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

Early stereotactic body radiation therapy improves progression-free survival of first-generation EGFR tyrosine kinase inhibitors in EGFR-mutated lung cancer: an observational cohort study

Background

Stereotactic body radiation therapy (SBRT) in treating non-small-cell lung cancer (NSCLC) exhibits a remarkable therapeutic efficacy. However, its effectiveness in overcoming resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in patients with advanced EGFR mutations (EGFRm) NSCLC remains uncertain.

Objective

We aimed to analyze the effect of SBRT on patients with first-line EGFR-TKIs.

Design and methods

Eligible patients with advanced NSCLC initially diagnosed with EGFRm were enrolled. Patients in the EGFR-TKIs group received only the first-generation EGFR-TKIs until disease progression or death, while the others in the EGFR-TKIs + SBRT group received EGFR-TKIs and early SBRT (dose of 40-60 Gy/5-8 F) targeting the primary lung tumor at 1 month after EGFR-TKIs. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were treatment-related adverse effects, overall survival (OS), and sites of initial failure.

Results

A total of 184 advanced NSCLC patients with EGFRm were enrolled, including 39 patients in the EGFR-TKIs + SBRT group and 145 patients in the EGFR-TKIs group. The median PFS was 15.50 months in the EGFR-TKIs + SBRT group compared to 9.33 months in the EGFR-TKIs group (p = 0.0020). However, the median OS was 29.10 months in the EGFR-TKIs + SBRT group and 26.33 months in the EGFR-TKIs group, with no significant difference observed (p = 0.22). SBRT is an independent positive prognostic factor for PFS in advanced EGFRm NSCLC. EGFR exon 19 deletion mutation (16.33 vs 11.55 months, p = 0.0087) and fewer metastases (0-5) (31.94 vs 9.59 months, p = 0.0059) were associated with improved PFS in EGFR-TKIs + SBRT versus EGFR-TKIs. Combination therapy increased radiation pneumonitis mainly in Grades 1-2 (89.74% vs 0.0%). The EGFR-TKIs + SBRT group mainly had new site failure (57.10% vs 32.10%) rather than the original site failure.

Conclusion

Early SBRT for primary lung tumors may overcome targeted resistance in advanced EGFRm NSCLC patients combined with EGFR-TKIs without serious toxicities, especially for EGFR exon 19-del.

Trial registration

ChiCTR-OIN-17013920.

Targeting ALK receptors in non-small cell lung cancer: what is the road ahead?

INTRODUCTION

Anaplastic lymphoma kinase (ALK) gene-rearrangements are identified in about 3-5% of non-small cell lung cancers (NSCLC), and ALK-rearranged NSCLC is to be considered an oncogene-addicted cancer with peculiar clinical characteristics.

AREAS COVERED

Several ALK inhibitors have been studied and approved for use in the treatment of advanced ALK-rearranged NSCLC with reported superiority in terms of efficacy and safety profile compared with chemotherapy. Second- and third-generation ALK inhibitors (alectinib, brigatinib, and lorlatinib) offer to NSCLC patients a clinically meaningful prolongment of survival with a very good quality of life profile. However, resistances to these agents always occur, with less satisfying options for second-line treatments. Direct comparisons among these agents are not available, and the choice among brigatinib, alectinib, and lorlatinib as first-line treatment remains challenging. Very recently, alectinib has been demonstrated to improve efficacy outcomes compared with chemotherapy also in resected stage IB-IIIA ALK-rearranged NSCLC, extending the clinical benefit offered by ALK inhibitors also to the adjuvant setting.

EXPERT OPINION

Future development of ALK inhibitors in NSCLC treatment includes the search for optimal management of acquired resistance to first-line treatments and the extension of use of ALK inhibitors also to neoadjuvant and preferably to perioperative setting.

Treatment sequences in EGFR mutant advanced NSCLC

Common EGFR gene mutations (exon 19 deletion and L858R in exon 21) are the most frequent cause of actionable genomic alterations in non-small cell lung cancer (NSCLC) patients. The introduction of EGFR tyrosine kinase inhibitors (TKIs) as 1st-line treatment of advanced stages of the disease has changed the natural history of the disease and extended survival rates, establishing third generation TKIs as a new standard of frontline treatment. Nonetheless, the prolongation of overall survival remains modest, as multiple escape pathways and tumor increasing heterogeneity inevitably develop over time. Several strategies are currently developed to improve these patients' outcome: prevent the emergence of resistance mechanisms by therapeutic combinations introduced from the first line, act on the residual disease at the time of maximum response to 1st line treatment, develop therapeutic strategies at the time of acquired resistance to TKIs, either dependent on the resistance mechanisms, or agnostic of the resistance pathways. Recent advancements in treatment combinations have shown promising results in prolonging progression-free survival, but often at the cost of more severe side effects in comparison with the current standard of care. These emerging new treatment options open up possibilities for diverse therapeutic sequences in the management of advanced NSCLC depending on common EGFR mutations. The impact on the disease natural history, the patients' survival and quality of life is not yet fully understood. In this review, we propose an overview of published and forthcoming advances, and a management algorithm considering the different first-line options, integrating the clinical and biological parameters that are critical to clinicians' decision-making process.

Navigating resistance to ALK inhibitors in the lorlatinib era: a comprehensive perspective on NSCLC

INTRODUCTION

The emergence of anaplastic lymphoma kinase (ALK) rearrangements in non-small cell lung cancer (NSCLC) has revolutionized targeted therapy. This dynamic landscape, featuring novel ALK inhibitors and combination therapies, necessitates a profound understanding of resistance mechanisms for effective treatment strategies. Recognizing two primary categories - on-target and off-target resistance - underscores the need for comprehensive assessment.

AREAS COVERED

This review delves into the intricacies of resistance to ALK inhibitors, exploring complexities in identification and management. Molecular testing, pivotal for early detection and accurate diagnosis, forms the foundation for patient stratification and resistance management. The literature search methodology involved comprehensive exploration of Pubmed and Embase. The multifaceted perspective encompasses new therapeutic horizons, ongoing clinical trials, and their clinical implications post the recent approval of lorlatinib.

EXPERT OPINION

Our expert opinion encapsulates the critical importance of understanding resistance mechanisms in the context of ALK inhibitors for shaping successful treatment approaches. With a focus on molecular testing and comprehensive assessment, this review contributes valuable insights to the evolving landscape of NSCLC therapy.

Management of oligometastatic and oligoprogressive epidermal growth factor receptor mutated non-small cell lung cancer patients: state of the art of a combined approach

Recently, the development of targeted therapy approaches such as those based on tyrosine kinase inhibitor (TKI) greatly improved the clinical outcomes of patients affected by oncogene addicted advanced non-small cell lung cancer (NSCLC). Similarly, the improvement of radiation therapy techniques has permitted to deliver high radiation doses to a limited number of metastatic target lesions (oligopersistent or oligoprogressive), with limited high-dose normal tissue exposure that leads to low severe toxicity rates. The aim of this narrative review was to provide an overview of the currently established definition of oligometastatic and oligoprogressive disease, to define first line and subsequent lines targeted therapies and the role of consolidative non-invasive local ablative treatments (LATs) in these settings. The potential benefit of local treatment (LT) such as radiotherapy (RT) or surgery might be represented by an overall reduction of switching to subsequent systemic treatments lowering the risk of further systemic dissemination. Further randomized clinical trials will clarify the role of LT and their correct timing in relation to systemic targeted therapies.

Alectinib continuation beyond progression in ALK-positive non-small cell lung cancer with alectinib-refractory

Background

Alectinib, a next-generation anaplastic lymphoma kinase tyrosine kinase inhibitor (ALK-TKI), has demonstrated noteworthy efficacy in the treatment of non-small cell lung cancer (NSCLC). Unfortunately, 53.3% of untreated patients receiving first-line treatment with alectinib developed resistance to alectinib. However, despite the widespread use of alectinib, studies on the efficacy and safety of continuing alectinib with other necessary therapies after progression of alectinib and possible population of benefit are still limited.

