Head and neck cancer
Epidemiology and risk factors
Head and neck cancer (H&N cancer) is the sixth commonest cancer worldwide. There were 3031 new cases in Australia in 2009. Risk factors for these cancers are the six S’s: Smoking, Spirits (alcohol), Sunlight exposure/previous radiation to head and neck, chronic Sepsis, Sexually transmitted infections (HPV & HIV) and male predominance and Spices (Betel quid chewing). Ninety-five percent of H&N cancers are associated with a significant smoking history. They are heterogeneous and challenging to treat as they involve multiple structures, including skin, muscle, cartilage, bone, nerves, blood vessels, lymphatics and both salivary and lymph glands.
Over the last two decades there has been a paradigm shift in the nature, age and cause of H&N cancers. Whereas in the past, the average age of presentation was 60-70 years associated with a heavy smoking and or alcohol history, we are now seeing a far younger cohort of patients in their thirties and forties who may never have smoked or consumed excessive alcohol. Human papillomavirus (HPV) causes the cancers in this group and predominately occurs in the oropharynx. These are the same high-risk subtypes of HPV that cause cancer of the cervix and are related to orogenital contact. Although over the past three decades the incidence of smoking has decreased by 30%, there has been no decline in H&N cancers. In fact, in Australia the prevalence of HPV related oropharyngeal tumours has tripled in the last two decades. The incidence is 22 per 100 000 in males and 7.5 per 100 000 in females.
The H&N cancers include six anatomic regions from the base of skull to the clavicles, and each anatomic region has a different Tumour, Nodal status, and Metastasis (TNM) classification and tumor patterns. These six regions include the Sino-nasal (nose and sinuses), Nasopharynx (the back of the nose and very top of the throat), Oral (from lips, hard palate to anterior 2/3rds of the tongue), Oropharynx (posterior 1/3rd of the tongue, tonsils and soft palate), Hypopharynx (the area of the throat behind the vocal cords and above the oesophageal opening) and the Larynx (area of the voice box and airway inlet).
In many patients, the rich vascular supply and lymphatic drainage of their tumour area leads to spread into the lymph nodes of the neck. There are multiple lymph nodes in the head and neck region. Most occur in Waldeyer’s ring around the jaw including the submandibular, parotid capsule and tonsillar lymphatic tissue. There is a large chain of lymph nodes that run with the internal jugular vein underneath the sternocleidomastoid muscle. This muscle runs from behind the ear (mastoid bone) to the clavicle (cleido) and divides the neck into anterior and posterior triangles. Lymph node spread is classified into levels by sites that are easily demonstrated on CT scanning and are constant and standardized. Level I is submandibular and submental region, Level II to IV is from angle of jaw down to clavicle, Level V includes the whole posterior triangle of the neck and level VI the paramedian tracheal and thyroid area.
Staging and prognosis
H&N cancers are classified by the TNM system that represents Tumour/Nodal status in the neck and Metastases to areas other than regional neck lymphnodes. In simplistic terms, the smaller the size of the tumour, the easier and more successful the treatment. Nodal spread is highly significant and reduces the overall prognosis by 50%.
Due to the complex structures that H&N cancer involves and the potentially devastating effects on basic daily functions such as breathing and swallowing, eating, drinking, speech, sense of smell and taste, these patients are best managed by a multidisciplinary team (MDT). This MDT meets weekly and includes ear nose and throat, plastic and reconstructive, maxillofacial surgeons, dentists, radiation and medical oncologists and allied health members that comprise speech pathology, dietetics, occupational and physiotherapists. A cancer care coordinator nurse, social worker and palliative care expert are essential to the MDT. A statistician’s participation is necessary for staging, treatment plans and outcomes for audit and review purposes.
Depending on the stage and site of the cancer, treatment may be curative or palliative and comprise one of three different plans: 1) a single modality of surgery or radiotherapy treatment, 2) surgery combined with pre or postoperative radiotherapy and 3) radiotherapy with concurrent or adjunctive chemotherapy and no surgery. The aim of management is to effectively treat the cancer whilst preserving as much function as possible (organ preservation) or reconstructing tissues to enable this. Where cancers are advanced and significant tissue in the mouth, neck or jaw is removed, reconstruction is achieved with free micro vascular skin, muscle and bone flaps from distant sites.
Many H&N cancers present in advanced stages and here palliative care plays an extremely important role.
Mr GB, 59 year old bus driver
- Initially presented with 3-4 month hx of hoarse voice
- Past Medical History
- Current smoker 40 pack yr history,
- Previous binge drinker
- HTN, cholesterol, T2DM, chronic back pain
- CT Head & Neck
- Subtle asymmetry of vocal cord
- Endoscopic laser excision (good view)
- Squamoproliferative lesion with features suggestive of early well differentiated squamous cell carcinoma, clear of margins. Adjacent epithelium shows dysplasia.
- T1N0 SCC-Highly curable
- Endoscopic laser excision (good view) performed with histopathology above
66 year old male smoker (30/d) with a 6 week history of hoarse voice, loss of weight of 6 kg and odynophagia
Past Medical History
- Mechanical fitter, lives with wife
- Tibial fracture
- Duodenal ulcer
- History of asbestos exposure in the navy.
- Laryngoscope-exophytic mass right aryepiglottic fold
- Vocal cords mobile
- Neck soft
- Microlaryngoscopy and biopsy of supraglottic (above vocal cords) mass
- Invasive moderately differentiated Squamous carcinoma in anterior glottis (vocal cord) & right supraglottic (above vocal cord) area
- CT neck and chest and PET
- Right supraglottic laryngeal neoplasia 26x17x23 mm.
- Level III involved lymph node
- No distant metastasis
- T4aN1M0 right supraglottic SCC
MDT treatment plan -- curative intent
- Primary chemoradiation therapy for organ preservation
- Dietetics, speech pathology, social work and dentist referals