Management of non-small cell lung cancer with oligometastasis

Pre-radiotherapy ctDNA liquid biopsy for risk stratification of oligometastatic non-small cell lung cancer

The optimal treatment paradigm for patients with oligometastatic non-small cell lung cancer (NSCLC) remains unclear. Some patients with oligometastatic disease experience prolonged remission after locally consolidative radiation therapy (RT), while others harbor micrometastatic disease (below limits of detection by imaging) and benefit from systemic therapy. To risk-stratify and identify the patients most likely to benefit from locally consolidative RT, we performed a multi-institutional cohort study of 1487 patients with oligometastatic NSCLC undergoing liquid biopsy analysis of circulating tumor DNA (ctDNA). In total, 1880 liquid biopsies were performed and approximately 20% of patients (n = 309) had ctDNA measured prior to RT and after their diagnosis of oligometastatic disease. Patients with undetectable ctDNA (pathogenic or likely pathogenic variants in plasma using the Tempus xF assay) before RT had significantly improved progression-free survival (PFS) (P = 0.004) and overall survival (OS) (P = 0.030). ctDNA maximum variant allele frequency (VAF) pre-RT and ctDNA mutational burden pre-RT were both significantly inversely correlated with PFS (maximum VAF P = 0.008, mutational burden P = 0.003) and OS (maximum VAF P = 0.007, mutational burden P = 0.045). These findings were corroborated by multivariate Cox proportional hazards models that included eight additional clinical and genomic parameters. Overall, these data suggest that in patients with oligometastatic NSCLC, pre-RT ctDNA can potentially identify the patients most likely to benefit from locally consolidative RT and experience prolonged PFS and OS. Similarly, ctDNA may be useful to identify undiagnosed micrometastatic disease where it may be appropriate to prioritize systemic therapies.

Pre-radiotherapy ctDNA liquid biopsy for risk stratification of oligometastatic non-small cell lung cancer

The optimal treatment for patients with oligometastatic non-small cell lung cancer (NSCLC) remains unclear. Some patients with oligometastatic disease can experience prolonged remission after locally consolidative radiation therapy (RT), while others harbor micrometastatic disease (below current limits of detection by imaging) that may benefit from further prioritization of systemic therapy. To better risk-stratify this population and identify the patients most likely to benefit from locally consolidative radiation therapy, we performed a multi-institutional cohort study of patients with oligometastatic NSCLC undergoing liquid biopsy analysis of circulating tumor DNA (ctDNA). Among this real-world cohort of 1,487 patients undergoing analysis (using the Tempus xF assay), a total of 1,880 ctDNA liquid biopsies along with paired clinical data were obtained across various timepoints. Approximately 20% (n=309) of patients had ctDNA obtained prior to RT and after their diagnosis of oligometastatic disease. Samples were de-identified and analyzed for mutational burden and variant frequencies of detectable deleterious (or likely deleterious) mutations in plasma. Patients with undetectable ctDNA before RT had significantly improved progression-free survival and overall survival compared to patients with detectable ctDNA prior to RT. In patients that received RT, 598 pathogenic (or likely deleterious) variants were identified. ctDNA mutational burden pre-RT and ctDNA maximum variant allele frequency (VAF) pre-RT were both significantly inversely correlated with both progression-free (P = 0.0031 for mutational burden, P = 0.0084 for maximum VAF) and overall survival (P = 0.045 for mutational burden, P = 0.0073 for maximum VAF). Patients without detectable ctDNA prior to RT had significantly improved progression-free survival (P = 0.004) and overall survival (P = 0.03) compared to patients with detectable ctDNA prior to RT. These data suggest that in patients with oligometastatic NSCLC, pre-radiotherapy ctDNA analysis can potentially identify the patients most likely to benefit from locally consolidative RT and experience prolonged progression-free and overall survival. Similarly, ctDNA may be useful to identify those patients with undiagnosed micrometastatic disease, in whom it may be appropriate to prioritize systemic therapy.

Apatinib plus Radiotherapy on the Expression of CEA and VEGF in Advanced Oligometastatic Non-Small-Cell Lung Cancer

Objective

The purpose of this study was to evaluate the clinical efficacy of apatinib plus concurrent radiotherapy on carcinoma embryonic antigen (CEA) and vascular endothelial growth factor (VEGF) expression in patients with non-small-cell lung cancer (NSCLC) with oligometastases.

