Prognosis of rectal cancer patients with wait and see strategy after near clinical complete res-ponse to neoadjuvant therapy and analysis of influencing factors for tumor recurrence

Objective To investigate the prognosis of rectal cancer patients with wait and see strategy after near clinical complete response(near-cCR) to neoadjuvant therapy and influencing factors for tumor recurrence.

Methods The retrospective cohort study was conducted. The clinico-pathological data of 463 patients with low advanced rectal cancer who underwent neoadjuvant therapy, including 89 cases in Shanxi Provincial People's Hospital and 374 cases in Shanxi Cancer Hospital, from January 2013 to December 2017 were collected. There were 258 males and 205 females, aged (62±7)years. Patients received efficacy evaluation at 6 weeks after neoadjuvant therapy, in which patients with near-cCR who adhered to wait and see strategy received 6 cycles of additional adjuvant chemotherapy after comprehensive reexaminations. Observation indicators: (1)situations of neoadjuvant therapy; (2) influencing factors for tumor recurrence of rectal cancer patients with wait and see strategy after near-cCR to neoadjuvant therapy; (3) prognostic analysis. Comparison of measurement data with normal distribution between groups was conducted using the independent sample t test. Comparison of count data between groups was conducted using the chi‑square test. Comparison of ordinal data was conducted using the nonparameter rank sum test. The Kaplan-Meier method was used to draw survival curve, and the log‑rank test was used for survival analysis. The binary logistic regression model was used for univariate and multivariate analyses.

Results (1)Situations of neoadjuvant therapy. There were 136 patients achieving near-cCR after neoadjuvant therapy, including 86 cases adhering to wait and see strategy and 50 cases undergoing laparoscopic radical resection of rectal cancer. Of 86 cases with wait and see strategy, 29 cases were in clinical stage Ⅱ and 57 cases were in stage Ⅲ. There were 27 cases of scar type, 16 cases of ulcer type, 20 cases of nodule type, 23 cases of inflammatory edema type based on endoscopic tumor regression. (2) Influencing factors for tumor recurrence of rectal cancer patients with wait and see strategy after near-cCR to neoadjuvant therapy. Results of multivariate analysis showed that age was an indepen-dent protective factor for tumor recurrence of rectal cancer patients with wait and see strategy after near-cCR to neoadjuvant therapy (odds ratio=0.88, 95% confidence interval as 0.81-0.97, P<0.05). Compared with scar type, the ulcer type was an independent risk factor (odds ratio=4.22, 95% confidence interval as 1.01-17.64, P<0.05). (3) Prognostic analysis. All the 136 patients achieving near-cCR were followed up for 65(range, 60-72)months. The 5-year overall survival rate was 84.9% of 86 patients with wait and see strategy, versus 76.0% of 50 patients undergoing laparoscopic radical resection of rectal cancer, showing no significant difference between them (χ²=1.94, P>0.05). Of 86 patients with wait and see strategy, the 5-year overall survival rate was 81.5%, 75.0%, 85.0%, 95.7% for cases of scar type, ulcer type, nodule type, inflammatory edema type, showing no significant difference among them (χ²=3.64, P>0.05).

Conclusions Compared with laparoscopic radical resec-tion of rectal cancer, wait and see strategy is safe and feasible for rectal cancer patients after near-cCR to neoadjuvant therapy. Age is an independent protective factor for tumor recurrence of rectal cancer patients with wait and see strategy after near-cCR to neoadjuvant therapy. Compared with scar type, ulcer type is an independent risk factor.