Methods

This retrospective cohort study included fifteen patients with ALK-positive NSCLC from nine institutions in China who experienced disease progression after first- or second-line treatment and continued to receive alectinib treatment between 2019 and 2022. This study aimed to evaluate the median progression-free survival (mPFS), objective response rate (ORR), median overall survival (mOS), and adverse events (AEs) of continuing alectinib combined with other therapies after the emergence of drug resistance.

Results

Among fifteen patients eligible for this study, all patients started continuing treatment with alectinib after oligoprogression or central nervous system (CNS) progression. The mPFS for the whole cohort receiving continuing alectinib with other necessary therapies was 8 months [95% confidence interval (CI): 4 to not applicable (NA)], with an ORR of 46.7%. The mOS was not reached. During continuing alectinib treatment, only one patient experienced grade 2 elevation of aspartate aminotransferase (AST) and serum glutamic-oxaloacetic transaminase (SGOT).

Conclusions

The continuation of alectinib treatment combined with other necessary therapies demonstrates favorable response and safety in patients with ALK-positive NSCLC who experienced oligoprogression or CNS progression following alectinib in first- or second-line therapy. Instead of immediately switching to another ALK-TKI, continuing alectinib combined with other necessary therapies may offer greater survival benefits to the patients.

[Drug Resistance Mechanism and Therapeutic Strategy of Targeted Therapy of Non-small Cell Lung Cancer with MET Alterations]

Mesenchymal to epithelial transition factor (MET) gene alterations involve in the proliferation, invasion, and metastasis of non-small cell lung cancer. MET-tyrosine kinase inhibitors (TKIs) have been approved to treat non-small cell lung cancer with MET alterations, and resistance to these TKIs is inevitable. Molecular mechanisms of resistance to MET-TKIs are completely unclear. The review focused on potential mechanisms of MET-TKIs resistance and therapeutics strategies to delay and prevent resistance.
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Strategies to overcome resistance to ALK inhibitors in non-small cell lung cancer: a narrative review

Background and Objective

Anaplastic lymphoma kinase (ALK) rearrangements are detected in 3-7% of advanced non-small cell lung cancer (NSCLC). There are currently 5 U.S Food and Drug Administration (FDA)-approved ALK tyrosine kinase inhibitors (TKIs) for the treatment of patients with ALK-positive lung cancer in the advanced/metastatic disease setting. Despite these advances, most patients with ALK-positive lung cancer who are treated with ALK TKI therapy ultimately experience disease progression due to various mechanisms of drug resistance. In this review, we discuss strategies to address acquired therapeutic resistance to ALK inhibition, novel agents and combinatorial strategies in development for both on and off-target resistance, and some emerging approaches to prolong response to ALK inhibitors.

Methods

We performed a search of peer-reviewed literature in the English language, conference abstracts, and trial registrations from the MEDLINE (Ovid), Embase (Elsevier), and CENTRAL (Cochrane Library) databases and major international oncology meetings up to August 2022. We then screened for studies describing interventions to overcome ALK resistance based on review of each title and abstract.

Key Content and Findings

For patients with oligo-progression, treatment may include maintaining the same systemic treatment beyond progression while adding local therapies to progressing lesions. Strategies to combat ALK TKI resistance mediated by on-target resistance mechanisms include 4th generation TKIs (TPX-0131, NVL-655) and proteolysis-targeting chimeras (PROTACs) currently in development. While for those patients who develop tumor progression due to off-target (ALK independent) resistance, options may include combination therapies targeting ALK and other downstream or parallel pathways, novel antibody drug conjugates, or combinations of ALK inhibitors with chemotherapy and immunotherapy. Lastly, other potential strategies being explored in the clinic include circulating tumor DNA (ctDNA) surveillance to monitor for molecular mediators of drug resistance prior to frank progression on imaging studies and utilization of ALK TKIs in the adjuvant and neoadjuvant settings.

Conclusions

Strategies to overcome resistance to currently available ALK inhibitors are urgently needed. Given the variety of resistance mechanisms, tailormade approaches are required for disease control.

Prediction Model for Tumor Volume Nadir in EGFR -mutant NSCLC Patients Treated With EGFR Tyrosine Kinase Inhibitors

PURPOSE

In patients with advanced non-small cell lung cancer (NSCLC) and oncogenic driver mutations treated with effective targeted therapy, a characteristic pattern of tumor volume dynamics with an initial regression, nadir, and subsequent regrowth is observed on serial computed tomography (CT) scans. We developed and validated a linear model to predict the tumor volume nadir in EGFR -mutant advanced NSCLC patients treated with EGFR tyrosine kinase inhibitors (TKI).

MATERIALS AND METHODS

Patients with EGFR -mutant advanced NSCLC treated with EGFR-TKI as their first EGFR-directed therapy were studied for CT tumor volume kinetics during therapy, using a previously validated CT tumor measurement technique. A linear regression model was built to predict tumor volume nadir in a training cohort of 34 patients, and then was validated in an independent cohort of 84 patients.

RESULTS

The linear model for tumor nadir prediction was obtained in the training cohort of 34 patients, which utilizes the baseline tumor volume before initiating therapy (V 0 ) to predict the volume decrease (mm 3 ) when the nadir volume (V p ) was reached: V 0 -V p =0.717×V 0 -1347 ( P =2×10 -16 ; R2 =0.916). The model was tested in the validation cohort, resulting in the R2 value of 0.953, indicating that the prediction model generalizes well to another cohort of EGFR -mutant patients treated with EGFR-TKI. Clinical variables were not significant predictors of tumor volume nadir.

CONCLUSION

The linear model was built to predict the tumor volume nadir in EGFR -mutant advanced NSCLC patients treated with EGFR-TKIs, which provide an important metrics in treatment monitoring and therapeutic decisions at nadir such as additional local abrasive therapy.

Oligoprogression in non-small cell lung cancer: a narrative review

Background and Objective

Non-small cell lung cancer (NSCLC) accounts for 80% of lung cancers and is the most common non-cutaneous cancer world-wide. In NSCLC, oligometastatic and oligoprogressive disease (OPD) have been recognized as separate entities within the realm of metastatic disease and are emerging concepts in the context of targeted systemic therapies. Our objectives are to discuss the current literature regarding the evolving definitions of OPD in the context of oligometastatic disease (OMD) for NSCLC. Further, to discuss current and future clinical trials that have shaped our local approach with stereotactic body radiation therapy (SBRT)/stereotactic ablative radiotherapy (SABR).

Methods

Literature on OPD in NSCLC and local ablative therapy (LAT) including SBRT/SABR and stereotactic radiosurgery (SRS) was reviewed.

Key Content and Findings

Oligoprogression is defined as limited (usually 3-5) metastatic areas progressing while on/off systemic therapy in the background of oligometastatic or polymetastatic disease. Prognosis in OPD with treatment (such as LAT and systemic therapy) may be more favorable. Outcomes for patients progressing on tyrosine kinase inhibitors (TKIs) with molecular mutations [such as epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK)] who receive LAT are promising.

Conclusions

Patients presenting with NSCLC metastasis with progression at a limited number of sites on/off a given line of systemic therapy may have favorable outcomes with aggressive LAT, which includes SBRT/SABR/SRS. Further studies need to be completed to further optimize treatment recommendations.

Radiotherapy of the Primary Disease for Synchronous Metastatic Cancer: A Systematic Review

In the case of synchronous metastatic disease, the local treatment of primary tumors by radiotherapy has long been reserved for palliative indications. The emergence of the concept of oligometastatic and oligopersistent diseases, the advent of new systemic therapies enabling longer overall survival with an enhanced quality of life, a better understanding of the biologic history of metastatic spread, and technical advances in radiation therapy are revolutionizing the management of patients with de novo metastatic cancer. The prognosis of these patients has been markedly improved and many studies have investigated the survival benefits from the local treatment of various primary tumors in cases of advanced disease at the time of diagnosis or in the case of oligopersistence. This article provides an update on the place of irradiation of the primary tumor in cancer with synchronous metastases, and discusses its interest through published or ongoing trials.

