For erlotinib and observation , respectively , the median progression-free survival was 12.7 and 12.4 months ( hazard ratio [ HR ] , 1.05 ; 95 % CI , 0.90 to 1.23 ) , and the median overall survival was 50.8 and 59.1 months ( HR , 0.99 ; 95 % CI , 0.81 to 1.20 months ) , respectively .