TABLE 3.

Published studies focusing on clinicopathological risk factors and prognosis of patients with oral cavity cancer and pathologically negative nodes

Authors (years of recruitment)	Tumor subsite/Number of patients/AJCC staging manual	Pathological variables (%)	Five‐year outcome/adjuvant therapy (%)/lymph node (LN) yield	Independent adverse risk factors (multivariable analysis)
Liao et al. (1996–2018), current study	Oral cavity/cN0pN0 (1019)cN+pN0 (290)/AJCC: 8th	pT (pT3–4, 44%), poor differentiation (6%), perineural invasion (22%), lymphatic invasion (1%), vascular invasion (1%), DOI (≥10 mm, 41%), margins (≤4 mm, 10%)	LC: 88% NC: 93% DM: 3% DFS: 83% DSS: 92% OS: 81%/adjuvant: 32%/mean: 42 LNs	LC: betel chewing NC: poor differentiation, perineural invasion, lymphatic invasion DM: poor differentiation, DOI ≥10 mm DFS: betel chewing, poor differentiation, perineural invasion, pT3–4 DSS: poor differentiation, perineural invasion, lymphatic invasion, DOI ≥10 mm OS: poor differentiation, lymphatic invasion, pT3–4, age ≥65 years
Amit et al. 13 (1990–2011)	Oral cavity/cN0pN0 (1913)cN+pN0 (345)/AJCC: 6th	pT (pT3–4, 45%)	DSS: 81%,OS: 72%/adjuvant: 51%/mean: 29 LNs	DSS: cN, age ≥65 years, pT, DOI >4 mm, positive margins OS: cN, age ≥65 years, pT, LN yield ≤18 nodes, DOI >4 mm, positive margins
So et al. 9 (1995–2016)	Tongue/pN0 (166)/AJCC: 7th	pT (pT3–4, 11%), perineural invasion (15%), lymphovascular invasion (12%), DOI (≥5 mm, 53%), margins (≤5 mm, 30%)	NC: 92% (3–year)/adjuvant: 25%/LNs: nr	NC: male sex
Cassidy et al. 10 (2003–2013)	Tongue/cN0pN0 (112)cN0pNx (68)/AJCC: 7th	pT (pT3–4, 9%), poor differentiation (8%), perineural invasion (31%), lymphovascular invasion (20%), DOI (≥3 mm, 74%), margins (<5 mm, 32%)	LRC, OS: nr/adjuvant: 27%/LNs: nr	LRC: lymphovascular invasion, no elective ND, margins <5 mm OS: lymphovascular invasion, age >44 years
Chang et al. 11 (2002–2015)	Oral cavity/pN0 (216)/AJCC: 8th	pT (pT3–4, 37%), perineural invasion (6%), lymphovascular invasion (2%), DOI (>5 mm, 62%), margins (≤5 mm, 26%)	OS: 74%/adjuvant: nr/LNs: nr	OS: DOI >5 mm, positive margins, perineural invasion, lymphovascular invasion
Chinn et al. 12 (1998–2009)	Oral cavity/pN0 (88)/AJCC: nr	pT (pT3–4, 44%), perineural invasion (23%)	LRC, DFS, DSS, OS: nr/adjuvant: 40%/LNs: nr	LRC: perineural invasion, vascular invasion DFS: perineural invasion DSS: poor differentiation OS: no significant predictor identified

Abbreviations: DFS, disease‐free survival; DM, distant metastases; DOI, depth of invasion; DSS, disease‐specific survival; LC, local control; LN, lymph node; LRC, locoregional control; NC, neck control; ND, neck dissection; nr, not reported; OS, overall survival.