Paratracheal lymph node dissection in cancer of the larynx, hypopharynx, and cervical esophagus: the need for guidelines.

In laryngeal, hypopharyngeal, and cervical esophageal carcinomas, the paratracheal lymph nodes (PTLN) may be at risk for lymph node metastasis. The presence of PTLN metastasis is an important prognostic factor for the development of mediastinal and distant metastases, stomal recurrence, and disease-free and overall survival. Studies on PTLN metastasis are scarce. In most studies, PTLN dissection has not been routinely performed, and selection criteria for PTLN dissection are usually not well defined. Therefore, in most reported studies, selection bias is present and results are difficult to compare. The reported prevalence of PTLN metastases varies according to the site and stage of the primary tumor: subglottic cancer, transglottic cancer, and glottic cancer with subglottic extension have a higher risk of PTLN metastases. Diagnostic imaging is not sufficiently reliable to detect occult PTLN metastases and avoid unnecessary PTLN dissections. PTLN dissection is associated with limited morbidity, but damage to major vessels may occur, and because of exposure of these vessels PTLN may increase the morbidity of fistulae that can occur after total laryngectomy. The dissection may produce hypocalcemia, if performed bilaterally. Nevertheless, the limited morbidity and high rate of metastasis in specific laryngeal, hypopharyngeal, and cervical esophageal carcinomas argue in favor of routine elective PTLN treatment for these tumors. Large prospective studies are needed to identify the patients at risk with primary tumors in more detail. Moreover, improved diagnostic imaging is needed to detect (occult) PTLN metastases more reliably. Based on future studies, clinical guidelines have to be developed to avoid undertreatment and overtreatment.