Assessment of the Clinical Utility of Circulating Tumor Cells at Different Time Points in Predicting Prognosis of Patients With Small Cell Lung Cancer: A Meta-Analysis oleh Ai-Min Jiang MMed, Hao-Ran Zheng MMed, Na Liu MMed, Rui Zhao PhD, Yu-Yan Ma MMed, Shu-Heng Bai MMed, Tao Tian MD, Xuan Liang MD, Zhi-Ping Ruan MD, Xiao Fu MD, Yu Yao MD, PhD