Impact of lymph node ratio in the colorectal cancer staging system.
ABSTRACT Some researchers have proposed the Lymph Node Ratio (LNR) as a prognostic index for post-surgical colorectal cancer follow up.
Two hundred patients with colorectal cancer (ratio F/M of 2:1) were studied. Patients were divided in subgroups according to N-stage and LNR score, subgroups of LNR were made on quartiles. For each subgroup 5 year survival rate was calculated and comparison between groups was carried out.
There were 104 patients on N0, 38 on N1 and 58 on N2 stage. Survival rate at 5 years was 61.30% for the NO subgroup, 18.70% for the N1 subgroup, and 12.31% for the N2 subgroup (Fig. 1). The most significant p value, was reported between N0 and N1 as well as between N0 and N2 subgroup (p=0.001). Nodes positive were 44 a LNR ranging from 1% to 25% (1% < LNR < 25%); 24 patients from 26% to 50% (26% < LNR < 50%). In 6 patients LNR was ranging from 51% to 75% (51% < LNR 75%) and in 8 patients from 76% to 100% (76% < LNR 100%); overall survival rate in different quartiles was respectively 27.12%, 9.38%, 16.67% and 1.56%.
LNR is a reliable prognostic index in post surgical colorectal cancer staging.
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ABSTRACT: Outcome prediction based on tumor stage reflected by the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) tumor node metastasis (TNM) system is currently regarded as the strongest prognostic parameter for patients with colorectal cancer. For affected patients, the indication for adjuvant therapy is mainly guided by the presence of regional lymph node metastasis. In addition to the extent of surgical lymph node removal and the thoroughness of the pathologist in dissecting the resection specimen, several parameters that are related to the pathological work-up of the dissected nodes may affect the clinical significance of lymph node staging. These include changing definitions of lymph nodes, involved lymph nodes, and tumor deposits in different editions of the AJCC/UICC TNM system as well as the minimum number of nodes to be dissected. Methods to increase the lymph node yield in the fatty tissue include methylene blue injection and acetone compression. Outcome prediction based on the lymph node ratio, defined as the number of positive lymph nodes divided by the total number of retrieved nodes, may be superior to the absolute numbers of involved nodes. Extracapsular invasion has been identified as additional prognostic factor. Adding step sectioning and immunohistochemistry to the pathological work-up may result in higher accuracy of histological diagnosis. The clinical value of more recent technical advances, such as sentinel lymph node biopsy and molecular analysis of lymph nodes tissue still remains to be defined.World Journal of Gastroenterology 12/2013; 19(46):8515-8526. DOI:10.3748/wjg.v19.i46.8515 · 2.43 Impact Factor