically equivalent dose (α/β ratio 10  Gy, BED10) of 48 Gy. Most patients (62%) were submitted to SBRT alone, while the others (38%) received chemo-, immune- or target- therapies. Median follow-up was 10.5 months, median OS 16 months and median d-PFS 3 months. 27 (70%) patients obtained a local control with a median LR-FS of 32 months. LR-FS was significantly related to BED10 with a better LC with BED10 ≥72 Gy, 1- and 2 year LR-FS rates were 54.1±11.6% and 45±12.7% vs 100 and 100% for BED ≤59.5 Gy and BED ≥72 Gy, respectively (p = 0.05). There was no severe toxicity.

CONCLUSION

SBRT was effective and safe in lung cancer adrenal metastases. A dose-response relationship was found between BED10 >72 Gy and better local control. No significant toxicity was registered thanks to the respect of dose constraints and suspension of chemo- and target-therapies.

ADVANCES IN KNOWLEDGE

SBRT with a BED10 >72 Gy is an effective treatment for adrenal oligometastatic lung cancer patients.

Nivolumab in disadvantaged subgroups of metastatic non-small-cell lung cancer patients: a single-institution experience

Aim: Immunotherapy opened new frontiers in metastatic non-small-cell lung cancer treatment, but not all patients benefit from it. Methods: We retrospectively evaluated 65 metastatic non-small-cell lung cancer patients, treated with nivolumab, considering as disadvantaged subgroups those with poor performance status, elderly, patients with brain metastases at baseline, with high disease burden and refractory to platinum. Results: No differences in overall survival or time to treatment failure were found according to performance status, age, presence of brain metastases at baseline or high disease burden. Conversely, patients refractory to platinum had a statistically significant shorter overall survival and time to treatment failure. At multivariate analysis only platinum resistance was confirmed as an independent predictive factor. Conclusion: Our study suggests that only refractoriness to platinum salts influence the efficacy of nivolumab.

Long-term Local Control of Primary Non-small Cell Lung Cancer and Adrenal Oligometastasis with Stereotactic Body Radiotherapy: A Case Report

Treatment options for non-small cell lung cancer (NSCLC) patients presenting with synchronous adrenal oligometastases (stage IV disease) include local treatment such as surgery, stereotactic body radiotherapy (SBRT) or systemic treatment such as chemotherapy. A case of successful SBRT treatment to a primary NSCLC with a synchronous left adrenal oligometastasis achieving long-term local control of both lesions is reported.

Efficacy of Local Consolidative Therapy for Oligometastatic Lung Adenocarcinoma Patients Harboring Epidermal Growth Factor Receptor Mutations

BACKGROUND

For oligometastatic lung adenocarcinoma patients with sensitive epidermal growth factor receptor (EGFR) mutations, the role of local consolidative therapy (LCT) remains debatable. The purpose of this study was to investigate the efficacy of LCT in oligometastatic lung adenocarcinoma patients.

PATIENTS AND METHODS

We conducted a retrospective study to assess the effects of LCT on progression-free survival (PFS) and overall survival (OS). Patients with advanced-stage oligometastatic lung adenocarcinoma harboring sensitive mutation of epidermal growth factor receptor (EGFR) who received EGFR-tyrosine kinase inhibitor (TKI) or EGFR-TKI plus LCT were admitted to Shanghai Chest Hospital from January 2010 to December 2016. The PFS and OS of the 2 groups were accordingly analyzed.

RESULTS

A total of 231 patients (143 patients who received LCT plus EGFR-TKI [combination group] and 88 patients who only received EGFR-TKI only [monotherapy group]) were included in this study. Median PFS was significantly longer in the combination group (15 months; 95% confidence interval [CI], 13.611-16.389) than in the monotherapy group (10 months; 95% CI, 8.936-11.064; hazard ratio = 0.610; 95% CI, 0.461, 0.807; P = .000). The median OS in the combination group was 34 months (95% CI, 27.889, 40.111) versus 21 months (95% CI, 18.445, 23.555) in the monotherapy group (hazard ratio = 0.593; 95% CI, 0.430-0.817; P = .001).

