Radiation therapy for oligometastatic non-small cell lung cancer

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.

[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.

Local Therapy for Oligoprogressive Disease in Patients With Advanced Stage Non-small-cell Lung Cancer Harboring Epidermal Growth Factor Receptor Mutation

INTRODUCTION

The effect of local therapy (LT) for oligoprogressive epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) has not been well established. Forty-six patients with stage IIIB/IV EGFR-mutated NSCLC were treated by LT and continuing tyrosine kinase inhibitors (TKIs) for oligoprogression. The median overall survival (OS) and progression-free survival (PFS) after LT were 13.0 and 7.0 months, respectively. EGFR mutation type, sites of LT, and time from first progressive disease (PD) to LT were prognostic of OS after LT.

PURPOSE

Patients with advanced stage EGFR-mutated NSCLC treated with EGFR TKIs could experience oligoprogression. This study investigated the benefits of LT and continuation of TKIs for oligoprogression retrospectively.

MATERIALS AND METHODS

Forty-six patients with stage IIIB/IV EGFR-mutated NSCLC on TKIs were treated by LT and continuation of TKIs for oligoprogressive disease. The impact of clinicopathologic variables on survival was explored using Cox regression.

RESULTS

With a median follow-up of 32 months, the 2-year OS was 65.2%, and the estimated OS was 35.0 months. The median OS after LT (LT-OS) was 13.0 months. The median PFS after LT (LT-PFS) was 7.0 months. Univariate analysis showed that stage at initial diagnosis, EGFR mutation type, site of LT, metastatic status at initial TKIs, and time from first PD to LT correlated with LT-OS significantly. Multivariate analysis suggested that EGFR mutation type (P = .001), sites of LT (P = .000), and time from first PD to LT (P = .034) were prognostic of LT-OS. Univariate analysis showed that metastatic status at initial TKIs and time from first PD to LT correlated with LT-PFS significantly. Multivariate analysis suggested that only time from first PD to LT (P = .000) was prognostic of LT-PFS.

CONCLUSION

This study revealed that LTs are feasible and effective for EGFR-mutated NSCLC with oligoprogression. EGFR mutation type, sites of LT, and time from first PD to LT were prognostic factors for LT-OS. Time from first PD to LT was a prognostic factor for LT-PFS.

Lung cancer and metastasis: new opportunities and challenges

Lung cancer continues to attract special attention since the real number of lung cancer mortality and incidence in 2014 was definitely higher than those estimated numbers according to the report from World Health Organization. The present special issue highly focuses on advanced discovery and development of lung cancer and metastasis and discusses about potential opportunities and challenges to be faced. The present issue explores clinical applications of cancer immunotherapies, gene therapies, radiotherapies, or target-oriented therapies. A new and novel methodology can be used to identify differential interactions of driver genes, cancer-predictive genes, subtype-specific genes, or disease-exclusive genes or gene pairs from imbalanced or heterogeneous datasets. We also demonstrate the importance of lung cancer-specific gene mutations, epigenetics, gene sequencing, heterogeneity, or biomarker discovery. Clinical bioinformatics is emphasized as a critical tool and merging science. Novel therapies are designed and expected on basis of oncogenic molecular aberrations in lung cancer.

The IASLC Lung Cancer Staging Project: Proposals for the Revision of the M Descriptors in the Forthcoming Eighth Edition of the TNM Classification of Lung Cancer

INTRODUCTION

The aim of this study is to analyze all metastatic (M) categories of the current tumor, node, and metastasis (TNM) classification of lung cancer with the objective of providing suggestions for modifications of the M component in the next edition of the TNM classification for lung cancer.

METHODS

The new International Association for the Study of Lung Cancer lung cancer database was created from 94,708 patients diagnosed as having lung cancer between 1999 and 2010. Including further patients submitted through the electronic data capture system to Cancer Research and Biostatistics until 2012, all together 1059 non-small-cell lung cancer cases were available for a detailed analysis of the clinical M categories. Overall survival was calculated using the Kaplan-Meier method, and prognosis was assessed using a Cox proportional hazards regression analysis.

RESULTS

No significant differences were found among the M1a (metastases within the chest cavity) descriptors. However, when M1b (distant metastases outside the chest cavity) were assessed according to the number of metastases, tumors with a single metastasis in a single organ had significantly better prognosis than those with multiple metastases in one or several organs.

CONCLUSIONS

In this revision of the TNM classification, cases with pleural/pericardial effusions, contralateral/bilateral lung nodules, contralateral/bilateral pleural nodules, or a combination of multiple of these parameters should continue to be grouped as M1a category. Single metastatic lesions in a single distant organ should be newly designated to the M1b category. Multiple lesions in a single organ or multiple lesions in multiple organs should be reclassified as M1c category. This new division can serve as a first step into providing rational definitions for an oligometastatic disease stage in non-small-cell lung cancer in the future.

Advances in the Treatment of Oligometastatic Disease: What the Radiologist Needs to Know to Guide Patient Management

RATIONALE AND OBJECTIVES

An ever-expanding body of biological, genetic, and clinical evidence has brought to light the presence of the oligometastatic state of cancer, which is considered between localized disease and widespread metastases. Indeed, in some patients with oligometastatic disease, curative therapy is possible.

CONCLUSIONS

For select cancer histologies, aggressive focal therapy of oligometastatic lesions is already the clinical standard of care (i.e. colorectal cancer and sarcomas), while for other tumor types the evidence is still emerging (i.e. prostate, breast, etc.). It is increasingly important, therefore, for the radiologist interpreting oncology patients' staging or restaging examinations to be aware of those diseases for which targeted therapy of oligometastases may be undertaken to effectively guide such management. The improved imaging resolution provided by technological advances promise to aid in the detection of subtle sites of disease to ensure the identification of patients with oligometastases amenable to targeted treatment.