Bombarding Oligoprogression: Oncologic Outcomes After Radiation to Patients With Oligoprogressive Non-Small Cell Lung Cancer on Maintenance Systemic Therapy

OBJECTIVES

This study aims to evaluate the efficacy and toxicity of radiotherapy (RT) to oligoprogressive metastatic non-small cell lung cancer (NSCLC).

METHODS

This is a retrospective analysis of 23 patients with metastatic NSCLC on maintenance systemic therapy, developed oligoprogression (1 to 5 sites), and all oligoprogressive sites amenable to and treated with RT. The primary endpoints included progression-free survival (PFS) and median time to start next-line therapy (MTT). Kaplan-Meier survival analysis and log-rank testing were performed using R-Studio software.

RESULTS

Twenty-three patients met the inclusion criteria. The median overall survival for the entire cohort was 31.3 months (interquartile range [IQR]: 17.86 to 45.4). The median event-free survival for the entire cohort was 8.3 months (IQR: 2.7 to 12). Patients with no prior radiation had longer median event-free survival of 11.9 months (IQR: 8.4 to 18.2) compared with patients with a history of prior radiation at 4.1 months (IQR: 2.7 to 12; P = 0.041). The local control rate for the treated lesions was 97.5%. At 12 months follow-up, 6 (43%) of 14 living patients maintained systemic therapy without initiating next-line therapy. The median PFS for the entire cohort was 8.4 months (IQR: 4.1 to 17.5). Patients who did not receive prior radiation had longer median PFS of 11.9 months (IQR: 8.4 to 18.2) compared with patients who received prior radiation 6.2 months (IQR: 2.7 to 8.5; P = 0.018). Two patients (9%) had grade 3 chronic toxicity related to RT and were medically managed.

CONCLUSION

We identified that in patients with oligoprogressive metastatic NSCLC, targeted RT to all progressive sites yielded high LC and favorable rates of PFS and MTT.

Role of radiotherapy in the management of brain oligometastases

The management of patients with brain oligometastases is complex and relies on specific reasoning compared to extracranial oligometastases. The levels of evidence are still low because patients with brain oligometastases are frequently excluded from randomized clinical trials. Stereotactic radiotherapy should be preferred in this indication over whole brain irradiation, both for patients with metastases in place and for those who have undergone surgery. The decision of local treatment and its timing must be a multidisciplinary reflection taking into account the histological and molecular characteristics of the tumor as well as the intracranial efficacy of the prescribed systemic treatments. Great caution must be observed when using stereotactic radiotherapy and concomitant systemic treatments because interactions are still poorly documented. We present the recommendations of the French society of radiation oncology on the management of brain oligometastatic patients with radiotherapy.

The real-life efficacy and safety of osimertinib in pretreated advanced non-small cell lung cancer patients with T790M mutation: a Turkish Oncology Group Study

INTRODUCTION

Osimertinib, an irreversible third-generation EGFR-TKI, is the standard of care for second-line treatment of T790M-mutant advanced NSCLC patients whose disease progressed after first-line EGFR-TKI therapy. In this multicenter study, we aimed to determine the real-life efficacy and safety of Osimertinib in pretreated advanced NSCLC patients with T790M mutation.

MATERIALS AND METHODS

This retrospective trial included advanced T790M-mutant pretreated NSCLC patients who received Osimertinib from 24 different centers in Turkey. Primary endpoint was time-to-treatment discontinuation (TTD). Secondary endpoints were objective response rate (ORR), overall survival (OS), and safety.

RESULTS

Of 163 patients, 68.7% had EGFR exon 19 deletion and 22.7% had exon 21 L858R mutation. Osimertinib was given as second-line treatment in 96 patients (58.9%) and third-line in 48 patients (29.4%). After median of 13-month follow-up, median TTD was 21.6 months with an 82.2% ORR. Estimated median OS was 32.1 months. Grade 3-4 adverse events were seen in 11.7% of the patients.

CONCLUSION

Osimertinib is a highly effective option in second- or third-line treatment of NSCLC patients with T790M mutation, with a favorable safety profile.