RESUMEN
BACKGROUND: Larynx cancer is a common site for tumors of the upper aerodigestive tract. In cases with a clinically negative neck, the indications for an elective neck treatment are still debated. The objective is to define the prevalence of occult metastasis based on the subsite of the primary tumor, T classification and neck node levels involved. METHODS: All studies included provided the rate of occult metastases in cN0 larynx squamous cell carcinoma patients. The main outcome was the incidence of occult metastasis. The pooled incidence was calculated with random effects analysis. RESULTS: 36 studies with 3803 patients fulfilled the criteria. The incidence of lymph node metastases for supraglottic and glottic tumors was 19.9% (95% CI 16.4-23.4) and 8.0% (95% CI 2.7-13.3), respectively. The incidence of occult metastasis for level I, level IV and level V was 2.4% (95% CI 0-6.1%), 2.0% (95% CI 0.9-3.1) and 0.4% (95% CI 0-1.0%), respectively. For all tumors, the incidence for sublevel IIB was 0.5% (95% CI 0-1.3). CONCLUSIONS: The incidence of occult lymph node metastasis is higher in supraglottic and T3-4 tumors. Level I and V and sublevel IIB should not be routinely included in the elective neck treatment of cN0 laryngeal cancer and, in addition, level IV should not be routinely included in cases of supraglottic tumors.
RESUMEN
La laringe constituye un órgano anatómicamente complejo. Glotis, supraglotis y subglotis son, en orden de importancia relativa, los sitios más frecuentes de asentamiento de tumores, los cuales se distinguen clínicamente por el modo en que afectan las principales funciones de la laringe: fonación y deglución. Describir la frecuencia, características sociodemográficas y tumorales correspondientes a los casos incidentes de cáncer de laringe en Cuba según subsitio anatómico dentro de la laringe. Se realizó un estudio descriptivo a partir de los casos nuevos de cáncer de laringe reportados al Registro Nacional de Cáncer durante el período 1988-2003. Se analizó información sociodemográfica de los casos y otras variables relacionadas con el diagnóstico y la enfermedad tumoral. Se utilizó la prueba Chi-cuadrado de independencia para determinar asociación entre las variables en estudio con un nivel de significación de 0,05. El cáncer de laringe ocupa una de las primeras causas de incidencia y mortalidad por cáncer en Cuba, fundamentalmente en hombres entre 50-74 años de edad. Mientras que el cáncer de subglotis es poco frecuente, el cáncer de glotis es hasta tres veces más frecuente que el de supraglotis. El cáncer de glotis da síntomas tempranamente pudiendo ser detectado mediante un examen relativamente sencillo. Considerando las características del sistema nacional de salud cubano, este hecho puede abrir una expectativa al diagnóstico temprano, por lo que es recomendable evaluar la factibilidad y eficacia del examen otorrinolaringológico -como parte del examen periódico anual- fundamentalmente en hombres de 50 años y más, con historia de tabaquismo o alcoholismo, con el fin de detectar y tratar tempranamente la enfermedad.
Larynx is an anatomically complex organ. Glottis, supraglottis and subglottis are, in order of relative importance, the most frequent tumor locations, which are clinically characterized by the way they affect the main functions of the larynx: phonation and deglutition. Objectives the present paper describes the frequency, socio-demographic and tumorous characteristics of laryngeal cancer cases in Cuba. A descriptive study was conducted, taking the new laryngeal cancer cases reported to the National Register of Cancer from 1988 to 2003 as a basis. Social and demographic information of cases and other variables related to diagnosis and to the tumorous disease were analyzed. Chi-square test of independence determined the association of variables under study, with significance level equal to0,05. Laryngeal cancer is one of the first causes of incidence and mortality due to cancer in Cuba, mainly in males aged 50-74 years. Although subglottis cancer is rare, glottis cancer is up to three times as frequent as that of supraglottis. Glottis cancer shows early symptoms, so it can be detected on a relatively simple examination. Considering the Cuban health system characteristics, this event could open up possibilities for early detection, therefore, it would be advisable to evaluate the feasibility and efficacy of the otorhinolaryngology test -as part of the annual systematic examination -mainly in men aged 50 years and more, with history of smoking/alcoholism, in order to detect and treat the disease early.