Methods

This is a prospective randomized controlled trial. Sixty-four patients with oligometastatic NSCLC who were treated in the Central South University Xiangya School of Medicine Affiliated Haikou Hospital from January 2017 to January 2019 were randomly assigned into the control group and the study group, with 32 cases in each group. The control group was treated with stereotactic body radiotherapy (SBRT), and the study group was treated with apatinib.

Results

The overall response rate (ORR) of the study group was significantly higher than that of the control group. The carcinoma embryonic antigen (CEA) and the vascular endothelial growth factor (VEGF) in the two groups were significantly decreased, with lower results in the study group compared to the control group. The 12-month and 24-month overall survival (OS) of the study group were significantly higher than those of the control group. There was no significant difference in progression-free survival (PFS) between the two groups. The median OS in the control group was 20.0 months, and the study group had not yet reached the median OS; the OS in the study group was significantly higher than that in the control group. There was no significant difference in adverse reactions between the two groups.

Conclusion

For patients with oligometastatic lung cancer, apatinib combined with chemotherapy can significantly improve clinical efficacy, reduce tumor marker expression, and extend overall survival with good safety profiles.

A ‘Hybrid’ Radiotherapy Regimen Designed for Immunomodulation: Combining High-Dose Radiotherapy with Low-Dose Radiotherapy

Simple Summary

Radiotherapy is an important cancer treatment. Aside from its direct killing effect, it also affects anti-tumor immunity. However, radiotherapy’s immune effect is not clear; it depends on the dose and fraction, cancer type, combined immunotherapy, and many other factors. Studies have focused on the optimal radiotherapy regimen to stimulate anti-tumor immunity, but conflicts exist, especially regarding the best radiation dose and fractions. Interestingly, high-dose radiotherapy and low-dose radiotherapy have complementary effects on stimulating anti-tumor immunity. Preclinical studies supporting this finding have accumulated, but gaps between theory and clinical practice still exist. This review summarizes the evidence supporting the use of this ‘hybrid’ radiotherapy approach to effectively stimulate anti-tumor immunity, explains the immune mechanisms of this combination, raises questions that must be addressed in clinical practice, and provides ideas for designing individualized treatment to increase efficiency in stimulating anti-tumor immunity using high-dose plus low-dose radiotherapy.

Abstract

Radiotherapy (RT) affects anti-tumor immunity. However, the exact impact of RT on anti-tumor immune response differs among cancer types, RT dose and fractions, patients’ innate immunity, and many other factors. There are conflicting findings on the optimal radiation dose and fractions to stimulate effective anti-tumor immunity. High-dose radiotherapy (HDRT) acts in the same way as a double-edged sword in stimulating anti-tumor immunity, while low-dose radiotherapy (LDRT) seems to play a vital role in modulating the tumor immune microenvironment. Recent preclinical data suggest that a ‘hybrid’ radiotherapy regimen, which refers to combining HDRT with LDRT, can reap the advantages of both. Clinical data have also indicated a promising potential. However, there are still questions to be addressed in order to put this novel combination therapy into clinical practice. For example, the selection of treatment site, treatment volume, the sequencing of high-dose radiotherapy and low-dose radiotherapy, combined immunotherapy, and so on. This review summarizes the current evidence supporting the use of HDRT + LDRT, explains possible immune biology mechanisms of this ‘hybrid’ radiotherapy, raises questions to be considered when working out individualized treatment plans, and lists possible avenues to increase efficiency in stimulating anti-tumor immunity using high-dose plus low-dose radiotherapy.

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.

Radiosurgery for brain oligometastases in lung cancer

INTRODUCTION Brain metastases are a common problem in oncology patients, especially in lung cancer. The usual treatment for cerebral oligometastases is whole brain radiation therapy. Given the persistent poor prognosis of this disease, other therapeutic alternatives such as stereotactic radiosurgery have been considered. However, there is no clarity regarding the effectiveness of its addition. METHODS We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS We identified 17 systematic reviews including seven studies overall, of which four were randomized trials. All trials assessed patients with brain oligometastases, but none of them included exclusively lung cancer population. We concluded that it is not possible to clearly establish whether radiosurgery decreases neurological functionality, cognitive impairment, mortality or serious adverse effects, as the certainty of the existing evidence has been assessed as very low.

Coexisting opportunities and challenges: In which scenarios can minimal/measurable residual disease play a role in advanced non-small cell lung cancer?

