[1] Chinese Univ Hong Kong, Clin Oncol, Hong Kong, Hong Kong, Peoples R China
[2] Guangdong Gen Hosp, Guangdong Lung Canc Inst, Guangzhou, Guangdong, Peoples R China
[3] Guangdong Acad Med Sci, Guangzhou, Guangdong, Peoples R China
[4] Merck & Co Inc, Clin Oncol, Kenilworth, NJ USA
[5] Merck & Co Inc, BARDS, Kenilworth, NJ USA
[6] Oncoclin Brasil Grp, Oncol, Sao Paulo, Brazil
[7] Johns Hopkins Univ, Sao Paulo, Brazil