Occult lymph node metastases in supraglottic cancers of the larynx.

Occult cervical lymph node metastases may often be associated with cancers of the supraglottic larynx. The aims of this investigation were: (1) to determine the incidence of occult lymph node metastases in patients with cancer of the larynx; (2) to assess whether the presence of such metastases was related to the extent of the primary tumor (T) and its grading (G); and (3) to discuss which therapeutic approach should be followed in treating clinically occult lymph node metastases. Our investigation included 97 patients who underwent supraglottic horizontal laryngectomy and elective cervical lymph node dissection. The incidence of occult lymph node metastases in the series considered was 27%. Based on the preoperative staging of the tumor, 14% of the cases had metastatically involved lymph nodes in the T1 tumors, 21% in the T2 tumors, 35% in the T3, and 75% in the T4. In the statistical analysis, a significant difference was shown to exist when T1 + T2 and T3 + T4 (P = 0.04) were compared. In terms of grading, occult metastases were found in 16% of the G1 tumors, 27% of the G2, and 42% of the G3. The statistical analysis demonstrated a significant difference between G1 and G3. In brief, the incidence of occult metastases was higher for the less differentiated tumors and for the ones with a higher T value; the effects of both factors are combined thereby increasing the rate of occult metastases (P = 0.05).