Efficacy and Failure Patterns of Early SBRT to the Primary Tumor in Advanced EGFR-Mutation-Positive Lung Cancer with EFGR-TKI Treatment: A Prospective, Single Arm, Phase II Study

Early stereotactic body radiation therapy (SBRT) to the primary tumor combined with epidermal growth factor receptor tyrosine kinase inhibitor (EFGR-TKI) treatment may increase progression-free survival (PFS) by delaying resistance in patients with advanced EGFR-mutant non-small cell lung cancer (NSCLC). In this prospective, single arm, phase II study, patients with advanced NSCLC were treated with EGFR-TKI (icotinib 125 mg tid or gefitinib 250 mg qd) for one month followed by SBRT (40-60 Gy/5-8 F/5-10 d) to the primary tumor with concurrent EGFR-TKI until disease progression. The primary endpoint was PFS and the patterns of failure. Overall survival (OS) and adverse effects (AEs) were secondary endpoints. Overall, 41 advanced NSCLC patients with EGFR mutations received treatment with 24.42 months of median follow-up time. On average, SBRT was initiated 1.49 months after EGFR-TKI administration. Tumors were found to have an average shrinkage rate of 42.50%. Median PFS was 15.23 months (95% CI 13.10-17.36), while median OS was 27.57 months (95% CI 23.05-32.09). Thirty-three patients were found to have disease progression, of which new site failure (NF) (22 patients, 66.66%) was the most common pattern, followed by original site failure (OF) (7 patients, 21.21%) and simultaneous OF/NF (ONF) (4 patients, 12.12%). There were no Aes equal to or greater than grade 3, with the most frequent AE being radiation pneumonitis. Therefore, administering therapy targeted at the primary tumor using early SBRT after EGFR-TKI initiation is a new potentially safe and effective approach to treat EGFR-mutant advanced NSCLC.

Oligoprogression of Solid Tumors on Immune Checkpoint Inhibitors: The Impact of Local Ablative Radiation Therapy

The breakthrough of a limited number of clones while on immune checkpoint inhibitors (ICIs), known as oligoprogression, has been previously described. The benefit of ablative radiation therapy (RT) directed at these clones, as opposed to changing systemic therapy, is unclear. We analyzed 30 patients with advanced solid tumors, the majority of whom (23/30, 86.7%) had either hepatocellular or urothelial carcinoma, who experienced oligoprogression on ICIs and were referred for RT. In this study, oligoprogression was defined as having experienced progression at three or fewer metastatic sites outside of the brain after achieving at least stable disease on ICIs for a minimum of three months. The median time to oligoprogression was 11.1 months from the initiation of immunotherapy. 24 patients had one oligoprogressive lesion and six had two. The median radiation dose delivered was 4650 cGy in a median of five fractions. The median progression-free survival (PFS) after RT was 7.1 months, and the time to oligoprogression was not a significant predictor of PFS2. 26 patients continued on ICIs after RT. While 17 patients subsequently progressed, 15 did so at three or fewer metastatic sites and could have theoretically stood to benefit from an additional course of salvage RT to further extend the lifespan of their ICIs. Overall survival at 6, 12, and 24 months was 100.0%, 96.3%, and 82.8%, respectively. These results suggest that RT may provide a PFS benefit and extend the lifespan of ICIs in patients who experience oligoprogression. Regardless of PFS, however, overall survival in this population appears to be excellent.

The quantum leap in therapeutics for advanced ALK+ non-small cell lung cancer and pursuit to cure with precision medicine

Since the discovery 15 years ago, we have seen a quantum leap in the treatment and survival for individuals diagnosed with ALK+ lung cancers. Unfortunately however, for most, the diagnosis is made in an incurable circumstance given the late presentation of symptoms. Through a revolutionary wave of therapeutics, individuals may remarkably live over a decade, however many fall short of this milestone, as the molecular profile of this disease is very heterogeneous, reflected in variable survival outcomes. Despite a significant improval in survival and quality of life with ALK-inhibitor monotherapies, now available across multiple-generations, drug resistance and disease relapse remains inevitable, and treatment is offered in an empiric, stepwise, non personalised biomarker informed fashion. A proposed future focus to treating ALK to improve the chronicity of this disease and even promote cure, is to deliver a personalised dynamic approach to care, with rational combinations of drugs in conjunction with local ablative therapies to prevent and constantly proactively alter clonal selection. Such an approach would be informed by precision imaging with MRI-brain and FDG-PETs sequentially, and by regular plasma sampling including for circulating tumour DNA sequencing with personalised therapeutic switches occurring prior to the emergence of radiological and clinical relapse. Such an approach to care will require a complete paradigm shift in the way we approach the treatment of advanced cancer, however evidence to date in ALK+ lung cancers, support this new frontier of investigation.

Third-generation EGFR and ALK inhibitors: mechanisms of resistance and management

The discoveries of EGFR mutations and ALK rearrangements as actionable oncogenic drivers in non-small-cell lung cancer (NSCLC) has propelled a biomarker-directed treatment paradigm for patients with advanced-stage disease. Numerous EGFR and ALK tyrosine kinase inhibitors (TKIs) with demonstrated efficacy in patients with EGFR-mutant and ALK-rearranged NSCLCs have been developed, culminating in the availability of the highly effective third-generation TKIs osimertinib and lorlatinib, respectively. Despite their marked efficacy, resistance to these agents remains an unsolved fundamental challenge. Both 'on-target' mechanisms (largely mediated by acquired resistance mutations in the kinase domains of EGFR or ALK) and 'off-target' mechanisms of resistance (mediated by non-target kinase alterations such as bypass signalling activation or phenotypic transformation) have been identified in patients with disease progression on osimertinib or lorlatinib. A growing understanding of the biology and spectrum of these mechanisms of resistance has already begun to inform the development of more effective therapeutic strategies. In this Review, we discuss the development of third-generation EGFR and ALK inhibitors, predominant mechanisms of resistance, and approaches to tackling resistance in the clinic, ranging from novel fourth-generation TKIs to combination regimens and other investigational therapies.

Impact of stereotactic body radiotherapy (SBRT) in oligoprogressive metastatic disease

PURPOSE

There is increasing interest in using stereotactic body radiation therapy (SBRT) in areas of oligoprogressive metastatic disease (OPD). Our main objective was to investigate the impact of SBRT on overall survival (OS) and the incidence of systemic therapy treatment switches in this population.

METHODS

A retrospective institutional review of patients treated with SBRT for OPD was performed. Patients were included if they received SBRT for 1-3 discrete progressing metastases, using a dose of at least 5 Gy per fraction. The study aimed to calculate progression-free survival (PFS), overall survival (OS), local control (LC), and incidence of treatment switch (TS). PFS and OS were calculated using the Kaplan-Meier methodology, while LC and TS were determined using cumulative incidence.

RESULTS

Eighty-one patients with a total of 118 lesions were treated with SBRT from July 2014 to November 2020. The Median SBRT dose was 40 (18-60) Gy in 5 (2-8) fractions. Patients had primarily kidney, lung, or breast cancer. Most patients were treated with a tyrosine kinase inhibitor (TKI) (30.9%) or chemotherapy (29.6%) before OPD. The median follow-up post-SBRT was 14 months. Median OS and PFS were 25.1 (95% CI 11.2-39.1) months and 7.8 (95% CI 4.6-10.9) months, respectively. The cumulative incidence of local progression of treated lesions was 5% at 1 year and 7.3% at 2 years. Sixty patients progressed after SBRT and 17 underwent additional SBRT. Thirty-eight patients (47%) changed systemic therapy following SBRT; the cumulative incidence of TS was 28.5% at 6 months, 37.4% at 1 year, and 43.9% at 2 years.

CONCLUSIONS

SBRT effectively controls locally progressing lesions but distant progression still occurs frequently. A sizeable number of patients can be salvaged by further SBRT or have minimally progressing diseases that may not warrant an immediate initiation/switch in systemic therapy. Further prospective studies are needed to validate this benefit.

