Head and neck cancer in general

Tumours of the head and neck include
- Eye and orbital tumours
- Oral cavity cancer
- Pharyngeal tumours
- Laryngeal tumours
  - Supraglottic
  - Glottic
  - Subglottic
- Tumours of the nasal cavity and paranasal sinuses
- Tumours of the salivary gland
- Tumours of the thyroid gland
Epidemiology
- Head and neck cancer is the 6th most common cancer worldwide
Etiology
- Smoking
- Alcohol
- Poor oral hygiene
- EBV – for nasopharyngeal carcinoma
- HPV – for oropharyngeal and laryngeal cancer
Pathology
- 80% are squamous cell
- 20% are adenocarcinoma, lymphoma, sarcoma, etc.
- Precancerous lesions
  - Leukoplakia
  - Erythroplakia
  - Lichen planus
- Metastasizes most often to lung
Clinical features
- Ulceration of mucosa
- Exophytic growth of mucosa
- Neck mass
- Sore throat
- Hoarseness
- Pain radiating into the ear
  - Due to cranial nerve affection
- Dysphagia
Diagnosis
- FNAB or direct excision biopsy
Work-up after diagnosis
- CT with contrast or MRI of head and neck
- Laryngoscopy
- Neck US
- PET scan
Treatment
- Majority of cases are treated with multiple modalities
- Surgery
  - Only used if R0 resection with acceptable functional results is expected
    - This means that surgery is not performed unless the surgeon believes that he can completely resect the tumour
  - If early stage cancer -> transoral surgery (TORS)
  - If cancer has spread to lymph nodes, neck dissection must be performed
    - Modified radical neck dissection
    - Selective neck dissection
  - Surgery, especially of pharynx and larynx, impairs quality of life, which must be taken into account when deciding treatment modality
- Radiotherapy
  - External beam radiotherapy or brachytherapy
  - Can be given with curative or palliative intention
  - Can be given postoperatively or primarily
  - Primary radiotherapy alone is usually sufficient in
    - Cancer of the lip
    - Cancer of the nose
    - Cancer of the floor of the mouth (brachytherapy)
    - Cutaneous lymphoma
- Chemotherapy
  - Cisplatin
  - Taxanes
  - 5-FU
- Biological and immunotherapy
  - Cetuximab (anti-EGFR)
  - Nivolumab (anti-PD-1)
  - Pembrolizumab (anti-PD-1)

Oral cavity and oropharynx cancer

Oral cavity cancer or (simply oral cancer) and oropharynx cancer are forms of head and neck cancer. These have similar etiology and pathology and are therefore often considered together. Squamous cell carcinoma is the most common histological type of oral cavity and oropharynx cancer. Oropharynx cancer is most commonly located in the tonsils and tongue base but may affect all parts of the oropharynx.

Etiology

These types of cancer are highly related to tobacco use, smoking, alcohol, and HPV. The combined use of tobacco and alcohol has a multiplicative effect on cancer risk.

Leukoplakia is a precursor to oral cavity cancer.

Clinical features

Oral cavity cancer most commonly presents as a non-healing ulcer or lesion. Oropharyngeal cancer is usually asymptomatic early, leading to late diagnosis. Later, it may cause sore throat, globus sensation, bloody saliva, halitosis, and pain. Lymph node metastasis may cause swollen lymph nodes on the neck, especially the mandibular angle.

Diagnosis and evaluation

Ultrasound is useful in the evaluation of oropharynx cancer, not usually necessary for oral cavity cancer. Biopsy is essential for the diagnosis.

Management

Oral cavity cancer

Management includes surgical removal, sometimes with adjuvant radiotherapy. Postoperative radiotherapy or radiochemotherapy is indicated if high-risk features are present

R1 or R2 resection
T3 or T4 tumours
Lymph node spread

Before radiotherapy of the oral cavity, dental care is essential. Dental infections can act as a source of inflammation after radiotherapy.

Oropharyngeal cancer

Oropharyngeal cancer is moderately radiosensitive. For this reason, radiochemotherapy is the preferred modality, but surgery is an option.

Nasopharynx cancer

Nasopharynx cancer is a rare type of head and neck cancer. The most common histological types are squamous cell carcinoma and lymphoepithelial carcinoma. It can cause symptoms like unilateral conductive hearing loss, middle ear effusion, and lymph node metastasis at the mandibular angle.

These tumours are very radiosensitive, which is lucky because surgery is difficult. Radiochemotherapy is the preferred treatment.

Hypopharynx cancer

Hypopharynx cancer is a rare form of head and neck cancer. The most common histological type is squamous cell carcinoma, and like oral cavity and oropharynx cancer it's related to alcohol and nicotine consumption.

Hypopharynx cancer causes symptoms late, delaying diagnosis. Symptoms include dysphagia, halitosis, cervical lymph node metastasis, and referred ear pain.

Hypopharyngeal cancer is not particularly radiosensitive so the treatment is mostly surgical. Treatment includes local surgical excision and sometimes neck dissection. Laryngectomy is often necessary.

Larynx cancer

A cancer of older men
40% of head and neck cancers
SCC
Etiology
- Smoking
- Alcohol
Types
- Supraglottic
  - 40% of cases
  - Gives late symptoms
- Glottic
  - Best prognosis because gives early symptoms (hoarseness)
  - Limited lymphatic drainage
  - 60% of cases
- Subglottic
  - 1% of cases
  - Gives late symptoms
  - Dyspnoea
  - Stridor
Clinical features
- Hoarseness
- Foreign body sensation
- Dyspnoea
- Dysphagia
- Stridor
Staging
- TNM
  - T1 – confined to one part of larynx
  - T2 – invades another part of larynx
  - T3 – tumor confined to larynx
  - T4 – tumor invades outside the larynx
  - N1 – single regional ipsilateral lymph node
  - N3 – large regional lymph node
  - M1 – distant metastasis
- AJCC stage
  - 0 – in situ
  - I – T1, N0, M0
  - II – T2, N0, M0
  - III – T3, N0, M0
  - IV – T4 OR N1 OR M1
Treatment
- Early – radiotherapy or laser resection
- Locally advanced cancer – radiochemotherapy or total laryngectomy
- Advanced cancer – total laryngectomy with adjuvant radiotherapy
- Neck dissection to remove lymph nodes is indicated if N1 is suspected