CONCLUSION

LCT combined with TKIs therapy was a feasible method that significantly improved PFS and OS among oligometastatic lung adenocarcinoma patients with EGFR mutations, and it thus might be considered as an important medical treatment during clinical management.

The effects of radiotherapy on the survival of patients with unresectable non-small cell lung cancer

INTRODUCTION

Lung cancer represents the leading cause of cancer mortality across the worlds. At present, less than 30% of the patients can undergo curative surgery, while the majority of them (65%) are diagnosed with metastatic disease and directed to systemic treatments. In this context there is a subset of patients (25%) with locally advanced stage disease whose outcome might be improved by using combined strategies of treatment including chemotherapy, radiotherapy and surgery. Areas covered: Here we reviewed possible combination strategies aimed to improve the outcome of lung cancer patients, focusing on the role of radiotherapy both in the adjuvant and oligo-metastatic setting and in synergy with immunotherapy, and finally, we afforded the new challenges concerning the advanced RT and precision oncology. We carried out a focused analysis concerning the key clinical management weaknesses as well as the potential that current research holds. Expert commentary: We believe that the most promising clinical trials in this specific patient subset will build their rationale on the results of well-designed translational models aimed to test the combination of cytotoxic drugs, radiobiology, and immune-pharmacology. In this context, remarkable investigational fields are focused on the attempt to combine radiotherapy with chemo-immunological strategies and precision medicine protocols.

Stereotactic ablative body radiation for oligometastatic and oligoprogressive disease

Stage IV non-small cell lung cancer (NSCLC) exists on a spectrum, with a subset of patients presenting with oligometastatic disease involving only a limited number of distant sites. For these patients, local consolidative therapy (LCT) has been demonstrated to improve outcomes through ablation or cytoreduction of metastatic disease, as shown in an increasing number of randomized controlled trials. In particular, stereotactic ablative body radiation (SABR) has emerged as a feasible treatment modality for elimination of oligometastatic sites. This focused review examines the underlying biologic mechanisms and clinical data in support of SABR in the setting of oligometastatic NSCLC. Following a comprehensive evaluation of the pertinent retrospective, prospective, and anticipated trials to date, we summarize the evidence regarding patient selection, treatment safety, and technical considerations to provide guidance of this approach for clinicians.

Patterns of Progression in Metastatic Estrogen Receptor Positive Breast Cancer: An Argument for Local Therapy

Purpose

Despite advances in endocrine therapy (ET), metastatic estrogen receptor positive breast cancer (BrCA) remains incurable. Though the mechanisms of resistance to ET have been studied extensively, the anatomic pattern of disease progression remains poorly characterized. The purpose of this study was to characterize the pattern of progression for patients receiving ET for metastatic BrCA.

Methods

The records of 108 patients with metastatic BrCA who progressed on ET were reviewed. Progression was characterized as follows: diffuse progression, progression in greater than 3 sites; oligoprogression, progression in fewer than 3 sites with prior diffuse metastases; and oligometastatic disease with progression, progression in 3 or fewer sites with prior limited metastases.

Results

Seventy-four patients (69%) displayed only diffuse disease progression. Conversely, 23 patients (21%) displayed oligoprogression and 11 patients (10%) displayed oligometastases with progression at least once in their disease course. Further analysis of the patients with oligoprogression suggested that in 14 patients the sites of progression would have been amenable to local therapy.

Conclusion

Oligoprogressive disease occurs in a significant subset of patients with metastatic BrCA treated with ET. These patients with oligoprogressive disease may be eligible for local therapy, potentially obviating the need to change of systemic therapy.

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.