Imaging of Oligometastatic Disease

Simple Summary

The imaging of oligometastatic disease (OMD) is challenging as it requires precise loco-regional staging and whole-body assessment. The combination of imaging modalities is often required. The more accurate imaging tool will be selected according to tumor type, the timing with regard to measurement and treatment, metastatic location, and the patient’s individual risk for metastasis. The most commonly used modalities are contrast-enhanced computed tomography (CT), magnetic resonance imaging and metabolic and receptor-specific imaging, particularly, ¹⁸F-fluorodesoxyglucose positron emission tomography/CT, used alone or in combination.

Abstract

Oligometastatic disease (OMD) is an emerging state of disease with limited metastatic tumor burden. It should be distinguished from polymetastatic disease due the potential curative therapeutic options of OMD. Imaging plays a pivotal role in the diagnosis and follow-up of patients with OMD. The imaging tools needed in the case of OMD will differ according to different parameters, which include primary tumor type, timing between measurement and treatment, potential metastatic location and the patient’s individual risk for metastasis. In this article, OMD is defined and the use of different imaging modalities in several oncologic situations are described in order to better understand OMD and its specific implication for radiologists.

Local Therapy Combined With First-Line EGFR Tyrosine Kinase Inhibitor Achieves Favorable Survival in Patients With EGFR-Mutant Metastatic Non-Small Cell Lung Cancer

BACKGROUND

EGFR tyrosine kinase inhibitor (TKI) is recommended as the first-line therapy for patients with EGFR-mutant metastatic non-small cell lung cancer (NSCLC). Yet, resistance often occurs in 1 year after therapy and most progressions occur at the initial sites of disease. Addition of local therapy to the first-line TKI therapy may delay the progression and provide survival benefit to the patients.

METHODS

From 2010 to 2017, metastatic NSCLC patients with EGFR activating mutations who received first-line TKI and relatively radical local therapy (RRLT) were reviewed. RRLT was defined as local curative therapy to the main site or any intensity of local therapy to all sites of disease. The Kaplan-Meier method and log-rank test were used for survival estimation and comparison.

RESULTS

A total of 45 patients were included in this retrospective study with a median follow-up of 48.0 months. The median progression-free survival (PFS) and overall survival (OS) was 17.0 months (95% confidence interval [CI]: 14.6-19.3) and 55.0 months (95% CI: 49.3-60.6), respectively. Univariate analysis indicated that age ⩽ 60 years (P = .019), first-line TKI duration ⩾ 10 months (P = .028), and accumulated TKI duration ⩾ 20 months (P = .016) were significantly associated with favorable OS. Among the 36 patients who progressed during the follow-up, 55.8% of the progressions occurred at the new sites. RRLT combined with TKI did not show any severe toxicity to the patients.

CONCLUSIONS

Combined application of RRLT and first-line TKI may improve the survival and alter the pattern of failure for metastatic NSCLC patients with EGFR activating mutations.

Management of Oligoprogression in Patients with Metastatic NSCLC Harboring ALK Rearrangements

Simple Summary

The growing efficacy and availability of new targeted systemic therapies have markedly improved the prognosis of metastatic lung cancer patients harboring ALK rearrangements. The use of effective targeted therapies capable of maintaining a prolonged control of disease, for as long as possible, is paramount to ensure the best survival outcomes. In this regard, in cases of oligoprogression, “beyond progression” systemic treatment added to local ablative therapies is considered a feasible option in an attempt to improve the quality and quantity of patients’ lives, even if based on retrospective data. Certainly, treatment of ALK rearranged lung cancer patients with oligoprogressive disease must be individualized and based on multidisciplinary decisions. Above all, when further molecular targeted therapies are available, options must always be evaluated, especially in case of cerebral progression. In this review, we provide an updated and comprehensive overview of the main treatment strategies in cases of ALK rearranged oligoprogression.

Abstract

Personalized treatment based on driver molecular alterations, such as ALK rearrangement, has revolutionized the therapeutic management of advanced oncogene-addicted NSCLC patients. Multiple effective ALK tyrosine kinase inhibitors (TKIs), with the amelioration of the activity at central nervous system level, are now available, leading to substantial prognosis improvement. The exposure to TKIs triggers resistance mechanisms and the sequential administration of other TKIs and chemotherapy is, for the most part, not targeted. In this context, extending the benefit deriving from precision medicine is paramount, above all, when disease progression occurs in a limited number of sites. Retrospective data indicate that, in oligoprogressive disease, targeted therapy beyond progression combined with definitive local treatment of the progressing site(s) is an effective alternative. In these cases, a multidisciplinary approach becomes essential for an integrated treatment strategy, depending on the site of disease progression, in order to improve not only survival, but also quality of life. In this review we provide an updated and comprehensive overview of the main treatment strategies in cases of ALK rearranged oligoprogression, including systemic treatment as well as local therapy, and report a real-world clinical story, with the final aim of identifying the most promising management for this subset of patients.

Evaluation of Lung Tumor Target Volume in a Large Sample: Target and Clinical Factors Influencing the Volume Derived From Four-Dimensional CT and Cone Beam CT

Background and Purpose

This study aimed to systematically evaluate the influence of target-related and clinical factors on volume differences and the similarity of targets derived from four-dimensional computed tomography (4DCT) and cone beam computed tomography (CBCT) images in lung stereotactic body radiation therapy (SBRT).

Materials and Methods

4DCT and CBCT image data of 210 tumors from 195 patients were analyzed. The internal gross target volume (IGTV) derived from the maximum intensity projection (MIP) of 4DCT (IGTV-MIP) and the IGTV from CBCT (IGTV-CBCT) were compared with the reference IGTV from 10 phases of 4DCT (IGTV-10). The target size, tumor motion, and the similarity between IGTVs were measured. The influence of target-related and clinical factors on the adequacy of IGTVs derived from 4DCT MIP and CBCT images was evaluated.

Results

The mean tumor motion amplitude in the 3D direction was 6.5 ± 5 mm. The mean size ratio of IGTV-CBCT and IGTV-MIP compared to IGTV-10 in all patients was 0.71 ± 0.21 and 0.8 ± 0.14, respectively. Female sex, greater BSA, and larger target size were protective factors, while the Karnofsky Performance Status, body mass index, and motion were risk factors for the similarity between IGTV-MIP and IGTV-10. Older age and larger target size were protective factors, while adhesion to the heart, coexistence with cardiopathy, and tumor motion were risk factors for the similarity between IGTV-CBCT and IGTV-10.

Conclusion

Clinical factors should be considered when using MIP images for defining ITV, and when using CBCT images for verifying treatment targets.

Oligoprogression in Non-Small Cell Lung Cancer

Simple Summary

Several retrospective studies present evidence of oligoprogressive disease (OPD) in patients with non-small cell lung cancer (NSCLC) with driver mutations such as EGFR. The strategy of local ablative therapy (LAT) with radiotherapy, followed by the continuation of the same anticancer drug therapy beyond progression disease, is recommended in the current NCCN guideline. Although evidence of the use of this strategy in the treatment of the driver mutation-negative NSCLC is missing, LAT with radiotherapy for OPD after combination therapy of immune checkpoint inhibitor with cytotoxic chemotherapy is expected. Tumors outside of the radiation field may further respond to the immune checkpoint inhibitors due to an abscopal effect. In the future, to achieve long-term survival in advanced NSCLC, it will be important to validate this treatment strategy via prospective comparative studies and to actively implement it in clinical practice.

Abstract

We reviewed the literature on oligoprogressive disease (OPD) and local ablative therapy (LAT) in patients with advanced non-small cell lung cancer (NSCLC). The frequency of OPD varies depending on its definition and is estimated to be between 15–47%. The implications of the strategy of continuing the same anticancer agents beyond progressive disease after LAT with radiation therapy for OPD are based on the concept of progression in which only a small number of lesions, not more than about four, proliferate after chemotherapy. In the case of OPD harboring driver mutations such as EGFR, prospective studies are underway. However, evidence from retrospective studies support this strategy, which is currently recommended in some guidelines. The prognosis in OPD cases during the administration of an immune checkpoint inhibitor (ICI) is relatively promising. Additionally, LAT with radiation for OPD after the first-line treatment of ICI with cytotoxic chemotherapy may overcome the resistance to the combination drug therapy due to an abscopal effect. To achieve long-term survival in advanced-stage NSCLC, it is important to verify the optimal method and timing of the therapy through prospective comparative studies as well as patient selection based on patient characteristics and biomarker levels.

