Objectives: Lymph node yields (LNYs) following neck dissection have been associated with differences in oral cavity cancer survival. The objective of this study was to evaluate temporal trends in LNYs in neck dissections for oral cavity carcinoma.

Methods: Data were obtained from the Surveillance, Epidemiology, and End Results (SEER 18) database. Inclusion criteria included diagnosis of malignant oral cavity cancer (tongue and floor of mouth) squamous cell carcinomas diagnosed from January 1, 2006-December 31, 2016. Patients with AJCC 6th Edition Stages 1-4a who underwent surgery were included. All-cause age-adjusted mortality for tongue and floor of mouth cancers during this period was assessed using SEER*Stat.

Results: The median LNY among 8,580 patients in the sample was 25 LNs (Interquartile range 14-39). LNY statistically increased over time from 22 LNs in 2004 to 27 in 2014 (p < 0.0001). In contrast, there was no change in the median number of positive LNs during the same period (median 2 positive LNs in 2004 and 2014). There was no significant difference in lymph node yield based on sex, region, insurance status, or relative location to a metropolitan center. After adjusting for patient age, sex, race, marital status, regional income, and percent current smokers in the county of residence, tumor subsite and TNM stage, LNY less than 18 was independently associated with a 44% greater risk of death from any cause, compared with greater LNYs (HR 1.44, 95% CI 1.29-1.60, p=.0001). During this period, all-cause age-adjusted mortality declined from 469.7 per 100,000 (468.2-471.2) to 429.0/100,000 (428.2-430.8).

Conclusion: LNY following neck dissection for oral tongue and floor of mouth cancers increased significantly over a decade, during which survival also improved. The cause of improved LNY is not known but may nevertheless be contributing to declining mortality in patients with oral tongue and floor of mouth cancers.

Citation Format: Punam Patel, Suraj Kedarisetty, Miriam Lango. Trends in lymph node yield for neck dissection and oral cavity carcinoma survival [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr B40.