Retrospective analysis of risk factors for lymph node metastasis in recurrent glottic cancer after primary laser surgery: a cohort study from China

Background: Although lymph node metastasis is a critical prognostic factor, the indications for neck dissection in recurrent glottic cancer after transoral laser microsurgery (TLM) are unclear. At present, there is no dear standard for simultaneous cervical lymph node dissection at home and abroad. Methods: We summarize the pattern of regional recurrence in glottic cancer after initial TLM and to evaluate the risk factors for neck metastasis. Seventy-five cases with recurrent glottic cancer after TLM between December 2004 and June 2014 were retrospectively analyzed. Survival, regional control rate, and neck metastasis were analyzed. The Kaplan-Meier method was used for survival analysis. Univariate analysis was performed with the log-rank test and multivariate analysis was completed using Cox regression. Results: The 5-year overall survival (OS), disease-specific survival (DSS), and regional control rate after the first TLM were 73.6%, 89.1%, and 69.7%, respectively. A total of 22 (29.3%) patients developed cervical metastases during long-term follow-up and showed a significant decline in OS and DSS rates. Multivariate analysis indicated that histological grading and type of TLM were both risk factors for neck metastasis. Patients treated with type Vc cordectomy were more likely to develop regional recurrence than patients treated with type III cordectomy [hazard ratio (HR) =14.737, 95% confidence interval (CI): 2.117-102.610, P=0.007]. No significant correlation was present between rT stage and neck metastasis. Conclusions: Multivariate analysis indicated that histological grading and type of TLM were both risk factors for neck metastasis. Patients with recurrence after type V cordectomy may have an increased risk of developing cervical lymph node metastasis, especially those with supraglottic spread or high-grade tumors.