The role of surgery in the treatment of oligoprogression after systemic treatment for advanced non-small cell lung cancer

OBJECTIVES

Patients with advanced stage non-small cell lung cancer (NSCLC) are generally considered incurable. The mainstay of treatment for these patients is systemic therapy. The addition of local treatment, including surgery, remains controversial. Oligoprogression is defined as advanced stage NSCLC with limited progression of disease after a period of prolonged disease stabilisation or after a partial or complete response on systemic therapy. In this retrospective study we evaluated outcome and survival of patients who underwent a resection for oligoprogression after systemic therapy for advanced stage NSCLC.

MATERIALS AND METHODS

Patients with oligoprogression after systemic treatment for advanced NSCLC who were operated in the Antoni van Leeuwenhoek Hospital were included. Patient and treatment characteristics were collected in relation to progression free survival (PFS) and overall survival (OS).

RESULTS

Between January 2015 and December 2019, 28 patients underwent surgery for an oligoprogressive lesion (primary tumor lung (n = 12), other metastatic site (n = 16)). Median age at time of resection was 60 years (39-86) and 57% were female. Postoperative complications were observed in 2 patients (7%). Progression of disease after resection of the oligoprogressive site was observed in 17 patients (61%). Median PFS was 7 months since date of resection (95% CI 6.0-25.0) and median OS was not reached. Seven patients (25%) died during follow-up. Age was predictive for OS and clinical T4 stage was predictive for PFS. M1 disease at initial presentation was predictive for better PFS compared to patients who were diagnosed with M0 disease initially. Patients who underwent resection because of oligoprogression of the primary lung tumour had a better PFS, when compared to oligoprogression of another metastastic site.

CONCLUSION

Surgical resection of an oligoprogressive lesion in patients with advanced NSCLC treated with systemic treatment is feasible and might be considered in order to achieve long term survival.

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.

Overcoming Osimertinib Resistance in Advanced Non-small Cell Lung Cancer

Osimertinib is used as a first-line treatment for metastatic non-small cell lung cancer with positive epidermal growth factor receptor mutations based on the results of the FLAURA trial. However, as with any other epidermal growth factor receptor tyrosine kinase inhibitor, resistance also develops for osimertinib. Various genetic aberrations associated with the molecular heterogeneity of cancer cells contribute to osimertinib resistance. It is also important to choose an appropriate subsequent treatment for osimertinib-resistant non-small cell lung cancer. In this overview, we discuss the underlying mechanisms of osimertinib resistance and the efficacy of possible subsequent treatment measures.

Salvage surgery following downstaging of advanced non-small cell lung cancer by targeted therapy

BACKGROUND

Advanced non-small cell lung cancer (NSCLC) accounts for a high proportion of lung cancer cases. Targeted therapy improve the survival in these patients, but acquired drug resistance will inevitably occur. If tumor downstaging is achieved after targeted therapy, could surgical resection before drug resistance improve clinical benefits for patients with advanced NSCLC? Here, we conducted a clinical trial showing that for patients with advanced driver gene mutant NSCLC who did not progress after targeted therapy, salvage surgery (SS) could improve progression-free survival (PFS). Herein, we retrospectively reviewed our former clinical trial and thoracic cancer database in our medical institutions.

METHODS

We identified patients with advanced driver gene mutant NSCLC treated with targeted therapy plus SS or targeted therapy alone in our former clinical trial and our thoracic cancer database from July 2016 to July 2019. PFS was compared between the targeted therapy plus SS group and the targeted therapy only group using the log-rank test.

RESULTS

We identified 73 patients with driver gene mutant NSCLC who were treated with targeted therapy and 18 treated with targeted therapy plus SS.Among the 18 patients treated with targeted therapy plus SS, there were no obvious perioperative complications and deaths. Targeted therapy followed by SS resulted in a significantly longer PFS compared with targeted therapy alone (23.4 months VS 12.9 months, p = 0.0004).

CONCLUSIONS

Salvage surgery after tumor downstaging is a promising therapeutic strategy for some patients with advanced (stage IIIB-IV) NSCLC and may offer a new therapeutic option for multidisciplinary comprehensive treatment of lung cancer.

Definitive radiotherapy for extracranial oligoprogressive metastatic renal cell carcinoma as a strategy to defer systemic therapy escalation

OBJECTIVE

To study whether delivering definitive radiotherapy (RT) to sites of oligoprogression in metastatic renal cell carcinoma (mRCC) enabled deferral of systemic therapy (ST) changes without compromising disease control or survival.

PATIENTS AND METHODS

We identified patients with mRCC who received RT to three or fewer sites of extracranial progressive disease between 2014 and 2019 at a large tertiary cancer centre. Inclusion criteria were: (1) controlled disease for ≥3 months before oligoprogression, (2) all oligoprogression sites treated with a biologically effective dose of ≥100 Gy, and (3) availability of follow-up imaging. Time-to-event end-points were calculated from the start of RT.

RESULTS

A total of 72 patients were identified (median follow-up 22 months, 95% confidence interval [CI] 19-32 months), with oligoprogressive lesions in lung/mediastinum (n = 35), spine (n = 30), and non-spine bone (n = 5). The most common systemic therapies before oligoprogression were none (n = 33), tyrosine kinase inhibitor (n = 23), and immunotherapy (n = 13). At 1 year, the local control rate was 96% (95% CI 87-99%); progression-free survival (PFS), 52% (95% CI 40-63%); and overall survival, 91% (95% CI 82-96%). At oligoprogression, ST was escalated (n = 16), maintained (n = 49), or discontinued (n = 7), with corresponding median (95% CI) PFS intervals of 19.7 (8.2-27.2) months, 10.1 (6.9-13.2) months, and 9.8 (2.4-28.9) months, respectively. Of the 49 patients maintained on the same ST at oligoprogression, 21 did not subsequently have ST escalation.

CONCLUSION

Patients with oligoprogressive mRCC treated with RT had comparable PFS regardless of ST strategy, suggesting that RT may be a viable approach for delaying ST escalation. Randomised controlled trials comparing treatment of oligoprogression with RT vs ST alone are needed.

Oligometastatic non-small cell lung cancer: Current management

BACKGROUND

In the past decade, major developments have improved the survival of patients with oligometastatic non-small cell lung cancer (NSCLC). About 20% - 50% of patients with NSCLC present with oligometastases at diagnosis. For this group of patients, it seems that an increase in survival would justify aggressive local therapies. The development of minimally invasive surgery and advanced radiotherapy techniques like stereotactic body radiation therapy (SBRT) makes local control possible for selected patients with metastatic NSCLC. The advantage of SBRT over surgery is that it is a non-invasive technique, with minimum side effects, and is more suitable for fragile and elderly patients, non-candidates for surgery, or patients who refuse surgery.

AIM

The purpose of this review is to summarize the latest scientific evidence on the management of oligometastatic NSCLC, focusing on the role of radiotherapy.

RELEVANCE FOR PATIENTS

The initial treatment recommended for patients with oligometastatic NSCLC is systemic therapy. Patients should be considered for radical treatment to both the primary tumor and oligometastases. Aggressive local therapy comprises surgery and/or definitive radiotherapy such as SRS or SBRT, and may be preceded or followed by systemic treatment. Recent clinical evidence from Phase II trials reports benefits in terms of PFS in patients with good performance status and long disease-free periods, with good response to systemic therapy, especially in EGFR wild-type tumors. Phase I and II trials have shown that radiotherapy combined with immunotherapy can improve tumor response rate and possibly overall survival. The recommendation is also to include OM patients in ongoing clinical trials.

