YU-TSO LIAOLin, Yu-LinYu-LinLinJOHN HUANGJI-SHIANG HUNGBEEN-REN LIN2021-05-032021-05-032021-0301791958https://scholars.lib.ntu.edu.tw/handle/123456789/558730Purpose: Current guidelines suggest that adjuvant chemotherapy (AC) be administered to all locally advanced (clinically T3-4 or N-positivity) rectal cancer patients undergoing neoadjuvant chemoradiotherapy (nCRT) and radical surgical resection regardless of the final pathological staging (yp staging). This study aimed to evaluate the necessity of AC for ypT0-2N0 rectal cancer. Methods: Patients with ypT0-2N0 rectal cancer, who received nCRT and radical surgical resection, were recruited retrospectively at a university hospital. The main outcome was to evaluate the 5-year overall survival (OS) and disease-free survival (DFS) between ypT0-2N0 rectal cancer patients with AC and those without AC. We also identified potential independent prognostic factors associated with poor outcomes. Results: One hundred and ten ypT0-2N0 rectal cancer patients (ypT0: n = 6; ypT1: n = 44; ypT2: n = 60) were followed up for a median of 60 months. No significant difference was observed in DFS and 5-year OS between patients with AC and those without AC. The risk of recurrence was associated with the postoperative pathological staging (0% with ypT0, 2.4% with ypT1, and 10% with ypT2). In the multivariate analysis, retrieval of < 12 lymph nodes was an independent favorable prognostic factor, which correlated with a higher OS (HR: 2.263; 95% CI: 1.093-4.687, P = 0.028). Intra-tumor lymphovascular and perineural invasion were poor prognostic markers for shorter DFS (HR: 5.940; 95% CI: 1.150-30.696, P = 0.033). Conclusion: Postoperative AC is not required for patients with ypT0-2N0 rectal cancer downstaged by nCRT, especially in those without poor prognostic factors.enAdjuvant chemotherapyLocally advanced rectal cancerNeoadjuvant chemoradiotherapyypT0-2N0[SDGs]SDG3capecitabine; fluorouracil; folinic acid; adult; aged; Article; cancer adjuvant therapy; cancer mortality; cancer patient; cancer prognosis; cancer recurrence; cancer staging; cancer surgery; chemoradiotherapy; clinical outcome; cohort analysis; controllejournal article10.1007/s00384-020-03787-5331280832-s2.0-85094676997https://api.elsevier.com/content/abstract/scopus_id/85094676997