Oral squamous cell carcinoma (SCC) is an increasing disease with over 263,000 diagnosed new cases and 128,000 deaths annually worldwide. Although there have been significant advances in diagnostics, surgery and anaesthetics there has been no increase in the survival rates and regional recurrence is a significant concern in these patients variously placed at between 6.9% and 37.4%. The identification of any risk factors is of significance in order to optimise diagnosis, follow-up and plan therapies. Currently, pathological markers are the tumour, node and metastasis (TNM) staging, margins, perineural invasion, perivascular invasion and extracapsular spread. Recently some studies have commented on the lymph node ratio – i.e. the ratio between the pathologically involved nodes as a ratio to the total yield in the dissection. These studies demonstrate this to be a superior prognosis indicator of recurrence than the conventional parameters listed above. This is a retrospective study from Germany. A review of 130 patients with newly diagnosed SCC of the tongue between 2003 and 2013. Patients with secondary tumours were excluded. Regional recurrence was accepted as recurrence within the lymph node chain and disease outside the head and neck was defined as distant metastasis. All patients had surgery and neck dissection, patients with locally advanced disease had radiotherapy.
This study confirms the lymph node ratio is a good marker of high risk of recurrence. While the authors have done well to reduce the confounding factors and only included the SCC of the tongue, as the oral cavity as a whole has different prognosis depending on the site. Within the tongue alone, posterior tumours have worse outcomes as do larger tumours. Also while this is an excellent study it is still affected by operator variability as in surgical technique in performing the neck dissection and processing of the pathological specimens, this is accepted by the authors. They do also reaffirm perineural involvement as a sign of poor prognosis. All in all a good paper, well-written and clearly laid out.