Efficacy and acquired resistance for EGFR-TKI plus thoracic SBRT in patients with advanced EGFR-mutant non-small-cell lung cancer: a propensity-matched retrospective study

Background

This retrospective study aimed to evaluate the efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) with stereotactic body radiation therapy (SBRT) and to elucidate potential mechanisms of acquired resistance.

Methods

Patients with advanced NSCLC harboring positive EGFR mutations after initial TKI therapy for at least 8 weeks were eligible for SBRT between August 2016 and August 2019. Eligible patients were treated with thoracic SBRT, and TKI was continued after SBRT until it was considered ineffective. The control group was treated with TKIs monotherapy. Propensity score matching (PSM, ratio of 1:2) was used to account for differences in baseline characteristics. Overall survival (OS), progression-free survival (PFS), treatment safety and resistance mechanisms were evaluated.

Results

Three hundred eight patients were included in the study population. Among them, 262 patients received TKIs alone, and 46 patients received TKIs with SBRT. Baseline characteristics were not significantly different between the two cohorts after PSM. The median PFS was 19.4 months in the TKIs +SBRT group compared to 13.7 months in the TKIs group (p = 0.034). An influence on OS has not yet been shown (p = 0.557). Of the 135 patients evaluated after PSM, 28 and 71 patients in the TKIs and TKIs +SBRT cohorts, respectively, had plasma cell-free DNA (cfDNA) next-generation sequencing (NGS) performed at baseline and disease progression. In the TKIs +SBRT cohort, the NGS results showed that T790M mutations were detected in 64.3% (18/28) of patients. Patients in the TKIs cohort exhibited fewer T790M-positive mutations (40.8%, p = 0.035) compared to patients in the TKIs +SBRT cohort.

Conclusion

Real world data prove that TKIs plus thoracic SBRT significantly extend PFS with tolerable toxicity. The mutation ratio of T790M was increased in the TKIs +SBRT group compared to the TKIs only group. Further randomized studies are warranted.

Clinical factors associated with shorter durable response, and patterns of acquired resistance to first-line pembrolizumab monotherapy in PD-L1-positive non-small-cell lung cancer patients: a retrospective multicenter study

Background

Despite the wide-spread use of immune checkpoint inhibitors (ICIs) in cancer chemotherapy, reports on patients developing acquired resistance (AR) to ICI therapy are scarce. Therefore, we first investigated the characteristics associated with shorter durable responses of ICI treatment and revealed the clinical patterns of AR and prognosis of the patients involved.

Methods

We conducted a retrospective multi-center cohort study that included NSCLC patients with PD-L1 tumor proportion scores of ≥50% who received first-line pembrolizumab and showed response to the therapy. Among patients showing response, progression-free survival (PFS) was investigated based on different clinically relevant factors. AR was defined as disease progression after partial or complete response based on Response Evaluation Criteria in Solid Tumors. Among patients with AR, patterns of AR and post-progression survival (PPS) were investigated. Oligoprogression was defined as disease progression in up to 5 individual progressive lesions.

Results

Among 174 patients who received first-line pembrolizumab, 88 showed response and were included in the study. Among these patients, 46 (52%) developed AR. Patients with old age, poor performance status (PS), at least 3 metastatic organs, or bone metastasis showed significantly shorter PFS. Among 46 patients with AR, 32 (70%) developed AR as oligoprogression and showed significantly longer PPS than those with non-oligoprogressive AR.

Conclusions

Patients with old age, poor PS, at least 3 metastatic organs, or bone metastasis showed shorter durable responses to pembrolizumab monotherapy. Oligoprogressive AR was relatively common and associated with better prognosis. Further research is required to develop optimal approaches for the treatment of these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08048-4.

Combining radiotherapy with targeted therapies in non-small cell lung cancer: focus on anti-EGFR, anti-ALK and anti-angiogenic agents

The combination of radiotherapy (RT) with targeted agents in non-small cell lung cancer (NSCLC) has been expected to improve the therapeutic ratio and tumor control. The EGFR blockade enhances the antitumor effect of RT. The ALK inhibition elicits anti-proliferative, pro-apoptotic and antiangiogenic effects in ALK-positive NSCLC cell lines, enhanced by the exposure to RT. The antiangiogenic agents normalize pathological tumor vessels, thus decrease tumor cell hypoxia and improve radiosensitivity. To date, however, none of the targeted agents combined with RT has shown proven clinical benefit over standard chemoradiation (CRT) in locally advanced NSCLC. The risk of potential excessive toxicity related to the therapeutic combination of RT and targeted agents cannot be ignored. Well-designed clinical trials may allow development of more effective combination strategies. Another potential application of combined RT and targeted therapies in oncogene-driven NSCLC is metastatic oligoprogressive or oligopersistent disease. The use of RT in oligoprogressive oncogene-driven NSCLC, while continuing first line targeted therapy, can potentially eradicate resistant cell clones and provide survival benefit. Likewise, the consolidation of oligopersistent foci (molecularly resistant to first line targeted therapy) may potentially interfere with the natural course of the disease by avoiding or delaying progression. We discuss here the molecular and radiobiological mechanisms of combining RT and targeted agents, and summarize current clinical experience.

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.

Metastasis directed stereotactic radiotherapy in NSCLC patients progressing under targeted- or immunotherapy: efficacy and safety reporting from the 'TOaSTT' database

Background

Metastasis directed treatment (MDT) is increasingly performed with the attempt to improve outcome in non-small cell lung cancer (NSCLC) patients receiving targeted- or immunotherapy (TT/IT). This study aimed to assess the safety and efficacy of metastasis directed stereotactic radiotherapy (SRT) concurrent to TT/IT in NSCLC patients.

Methods

A retrospective multicenter cohort of stage IV NSCLC patients treated with TT/IT and concurrent (≤ 30 days) MDT was established. 56% and 44% of patients were treated for oligoprogressive disease (OPD) or polyprogressive disease (PPD) under TT/IT, polyprogressive respectively. Survival was analyzed using Kaplan–Meier and log rank testing. Toxicity was scored using CTCAE v4.03 criteria. Predictive factors for overall survival (OS), progression free survival (PFS) and time to therapy switch (TTS) were analyzed with uni- and multivariate analysis.

Results

MDT of 192 lesions in 108 patients was performed between 07/2009 and 05/2018. Concurrent TT/IT consisted of EGFR/ALK-inhibitors (60%), immune checkpoint inhibitors (31%), VEGF-antibodies (8%) and PARP-inhibitors (1%). 2y-OS was 51% for OPD and 25% for PPD. After 1 year, 58% of OPD and 39% of PPD patients remained on the same TT/IT. Second progression after MDT was oligometastatic (≤ 5 lesions) in 59% of patients. Severe acute and late toxicity was observed in 5.5% and 1.9% of patients. In multivariate analysis, OS was influenced by the clinical metastatic status (p = 0.002, HR 2.03, 95% CI 1.30–3.17). PFS was better in patients receiving their first line of systemic treatment (p = 0.033, HR 1.7, 95% CI 1.05–2.77) and with only one metastases-affected organ (p = 0.023, HR 2.04, 95% CI 1.10–3.79). TTS was 6 months longer in patients with one metastases-affected organ (p = 0.031, HR 2.53, 95% CI 1.09–5.89). Death was never therapy-related.

Conclusions

Metastases-directed SRT in NSCLC patients can be safely performed concurrent to TT/IT with a low risk of severe toxicity. To find the ideal sequence of the available multidisciplinary treatment options for NSCLC and determine what patients will benefit most, a further evaluated in a broader context within prospective clinical trials is needed continuation of TT/IT beyond progression combined with MDT for progressive lesions appears promising but requires prospective evaluation.

