In reference to Value of lingual lymph node metastasis in patients with squamous cell carcinoma of the tongue

As faithful readers of The Laryngoscope, we read with great interest the article titled “Value of Lingual Lymph Node Metastasis in Patients With Squamous Cell Carcinoma of the Tongue” by Fang et al. We would like to compliment the authors on their long-term, prospective, large-scale analysis of mouth floor lingual lymph node (LLN) metastasis in 231 patients with cT3-4 or cT2N+ tongue squamous cell carcinoma (SCC). They found LLN at the mouth floor in 58 (25.1%) patients, and 33 (14.3%) had SCC metastasis of the LLN. LLN metastasis was statistically related to adverse clinical and pathologic characteristics such as high neutrophil-to-lymphocyte ratio (NLR), perineural invasion (PNI), lymphovascular invasion (LVI), poor tumor differentiation, later T stages, and lateral neck lymph node metastasis. More importantly, the 5-year locoregional control (LRC) in patients with LLNmetastasis was significantly worse than in those without LLN metastasis. The authors concluded that the LLN should be routinely dissected with mouth floor resection. However, we believe this conclusion does not appear to be fully supported by their data, and thus we would like to invite the authors to elaborate on the controversial issue as to whether LLN dissection is required in tongue SCC. In our view, the following issues pertaining to the study conducted by Fang et al. need to be scrutinized. First, all of thepatients had routinely receivedmouthfloor resectionand LLN dissection. However, the patients with LLNmetastasis still had worse LRC. It therefore appears that LLN dissection did not improve the LRC and in turn did not confer any survival benefit. As such, we believe there is currently insufficient evidence to recommend routine mouth floor dissection and that further research is needed. Second, although lymphatic drainage from the oral tongue travels through the mouth floor before entering the upper neck, LLN metastasis is rare, and there is considerable debate in the literature regarding its surgical management. For patients with T3–4 tongue SCC, the decision to perform mouth floor resection is generally straightforward, because an advanced tumor usually needs a wider excision including the mouth floor and flap reconstruction. However, for patients with an early-stage tumor such as the T2 disease presented in Fang et al.’s article, only six (8.8%) of the 68 patients had LLN metastasis. Routine mouth floor resection with LLN dissection does not appear to be necessary in the majority of patients. Also, whenever the mouth floor is resected, there is greater morbidity, and reconstruction is needed. Tesseroli et al. also discouraged LLN dissection because their study showed no survival benefit. From our perspective as head neck surgeons, we think it is essential to establish guidelines for LLN dissection in early-stage tongue cancer. In studies conducted by Fang et al. and Wu et al., higher pretreatment NLR was significantly correlated with poor prognosis. It would be useful to knowwhether higher pretreatmentNLRwas also correlated with LLN metastasis in the data reported by Fang et al. If there was a correlation, high NLR could have value as an indicator of LLN dissection in patients with early tongue cancer. In addition, if adverse postoperative pathologies such as PNI and LVI were correlated with LLN metastasis, postoperative irradiation should probably be recommended for LLNat themouth floor.