P2.02-010 Prognosis Impact of Oligoprogression Following Definitive Chemo-Radiotherapy in Stage III Non-Small Cell Lung Cancer

Abstract

The influence of recurrence pattern on outcome in stage III NSCLC following definitive chemo-radiotherapy (CRT) has been scarcely addressed in the literature. Our aim was to analyze the relevance of oligoprogression (OP) in this clinical setting. Patients (pts) with stage III NSCLC who underwent concurrent CRT from 2010 to 2014 at the Catalan Institute of Oncology were retrospectively reviewed (n=170). Recurrence pattern at first progression was recorded. OP was defined as a single metastatic organ with up to 3 lesions. Overall Survival (OS) and Progression-Free Survival (PFS) were plotted using Kaplan Meier method, and multivariate Cox proportional hazards model was developed. Median age 64 (37-87); male 87%; ECOG-PS≤1 92%; histology: adenocarcinoma 34%, squamous 43%, NOS+large cell 23%; cN0-1 21%, cN2 60%, cN3 19%. Platinum doublet: cisplatin 62%, carboplatin 38%. RT between 60-70 Gy (2Gy/fr): 94%. At a median follow-up of 38 months (m), 108 of 170 pts relapsed (63%) and 66% died. mPFS was 13m (95% CI 10-16), mOS was 28m (95% CI 22-34). Twenty-five of pts who relapsed (23%) developed OP. Sites involved: visceral 17, brain 4, lymph nodes 3, bone 1. Treatments delivered: local therapy with curative intent 9; palliative intention 12; no treatment 4 (table 1). Among pts who relapsed, mOS was longer in those with OP (32m) compared to pts without OP (18m, p=0.007). Pts with OP who received treatment, mOS according to curative or palliative intention was 53m versus 32m (p=0.1), respectively. In the multivariate Cox analysis of post-progression OS, OP remained a favorable prognostic factor (HR=0.36, 95% CI 0.17-0.74) independently of age, PS, stage, histology, smoking history, and platinum doublet. OP was associated with substantial better prognosis in this cohort of pts treated with concurrent CRT. Local ablative therapies in the context of OP yielded promising results in terms of survival and warrants further investigation.