A novel classification scheme for advanced laryngeal cancer midline involvement: implications for the contralateral neck

Purpose There are insufficient data concerning risk factors for contralateral regional metastases in laryngeal cancer. The aim of this study was to investigate the frequency and risk factors for contralateral lymph node metastases and their dependence on midline involvement of the primary tumor in patients with advanced laryngeal squamous cell carcinoma. Methods 58 consecutive patients (8 females, 50 males; mean age 64.2 +/- 9.8 years; AJCC stage III disease in 43.1%, IVA disease in 54.4%) undergoing primary total laryngectomy with bilateral neck dissection between 2002 and 2016 have been retrospectively investigated at one of the largest university medical centers in Europe. Preoperative staging computed tomography (CT) scans were analyzed for midline involvement of the primary laryngeal cancer. As a result, a classification scheme has been established (type A: clear, type B: involved, type C: exceeded, and type D: bilateral/origin side indeterminable). Results Contralateral lymph node metastases (pN2c necks) were found in six cases (10.3%), from which four were diagnosed with type D (23.5% of type D cases), and one each with type B and type C midline involvement. In cases with no midline involvement (type A), a risk ratio reduction of 100% was seen. CT-based midline typing resulted in fourfold increased sensitivity for predicting contralateral metastases compared to conventional staging. Positive nodal status (pN+) significantly reduced overall and disease-free survival (HR 2.706, p < 0.05). Conclusions As a consequence, for type A category, a contralateral neck dissection might be avoidable accompanied by a reduction in surgical complications and operating time.