Prognostic significance of clinically false positive cervical lymph nodes in patients with laryngeal carcinoma.

Abstract

A significant proportion of clinically positive palpable cervical lymph nodes in patients with head and neck cancer are histologically benign. The biologic and prognostic significance of this reactive lymph node enlargement has not been fully clarified. In this study, the incidence of clinically positive microscopically negative cervical lymph nodes in a series of 902 patients who had neck procedures as a part of their primary treatment for N0-2 laryngeal cancer was analyzed and survival rates of 342 patients with true negative lymph nodes (N0- necks) were compared with those of 106 patients with clinically false positive lymph nodes (N1-2b- necks). In 86 patients with false positive lymph nodes, a histopathologic analysis was performed to determine the histomorphologic pattern of the enlarged lymph nodes and to evaluate which parameters, if any, correlated with 5-year patient survival. Overall actuarial survival did not differ significantly in the two groups. However, the actuarial survival curves in the false positive group were clearly better compared with those of the true negative group with more advanced laryngeal cancers, particularly T4 lesions (P < 0.05). Interestingly, the analysis of pattern of recurrence showed a higher incidence of distant metastases in false positive patients with advanced stage laryngeal cancer than in true negative subjects. In addition, the histologic examination of 375 enlarged hyperplastic cervical lymph nodes from 86 neck specimens showed the prevalence of sinus histiocytosis in the false positive group and its favorable prognostic significance. No statistically significant differences with regard to the number and size of enlarged lymph nodes were found. On the contrary, lymph node location seems to have a prognostic impact on survival and the reactive benign enlargement of a digastric lymph node is a possible poor prognostic factor. Survival of patients with clinically false positive, histologically benign hyperplastic cervical lymph nodes who have more advanced laryngeal carcinoma is higher than clinically negative patients, suggesting that the presence of palpable benign nodes may be a sign of the host's immune activation, with favorable prognostic significance.