Curative therapy was not previously available for patients with advanced non-small cell lung cancer (NSCLC); thus, the concept of minimal/measurable (or molecular) residual disease (MRD) was not applicable to these patients. However, advances in targeted and immunotherapy have revolutionized the treatment landscape for patients with advanced NSCLC, with emerging evidence of long-term survival and even the hope of complete remission (CR) by imaging examination. The latest research shows that patients with oligometastatic lung cancer can benefit from local treatment. After removing the lesions, the choice of follow-up therapy and monitoring of the lesions could remain uncertain. MRD plays a role in identifying early-stage NSCLC patients with high risks of recurrence and determining adjuvant therapy after radical treatment. In recent years, evidence has been accumulating regarding the use of circulating cell-free tumor DNA (ctDNA) to assess MRD in solid tumors. This study discussed the possible applications of ctDNA-based MRD monitoring in advanced NSCLC and described the current challenges and unresolved problems in the application of MRD in advanced NSCLC.

The structure of blood-tumor barrier and distribution of chemotherapeutic drugs in non-small cell lung cancer brain metastases

Background

Brain metastasis is an important cause of increased mortality in patients with non-small cell lung cancer (NSCLC). In brain metastasis, the blood–brain barrier (BBB) is frequently impaired, forming blood–tumor barrier (BTB). The efficacy of chemotherapy is usually very poor. However, the characteristics of BTB and the impacts of BTB on chemotherapeutic drug delivery remain unclear. The present study investigated the structure of BTB, as well as the distribution of routine clinical chemotherapeutic drugs in both brain and peripheral tumors.

Methods

Bioluminescent image was used to monitor the tumor load after intracranial injection of lung cancer Lewis cells in mice. The permeability of BBB and BTB was measured by fluorescent tracers of evans blue and fluorescein sodium. Transmission electron microscopy (TEM), immunohistochemistry and immunofluorescence were performed to analyze structural differences between BBB and BTB. The concentrations of chemotherapeutic drugs (gemcitabine, paclitaxel and pemetrexed) in tissues were assayed by liquid chromatography with tandem mass spectrometry (LC-MS/MS).

Results

Brain metastases exhibited increased BTB permeability compared with normal BBB detected by fluorescence tracers. TEM showed abnormal blood vessels, damaged endothelial cells, thick basement membranes, impaired intercellular endothelial tight junctions, as well as increased fenestrae and pinocytotic vesicles in metastatic lesions. Immunohistochemistry and immunofluorescence revealed that astrocytes were distributed surrounded the blood vessels both in normal brain and the tumor border, but no astrocytes were found in the inner metastatic lesions. By LC-MS/MS analysis, gemcitabine showed higher permeability in brain metastases.

Conclusions

Brain metastases of lung cancer disrupted the structure of BBB, and this disruption was heterogeneous. Chemotherapeutic drugs can cross the BTB of brain metastases of lung cancer but have difficulty crossing the normal BBB. Among the three commonly used chemotherapy drugs, gemcitabine has the highest distribution in brain metastases. The permeability of chemotherapeutic agents is related to their molecular weight and liposolubility.

Management of Oligometastasis and Oligoprogression in Patients with Epidermal Growth Factor Receptor Mutation-Positive NSCLC in the Era of Third-Generation Tyrosine Kinase Inhibitors

This review covers the importance of local consolidative therapy (LCT) in patients with epidermal growth factor receptor (EGFR) mutation-positive with oligometastatic and oligoprogressive non-small-cell lung cancer (NSCLC). With the advent of third-generation EGFR tyrosine kinase inhibitors, a more updated review is necessary. We review the efficacy of LCT, pathophysiological background, and treatment modalities other than radiotherapy. In addition, we also discussed when and how LCT should be applied to patients with oligometastatic and oligoprogressive NSCLC.

Stereotactic Body Radiotherapy for Oligometastatic Disease in Non-small Cell Lung Cancer

Metastatic non-small cell lung cancer (NSCLC) is associated with a limited survival when treated with palliative intent platinum-based chemotherapy alone. Recent advances in imaging and therapeutic strategy have identified a subset of patients with limited metastases who may benefit from early local ablative therapy with either surgery or radiotherapy, in addition to standard treatment. Stereotactic body radiotherapy (SBRT) is increasingly used in the treatment of extra-cranial oligometastatic NSCLC (OM-NSCLC) due its non-invasive conduct and ability to deliver high doses. Clinical evidence supporting the use of SBRT in OM-NSCLC is emerging and consistently demonstrates significant benefit in local control and progression-free survival. Here, we discuss the definition of oligometastases (OM), review current available data on SBRT treatment in extra-cranial OM-NSCLC including evidence for site-specific SBRT in lung, liver, and adrenal metastases.

