SRC and adenocarcinoma: According to the proportion of SRC components (0, 1–50, or >50%), all cases were categorized into three groups: (1) 3,479 pure adenocarcinoma cases (without SRC component), (2) 406 adenocarcinomas cases mixed with SRC (SRC component 1–50%), and (3) 254 SRC cases (SRC component >50%).