Increased incidence of brain metastases in ERCC1-negative NSCLC patients treated with adjuvant cisplatin-based chemotherapy

Abstract

7581 Background: We have recently demonstrated that ERCC1 is a predictor of the benefit of cisplatin-based adjuvant chemotherapy in resected non-small cell lung cancer (NSCLC). Non-squamous carcinomas have an increased risk of brain metastases (BM). Since brain is considered as a sanctuary site for chemotherapy, we hypothesised that there was an increased incidence of BM in ERCC1- negative non-squamous NSCLC patients treated with adjuvant cisplatin-based chemotherapy. Methods: Incidence of BM and histo- clinical parameters were analyzed in a population of 783 patients enrolled in the IALT trial. A subgroup analysis was performed in ERCC1 negative non-squamous NSCLC patients. Results: One hundred and one patients out of 783 (13%) developed BM alone or in association with other metastatic sites. In multivariate analysis, the clinical parameters associated with the occurrence of BM were nodal status (p=0.02), histological type (p=0.001) and pleural invasion (p=0.02). There is no effect of chemotherapy on BM (HR 1.38 [0.91–2.07], p=0.13). In patients with non-squamous histology (n=335) adjuvant chemotherapy was associated with an increased risk of BM (HR=2.10, [1.01–4.32], p=0.04) for ERCC1-negative tumours whereas there was no evidence of an effect on brain metastasis for ERCC1-positive tumours (HR=1.07 [0.38–2.99] p=0.90). These 2 effects are nevertheless not different (p for interaction=0.30) possibly by lack of power in this subsample. Conclusions: This study would suggest that cisplatin-based adjuvant chemotherapy is associated with an increased risk of BM in resected NSCLC patients with chemosensitive tumors. This data, if confirmed, could provide a rationale to evaluate prophylactic strategies in this subset of patients. No significant financial relationships to disclose.