Management of oligometastatic non-small cell lung cancer patients: Current controversies and future directions

Oligometastatic non-small cell lung cancer (NSCLC) describes an intermediate stage of NSCLC between localized and widely-disseminated disease. This stage of NSCLC is characterized by a limited number of metastases and a more indolent tumor biology. Currently, the management of oligometastatic NSCLC involves radical treatment (radiotherapy or surgery) that targets the metastatic lesions and the primary tumor to achieve disease control. This approach offers the potential to achieve prolonged survival in patients who, in the past, would have only received palliative measures. The optimal therapeutic strategies for the different scenarios of oligometastatic disease (intracranial vs extracranial disease, synchronous vs metachronous) remain undefined. Given the lack of head-to-head studies comparing radiotherapy to surgery in these patients, the decision to apply surgery or radiotherapy (with or without systemic treatment) must be based on prognostic factors that allow us to classify patients. This classification will allow us to select the most appropriate therapeutic strategy on an individualized basis. In the future, the molecular or microRNA profiles will likely improve the treatment selection process. The objective of the present article is to review the most relevant scientific evidence on the management of patients with oligometastatic NSCLC, focusing on the role of radiotherapy and surgery. We also discuss areas of controversy and future directions.

Curative thoraco-systemic therapy plus local treatment to the brain for extensive disease-small-cell lung cancer with metastasis only to the brain

We reviewed 11 cases of extensive disease (ED)-SCLC and metastasis only to the brain treated during 2011-14. All patients underwent definitive therapy similar to that for limited disease (LD), combined with local treatment for BM. We compared the survival outcomes of these patients to those of patients with LD (n = 29) or other ED (n = 38) during the same period. Three patients had progression of BM at completion of chemotherapy. Ten patients received whole-brain radiotherapy (4 prophylactic, 6 therapeutic), and remaining one elderly patient underwent stereotactic radiosurgery. Finally, 8 and 3 patients achieved a CR or PR of BM, respectively. Five remained free of progression for 21.1-73.2 months. The progression-free and overall survival outcomes of ED-SCLC with brain only metastases were comparable to those of LD and superior to those of other ED. In conclusion, ED-SCLC with metastasis limited to the brain could be treated with curative intent.

Evidence for surgical resections in oligometastatic lung cancer

With the advent of advanced technology in performing diagnostics for lung cancer, an incremental increase in the number of patients with oligometastatic disease is currently being managed with intent to cure. As treatment of selected types of patients with oligometastasis show favourable outcomes, the past notion of managing these patients palliatively is fast becoming extinct. Selection of patients based on established criterion together with surgical metastasectomy combined with multiple ablative techniques with or without systemic chemotherapy offers a reasonable rate of treatment success which provides basis for treating such patient population. As more evidence becomes available to suggest that the oligometastatic state of lung cancer does exist, and are potentially curable, a better understanding of the condition is necessary for clinicians, and surgeons to provide optimal care. In this review we present some of the clinical basis which may cause a paradigm shift in management of patients with oligometastatic lung disease.

18 Fluorodeoxyglucose-positron emission tomography/computed tomography features of suspected solitary pulmonary lesions in breast cancer patients following previous curative treatment

Background

Differentiating pulmonary metastasis from primary lung cancer can be challenging in patients with breast malignancy. This study aimed to characterize the imaging features of ¹⁸fluorodeoxyglucose‐positron emission tomography/computed tomography (¹⁸F‐FDG‐PET/CT) for distinguishing between these diseases.

Methods

We enrolled 52 patients who received curative treatment for breast cancer but later presented with suspected solitary pulmonary lesions (SPLs) and subsequently underwent ¹⁸F‐FDG‐PET/CT to investigate.

Results

Subsolid lesions, ill‐defined borders, lung lesions with negative maximum standardized uptake value, and lesions without ¹⁸F‐FDG‐PET/CT‐diagnosed hilar and/or mediastinal lymph nodes and pleural metastases were more likely to be associated with primary lung cancer.

Conclusions

CT border, FDG uptake, hilar and/or mediastinal lymph node metastasis, and pleural metastasis are potential markers for diagnosis.

