Lymph node ratio as prognostic variable in oral squamous cell carcinomas: Systematic review and meta-analysis

Area of Science:

• Oncology
• Surgical Pathology
• Cancer Prognostics

Background:

• The lymph node ratio (LNR) has emerged as a potential prognostic indicator in oral squamous cell carcinoma (OSCC).
• Existing center-based studies suggest LNR's independent prognostic value, but a standardized approach and optimal cut-off values are lacking.

Purpose of the Study:

• To conduct a meta-analysis evaluating the prognostic impact of LNR in oral squamous cell carcinoma (OSCC).
• To investigate and identify potential significant cut-off values for LNR in predicting patient outcomes.

Main Methods:

• A comprehensive electronic and manual literature search was performed across major databases (PubMed, Embase, Cochrane Library) up to January 2018.
• Included 19 studies (2009-2017) involving 14,254 patients with OSCC, analyzing outcomes like overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS).
• Data was stratified into two groups: Group A (pN+) and Group B (pN+ and pN-) for analysis.

Main Results:

• High LNR significantly correlated with shorter OS, DSS, and DFS in both analyzed groups (pN+ and pN+/pN-).
• A high LNR was also associated with shorter locoregional recurrence-free survival (LRF) specifically in Group B.
• All tested LNR cut-off values demonstrated statistical significance, with no evidence supporting a second significant threshold.

Conclusions:

• The lymph node ratio (LNR) is confirmed as an independent prognostic factor in oral squamous cell carcinoma (OSCC).
• LNR's established prognostic capability suggests its potential incorporation into future oncologic staging systems for improved patient risk stratification.