In the present study, the investigators utilize the CTCBIOPSY® system (YZYBIO Company, Wuhan, China), which has been approved by CFDA (Chinese Food and Drug Administration), to detect CTCs, and try to compare both short-term and long-term treatment effect of laparoscopic vs. open approach on progressive gastric and rectal cancer, based on circulating tumor cell (CTC) test results as well as disease-free survivals, and figure out principles of laparoscopic approach for progressive gastric and rectal cancer. Secondary purpose is to establish an evaluation system for laparoscopic surgery for progressive gastric and rectal cancer treatment using CTC as a biomarker.