Trial registration: retrospectively registered

Efficacy of local therapy for oligoprogressive disease after programmed cell death 1 blockade in advanced non-small cell lung cancer

Immune checkpoint inhibitors (ICIs) have dramatically changed the strategy used to treat patients with non-small-cell lung cancer (NSCLC); however, the vast majority of patients eventually develop progressive disease (PD) and acquire resistance to ICIs. Some patients experience oligoprogressive disease. Few retrospective studies have evaluated clinical efficacy in patients with oligometastatic progression who received local therapy after ICI treatment. We conducted a retrospective analysis of advanced NSCLC patients who received PD-1 inhibitor monotherapy with nivolumab or pembrolizumab to evaluate the effects of ICIs on the patterns of progression and the efficacy of local therapy for oligoprogressive disease. Of the 307 patients treated with ICIs, 148 were evaluated in our study; 42 were treated with pembrolizumab, and 106 were treated with nivolumab. Thirty-eight patients showed oligoprogression. Male sex, a lack of driver mutations, and smoking history were significantly correlated with the risk of oligoprogression. Primary lesions were most frequently detected at oligoprogression sites (15 patients), and 6 patients experienced abdominal lymph node (LN) oligoprogression. Four patients showed evidence of new abdominal LN oligometastases. There was no significant difference in overall survival (OS) between the local therapy group and the switch therapy group (reached vs. not reached, P = .456). We summarized clinical data on the response of oligoprogressive NSCLC to ICI therapy. The results may help to elucidate the causes of ICI resistance and indicate that the use of local therapy as the initial treatment in this setting is feasible treatment option.

Durable disease control with local treatment for oligoprogression of metastatic solid tumors treated with immune checkpoint blockade

BACKGROUND

While the concept of oligometastatic disease is increasingly recognized as a distinct clinical disease state, the concept of oligoprogression is less well-characterized. Oligoprogression may be particularly relevant in the context of immune checkpoint inhibitors (CPI) given the underlying mechanism of action and insights regarding acquired resistance. In this study, we sought to characterize the incidence of oligoprogression in patients on CPI and explore the impact of local therapy.

MATERIALS AND METHODS

We performed a retrospective analysis of all patients with advanced solid tumors (excluding glioblastoma multiforme) who received a PD-1, PD-L1, or CTLA-4 inhibitor at a single institution between 2011 and 2017. Oligoprogression was defined as progression at ≤3 metastatic lesions outside of the brain after achieving at least stable disease on CPI for 3 months. Progression-free survival (PFS) was calculated using the Kaplan-Meier method.

RESULTS

Among 425 patients treated with CPI, 390 had advanced primary solid tumors outside of the central nervous system. 321 of these patients were evaluable for response, among whom 102 achieved at least stable disease. Oligoprogression was observed in 4.1% of the entire cohort and 15.7% of patients achieving at least stable disease on CPI. Among 16 patients experiencing oligoprogression, 15 received local therapy to the oligoprogressive lesions, many of whom continued CPI. At a median follow-up of 25.8 months, the median PFS for patients with oligoprogression after local therapy was 15.4 months.

CONCLUSIONS

Oligoprogression occurs in a subset of patients after an initial response to CPI. However, patients receiving local therapy to oligoprogressive sites may experience durable disease control. Further study is warranted.

MICROABSTRACT

Oligoprogression was observed in 4.1% of the entire cohort of patients on immune checkpoint inhibitors in this study and 15.7% of patients achieving at least stable disease. Among 16 patients experiencing oligoprogression, 15 received local therapy. At a median follow-up of 25.8 months, the median progression-free survival for patients with oligoprogression after local therapy was 15.4 months and zero patients had died. Oligoprogression occurs in a subset of patients after an initial response to CPI and local therapy to oligoprogressive sites may result in durable disease control.

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.

The use of radiation therapy for oligoprogressive/oligopersistent oncogene-driven non small cell lung cancer: State of the art

Oncogene-driven non small cell lung cancer (NSCLC) is a distinct entity in thoracic oncology. The availability of effective target therapies, like EGFR inhibitors or ALK inhibitors, have revolutionized the prognosis of these patients. However, despite an initial response in the majority of patients, drug resistance ultimately occurs. In some cases, this resistance develops in few clonal cells (oligoprogression), so that a local ablation of these resistant deposits could allow to maintain the same systemic therapy and possibly to prolong patients' survival. For these purposes, stereotactic body radiation therapy (SBRT) is an ideal local ablative treatment, because it is effective, non invasive and with limited side effects. In this review, we aim to analyze available clinical data to verify whether SBRT can allow these patients to continue with existing target therapy longer, delay the switch to other systemic therapies and improve their outcome modifying the natural history of the disease.

Additional bevacizumab in EGFR-mutant lung adenocarcinoma patients who had oligo-progression after the failure of EGFR-TKI: A single-institute retrospective study

INTRODUCTION

In EGFR-mutant NSCLC patients with oligo-progression disease (oligo-PD) after the EGFR-TKI failure, additional local ablative therapy (LAT) including stereotactic ablative radiotherapy reportedly extends the duration of the current EGFR-TKI and prolongs survival times. In clinical practice, however, all the patients cannot receive LAT for oligo-PD.

METHODS

We retrospectively evaluated the efficacy and tolerability of additional bevacizumab as an alternative to LAT for oligo-PD after the EGFR-TKI failure in previously treated lung adenocarcinoma patients (median number of previous therapies, 2 regimens). Oligo-PD was defined as a situation in which disease progression has occurred in less than 5 anatomical sites after EGFR-TKI that has achieved at least stable disease.

RESULTS

During a median 29.6-month follow-up period from the initiation of EGFR-TKI, 9 patients developed oligo-PD. One patient underwent LAT, but other 8 patients did not because of a few micro-metastatic lesions (n = 2), meningitis (n = 1), no indication of pleurodesis (n = 1), patient refusal (n = 2) or oligo-PD in the LAT treated sites (n = 3). Additional bevacizumab with continuation of the current EGFR-TKI had a disease control rate of 100% and a median time of progression-free survival from additional bevacizumab until another PD was 8.8 months. The reason for the discontinuation was because of another PD (n = 6) or treatment-related adverse events (n = 3). Four patients received sequential therapy and overall survival from additional bevacizumab was 10.1 months.

CONCLUSIONS

Additional bevacizumab could be useful for EGFR-mutant adenocarcinoma patients with oligo-PD after the EGFR-TKI failure.

When Should we Irradiate the Primary in Metastatic Lung Cancer?

Metastatic lung cancer encompasses a heterogenous group of patients in terms of burdens of disease, ranging from patients with extensive metastases to those with a limited number of metastatic lesions (oligometastatic disease). Histopathological heterogeneity also exists within two broad categories, non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), portraying different patterns and evolution of disease. Local consolidative therapy to the primary tumour and metastatic sites, including surgery and/or radical dose radiotherapy, is increasingly being used to improve survival outcomes, particularly in the context of oligometastatic disease, with or without the use of molecular targeted therapy and immunotherapy. Recently, randomised studies in oligometastatic NSCLC have shown that local consolidative therapy may confer a survival advantage. This review explores whether treating just the primary tumour with radiotherapy may similarly produce improved clinical outcomes. Such a treatment strategy may carry less potential toxicity than treating multiple sites upfront. The biological rationale behind the potential benefits of treating just the primary in metastatic malignancy is discussed. The clinical evidence of such an approach across tumour sites, such as breast and prostate cancer, is also explored. Then the review focuses on treating the primary in NSCLC and SCLC with radiotherapy, by first exploring patterns of failure in metastatic NSCLC and second exploring evidence on survival outcomes from studies in metastatic NSCLC and SCLC. It is challenging to draw conclusions on the clinical benefit of treating the primary cancer in isolation from the evidence available. This highlights the need to collect data within the ongoing clinical trials on the clinical outcome and toxicity of radiotherapy delivery to primary thoracic disease specifically. This challenge also identifies the need to design future clinical trials to produce randomised evidence for such an approach.

