OUTLINE: This is a multicenter, randomized, double-blind, placebo-controlled study. Patients are stratified according to chemotherapy regimen (first-line chemotherapy vs other), epidermal growth factor receptor (EGFR) inhibitor therapy (small molecule vs monoclonal antibodies), concurrent medication that increases sun hypersensitivity (yes vs no), and gender. Patients are randomized to 1 of 2 treatment arms.