Surgical approach in the oligometastatic patient

In the setting of a stage IV non-small cell lung cancer (NSCLC), oligometastatic patients represent a heterogeneous group whose incidence is increasing as far as with the adoption of new therapeutic regimens, the improvement of the molecular characterization assays and the increasing number of long-survivor patients. The oligometastatic state undergone a major revision with the introduction of the new TNM lung cancer staging system, being characterized by a different prognosis compared to multi-metastatic patients. Furthermore, the presence of a limited number of metastases imposes a local control especially when clonal selections occur during adjuvant therapy. In this regard, the review seeks to clarify the indications for surgical treatment by organ according to recent guidelines, by analyzing prognostic factors and outcome of patients. Although accurate patient stratification is mandatory, aggressive local control strategies represent a valid therapeutic approach in patients with oligometastatic NSCLC. At the same time, persevering with ablative strategies raises both medical and ethical issues about limits and reiteration, which certainly requires a deep reflection, being, on the other hand, in front of a metastatic disease.

Treatment planning with intensity modulated particle therapy for multiple targets in stage IV non-small cell lung cancer

Intensity modulated particle therapy (IMPT) can produce highly conformal plans, but is limited in advanced lung cancer patients with multiple lesions due to motion and planning complexity. A 4D IMPT optimization including all motion states was expanded to include multiple targets, where each target (isocenter) is designated to specific field(s). Furthermore, to achieve stereotactic treatment planning objectives, target and OAR weights plus objective doses were automatically iteratively adapted. Finally, 4D doses were calculated for different motion scenarios. The results from our algorithm were compared to clinical stereotactic body radiation treatment (SBRT) plans. The study included eight patients with 24 lesions in total. Intended dose regimen for SBRT was 24 Gy in one fraction, but lower fractionated doses had to be delivered in three cases due to OAR constraints or failed plan quality assurance. The resulting IMPT treatment plans had no significant difference in target coverage compared to SBRT treatment plans. Average maximum point dose and dose to specific volume in OARs were on average 65% and 22% smaller with IMPT. IMPT could also deliver 24 Gy in one fraction in a patient where SBRT was limited due to the OAR vicinity. The developed algorithm shows the potential of IMPT in treatment of multiple moving targets in a complex geometry.

Surgical approaches in patients with oligometastatic non-small cell lung cancer

In recent years, retrospective analyses have suggested that an oligometastatic state could exist, but the best evidence to date that a temporary oligometastatic disease exists for lung cancer mainly derives from the survival data on retrospective patients underwent surgical resection of a single M1 site and all intrathoracic disease. The critical determinates of long-term survival include definitive treatment of the primary non-small cell lung cancer (NSCLC), a single organ site of synchronous or metachronous disease, a long disease-free interval between treatment of the primary NSCLC and development of metastases, and the absence of intrathoracic lymph node (N0) disease. The ongoing development of innovative approaches to local therapy and treatment directed to the oligometastatic sites should be defined in future studies.

[Hypofractionated stereotactic body radiation therapy for adrenal metastases]

Adrenal glands are a common site for metastatic spread since they represent the fourth metastatic site of solid tumors. Interest in local ablative treatments of oligometastases is growing since literature suggests better progression-free survival, quality of life and potentially overall survival in selected patients. Surgery remains the first treatment of adrenal oligometastases because results are good, with a long enough follow-up. However, stereotactic radiotherapy appears to be comparable to surgery and could be proposed to elderly, unfit, inoperable patients, or even to patients whose systemic treatment should not be suspended for too long. This article aims to present a review of published studies to date on stereotactic radiotherapy of adrenal metastases and to propose a treatment protocol.

Down-regulated microRNA-375 expression as a predictive biomarker in non-small cell lung cancer brain metastasis and its prognostic significance

Brain metastases (BM) are common among patients with non-small cell lung cancer (NSCLC) and have been associated with significant morbidity and limited survival. Early and sensitive detection of BM is essential for improving prognosis. Recently, microRNA-375(miR-375) which is specifically expressed in the brain has been found significantly dysregulated in many human cancers. However, there is still no data whether miR-375 is associated with higher risk of BM development in NSCLC. In this study, we detected the miR-375 expression using quantitative real-time PCR (qRT-PCR) and assessed its predictive and prognostic significance. Our result showed that miR-375 expression was significantly down-regulated in NSCLC patients with BM(BM+, N=30) compared with NSCLC without BM(BM-, N=30) (P<0.001). Statistical analysis indicated that low miR-375 expression was linked to advanced disease stage (P<0.001) and brain metastasis (P<0.001) in NSCLC patient. Survival analysis suggested that low-expression group had significantly shorter overall survival than high-expression group in NSCLC patients with BM(log-rank test: P<0.05) as well as the total cases(log-rank test: P<0.01). Multivariate Cox proportional hazards model analysis indicated that low miR-375 expression was independently linked to poor survival of patients with NSCLC (HR=5.48, 95% CI: 1.93-15.56, P=0.001). In addition, we found that VEGF and MMP-9 were over-expressed in down-regulated miR-375 expression cases. Collectively, this study demonstrated that miR-375 may play an important role as a predictive biomarker in brain metastasis and an independent prognostic factor in NSCLC. Over-expression of VEGF and MMP-9 may be the reason for poor prognosis of NSCLC patients with low miR-375 expression.

