Total neoadjuvant treatment (consolidation chemotherapy) provides highest rate of clinical complete response for rectal cancer: analysis of 5-year long-term oncological outcomes with watch and wait protocol

Abstract

Abstract Aim To reveal whether chemoradiotherapy-consolidation chemotherapy (CRT-CNCT) treatment provides more organ preservation in locally advanced rectal cancer (LARC) and its effect on oncological outcomes. Method Retrospective analysis of prospectively maintained database was performed. Oncological outcomes of mid-low LARC patients (n = 60) were analyzed after a follow-up of 63 (50–83) months. Patients with clinical complete response (cCR) were treated with the watch-and-wait (WW) protocol. Patients who could not achieve cCR were treated with total mesorectal excision (TME) or local excision (LE). Results Thirty-nine (65%) patients who achieved cCR were treated with the WW protocol. TME was performed in 15 (25%) patients and LE was performed in 6 (10%) patients. During the follow-up period, 10 (25.6%) patients in the WW group had regrowth (RG) and 3 (7.6%) had distant metastasis (DM). 5-year overall survival (OS) and disease-free survival (DFS) were 90.1% and 71.6%, respectively, in WW group. 5-y OS and DFS were 94.9% (95% CI: 88–100%) and 80% (95% CI: 55.2–100%), respectively, in the RG group. 5-y OS and DFS were 90.1% (95% CI: 78.9–100%) and 96.6% (95% CI: 89.9–100%) in the non-RG group. 5-y OS and DFS were 78% (95% CI: 55.8–100%) and 60% (95% CI: 35.2–84.8%) in TME group. Conclusion CRT-CNCT provides cCR as high as 2/3 of LARC patients. While the WW protocol provides organ preservation, RGs developed during follow-up can be successfully salvaged without causing oncological disadvantage.