Extracapsular spread in the clinically negative neck (N0): implications and outcome

Cervical metastasis is the most important prognostic factor in head and neck cancer patients. The prognostic significance of extracapsular spread of tumor in metastatic lymph nodes has also been documented. The presence of extracapsular spread further reduces the survival by 50% in those patients with cervical metastatic disease. Most patients with clinically negative necks (stage N0) have a good prognosis. However, some of these patients will have neck disease and distant metastasis and will eventually die. Because the presence of extracapsular spread is a predictor of poor outcome, we hypothesized that extracapsular spread may be a factor in the subset of patients with clinically negative necks who have poor outcomes. One hundred nine patients with clinically negative necks who had undergone neck dissection were identified. Occult metastasis was observed in 34% of patients. In this group, extracapsular spread was present in 18 (49%) patients. Overall, 103 patients were evaluable, of whom 70 (68%) remain free of disease 2 or more years after treatment. A subgroup of 68 patients had histologically negative nodes, of whom 56 (82%) are free of disease. Of patients with extracapsular spread, only 5 (31%) of 16 are free of disease. This is in contrast to patients with metastasis confined to the lymph node, of whom 9 (47%) of 19 are free of disease. Statistical analysis of these data shows that for this sample size this difference is significant. The addition of radiation therapy did not improve outcome in these patients. Extracapsular spread predicts a worse outcome in patients with subclinical cervical metastasis. Alternative modes of adjuvant therapy are suggested because of the poor results of postoperative radiation therapy in patients with extracapsular spread.