V. To evaluate the prognostic effect of EGFR expression as measured by IHC separately by treatment arm, i.e., is there a difference in outcome for IHC(+) patients receiving erlotinib compared to IHC (-) patients receiving erlotinib, and similarly is there a difference in outcome for IHC(+) patients receiving pemetrexed compared to IHC (-)patients receiving pemetrexed.