Local consolidative therapy versus maintenance therapy or observation for patients with oligometastatic non-small-cell lung cancer without progression after first-line systemic therapy: a multicentre, randomised, controlled, phase 2 study

BACKGROUND

Evidence from retrospective studies suggests that disease progression after first-line chemotherapy for metastatic non-small-cell lung cancer (NSCLC) occurs most often at sites of disease known to exist at baseline. However, the potential effect of aggressive local consolidative therapy for patients with oligometastatic NSCLC is unknown. We aimed to assess the effect of local consolidative therapy on progression-free survival.

METHODS

In this multicentre, randomised, controlled, phase 2 study, eligible patients from three hospitals had histological confirmation of stage IV NSCLC, three or fewer metastatic disease lesions after first-line systemic therapy, an Eastern Cooperative Oncology Group performance status score of 2 or less, had received standard first-line systemic therapy, and had no disease progression before randomisation. First-line therapy was four or more cycles of platinum doublet therapy or 3 or more months of EGFR or ALK inhibitors for patients with EGFR mutations or ALK rearrangements, respectively. Patients were randomly assigned (1:1) to either local consolidative therapy ([chemo]radiotherapy or resection of all lesions) with or without subsequent maintenance treatment or to maintenance treatment alone, which could be observation only. Maintenance treatment was recommended based on a list of approved regimens, and observation was defined as close surveillance without cytotoxic treatment. Randomisation was not masked and was balanced dynamically on five factors: number of metastases, response to initial therapy, CNS metastases, intrathoracic nodal status, and EGFR and ALK status. The primary endpoint was progression-free survival analysed in all patients who were treated and had at least one post-baseline imaging assessment. The study is ongoing but not recruiting participants. This study is registered with ClinicalTrials.gov, number NCT01725165.

FINDINGS

Between Nov 28, 2012, and Jan 19, 2016, 74 patients were enrolled either during or at the completion of first-line systemic therapy. The study was terminated early after randomisation of 49 patients (25 in the local consolidative therapy group and 24 in the maintenance treatment group) as part of the annual analyses done by the Data Safety Monitoring Committee of all randomised trials at MD Anderson Cancer Center, and before a planned interim analysis of 44 events. At a median follow-up time for all randomised patients of 12·39 months (IQR 5·52-20·30), the median progression-free survival in the local consolidative therapy group was 11·9 months (90% CI 5·7-20·9) versus 3·9 months (2·3-6·6) in the maintenance treatment group (hazard ratio 0·35 [90% CI 0·18-0·66], log-rank p=0·0054). Adverse events were similar between groups, with no grade 4 adverse events or deaths due to treatment. Grade 3 adverse events in the maintenance therapy group were fatigue (n=1) and anaemia (n=1) and in the local consolidative therapy group were oesophagitis (n=2), anaemia (n=1), pneumothorax (n=1), and abdominal pain (n=1, unlikely related).

INTERPRETATION

Local consolidative therapy with or without maintenance therapy for patients with three or fewer metastases from NSCLC that did not progress after initial systemic therapy improved progression-free survival compared with maintenance therapy alone. These findings suggest that aggressive local therapy should be further explored in phase 3 trials as a standard treatment option in this clinical scenario.

FUNDING

MD Anderson Lung Cancer Priority Fund, MD Anderson Cancer Center Moon Shot Initiative, and Cancer Center Support (Core), National Cancer Institute, National Institutes of Health.

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.

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.

Solitary dural metastasis at presentation in a patient with untreated human papillomavirus-associated squamous cell carcinoma of the oropharynx

BACKGROUND

Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (SCC) is associated with high cure rates and distant metastases are rare.

METHODS AND RESULTS

We report a case of a 61-year-old man presenting with acute left-sided weakness. An enhancing dural mass was noted and resected. Histology revealed p16-positive SCC. Further workup revealed a p16-positive right tonsillar primary with ipsilateral nodal disease and was classified as T2N2bM1. The patient underwent whole brain irradiation and definitive chemoradiation with curative intent. Complete clinical response was achieved and the patient continues to be disease-free 6 months posttreatment.

