Survival landscape of different tumor regression grades and pathologic complete response in rectal cancer after neoadjuvant therapy based on reconstructed individual patient data oleh Jia-yi Li, Xuan-zhang Huang, Peng Gao, Yong-xi Song, Xiao-wan Chen, Xing-er Lv, Yv Fu, Qiong Xiao, Shi-yv Ye, Zhen-ning Wang