Beneficiaries of radical surgery among clinical complete responders to neoadjuvant chemoradiotherapy in rectal cancer

• Published in: Cancer science Vol. 112; no. 9; pp. 3607 - 3615
• Main Authors: Zhang, Shu, Zhang, Rong, Li, Rong‐zhen, Wang, Qiao‐xuan, Chang, Hui, Ding, Pei‐rong, Li, Li‐ren, Wu, Xiao‐jun, Chen, Gong, Zeng, Zhi‐fan, Xiao, Wei‐wei, Gao, Yuan‐hong
• Format: Journal Article
• Language: English
• Published: Tokyo John Wiley & Sons, Inc 01-09-2021; John Wiley and Sons Inc
• Subjects: Antigens; Cancer; Care and treatment; Chemoradiotherapy; Chemotherapy; clinical complete response; Colonoscopy; Colorectal cancer; Comparative analysis; Endoscopy; Fecal incontinence; locally advanced rectal cancer; long‐term survival; Magnetic resonance imaging; Medical prognosis; Metastases; Metastasis; Multivariate analysis; Oncology, Experimental; Original; Patients; Radiation therapy; Rectum; risk classification; Surgery; Surveillance; Survival; watch‐and‐wait
• ISSN: 1347-9032; 1349-7006
• DOI: 10.1111/cas.15039

This study aimed to identify patients who benefit from radical surgery among those with rectal cancer who achieved clinical complete response (cCR). Patients with locally advanced rectal cancer (LARC; stage II/III) who achieved cCR after neoadjuvant chemoradiotherapy (nCRT) were included (n = 212). Univariate/multivariate Cox analysis was performed to validate predictors for distant metastasis‐free survival (DMFS). A decision tree was generated using recursive partitioning analysis (RPA) to categorize patients into different risk stratifications. Total mesorectal excision (TME) was compared with the watch‐and‐wait (W&W) strategy in each risk group. Two molecular predicators of CEA and CA19‐9 were selected to establish the RPA‐based risk stratification, categorizing LARC patients into low‐risk (n = 139; CA19‐9 < 35 U/mL and CEA < 5 ng/mL) and high‐risk (n = 73; CA19‐9 ≥ 35 U/mL or CEA ≥5 ng/mL) groups. Superior 5‐y DMFS was observed in the low‐risk group vs. the high‐risk group (92.9% vs. 76.2%, P = .002). Low‐risk LARC patients who underwent TME had significantly improved 5‐y DMFS compared with their counterparts receiving the W&W strategy (95.9% vs. 84.3%; P = .028). No significant survival difference was observed in high‐risk patients receiving the 2 treatment modalities (77.9% vs. 94.1%; P = .143). LARC patients with cCR who had both baseline CA19‐9 < 35 U/mL and CEA < 5 ng/mL may benefit from radical surgery.
In total, 212 patients with cCR were retrospectively analyzed and were categorized into low‐risk and high‐risk groups according to their baseline serum concentration of CEA and CA19‐9. Significantly better survival was observed in low‐risk patients when they underwent radical surgery, compared with their counterparts who underwent the watch‐and‐wait strategy.