Laryngeal Cancer

Detailed Overview

Laryngeal cancer is the most common malignancy of the head and neck, typically presenting as squamous cell carcinoma (SCC) in over 90% of cases. The exact location of the tumor determines the clinical presentation, lymphatic spread potential, and treatment approach. Glottic cancers typically present early with hoarseness and have poor lymphatic drainage, leading to lower rates of early nodal metastasis. Conversely, supraglottic tumors have rich lymphatic drainage, often presenting later with nodal involvement. Treatment requires a multidisciplinary approach balancing oncological cure with voice, swallowing, and airway preservation.

Epidemiology & Demographics

Incidence is approximately 3 per 100,000 annually. It predominantly affects males with a male-to-female ratio of 4:1. Peak incidence occurs in the 6th and 7th decades of life (ages 55-70). African Americans have a higher incidence and lower survival rates compared to Caucasians.

Etiological Mechanism

The primary etiology involves genetic mutations (e.g., TP53, CDKN2A) triggered by prolonged exposure to carcinogens. Human papillomavirus (HPV), particularly HPV-16, plays a role in a minority of cases, especially in non-smokers.

Primary Causes

Primary causes are DNA damage from tobacco smoke (polycyclic aromatic hydrocarbons) and alcohol (acetaldehyde). Synergistic effects occur when both are used.

• Tobacco smoking: The most significant risk factor; risk increases with pack-years (e.g., >20 pack-years significantly elevates risk).
• Alcohol consumption: Acts synergistically with tobacco; heavy daily drinking (>50g/day) increases risk 2-5 fold.
• HPV infection: HPV-16 is implicated in ~5-15% of laryngeal SCCs.
• Occupational exposures: Exposure to asbestos, wood dust, paint fumes, and certain chemicals.

Carcinogens in tobacco and alcohol induce progressive genetic and epigenetic alterations in laryngeal epithelial cells. This sequence progresses from normal squamous epithelium to hyperplasia, dysplasia, carcinoma in situ (CIS), and finally invasive squamous cell carcinoma. Mutations in the p53 tumor suppressor gene are early and frequent events. Tumor invasion disrupts normal laryngeal anatomy, affecting vocal cord mobility and airway patency, while facilitating metastasis through regional cervical lymphatics.

Characteristic Clinical Presentation

• Hoarseness: Persistent change in voice quality lasting >3 weeks (especially in glottic tumors).
• Dysphagia: Difficulty swallowing (more common in supraglottic tumors).
• Odynophagia: Pain upon swallowing, which may radiate to the ear.
• Dyspnea and Stridor: Airway compromise due to large tumor bulk causing obstruction.
• Hemoptysis: Coughing up blood or blood-tinged sputum.

Physical Examination Signs

• Exophytic or ulcerative laryngeal mass visualized on laryngoscopy.
• Vocal cord fixation or impaired mobility.
• Palpable cervical lymphadenopathy (firm, fixed, painless nodes).
• Stridor (high-pitched inspiratory sound indicating upper airway obstruction).

• Airway Obstruction: Requires emergency tracheostomy due to tumor growth.
• Aspiration Pneumonia: Due to impaired laryngeal closure during swallowing.
• Voice Loss: Complete loss of natural voice following total laryngectomy.

Diagnostic Criteria & Guidelines

Definitive diagnosis requires direct visualization via flexible or rigid laryngoscopy followed by a tissue biopsy confirming invasive squamous cell carcinoma. Staging requires contrast-enhanced CT or MRI of the neck.

Differential Diagnosis

• Vocal cord polyps or nodules
• Laryngeal papillomatosis (HPV 6/11)
• Laryngopharyngeal reflux (LPR)

Laboratory Tests & Biomarkers

• Complete Blood Count (CBC): May show anemia of chronic disease (Hb < 12 g/dL).
• p16 Immunohistochemistry: Positive in HPV-associated tumors (surrogate marker for HPV).

Imaging Modalities & Findings

• CT Neck with Contrast:
• PET/CT (FDG):

• Stage I
  Tumor confined to one subsite with normal vocal cord mobility; no nodal involvement (T1N0M0).
• Stage II
  Tumor involves adjacent subsite(s) of the larynx with normal or impaired vocal cord mobility; no nodes (T2N0M0).
• Stage III
  Tumor limited to larynx with vocal cord fixation (T3) OR single ipsilateral node <=3 cm (N1).
• Stage IV
  Tumor invades beyond the larynx, multiple/large nodes (N2/N3), or distant metastasis (M1).

Second-Line & Adjunctive Therapy

Salvage total laryngectomy with bilateral neck dissection. For recurrent/metastatic disease: Pembrolizumab 200 mg IV every 3 weeks +/- Platinum/5-FU chemotherapy.

Surgical & Procedural Management

Procedures range from transoral laser microsurgery (TLM) for early disease to Total Laryngectomy with placement of a tracheoesophageal puncture (TEP) prosthesis for voice rehabilitation.

Recommended Lifestyle Changes

• Complete and immediate cessation of tobacco smoking.
• Complete cessation of alcohol consumption.
• Speech therapy for vocal rehabilitation and swallowing exercises.

Patient Counseling & Advice

Discuss the permanent nature of a stoma if total laryngectomy is required. Explain the acute side effects of radiation, including severe sore throat (mucositis) and dry mouth (xerostomia).

Follow-Up & Monitoring Schedule

Physical exam with flexible laryngoscopy every 1-3 months for year 1, every 2-6 months for year 2, every 4-8 months for years 3-5, then annually.

Preventive Strategies

Primary prevention involves avoidance of tobacco and excessive alcohol. HPV vaccination is recommended.

5-year survival for Stage I glottic cancer is ~90%. Stage III/IV 5-year survival drops to 40-50%.