PROGNOSTIC-SIGNIFICANCE OF CLINICALLY FALSE-POSITIVE CERVICAL LYMPH-NODES IN PATIENTS WITH LARYNGEAL CARCINOMA

Background. A significant proportion of clinically positive palpable c ervical lymph nodes in patients with head and neck cancer are histolog ically benign. The biologic and prognostic significance of this reacti ve lymph node enlargement has not been fully clarified. Methods. In th is study, the incidence of clinically positive microscopically negativ e cervical lymph nodes in a series of 902 patients who had neck proced ures as a part of their primary treatment for NO-2 laryngeal cancer wa s analyzed and survival rates of 342 patients with true negative lymph nodes (NO- necks) were compared with those of 106 patients with clini cally false positive lymph nodes (N1-2b- necks). In 86 patients with f alse positive lymph nodes, a histopathologic analysis was performed to determine the histomorphologic pattern of the enlarged lymph nodes an d to evaluate which parameters, if any, correlated with 5-year patient survival. Results. Overall actuarial survival did not differ signific antly in the two groups. However, the actuarial survival curves in the false positive group were clearly better compared with those of the t rue negative group with more advanced laryngeal cancers, particularly T4 lesions (P < 0.05). Interestingly, the analysis of pattern of recur rence showed a higher incidence of distant metastases in false positiv e patients with advanced stage laryngeal cancer than in true negative subjects. In addition, the histologic examination of 375 enlarged hype rplastic cervical lymph nodes from 86 neck specimens showed the preval ence of sinus histiocytosis in the false positive group and its favora ble 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 impac t on survival and the reactive benign enlargement of a digastric lymph node is a possible poor prognostic factor. Conclusions. Survival of p atients with clinically false positive, histologically benign hyperpla stic cervical lymph nodes who have more advanced laryngeal carcinoma i s higher than clinically negative patients, suggesting that the presen ce of palpable benign nodes may be a sign of the host's immune activat ion, with favorable prognostic significance.