Clinicopathology, Adjuvant Chemotherapy And Prognosis Of Stage Ⅱ Colorectal Cancer:Ten-year Case Series In A Tertiary Hospital

[Aims] To retrospectively analyze the clinicopathological characteristics of post-operative (R0resection) followed with adjuvant chemotherapy patients of stage II colorectal cancer, evaluating risk factors for prognosis and survival.[Methods] The medical records of stage II post-operative colorectal cancer patients who were hospitalized in Department of Oncology, Chinese PLA general hospital, from Jan.2001to Dec.2006, were retrospectively reviewed. We retrieved clinicopathological characteristics including parameters of adjuvant chemoradiotherapy, tumor recurrence and survival, disease free survival (DFS), overall survival (OS) and incidence of tumor recurrence. Statistical analysis was done using JMP10.1software, and univariate and multivariate regression models were applied to identify the independent risk factors for tumor progression and survival.[Results] A total of176patients were involved for the study, and125(70.9%) subjects were male. The average age of our cohort was56.4±10.2years, median follow-up was109.6months (14.4-177.8months). Up to Feb16th2014, tumor recurrence was documented in49patients (28.0%),53(30.1%) patients died. The predicted median DFS was102.1months (4.9-177.8months), and predicted median OS was109.6months (14.4-177.8months). According to AJCC staging system (published in2010,7th edition),52cases (29.3%) belonged to IIA stage,88(50%) belonged to IIB stage, and the remaining36went to the category of IIC stage. All patients received adjuvant chemotherapy, for an average of4.9±2.4cycles (0-12cycles). Among those patients,102cases (57.9%) undergone≥6cycles of chemotherapy. In our cohort, neither DFS nor OS were correlated with baseline characters (age of onset, gender, tobacco use, alcohol abuse, family history) and other factors such as:TNM stage, adjuvant chemotherapy, CEA levels, location of tumor (P>0.05). However, biopsying≥12lymph nodes (LN) was associated with a significantly longer DFS (median DFS,≥12LN vs.<12LN:143.8vs.33.4months, P=0.007), as demonstrated by logistic regression analysis and COX proportional hazards regression analysis (P<0.05). In multiple regression model, intraoperative biopsying less than12lymph nodes was an independent risk factor for tumor recurrence (RR=3.15,95%CI=1.13-11.13, P=0.027).[Conclusions] For stage II colorectal cancer, number of lymph node biopsied during surgery is an independent risk factor for tumor recurrence and DFS.2014NCCN guideline focusing on intraoperative lymph node biopsy number more than12is of critical importance for the management of stage Ⅱ colorectal cancer.