Laryngeal Carcinoma

Laryngeal Carcinoma

laryngeal carcinoma accounts for approximately 40% of carcinomas of the head and neck. It is most common between the ages of 45 and 75 years. At the present time men are ten times more frequently affected than women, although in the last few decades the number of female patients in Gurope and the United States has increased due to increased incidence of smoking in women.

Symptoms. Hoarseness is the first and main symptom when the tumor affects the glottis. Further symptoms, which may occur alone or in combination depending upon site and extent, include a feeling of a foreign body, clearing the throat, pain in the throat or referred elsewhere, dyspnea, dysphagia, congh, and hemoptysis. Regional lymph node metastases may also occur.

Note: Hoarseness persisting for more than 2 to 9 weeks must always be investigated by a speclalist, and omission of this step is dangerous.

Pathogenesis. Invasive carcinoma may develop from epithelial dysplasia especially from carcinoma in situ. More tban 90% of laryngeal carcinomas are keratinizing or nonkeratinlizing squamous cell carcinomas. Rare malignant forms include verrucous carcinoma, adenocarcinoma, carcinosarcoma,fibrosarcoma,and chondrosarcoma.

Most patients with squamous carcinoma of the larynx were or are heavy cigarette smokers and, in addition, often heavy drinkers. Chronic expisure to initation with heavy metals such as chromium. nickel, uranium, or asbestos, and irradiation are rarer causes.There are racial differences in the frequency of site distribution within the larynx.For example. supraglottic carcinoma is commoner in Spain and in parts of South America than in the Federal Republic of Grmany.

Laryngeal carcinoma infiltrates locally in the mucosa and beneath the mucosa and metastasizes via the lymphatics and the bloodstream. The limits of vascular spread are embryologically determined .Thus, supraglottic carcinomas usually remain confined to the supraglottic space and spread anteriorly into the preepiglottic space, whereas glottic carcinomas seldom spread into the supraglottic area bat rather info the subglottic space.

A transgloltic carcinonza is a glottic carcinoma involving the ventricle and the vestibalar folds in which the site of origin can no longer be recognized . The characteristics of the intralaryngeal lymphatics inpflence the frequency of regional lymph node metartases. Other factors infiuencing the frequency of metastases are the duration of the sylnptoms, the histologic differentiation, and the size and site of the tumor. Lymph node metastases at this time of presentation are rare in carcinomas of the vocal cord, bnt are found in about 20% of subglottic carcinomas, about 40% of supraglottic carcinomas, and in about 40% of transglottic carcinomas.

Contralaleral metastases are unusual in unilateral glottic tumors. Bilateral nlerastases become more common if the carcinoma crosses the midline, e.g., at the anterior or posterior commissure or in the trachea, or if the tumor arises primarily in the supraglottic space.

Distant hernatogenoIH Hlerasrases are relatively unusual in laryngeal carcinoma at the time the patient is first seen. Second primary carcinomas of the respiratory and digestive tracts (synchronous or metachronous) also occur.

Diagnosis. The clinical diagnosis rests initially on the findings of indirect laryngoscopy and telescopic laryngoscopy. The site and extent of the tumor and the mobility of the vocal cord must be assessed . It is very important to carry out microlaryngoscopy. This allows accurate evaluation of the site and extent of the tumor, provides a view of hidden angles such as the ventrtcle and the piriform sinus,

and allows assessment of the snperficial characteristics such as nodular, exophytic,granulomatous, ulcerating, etc. .Increasingly, CT and MRI are used to acquire data on the depth of involvement.Differential diagnosis. This includes chronic laryngttis and its specific forms, and benign laryngeal tumors.

Table 4.9 Classincalion and involvement of Larnygeal Carcinomas According to the TNM System Glottis(80%) Tis = preinvasive carcinoma, carcinoma in situ T1 = tumor confined to the glottis with normal cord movement T1a = one cord T1b = both cords T2 = cord tumor with extension subglottically or supraglottically with normal or slightly impaired cord mobility T3 = tumor confined to the larynx with fixation of one or both cords T4 = tumor extending beyond the larynx, e.g., extending into the thyroid cartilage, piriform sinus, postcricoid region or into adlacant skin

Subglottis(5%) Tis = preinvasive carcinoma, carcinoma in situ T1 a=tumor of the subglottic region with normal cord mobility T1a = one side subglottis Tlb = both subglottis areas T2 = tumor of the subglottic region with extension to one or both cords T3 = tumor confined to the larynx wilh fixation of one or both cords T4 = tumor extending bnyond the larynx, e.g. into the postcricoid region, trachea or skin

Supragloffis (15%) Tis = preinvasive carcinoma, carcinoma in situ T1 = tumor confined to the supragloltic area with normal cord mobility T1a = tumor confined to the laryngeal surface of the epiglottis, one aryepiglottic fold, one ventricle or one false cord T1b = tumor of epigloffis involvemenl of one ventricle or false cord T2 = tumor ofthe epiglotis, ventricle or false cord extending to the cord without fixation T3 = tumor confined to the larynx with vocal cord fixation and destruction or other signs of deeo infiltration T4 = tumor axtending beyond the limits of the larynx with involvement of the piriform sinus, postcricoid region vallecula or tongue base

Treatment. If untreated, laryngeal carcinoma leads to death within an average of 12 months by asphyxia, bleeding, metastases, infection, or cachexia. The existence of cardiovascular or pulmonary diseases and diabetes mellitus determines the course of treatment and the course of the disease. The indications for radiotherapy or surgery for laryngeal carcinoma vary depending on the site and stage of the tumor.

They are often used in combination. Chemotherapy alone has so far proved to be useless for this type of tumor. Radiotherapy is mainly given as telecobalt megavoltage radiation. Except for T1 N0 glottic tumors and for some T2 N0 tumors, and especially if lymph node metastases are present, surgery is clearly superior to radlotherapy .

Radiotherapy is appropriate for patients with inoperable tumors. patients who refuse cancer surgery, and laryngeal tumor manifestations that are not amenable to surgical palliation. Extension of laryngeal carcinoma to the hypopharynx is another possible indication for radiotherapy.

The combination of surgery and postoperative radiotherapy appears to yield the best results for selected patients in advanced stages.

Complicalions after radiotherapy include persistent edema which makes it difficult to assess the local appearances and detect a recurrence. The edema is usually due to chondroradionecrosis leading to cartilaginous necrosis and which may reqoire laryngectomy. Other complications include dysphagia, ageusia, xerostomia and the sicca syndrome. If surgery must be undertaken after a full course of radiotherapy, the wound healing and prognosis are considerably worse.