Prognostic Value of Total Lymph Node Identified and Ratio of Lymph Nodes in Resected Colorectal Cancer

Abstract

Background:The extent of lymph node involvement is the most significant prognostic indicator in resected locoregional colorectal cancer. Objectives: This study aimed to investigate the prognostic value of total lymph nodes identified and ratio of lymph nodes in resected colorectal cancer. Patients and Methods: Two hundred seventy five patients with histologically proven resected locoregional invasive colorectal adenocarcinoma from 2003 to 2011 were included. All patients were treated with standard surgical resection for their colorectal cancer. Patients with incomplete data, or unresectable tumors or distant metastases were excluded from the study. All potential prognostic variables were evaluated for their impact on the local control, disease-free, and overall survival rates. Results: Of the 275 patients, 162 were men and 113 were women with a median age of 54 (range 23-84) years. The mean total lymph nodes were significantly higher in colon cancer than rectal cancer (11 versus 7.5, P = 0.001). In node positive (stage III) patients, the mean lymph nodes ratio was 0.5 for rectal cancers and 0.37 for colon cancers respectively showing a nonsignificant (P = 0.05) trend toward higher lymph nodes ratio in rectal cancer patients. In univariate analysis, the mean total number of lymph node identified was a prognostic factor for 5-year disease free (P = 0.04) and overall survival (P = 0.02) rates. In node positive patients, lymph nodes ratio was a prognostic factor for 5-year local control (P = 0.04), disease free survival (P = 0.01), and overall survival (P = 0.01) rates. On multivariate analysis, advanced primary tumor stage, rectal primary site and the presence of perineural invasion were independent adverse prognostic factors for overall survival. Conclusions: Total lymph nodes identified and ratio of lymph nodes are associated with oncological outcomes outcomes in patients with colorectal cancer.

An Overview of Clinical and Pathological Characteristics and Survival Rate of Colorectal Cancer in Iran

“…Colorectal cancer tends to have a high mortality rate, and its outcome is closely related to the extent of lymph node involvement and disease stage at presentation (7). Abdominal pain, change in bowel habits, rectal bleeding, weakness, anemia, and weight loss are the most frequent symptoms in the patients with colorectal cancer.…”

“…In addition, age, tumor grade and differentiation, mucinous subtype, geographic region, total lymph node harvested, and lymph node ratio were found as prognostic factors for overall survival in the patients with colorectal cancer (7,10,13). There are some concerns regarding the adequacy of lymph node staging as well as different patterns of clinical and pathological features and outcomes of Iranian patients with colorectal cancer compared to other parts of the world (13)(14)(15)(16)(17).…”

Staging Accuracy in Colorectal Cancer: A Pathologic and Therapeutic Dilemma

“…In addition, many recent studies investigated the prognostic impact of total lymph node identified and ratio of lymph nodes in resected colorectal cancer [2,9]. In another review, Ghahramani et al [10] found the higher number of assessed lymph nodes as a favorable prognostic factor for overall survival in 10 out of 11 studies on node negative colorectal cancer. Furthermore, in 14 out of 15 studies on node positive (stage III) colorectal cancer, higher lymph node ratio was a poor prognostic indicator for overall and/or disease free survival.…”

“…Furthermore, in 14 out of 15 studies on node positive (stage III) colorectal cancer, higher lymph node ratio was a poor prognostic indicator for overall and/or disease free survival. The authors concluded that tumor stage might be a more useful prognostic indicator compared to node stage in the patients with inadequate lymph node staging [10].…”

Characteristics of the Patients With Colorectal Cancer: Epidemiologic Study or Pathology Report-Based Study

“…Nonetheless, some important pathologic data, including the type of surgery, surgical margin status, total number of identified lymph nodes, number of positive lymph nodes, presence of lymphatic-vascular and perineural invasion, presence of obstruction and/or perforation, and primary tumor stage, have been missed. These pathologic characteristics are important indicators for defining accurate tumor and lymph node staging and predicting the prognosis ( 2 , 3 ). Furthermore, the findings of this study were influenced by an institutional referral bias.…”