Lymph node ratio relationship to regional failure and distant metastases in oral cavity cancer

Radiother Oncol. 2017 Aug;124(2):225-231. doi: 10.1016/j.radonc.2017.06.018.

Abstract

Background: We aimed to investigate the impact of lymph node ratio (LNR, number of positive nodes/total number of excised nodes) on regional-only-failure, distant-only-failure and overall survival (OS) in oral squamous cell carcinoma (OSCC).

Methods: Retrospective review of pN0-2 OSCC-patients (1994-2012) treated with curative-surgery with neck dissection±postoperative radiotherapy (PORT)±concurrent chemotherapy. LNR was subjected to multivariable analysis (MVA) of regional-only-failure, distant-only-failure and OS.

Results: Overall 914 patients were identified; median follow-up: 51months (1-189); pN0: 482 (52.7%), pN1: 128 (14%), pN2a: 6 (0.7%); pN2b: 225 (24.6%); pN2c: 73 (8%); median number of dissected nodes: 36 (6-125); median number of pN+: 2 (1-49); median LNR for pN+ patients: 6%; extranodal extension: 187 (20.5%). Bilateral neck dissection: 368 (40.3%); PORT: 452 (49.5%); and concurrent chemotherapy: 80 (8.8%). High grade, lymphovascular invasion perineural invasion and pT3-4 were associated with high LNR. On MVA, LNR was associated with regional-only-failure (HR=1.06; 95%CI: 1.04-1.08; p<0.001), distant-only-failure (HR=1.03; 95%CI: 1.02-1.05; p=0.004) and lower OS (HR=1.03; 95%CI: 1.02-1.05; p<0.001). Similarly, in pN2-subgroup: LNR was associated with regional-only-failure (HR=1.04; 95%CI: 1.02-1.06; p<0.001), distant-only-failure (HR=1.03; 95%CI: 1.01-1.06; p=0.045) and lower OS (HR=1.03; 95%CI: 1.02-1.04; p<0.001).

Conclusion: High LNR is associated with higher regional-only-failure/distant-only-failure and lower OS. LNR should be assessed in future prospective trials for selection of adjuvant therapy.

Keywords: Distant metastases; Lymph node ratio; Oral cancer; Prognostic factors; Regional failure.

MeSH terms

  • Adult
  • Aged
  • Carcinoma, Squamous Cell / pathology*
  • Carcinoma, Squamous Cell / surgery
  • Carcinoma, Squamous Cell / therapy*
  • Chemoradiotherapy
  • Female
  • Head and Neck Neoplasms / pathology*
  • Head and Neck Neoplasms / surgery
  • Head and Neck Neoplasms / therapy*
  • Humans
  • Lymph Node Excision
  • Lymph Nodes / pathology*
  • Lymph Nodes / surgery
  • Lymphatic Metastasis
  • Male
  • Middle Aged
  • Mouth Neoplasms / pathology*
  • Mouth Neoplasms / surgery
  • Mouth Neoplasms / therapy*
  • Neoplasm Staging
  • Prospective Studies
  • Randomized Controlled Trials as Topic
  • Retrospective Studies
  • Squamous Cell Carcinoma of Head and Neck