P14.17 What is the optimal therapeutic strategy for limited brain metastases (BMs) from non small cell lung cancer (NSCLC)? Prognostic factors conditioning brain control and patients outcome

Abstract

INTRODUCTION: Non small cell lung cancer (NSCLC) is the most common cause of brain metastases (BMs). For limited BMs, ≤4 lesions, several local approaches were been used: whole brain radiotherapy (WBRT), single dose radiosurgery (SRS), hypofractionated stereotactic radiosurgery (HSRS) or surgery followed or not by radiation therapy (RT). The aim of this retrospective analysis was to evaluate the outcome of NSCLC patients with limited BMs treated with local approach, surgery and/or radiosurgery omitting WBRT, in terms of local control (LC), incidence of brain distant failure (BDF), and overall survival(OS). MATERIALS AND METHODS: Surgery followed by HSRS on the tumor bed was performed in case of single, large BMs, controlled extracranial disease and KPS 90-100. SRS or HSRS in all other cases. The total doses prescribed were 24Gy/1fraction for lesions <2.5cm, and a median total dose of 30Gy (range 24-40Gy) in 3-5 fractions in case of lesions >2.5cm. Systemic therapy were used in relation to previous chemotherapy received, patients age, KPS, EGFR and ALK status. Clinical outcome was evaluated by neurological examination and MRI at 2 months after RT and then every 3 months. RESULTS: From June 2009 to December 2015, 156 patients for 228 BMs treated were included in this evaluation. Fifty (32.1%) were female and 106 (67.9%) male with a median age of 62 years (range 27-93 years). The greater number of patients had a KPS 90-100, were in RPA class II, had DS-GPA score 2.5-3, and had 1-2 BMs (88.4%). Surgical resection only was performed in 3 cases, plus HSRS in 16 (19%) cases, and as rescue after local progression in 11 cases; SRS and HSRS only in 160 (70.1%) and 65 (28.5%), respectively. Eighty-four (53.8%) patients received systemic therapy after BMs treatment, consisted in chemotherapy platinum based in 56, mono-chemotherapy in 14, EGFR TKIs in 10 and ALK inhibitors in 4. The median follow-up time was 14.8 months (0.9-90.5 months) and 23.6 months (13.5-90.5 months) for alive patients. The 1 and 2 years LC rate were 87.2%±3 and 72.8%±5; the median BDF time and the 1 and 2 years BDF rate were 21.7 months, 30.8% ±4, 58.1%±6. The median OS time, the 1 and 2 years OS rate from BMs diagnosis were 15 months, 60.9%±3.9, 31.4%±4. On univariate analyses prognostic factors recorded as conditioning survival were age (p=0.01), presence of lymph-node involvement (p=0.03), KPS (p<<0.01), presence of extra-cranial metastases at the time of BMs treatment (p<0.01), and numbers of BMs (p=0.02), confirming the prognostic and predictive role of DS-GPA (p<<0.01). The treatment performed (surgery+HSRS) has proven to significantly improve OS (p<0.01) too. CONCLUSIONS: The choice of an adequate local treatment can impact on survival in patient with limited BMs from NSCLC. A careful evaluation of prognostic and predictive factors is a pivotal additional aid.