In our series, 3R/3R polymorphism correlated with a superior OS. Also, this polymorphism, when associated to wild type EGFR, was related to a higher ORR to pemetrexed. Toxicity was not significantly correlated with a specific TS genotype.

Interesting neurological and cytological response rates after intrathecal (i.t) liposomal cytarabine have been observed in patients with leptomeningeal carcinomatosis (LMC) from solid tumors. However, the potential use of those responses as early predictors of time-to-progression (TTP) and overall survival (OS) is unexplored. 27 consecutive patients with LMC treated with 50 mg i.t liposomal cytarabine under compassionate drug use were retrospectively studied. All patients received i.t treatment every 2 weeks during induction and every 4 weeks during maintenance periods. Neurological and cytological responses were assessed before every liposomal cytarabine cycle. Most of the patients were female (17/27) diagnosed with breast cancer (15/27). A complete neurological response was seen among 11 % of the patients; partial response in 22 % of the patients; stable disease in 30 % of the patients and progressive disease in 37 % of them. Cytological assessment was available in 11/27 patients showing a 26 % complete response rate. The median time to neurological and cytological response was 15 days and 14 days, respectively. Patients showing a combined neurological and cytological response showed a significantly longer median TTP (122 vs. 3 days; p = 0.001) and OS (141 vs. 3 days; p = 0.002) compared to those showing both neurological and cytological progression. No grade 4 toxicities were recorded. According to these preliminary results, early neurological and cytological responses may be further studied as early predictors of TTP and OS in patients receiving i.t liposomal cytarabine for LMC.