CONCLUSION

HPV-associated oligometastatic oropharyngeal SCC is a rare entity that may have a unique natural history and behavior. Given the excellent treatment response and prognosis of HPV-positive disease in general, these patients may be appropriate for definitive treatment approaches.

Rationale for ablation of oligometastatic disease and the role of stereotactic body radiation therapy for hepatic metastases

Management paradigms for metastatic solid tumors are evolving. Once regarded as uniformly incurable, today there is recognition of an intermediate oligometastatic state, where ablation of metastatic foci may improve disease control and prolong survival. In the setting of limited colorectal liver metastases, hepatic resection has resulted in favorable long-term outcomes, but is technically unsuitable for most patients. Stereotactic body radiation therapy represents an effective, noninvasive means of tumor ablation, supported by a large body of prospective evidence specific to hepatic metastases. This review examines the current rationale for ablation of oligometastatic disease, including various objectives beyond indefinite disease-free survival. The role of stereotactic body radiation therapy for ablation of hepatic metastases is then comprehensively reviewed.

Radiation therapy as a backbone of treatment of locally advanced non-small cell lung cancer

Locally advanced non-small cell lung cancer (LA-NSCLC) is a heterogeneous disease, encompassing stage IIIA, for which surgery in combination with chemotherapy and/or radiation therapy (RT) represents a potential treatment approach for select patients, and stage IIIB, for which chemoradiation represents the standard of care. Recent advances in systemic cytotoxic and molecularly targeted therapies coupled with technologic innovations in radiotherapy have the potential to improve outcomes for this patient population. Many ongoing clinical trials use specific genetic mutations or histologic status to determine the combination of targeted therapies and RT, as well as to determine the optimal chemoradiotherapy platforms. Additionally, use of modern RT techniques has improved outcomes for some patients with limited metastatic disease, thereby prompting further studies on how to best integrate aggressive management of oligometastases using RT with chemotherapeutic regimens.

Is there an oligometastatic state in non-small cell lung cancer? A systematic review of the literature

OBJECTIVES

Long-term survival has been observed in patients with oligometastatic non-small cell lung cancer (NSCLC) treated with locally ablative therapies to all sites of metastatic disease. We performed a systematic review of the evidence for the oligometastatic state in NSCLC.

MATERIALS AND METHODS

A systematic review of MEDLINE, EMBASE and conference abstracts was undertaken to identify survival outcomes and prognostic factors for NSCLC patients with 1-5 metastases treated with surgical metastatectomy, Stereotactic Ablative Radiotherapy (SABR), or Stereotactic Radiosurgery (SRS), according to PRISMA guidelines.

RESULTS

Forty-nine studies reporting on 2176 patients met eligibility criteria. The majority of patients (82%) had a controlled primary tumor and 60% of studies included patients with brain metastases only. Overall survival (OS) outcomes were heterogeneous: 1 year OS: 15-100%, 2 year OS: 18-90% and 5 year OS: 8.3-86%. The median OS range was 5.9-52 months (overall median 14.8 months; for patients with controlled primary, 19 months). The median time to any progression was 4.5-23.7 months (overall median 12 months). Highly significant prognostic factors on multivariable analyses were: definitive treatment of the primary tumor, N-stage and disease-free interval of at least 6-12 months.

CONCLUSIONS

Survival outcomes for patients with oligometastatic NSCLC are highly variable, and half of patients progress within approximately 12 months; however, long-term survivors do exist. Definitive treatment of the primary lung tumor and low-burden thoracic tumors are strongly associated with improved long-term survival. The only randomized data to guide management of oligometastatic NSCLC pertains to patients with brain metastases. For other oligometastatic NSCLC patients, randomized trials are needed, and we propose that these prognostic factors be utilized to guide clinical decision making and design of clinical trials.