Purpose: The standard treatment for locally advanced rectal cancer involves neoadjuvant chemoradiation followed by total mesorectal excision surgery. A subset of patients achieves pathologic complete response (pCR), representing the optimal treatment outcome. This study compares the long-term oncological outcomes of patients who achieved pCR with those who attained clinical complete response (cCR) after total neoadjuvant therapy, managed using a watch-and-wait approach.Methods: This study retrospectively evaluated patients with mid-low locally advanced rectal cancer who underwent neoadjuvant treatment from January 1, 2005, to May 1, 2023. The pCR and cCR groups were compared based on demographic, clinical, histopathological, and long-term survival outcomes.Results: The median follow-up times were 54 months (range, 7–83 months) for the cCR group (n=73), 96 months (range, 7–215 months) for the pCR group (n=63), and 72 months (range, 4–212 months) for the pathological incomplete clinical response (pICR) group (n=627). In the cCR group, 15 patients (20.5%) experienced local regrowth, and 5 (6.8%) developed distant metastasis (DM). The pCR group had no cases of local recurrence, but 3 patients (4.8%) developed DM. Among the pICR patients, 58 (9.2%) experienced local recurrence, and 92 (14.6%) had DM. Five-year disease-free survival rates were 90.0% for cCR, 92.0% for pCR, and 69.5% for pICR (P=0.022). Five-year overall survival rates were 93.1% for cCR, 92.0% for pCR, and 78.1% for pICR. There were no significant differences in outcomes between the cCR and pCR groups (P=0.810); however, the pICR group exhibited poorer outcomes (P=0.002).Conclusion: This study shows no significant long-term oncological differences between patients who exhibited cCR and those who experienced pCR.

Objective: This study aimed to assess the outcomes of minimally invasive surgery (MIS) for colon cancer and analyze the impact of tumor localization on survival. Patients and Methods: A retrospective analysis was conducted on 842 consecutive patients who underwent curative MIS (laparoscopic and robotic) for stage I to III colon adenocarcinoma between 2001 and 2024. The surgical technique adhered to oncological principles, ensuring adequate resection margins and proper lymph node dissection. Patient characteristics, operative data, perioperative outcomes, histopathologic findings, and oncological outcomes were analyzed. Results: The study included 842 patients (59.4% male, 40.6% female) with a median age of 60.3 years. Tumor localization was right colon in 29.5%, transverse colon in 6.5%, and left colon in 64% of cases. In our study, 814 cases (96.7%) were performed using laparoscopic surgery, while 28 cases (3.3%) were performed using robotic surgery. The mean operative time was 135 minutes, with a mean hospital stay of 6 days. Conversion to open surgery occurred in 3% of cases. The mean number of lymph nodes removed was 35 (range: 8 to 72). Pathologic examination revealed that 65% of cases were node-positive stage III. During a mean follow-up of 10 years, local recurrence (LR) was observed in 2.8% of patients, with no significant difference based on tumor localization. Distant metastases (DM) occurred in 12.7% of patients. The 10-year disease-free survival (DFS) rate for all patients was 75%, and the overall survival (OS) rate was 78.7%. The 10-year DFS rates for right colon, transverse colon, and left colon cancers were 74%, 71%, and 76%, respectively. Similarly, the OS rates for the same groups were 78.9%, 75%, and 79%, respectively. Statistical analysis revealed no significant differences in DFS ( P =0.851) or OS ( P =0.789) among the 3 tumor localization groups. Conclusion: Our study demonstrated that MIS is a promising approach for achieving favorable long-term oncological outcomes in colon cancer patients. Consequently, MIS is established as the standard approach in colon cancer surgery. Although right colon tumors are often associated with poorer disease-free and overall survival rates, this study found no significant differences in DFS or OS among left, transverse, and right colon tumors.