The Effect of Occult Nodal Metastases on Survival and Regional Control in Patients With Head and Neck Squamous Cell Carcinoma

Objectives: To determine factors associated with disease-free survival (DFS)and regional control in clinically node-negative head and neck squamous cell cancer (HNSCC) patients with occult metastasis. Study Design: Non-randomized retrospective analysis. Materials and Methods: Patients who underwent elective neck dissection (END) from 1985 to 2002 were analyzed. Results: A total of 337 patients underwent END. The majority of patients (67%) had advanced stage disease (T3/T4). Occult metastases were present (pN+) in 168 patients (50%), with extracapsular spread (ECS) present in 72 patients (43%). Five-year DFS for patients with histologically node negative necks was 62% versus 36% for pN+ patients (P <.0001). Postoperative radiation (XRT) did not significantly influence DFS for pN+ patients with less than three nodes involved, but had a significant association with DFS with three or more nodes involved (P <.0001). XRT showed a trend toward improved regional control rates in patients with less than three positive nodes (86% vs. 78%; P = .7579) and patients with three or more positive nodes (62% vs. 50%; P = .0014). When ECS was present, XRT did not affect DFS in patients with less than three nodes (36%), but had a significant effect on DFS in patients with three or more nodes (20% vs. 0%; P = .0075). Regional control rates were not improved with YCRT in ECS-positive patients with less than three nodes (62% vs. 75%) or with three or more nodes involved (43% vs. 50%; P = .0678). Conclusions: There is a high incidence of occult metastases in clinically node-negative patients which adversely affects survival, regardless of the use of adjuvant XRT. Postoperative XRT did not significantly affect regional control or survival rates in patients with < 3 positive nodes. When ECS was present, survival was poor regardless of the number of nodes. These data emphasize the prognostic and therapeutic role of END and highlight the need for the development of novel therapeutic regimens to improve disease control and survival in HNSCC patients with nodal metastases.