Stereotactic ablative body radiosurgery (SABR) or Stereotactic body radiation therapy (SBRT)

While conventional treatment relies on protracted courses of therapy using relatively small dose-per-fraction sizes of 1.8-2Gy, there is substantial evidence gathered over decades that this may not be the optimal approach for all targetable disease. Stereotactic ablative body radiosurgery (SABR) or stereotactic body radiation therapy (SBRT) is a technique which uses precise targeting to deliver high doses of radiation capable of ablating tumors directly. In this review, we will discuss the justification for and techniques used to deliver ablative doses to improve treatment outcomes, interactions with biological and immunologic therapy, and special procedures to spare normal tissue, which have facilitated the expanding role for these techniques in the management of a wide range of malignant histologies and disease states.

Prognostic Value of Volumetric Parameters on Staging and Posttreatment FDG PET/CT in Patients With Stage IV Non-Small Cell Lung Cancer

PURPOSE

This study aimed to evaluate the prognostic value of metabolic tumor burden as measured with metabolic tumor volume (MTV) and total lesion glycolysis (TLG), as well as SUVmax on initial staging and posttreatment F-FDG PET/CT in patients with stage IV non-small cell lung cancer (NSCLC).

METHODS

Sixty-three NSCLC patients with stage IV who underwent staging and posttreatment FDG PET/CT after completion of the first-line chemotherapy were retrospectively enrolled. SUVmax, MTV, and TLG of primary cancer and all metastatic lesions (lymph node and distant metastases) on both PET/CT images were measured and their association with progression-free survival (PFS) and overall survival (OS) analyzed.

RESULTS

Median PFS and OS in the patient population were 5.9 and 23.1 months, respectively. Among the PET/CT parameters, MTV and TLG of primary cancer lesions on initial PET/CT and MTV and TLG of metastatic lesions on posttreatment PET/CT were independent prognostic factors for both PFS and OS (P < 0.05). The median OS in patients who showed low values of those PET/CT parameters was more than 26.0 months, whereas patients with high values of those parameters had a median OS of less than 15.0 months.

CONCLUSIONS

Metabolic tumor burdens of primary cancer lesions on staging PET/CT and metastatic lesions on posttreatment PET/CT were independent prognostic factors in patients with stage IV NSCLC. Volume-based PET parameters could further stratify the prognosis of stage IV NSCLC patients.

Surgical management of oligometastatic non-small cell lung cancer

The oligometastatic stage IV non-small cell lung cancer (NSCLC) offers a new surgical opportunity. New reported data is showing that surgery can offer a reasonable benefit, in terms of long-term survival, to some patients. The advantages of surgical treatment rely on a more adequate patient selection and a better understanding of the biology of these tumors. Currently, mediastinal involvement of the primary tumor can be identified as the most important prognostic variable after curative-intent of synchronous or metachronous metastasis. It seems clear that the routine use of combined FDG-PET and CT will help to detect the more favorable cohort of oligometastatic patients. As expected, pathological T staging of the primary tumor and the completeness of its resection are also crucial factors influencing final results. The real benefit of the local treatment over synchronous or metachronous metastasis is controversial with series showing better outcomes for metachronous lesions than for synchronous and others offering equal results. Also non conclusive results appear when analyzing different sites of metastasis. Retrospective series tend to show different outcomes depending on the affected organ while usually no differences are found in prospective ones. Most of the current evidence is based on retrospective studies on patients collected along extended periods of time. That represents a great limitation to the knowledge on this topic. Some prospective analyses have added some insight, but still the quality of the evidence is too low to allow drawing robust conclusions. As frequently concluded, prospective well designed investigation is requested to ascertain the value of surgery in this specific population of patients with extended NSCLC.

