• Clinical science

Laryngeal carcinoma

Abstract

Laryngeal carcinoma is a malignant tumor of the larynx that occurs most commonly in older men. Smoking and alcohol consumption are the most important risk factors. Based on the location of the tumor, laryngeal carcinomas may be classified as glottic (involving the vocal cords), supraglottic, or subglottic carcinomas. Glottic carcinoma, which is the most common form, presents early with hoarseness and is usually associated with a good prognosis. Supraglottic and subglottic carcinomas present late and are therefore associated with a poor prognosis. Direct laryngoscopy is required to visualize the tumor and assess vocal cord mobility. Imaging of the neck may be required to determine the extent of the tumor and check for spread to cervical lymph nodes. The method of treatment depends on the site and stage of the tumor. Early stages are treated by either radiotherapy or endoscopic laser resection with the goal of preserving the voice. Late stages require some form of laryngectomy. After laryngectomy patients must undergo vocal rehabilitation, which involves using vibrations in the pharynx to produce speech sounds.

Epidemiology

  • Sex: >
  • Age of onset: 40–70 years

References:[1]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

  • Smoking
  • Alcohol use
  • Exposure to asbestos
  • Precancerous lesions: leukoplakia or laryngeal papillomatosis in adults (see benign tumors and precanceroses of the larynx)
  • Irradiation of the head and neck region
  • Rarely, infection with human papillomavirus (HPV 6 and 11)
  • Diets rich in salt-preserved meats (nitrosamines) and dietary fats

References:[1][2]

Classification

Laryngeal carcinomas are classified according to their location in relation to the glottis.

TNM classification of laryngeal carcinoma

TNM Tumor extent
T1

Tumor is restricted to one area (supraglottis, glottis, or subglottis); vocal cords are mobile. In the case of glottic carcinoma: T1a → involvement of one vocal cord; T1b → involvement of both vocal cords

T2

Tumor extends to more than one area (supraglottis, glottis, or subglottis).

T3

Tumor is still confined to larynx; vocal cords are no longer mobile

T4

Tumor is no longer confined to the larynx.

N1 Solitary ipsilateral lymph node, measuring 3 cm (1.2 inches) or less
N2

Single ipsilateral node greater than 3 cm (1.2 inches) but less than 6 cm (1.2 inches) in size OR multiple ipsilateral/contralateral lymph nodes measuring less than 6 cm (1.2 inches)

N3 Lymph nodes > 6 cm
M1 Distant metastases

Laryngeal carcinomas are almost always squamous cell cancers (SCC)!

References:[1]

Clinical features

  • Hoarseness/change in voice
  • Foreign body sensation
  • Dyspnea
  • Dysphagia
  • Stridor (due to airway narrowing)
  • Aspiration while eating or drinking

Unexplained hoarseness for longer than 3 weeks should always be investigated by laryngoscopy!

References:[3][1]

Stages

Staging by UICC (Union for International Cancer Control)

Stadium TNM
Stage 0 CIS (Carcinoma in situ)
Stage I T1
Stage II T2
Stage III Starting with T3 or N1
Stage IV Starting with T4 or N2 or M1

Diagnostics

  • Direct laryngoscopy reveals irregular, nodular, or ulcerative lesions
    • Microlaryngoscopic examination and tissue biopsy: required to visualize very small tumors and to differentiate laryngeal cancer from benign laryngeal lesions (e.g., vocal nodules, vocal polyps)
    • Stroboscopic examination: assesses vocal cord mobility during phonation
  • Imaging: CT, MRI, and/or ultrasound of the neck to assess tumor size and spread to surrounding tissue (e.g., lymph nodes)

References:[1]

Treatment

  • Early stages (I and II): radiotherapy or transoral endoscopic laser resection; :
  • Advanced stages (with lymph node and/or distant organ metastasis): laryngectomy
    • Stage III: external partial laryngectomy
    • Stage IV: total laryngectomy + adjuvant postoperative radiotherapy ± chemotherapy
  • Voice rehabilitation after laryngectomy: The patient can be trained to produce speech from vibration in the pharynx by one of the following means:

References:[4]

Prognosis

  • Glottic carcinomas have the best prognosis (5-year survival rates of approximately 90%).
  • The 5-year survival rate drops drastically when the supraglottis and/or subglottis are involved.

References:[1]