Lymph Node Ratio as a Prognostic Marker in Rectal Cancer Survival: A Systematic Review and Meta-Analysis

Abstract

The lymph node ratio (LNR) is defined as the ratio of the number of positive lymph nodes to the total number of nodes retrieved. LNR has recently emerged as a prognostic factor in rectal cancer. The objective of our study was to pool eligible studies to elucidate the prognostic role of LNR on overall survival (OS) and disease-free survival (DFS) in rectal cancer patients using a meta-analysis. Methods A systematic database search was performed in MEDLINE and Embase for relevant studies that reported LNR in rectal cancer. Two authors independently screened the relevant articles for selection and data extraction. As a result, a list of such studies and references, published in English up to December 2019, was obtained, and a total of 4,486 node-positive patients in 18 studies were included in this meta-analysis. RevMan software 5.3 (Cochrane Collaboration, the Nordic Cochrane Centre, Copenhagen) was used for conducting all statistical analyses. Results A higher LNR was significantly correlated with worse OS [hazard ratio (HR): 2.60; 95% confidence interval (CI): 2.21-3.06; p≤.00001] and DFS (HR: 2.43; 95% CI: 2.11-2.80; p≤.00001) in node-positive rectal cancer patients. Besides, LNR is an independent predictive and prognostic marker of OS and DFS (HR: 2.52; 95% CI: 2.17-2.94; p≤.00001 with I 2 =0%; p=.32 and HR: 2.63; 95% CI: 2.17-3.18; p≤.00001 with I 2 =0%; p=.63 respectively, irrespective of lymph nodal harvest). Conclusions Our present study demonstrates that LNR is an independent predictor of survival in rectal cancer. LNR should be considered as a parameter in future oncological staging systems. Further well-designed randomized control trials to prospectively assess LNR as an independent predictor of rectal cancer survival are necessary before its application in daily practice.

Lymph Node Ratio as a Prognostic Marker in Pancreatic Cancer Survival: A Systematic Review and Meta-Analysis

“…In recent times, LN ratio (LNR) is being evaluated as a prognostic indicator in several of the published studies apart from just using the number of positive LN [2][3][4][7][8][9][10][11][12][13][14][15][16][17][18]. The LNR is defined as the ratio of metastatic to the total number of harvested LNs, and it has emerged as an indicator of cancer-specific survival in recent years.…”

“…The LNR is defined as the ratio of metastatic to the total number of harvested LNs, and it has emerged as an indicator of cancer-specific survival in recent years. The importance of LNR has been studied in various other solid malignancies and has been shown to be of significant prognostic value in rectal cancer survival in a recent meta-analysis [8].…”

Prognostic Role of Tumor Budding in Carcinoma Tongue: A Systemic Review and Meta-Analysis

“…This most common lymph nodal involvement occurs in up to 60%-70% of tongue cancers [14]. The total number of positive nodes has been recognized as a prognostic marker of adverse outcomes [15]. The OS benefit with LNM and the actuarial OS in patients without LNM is 95% and 71%, respectively [16].…”

Biomarkers and cell-based models to predict the outcome of neoadjuvant therapy for rectal cancer patients

“…In another study there was no significant difference in LNR value in patients with stage III rectal cancer regarding overall as well as diseasefree survival [91]. However, a recent systematic review using meta analysis has reported that a high LNR value is highly correlated with inferior overall survival and disease-free survival [90]. Although many studies have shown that LNR could be used as a prognostic tool for survival of rectal cancer patients, assessment of whether neoadjuvant chemo-radiotherapy impacts the lymph node ratio in patients with rectal cancer and LNR value in patients treated with neoadjuvant therapy affects the outcome of treatments, needs further evaluation.…”

“…The lymph node ratio (LNR), the ratio between the number of surgically removed metastatic and healthy lymph nodes, has been used as a prognostic marker in rectal cancer. Studies have shown that the LNR is an independent biomarker for survival in rectal cancer [87][88][89][90]. In one of the studies, 131 patients with rectal cancer were separated into two different groups based on the LNR value (≤0.2 [n = 86], > 0.2 [n = 45]) [87].…”