Observed and relative survival trends of lung cancer: A systematic review of population‐based cancer registration data oleh Jing‐Hao Bi, Jia‐Yi Tuo, Yu‐Xuan Xiao, Dan‐Dan Tang, Xiao‐Hui Zhou, Yu‐Fei Jiang, Xiao‐Wei Ji, Yu‐Ting Tan, Hui‐Yun Yuan, Yong‐Bing Xiang