Surgical treatment of the neck in cancer of the larynx.
Current concepts in management of the clinically negative and clinically positive neck in laryngeal cancer are reviewed. Occult disease in the neck not detected by physical and radiographic examination may also be difficult to identify on routine histologic examination. Immunohistochemistry or molecular analysis may detect metastatic involvement not apparent by light microscopy. The surgeon should be aware of the relatively high incidence of micrometastases in patients with laryngeal cancer to establish optimal treatment approaches. Elective treatment of the neck is recommended for supraglottic tumors staged T2 or higher, and glottic or subglottic tumors staged T3 or higher. The neck may be treated electively by either surgery or irradiation, but irradiation is best reserved for cases where that modality is employed for the primary tumor. Elective neck dissection provides important information for prognostic purposes and therapeutic decisions, by establishing the presence, number, location and nature of occult lymph node metastases. The selective lateral neck dissection (levels II, III and IV), unilateral or bilateral, is the procedure of choice for elective treatment. Paratracheal nodes (level VI) should be dissected in cases of advanced glottic and subglottic cancer. Complete radical or functional neck dissections are excessive in extent, as levels I and V are almost never involved. Sentinel lymph node biopsy may fail to detect tumor on frozen section examination or may not reveal 'skip' metastases. The clinically involved neck is usually treated by complete radical or functional neck dissection of levels I through V. Selective neck dissection has been employed successfully in selected cases, particularly for N1 or occasionally N2 nodal involvement. The selective neck dissection can be extended to include structures at risk. More advanced disease has been treated in this manner often in association with adjuvant chemotherapy and/or irradiation. While the benefit of adjuvant treatment is difficult to assess, it appears most useful in cases with extranodal spread of disease, a factor associated with the worst prognosis.