Local ablative therapy of oligoprogressive TKI-treated thyroid cancer

Metastatic cancer patients generally respond well to treatment with tyrosine kinase inhibitors (TKIs). However, TKI resistance occurs in almost all cases and often leads to a change in treatment. Recent guidelines, including thyroid cancer, raised the possibility of locally treating TKI-resistant oligoprogressive disease, i.e., one or a few progressing lesions in an otherwise treatment-responsive metastatic cancer, thereby obviating the need to change the ongoing TKI. To determine the benefits of this intervention, we reviewed studies on the use of LAT for TKI-treated oligoprogressive cancers. We found that in non-small cell lung cancer at least, LAT prolongs disease control and the duration of exposure to a TKI irrespective of the LAT used. Moreover, we reviewed the local ablative therapies (LATs) that are feasible for the local control of oligoprogressive thyroid cancer. Lastly, we report two illustrative cases of patients with oligoprogressive thyroid cancer treated with two different LATs while on therapy with TKIs. Both LATs extended the duration of disease control and the time of exposure to the ongoing TKI, thereby indicating that LAT is a favorable option for TKI-treated oligoprogressive thyroid cancer. Prospective randomized studies are needed to verify the benefit of LATs in terms of progression-free and overall survival in this increasingly frequent clinical setting.

Stereotactic radiotherapy in targeted therapy treated oligo-metastatic oncogene-addicted (non-small-cell) lung cancer

While the prognosis of metastatic non-small-cell lung cancer has shown significant progress these last years, notably with the discovery of oncogen-driven subtypes and the development of targeted therapies, significant improvements are still needed. More recently, numerous authors studied the oligo-metastasis concept, where the metastasis are limited in number and sites involved, and that could benefit from an aggressive approach of these lesions, for instance with the help of stereotactic radiotherapy. Nevertheless, there is no clear consensus existing for the time being for the treatment of these tumors. Three main clinical situations can be distinguished: oligo-metastasis state de novo at diagnosis (synchronous) or as first metastatic event of an initially locally limited affection (metachronous); oligo-progression during systemic treatment of a pluri-metastatic disease; and finally oligo-persistence of some remaining metastatic lesions at the nadir of the systemic therapy effect. In this review, we will discuss the place of stereotactic radiotherapy in the treatment of non-small-cell oligo-metastatic oncogene-addicted cancers treated with targeted therapies, differentiating these three main clinical situations. In all these indications, this technique could provide a benefit in terms of local control, possibly even in specific survival, when associated with targeted therapy continuation, related to local control of the oligo-metastatic cerebral or extracerebral lesions.

Mixed response to osimertinib and the beneficial effects of additional local therapy

BACKGROUND

Although non-small cell lung cancers (NSCLCs) harboring EGFR mutations initially respond well to EGFR-tyrosine kinase inhibitors (TKIs), they typically progress after approximately one year. The EGFR T790M mutation is the most common resistance mechanism. NSCLCs with T790M respond well to osimertinib; however, the heterogeneity of NSCLCs may limit the efficacy. Some patients exhibit a mixed response (MR), in which some lesions shrink and others progress, but little is known of the incidence and characteristics of such a response. We sought to determine the frequency and clinical course in MR patients.

METHODS

We retrospectively reviewed the records of patients who had received osimertinib for NSCLC with EGFR T790M.

RESULTS

Between April and December 2016, 48 patients were administered osimertinib. Seven patients (15%) exhibited one of two MR types: (i) progressive lesions that did not include the re-biopsy site (5 patients), and (ii) progressive lesions that included the re-biopsy site (2 patients). The most frequent progressive sites were liver and lung metastases (4 patients). Three patients continued osimertinib following an MR, one of whom had received local therapy for liver metastasis and achieved disease control on osimertinib for an additional four months.

CONCLUSION

An MR was detected in 15% of NSCLC patients with T790M. This finding suggests that several different resistance mechanisms are active within a single patient who develops resistance to EGFR-TKIs. Osimertinib is basically effective for tumors that acquire resistance to EGFR-TKIs as a result of T790M mutation. Therefore, additional local therapy may be beneficial for patients who develop an MR to osimertinib.

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.

First-line continual EGFR-TKI plus local ablative therapy demonstrated survival benefit in EGFR-mutant NSCLC patients with oligoprogressive disease

Introduction: The effect of local ablative therapy (LAT) for oligoprogressive epidermal growth factor receptor (EGFR) mutation non-small cell lung cancer (NSCLC) remains undetermined. This study aimed to investigate the survival benefit of addition of LAT to EGFR-TKIs in EGFR-mutant NSCLC patients with oligoprogression during TKI therapy.

Materials and Methods: Patients with stage IIIB/IV EGFR mutant NSCLC who had oligoprogressive disease during the first-line EGFR-TKI therapy from March 2011 to February 2016 were identified. The primary research point were progression-free survival1 (PFS1), defined as time of initiation of TKI therapy to Response Evaluation Criteria in Solid Tumours (RECIST) 1.1 defined progress disease (PD) or death and PFS2, defined as time of initiation of TKI therapy to off-TKI PD. The second research piont inclued overal survival (OS) and safety.

Results: A total of 206 patients were included. The median follow-up time was 42 months (20.0-69.6 months). The median PFS1, median PFS2 and median OS for the related cohort were 10.7 months (95% CI, 10.1-13.3 months), 18.3 months (95% CI, 17.4-19.2 months) and 37.4 months (95% CI, 35.9-38.9 months) respectively. Survival rates of 1 year, 2 years and 3 years were 94.1%, 78.9%, and 54.7%, respectively. Multivariate analysis revealed that female, EGFR exon 19 mutation, one metastatic lesion, partial or complete response to prior EGFR TKIs therapy were the independent prognostic factors. No unexpected toxicities were observed.

Conclusion: The current study suggested that the addition of LAT to EGFR-TKI could provide satisfactory survival benefit for EGFR-mutant NSCLC patients with oligoprogression during first-line EGFR-TKI treatment.

The comparison of EGFR-TKI failure modes and subsequent management between exon 19 deletion and exon 21 L858R mutation in advanced non-small-cell lung cancer

Background: Advanced non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 19 deletion (19 Del) and exon 21 L858R mutation (L858R) might be distinct diseases. Therefore, it is necessary to take EGFR mutation subgroups into consideration for making choices of subsequent treatment after tyrosine kinase inhibitors (TKIs) failure.

Patients and methods: 174 patients who developed to EGFR-TKI failure were categorized into three cohorts of dramatic progression, gradual progression and local progression. Chi-square was used to compare the distribution of failure modes between 19 Del and L858R. Kaplan-Meier method and Cox Regression were performed for analyses of survival in different subsequent treatments.

Results: The distribution of EGFR-TKI failure modes showed no significant difference between 19 Del and L858R. Patients in gradual progression had a longer progression-free survival (PFS) and overall survival (OS) compared with other failure modes in whole population, 19 Del cohort and L858R cohort. 19 Del patients with dramatic progression would obtain survival benefit from chemotherapy, while those with gradual progression got no survival benefit neither from chemotherapy nor previous TKI continuation. However, patients with dramatic or gradual progression would benefit from previous TKI continuation in L858R cohort.

Conclusion: For advanced EGFR-positive NSCLC patients with acquired resistance to EGFR-TKI, subsequent treatment should be personalized according to EGFR-TKI failure modes & EGFR mutation subtypes.

Targeting ALK: Precision Medicine Takes on Drug Resistance

Anaplastic lymphoma kinase (ALK) is a validated molecular target in several ALK-rearranged malignancies, including non-small cell lung cancer. However, the clinical benefit of targeting ALK using tyrosine kinase inhibitors (TKI) is almost universally limited by the emergence of drug resistance. Diverse mechanisms of resistance to ALK TKIs have now been discovered, and these basic mechanisms are informing the development of novel therapeutic strategies to overcome resistance in the clinic. In this review, we summarize the current successes and challenges of targeting ALK.

SIGNIFICANCE

Effective long-term treatment of ALK-rearranged cancers requires a mechanistic understanding of resistance to ALK TKIs so that rational therapies can be selected to combat resistance. This review underscores the importance of serial biopsies in capturing the dynamic therapeutic vulnerabilities within a patient's tumor and offers a perspective into the complexity of on-target and off-target ALK TKI resistance mechanisms. Therapeutic strategies that can successfully overcome, and potentially prevent, these resistance mechanisms will have the greatest impact on patient outcome. Cancer Discov; 7(2); 137-55. ©2017 AACR.