Predictive Value Of Tumor Deposit In The Prognosis Of Patients With Yp-stage ? Rectal Cancer

Purpose: The incidence of Tumor Deposit(TD)in colorectal cancer is 5%~45%,which is associated with high risk of local recurrence and distant metastasis.However,the predictive value of TD for the prognosis of patients with yp-stage III rectal cancer who underwent multidisciplinary treatment is still unclear.Hence,we designed this retrospective study and try to analyze the prognostic effect of TD and its effect on the benefit of postoperative adjuvant chemotherapy for such patients.Materials and Methods: 1481 rectal cancer patients who admitted to the Department of Radiation Oncology,Fujian Medical University Affiliated Union Hospital from May 2007 to March 2017,were retrospectively reviewed.Patients were divided into TD+ group and TD-group according to postoperative pathology for tumor deposits.Overall survival(OS),progression-free survival(PFS),distant metastasis free survival(DMFS)and local recurrence free survival(LRFS)were evaluated by Kaplan-Meier method,log-rank test and Cox models.Results: 37 patients in the TD+ group and 301 patients in the TD-group.The age of patients in the TD+ group was higher than that in the TD-group(median age 57 years vs 53 years,p=0.029);patients in TD+ group were mostly middle(43.2%)and low(45.9%)rectal cancer,while mostly low(56.1%)rectal cancer in TD-group(p=0.021).Patients in TD+ group had stronger invasive features,such as mesangial fascia invasion,peripheral nerve invasion,circumferential margin positive and vascular tumor thrombus,and their incidence in the TD+ group was higher than that in the TD-group,but only peripheral nerve invasion reached significant difference between the two groups(p=0.002).The median follow-up time was 64 months.The 5-year OS,PFS,and DMFS in the TD-group were higher than those in the TD+ group(p?0.001),and there was no significant difference in LRFS between the two groups(p=0.679).The 5-year OS,DMFS,RFS,and PFS of p N2 patients(n=68)in the TD-group were superior to those of the TD+ group(n=34)(p<0.001).Administration of adjuvant chemotherapy and number of TDs did not influence the prognosis of these two groups(p=0.103;p=0.923).In multivariate analysis,TD is associated with a worse OS [HR=2.343(1.257-4.363),P=0.007].Conclusion: For patients with yp-stage III rectal cancer undergoing multidisciplinary treatment,TD+ patients have a worse prognosis.TD is an independent predictor of survival.No benefit from postoperative adjuvant chemotherapy,regardless of the presence or absence of TD.Prospective randomized trials are expected to validate the impact of tumor deposit on the prognosis of patients with yp-stage III rectal cancer and whether they benefit from postoperative adjuvant chemotherapy.