[Study on the recurrence pattern of rectal cancer patients undergoing radical surgery after neoadjuvant chemoradiotherapy].

Objective: To analyze the recurrence pattern of rectal cancer patients with radical surgery after neoadjuvant chemoradiotherapy. Methods: The clinicopathological characteristics and follow-up information of rectal cancer patients with radical surgery after neoadjuvant chemoradiotherapy in the Cancer Hospital of the Chinese Academy of Medical Sciences from June 2004 to December 2017 were retrospectively collected. The recurrence pattern including the time and site was investigated. Results: The age of 537 patients was (55.5±11.7) years, of whom 361 were male (67.2%). The median follow-up time [M(Q1,Q3)] was 77.9 (64.5, 95.6) months. Moreover, 30.7% (165/537) of patients had distant metastasis or local recurrence; 26.8% (144/537) of patients had distant metastasis; 5.6% (30/537) of patients had local recurrence; 1.7% (9/537) of patients had both distant metastasis and local recurrence. In all the recurrent patients, 23.6% (39/165) were in the first year after surgery, followed by 27.3% (45/165) in the second year, 17.0% (28/165) in the third year, and 15.8% (26/165) after five years. According to the risk curve drawn by the life table, the highest metastasis risk of patients occurred in the second year after surgery, and the metastasis risk peak occurred again after more than five years. The lung was the most common metastatic organ, accounting for 47.9% (69/144), followed by the liver (18.8%, 27/144). The ratios of the recurrent patients in each ypTNM stage were 9.5% (8/84), 12.0% (12/100), 26.5% (41/155), 52.5% (104/198), respectively. The proportion of recurrent patients in tumor regression grade (TRG) 1-2 and TRG 3-5 patients were 19.2% (38/198) and 37.5% (127/339), respectively. Conclusions: The recurrence pattern of patients undergoing radical surgery after neoadjuvant chemoradiotherapy is mainly distant metastasis. The lung is the primary metastatic organ. The risk of distant metastasis and local recurrence is high in the first three years after surgery, and there is still high risk of recurrence after five years. For patients with ypTNM stage 2, 3 and TRG3-5, the postoperative adjuvant chemotherapy and long-term follow-up should be strengthened.

[A long-term follow-up study on recurrence and benefit of standardized postoperative chemotherapy of rectal cancer patients with complete pathological response after neoadjuvant chemoradiotherapy].

Objective: To analyze the clinicopathological factors affecting long-term disease-free survival and the characteristics of local recurrence or distance metastasis of rectal cancer patients with complete pathological response after neoadjuvant chemoradiotherapy. Methods: The clinicopathological data and follow-up information of patients with a complete pathological response of rectal cancer after neoadjuvant chemoradiotherapy in the Cancer Hospital of Chinese Academy of Medical Sciences from June 2004 to December 2019 were retrospectively collected. The clinicopathological factors affecting the long-term disease-free survival of patients were analyzed to build a prediction model of local recurrence and distant metastasis and to evaluate the benefits of postoperative chemotherapy. Results: The age of 108 patients was(56.3±11.6) years, of which 68 were males (63.0%); The median follow-up time was 79.9 (61.8, 112.6) months. There were 12 patients (11.1%) who had a local recurrence or distant metastasis. The 5-year disease-free survival rate was 91.1% with 9 patients who experienced recurrence. Multivariate Cox proportional hazards regression analysis showed that the maximum diameter of the residual tumor or scar (HR=8.41, 95%CI: 1.08-65.22, P=0.042) and the distance from the lower edge of the tumor to the anal margin before treatment (HR=4.54, 95%CI: 1.23-16.81, P=0.023) were independent risk factors affecting the prognosis. The prognosis of patients was stratified based on relevant factors. The 5-year cumulative disease-free survival rate of those patients receiving postoperative standardized chemotherapy was 92.0%, while for patients who did not receive or complete standardized chemotherapy, the 5-year cumulative disease-free survival rate was 82.3%. Conclusions: The maximum diameter of the residual tumor or scar and the distance from the lower edge of the tumor to the anal margin before treatment were independent risk factors affecting the prognosis of patients with a complete pathological response. Patients with independent risk factors could benefit from the standardized postoperative chemotherapy.