Clinical applications of stereotactic radiation therapy for oligometastatic cancer patients: a disease-oriented approach

Oligometastases from solid tumors are currently recognized as a distinct clinical entity, corresponding to an intermediate state between local and widespread disease. It has been suggested that local ablative therapies (including surgery, radiofrequency ablation and radiation therapy) play an important role in this setting, in combination or not with systemic therapies, particularly in delaying disease progression and hopefully in increasing the median survival time. Stereotactic body radiation therapy (SBRT) rapidly emerged in recent years as one of the most effective and less toxic local treatment modalities for lung, liver, adrenal, brain and bone metastases. The aim of this review was to focus on its clinical role for oligometastatic disease in four major cancer subtypes: lung, breast, colorectal and prostate. On the basis of the available evidence, SBRT is able to provide high rates of local tumor control without significant toxicity. Its global impact on survival is uncertain; however, in specific subpopulations of oligometastatic patients there is a trend towards a significant improvement in progression-free and overall survival rates; these important data might be used as a platform for clinical decision-making and establish the basis for the current and future prospective trials investigating its role with or without systemic treatments.

Integration of Stereotactic Body Radiation Therapy With Tyrosine Kinase Inhibitors in Stage IV Oncogene-Driven Lung Cancer

: Genotype-based selection of patients for targeted therapies has had a substantial impact on the treatment of non-small cell lung cancers (NSCLCs). Tyrosine kinase inhibitors (TKIs) directed at cancers driven by oncogenes, such as epidermal growth factor receptor mutations or anaplastic lymphoma kinase rearrangements, often achieve dramatic responses and result in prolonged survival compared with chemotherapy. However, TKI resistance invariably develops. Disease progression can be limited to only one or a few sites and might not be symptomatic, raising the important question of whether this type of oligoprogression warrants a change in systemic therapy or consideration of local treatment. Recent clinical observations suggest a growing role for stereotactic body radiation therapy (SBRT) in the treatment of oligoprogressive and perhaps even oligopersistent disease (primary and/or metastases) in oncogene-driven NSCLC. SBRT might allow patients to continue with existing TKI treatments longer and delay the need to switch to other systemic options. We review the current data with regard to the use of SBRT for metastatic NSCLC and particularly oncogene-driven disease. Although there is great promise in the marriage of targeted therapies with SBRT, prospective data are urgently needed. In the meantime, such strategies are being used in carefully selected patients, with risk-adapted SBRT dose-fractionation regimens used to optimize the therapeutic index.

IMPLICATIONS FOR PRACTICE

Stereotactic body radiation therapy (SBRT) or SBRT-like treatments are increasingly being used for oligoprogression in patients with oncogene-driven non-small cell lung cancer. This approach allows patients to extend the duration of tyrosine kinase inhibitor therapy and has the potential to prolong survival times. Careful patient selection and risk-adapted radiation dosing is of critical importance to minimize toxicity and preserve patient quality of life.

Oligometastatic non-small cell lung cancer (NSCLC): adrenal metastases. Experience in a single institution

Though the actual incidence of an adrenal oligometastasis is between 1.5 and 3.5 %, secondary adrenal neoplasms occur in less than 10 % patients with non-small cell lung cancer (NSCLC). According to 7° ed. TNM staging system, the presence of an adrenal metastasis (M1b disease) configures stage IV, which is usually associated with poor prognosis. We evaluated if metastasectomy in selected patients with oligometastatic disease improves overall survival. A 15-year retrospective study concerning patients with NSCLC was performed and an oligometastatic disease was found in 1.61 % of the patients. 18 adrenalectomies were performed. Clustering the population according to different therapeutic strategies, a benefit in terms of survival was found in patients who underwent adrenalectomy. A statistical relevance was found, indeed, between adrenalectomy (p < 0.01), metachronous disease (p < 0.01), the presence of a homolateral disease (p < 0.05) and overall survival. Adrenalectomy should be offered in selected patients with oligometastatic disease.

Stereotactic ablative radiotherapy for pulmonary oligometastases and oligometastatic lung cancer

An increasing body of experience suggests that oligometastasis represents a minimal metastatic state with the potential for cure or prolonged survival in selected patients treated with radical local therapy to all identified sites of disease. The main clinical scenarios managed by thoracic oncology specialists are pulmonary oligometastases from primary malignancies of other anatomic sites and primary lung cancer with oligometastases to lung or other organs. Surgery has been a mainstay of treatment in these situations, with remarkably favorable outcomes following pulmonary metastasectomy in well-selected patient cohorts. As with early stage lung cancer in patients who are medically inoperable, stereotactic ablative radiotherapy is emerging as a prominent local treatment option for oligometastatic disease. We review the role and clinical experience of stereotactic ablative radiotherapy for pulmonary oligometastases and oligometastatic lung cancer.

