Ding D, et al. - Researchers assessed the significance of lymph node ratio (LNR) in estimating the tumor recurrence and survival outcomes of oral cavity squamous cell carcinoma (OCSCC) and its relation to other histopathologic prognostic factors. They observed a link between worse outcomes and advanced pathologic stage of disease as well as non-white race. They noted LNR was the strongest prognostic factor which could impact risk stratification in OCSCC.

Methods

• They conducted a retrospective cohort study (between January 1, 2000 and December 31, 2015) at an academic hospital in Denver, CO.
• They enrolled 149 subjects with primary OCSCC who received curative-intent surgery and/or postoperative adjuvant treatments.
• They analyzed data from December 8, 2017 to August 15, 2018.
• Main outcomes and measures included overall survival (OS), disease-free survival (DFS), locoregional disease-free survival (LRDFS), and distant metastasis–free survival (DMDFS) adjusted for known prognostic risk factors, as well as correlation of LNR with other histopathologic prognostic factors.

Results

• Among 149 candidates involved in the analysis, 105 were males (70.5%) with median age of 59 years (range, 28-88 years) at diagnosis.
• They observed the 5-year survival estimates for OS rate of 40.4% (95% CI, 31.3%-49.3%); DFS, 48.6% (95% CI, 38.6%-58.0%); LRDFS, 57.7% (95% CI, 46.6%-67.2%); and DMDFS, 74.7% (95% CI, 65.1%-82.0%), using the Kaplan-Meier method.
• The median follow-up was estimated 20 months for all individuals and 34.5 months (range, 0-137 months) for surviving cases.
• They noted an association of nonwhite race (hazard ratio [HR], 2.15; 95% CI, 1.22-3.81), T3-T4 category (HR, 1.99; 95% CI, 1.18-3.35), and LNR greater than 10% (HR, 2.71; 95% CI, 1.39-5.27) with poorer OS.
• Females were more prone to distant metastasis (HR, 2.55; 95% CI, 1.14-5.71), whereas nonwhite candidates had greater risk of locoregional failures (HR, 2.47; 95% CI, 1.28-4.79).
• They recorded lesser locoregional recurrences at floor-of-mouth as compared to other subsites (HR, 0.45, 95% CI, 0.21-0.99).
• An LNR higher than 10% independently correlated with worse OS (HR, 2.71; 95% CI, 1.39-5.27), DFS (HR, 2.48; 95% CI, 1.18-5.22), and DMDFS (HR, 6.05; 95% CI, 1.54-23.71).
• They found an association of LNR with N-stage (Cramer V, 0.69; 95% CI, 0.58-0.78), extracapsular extension (Cramer V, 0.55; 95% CI, 0.44-0.66), lymphovascular invasion (Cramer V, 0.46; 95% CI, 0.27-0.61); number of excised lymph nodes (Cramer V, 0.24; 95% CI, 0.06-0.37), margin (Cramer V, 0.22; 95% CI, 0.05-0.38), and tumor thickness combined with depth of invasion (Cramer V, 0.25; 95% CI, 0.05-0.38).