A Correlation Study Of Prognosis And The Number Of Lymph Nodes After Neoadjuvant Therapy For Câ…¡-â…¢ Rectal Adenocarcinoma

BackgroundThe literature lacks consensus regarding the minimal number of lymph nodes needed to accurately identify early-stage rectal adenocarcinoma. A minimum of12examined lymph nodes (LN) is recommended to ensure adequate staging and oncologic resection of patients undergoing proctectomy for rectal adenocarcinoma. Furthemore, the mean number of LN retrieved from rectal adenocarcinomas treated with neoadjuvant therapy is significantly less than those treated by surgery alone.PurposeTo investigate that decreased number of LN retrieved from those patients received neoadjuvant therapy should be a symbol of worse prognosis or an indicator of tumor response and be associated with improved prognosis.Patients and MethodsA single-center rectal adenocarcinoma database was queried for c-stage Ⅱ-Ⅲ rectal adenocarcinoma patients undergoing neoadjuvant chemoradiation followed by TME proctectomy within6-9weeks between2004and2012in Sir Run Run Shaw Hospital of ZheJiang University.84patients were categorized into two groups according to the number of LN retrieved from the proctectomy specimen:<8LN versus>8LN. Groups were compared with respect to demographics, tumor and treatment characteristics, and the following oncologic outcomes:overall-survival (OS), Disease-free-survival (DFS), distant (DR), and local recurrences (LR). A Cox Regression analysis of factors affecting oncologic outcomes was available.ResultsThe query returned for all of the84patients. There were62(73.8%) males, and the median age was56years [interquartile range (IQR)46-63years]. The average number of LN retrieved was7.7±5.1and46(54.8%) patients had less than8nodes examined. The<8nodes group was given more radiotherapy (p=0.026). No<8nodes patients didn’t suffer a LR, whereas the2-year LR rate was7.9%in the≥12nodes group (n=38,p=0.053) as well as the5-year LR rate was20%(n=10,p=0.02). Other oncologic outcomes were not significantly different. The Cox Regression Analysis demonstrates improved outcomes of2-year DFS with increasing pathologic response (ypCR,Ⅰ vs ypⅡ,Ⅱ,97.1%vs81.6%, p=0.035) to preoperative therapy as well as the adjuvant chemotherapy (≥80%vs<80%of planned,94.6%vs83.0%, p=0.039).ConclusionRetrieval of<8nodes in the proctectomy specimen of rectal adenocarcinoma following neoadjuvant therapy does not affect OS, DFS, or DR, may be an indicator of higher tumor response and, consequently, decreased LR rate.