Molecular determinants of lung cancer metastasis to the central nervous system

Lung cancer remains the leading cause of cancer-related mortality worldwide. The propensity for metastasis to the central nervous system (CNS) is a major clinical hurdle contributing to the low five-year survival rate of advanced disease. CNS metastases significantly outnumber primary brain tumors and carry a dismal prognosis in part due to the inability of therapeutic agents to cross the blood brain barrier. Standard treatment using radiation has been largely ineffective in improving mortality, suggesting the need for new agents targeting the critical metastatic drivers. The genetic and molecular events governing CNS metastasis from the lung are poorly understood at this time. This review highlights genetic events associated with CNS dissemination from the lung and molecular mechanisms associated with CNS metastasis. In vivo model systems that faithfully recapitulate escape from the lung and colonization of the CNS are described as tools for understanding the metastatic phenotype and for testing new therapeutic agents. A deeper understanding of the mechanisms of lung cancer metastasis to the CNS is needed to elucidate novel therapeutic avenues towards the improvement of the mortality associated with advanced stage lung cancer.

Phase II trial of stereotactic body radiation therapy combined with erlotinib for patients with limited but progressive metastatic non-small-cell lung cancer

PURPOSE

Patients with stage IV non-small-cell lung cancer (NSCLC) who progress through first-line therapy have poor progression-free survival (PFS) and overall survival (OS), most commonly failing in original sites of gross disease. Cytoreduction with stereotactic body radiation therapy (SBRT) may help systemic agents delay relapse.

PATIENTS AND METHODS

Patients in our single arm phase II study had stage IV NSCLC with no more than six sites of extracranial disease who failed early systemic chemotherapy and were able to receive SBRT and concurrent erlotinib until disease progression. After erlotinib commencement, SBRT with equipotent fractionation was delivered to all sites of disease. PFS, OS, and other end points were evaluated.

RESULTS

Twenty-four patients (13 men and 11 women) with a median age of 67 years (range, 56-86 years) were enrolled with median follow-up of 11.6 months. All patients had progressed through platinum-based chemotherapy. A total of 52 sites were treated with 16 of 24 patients receiving SBRT to more than one site. Lung parenchyma was most often irradiated. Median PFS was 14.7 months, and median OS was 20.4 months. Most patients progressed in new distant sites with only three of 47 measurable lesions recurring within the SBRT field. Two grade 3 toxicities were radiation related. Zero of 13 patients tested were positive for an EGFR mutation.

CONCLUSION

Use of SBRT with erlotinib for unselected patients with stage IV NSCLC as a second- or subsequent line therapy resulted in dramatic changes in patterns of failure, was well tolerated, and resulted in high PFS and OS, substantially greater than historical values for patients who only received systemic agents.

Oligometastatic non-small cell lung cancer: a significant entity outside of specialized cancer centers?

OBJECTIVE

To report the incidence, patterns of care, and outcomes of oligometastatic non-small cell lung cancer (NSCLC) in a rural practice setting in Norway.

MATERIALS AND METHODS

A retrospective analysis was conducted of all patients with stage IV NSCLC at the initial diagnosis who received active treatment in the central part of Nordland, a rural county in northern Norway, during the period of 2006-2012. We analyzed overall survival and prognostic factors.

RESULTS

The initial study population included 113 patients with stage IV disease who received active therapy; of these, 23 (20%) had oligometastatic spread (a maximum of 3 metastases to 1 organ). The median age was 71 years. Of the 23 patients, 16 (70%) did not receive radical or at least moderately aggressive local treatment for their thoracic disease. Of the remaining 7 patients, 4 (17.4%) did not receive systemic therapy. The median actuarial survival was 5.6 months in patients with more advanced metastases and 11.7 months in those with oligometastases (p = 0.03). Significant differences were also seen between the 2 oligometastatic patient groups with and without more intense thoracic treatment (median 19.7 vs. 7.6 months, p = 0.004). Further significant predictors of survival in patients with oligometastases were nodal stage (p = 0.028) and weight loss (p = 0.045). Trends were seen for T stage (p = 0.058) and performance status (p = 0.07).

CONCLUSION

Oligometastatic NSCLC was diagnosed in a relevant proportion of patients; therefore, warranting prospective studies are recommended. Such studies are also needed to confirm the treatment-dependent survival differences observed in our patient population.

[Advances in diagnosis and treatment of brain metastases from the primary lung cancer]

肺癌脑转移的发生率为23%-65%，是脑转移性肿瘤中最常见的类型，且预后较差。目前肺癌脑转移的诊治和分子机理已成为众多研究的热点之一。本文就肺癌脑转移的临床特征、诊断和治疗方面的进展以及最新脑转移的机制学研究做了系统的综述。