摘要
Background:The number of lymph nodes examined(LNe)is often insufficient in patients with rectal cancer(RC)treated with neoadjuvant therapy;however,its prognostic value remains controversial.Thus,we retrospectively explored whether LNe had an influence on staging and prognosis and investigated whether there was a cut-off value for better prognosis in patients with RC treated with neoadjuvant therapy.Methods:Data were collected from seven prospective hospital databases in China from July 2002 to May 2018.Binary logistic regression models were used to predict lymph node metastasis.The cut-off value for LNe was determined using X-tile 3.6.1.Survival outcomes and risk factors were analyzed using the log-rank test and Cox regression model.Results:A total of 482 patients were included,of whom 459 had complete overall survival(OS)information.Using the percentile method,the total number of lymph nodes examined(TLNe)was 14-16(40th-60th percentile),and the proportion of patients with lymph node metastasis reached a maximum of 48.1%.Cox multivariate analysis showed that the odds ratio(OR)remained the highest when TLNe was 14-16(OR=3.379,P=0.003).The 3-year and 5-year OS were 85.4% and 77.8%,respectively.Negative lymph nodes examined(NLNe)of≤6 was an independent risk factor for 3-year and 5-year OS(3-year OS 71.1%vs.85.9%,P=0.004;5-year OS 66.3%vs.74.3%,P=0.035).Subgroup analysis for patients with ypN+showed that higher 3-year and 5-year OS were achieved when the TLNe was>10,78.8%vs.54.0%(P=0.005),and 60.8%vs.36.0%(P=0.012),respectively.Patients with ypN0M0 had a higher 5-year OS when the TLNe was>19(P=0.055).Conclusion:The TLNe and NLNe influenced the staging accuracy and demonstrated prognostic value in patients with RC treated with neoadjuvant therapy.
