HEAD AND NECK CANCER
Tumors arising from the epithelial lining of oral cavity, pharynx, larynx and paranasal sinuses are collectively called Head and Neck Cancer. In 90% of cases, they are of squamous cell type. They are heterogeneous group of malignancies with differences in risk factors, presentation, spread and treatment approach.
Cigarette smoking and alcohol are the most important risk factors. Nasopharyngeal and paranasal sinus cancers are exceptions. Cancer of nasopharynx is specially common in southern China. Epstein-Barr virus is associated with cancer in this site. Tumors of the Sinonasal act are associated with certain occupational exposure like nickel, radium, chromium, leather, woodworking. Given the central role of tobacco and alcohol, synchronous and metasynchronous second primary cancers are common to these patients. Certain premalignant lesions are commonly found in patients with above risk factors. These include leukoplakia and erythroplasia.
The presentation is mostly locoregional. Cancer of hypopharynx and larynx present with sore throat and hoarseness. Cancer of nasopharynx present with otitis media. Cancer of oral cavity spread to submental and submandibular lymph nodes. Cancer of larynx spread to upper neck. Cancer of nasopharynx spread to upper neck and posterior triangle. It is uncommon for patients with cancer of glottis(larynx) and paranasal sinuses to spread to neck nodes. Because of risk factors of smoking and alcohol, these patients commonly have comorbid medical problems. After clinical diagnosis, the patients require careful medical examination. This includes CT scan or MRI, examination under anesthesia by an ENT surgeon, endoscopy to detect any synchronous lesions in lungs and upper GI tract, chest X-ray. Cancer of nasopharynx and hypopharynx require extensive work up to look for distant spread.
Head and neck cancer are treated with surgery and/or radiation. Cancer of hypopharynx cannot be treated surgically even in very early stages and hence are treated with radiation and chemotherapy. Cancer of larynx and hypopharynx can be treated with radiation and chemotherapy with preservation of larynx with equal success.
T1-2N0-1M0: These early stage tumors require either surgery or radiation. Cure rates are 50-100%.
T3-4N2-3M0: Tumors at this stage require surgery along with radiation. For unresectable tumors, radiation alone is used. Chemotherapy is investigational. Cure rates are 10%-60%.
Metastatic disease: These are incurable and are treated palliatively with radiation and chemotherapy.
Recurrent disease: If feasible, surgery and radiation are an option. Chemotherapy can be used with radiation.
Because of frequent spread to lymph nodes of neck, surgical treatment and radiation treatment is also given to neck area.
Because head and neck region involves some of the basic functions like swallowing, speech, voice and vision, surgical or radiation treatment to this area has significant effect on quality of life by compromising these functions. Plans for rehabilitation are extremely important. Complete patient management requires multidisciplinary approach with cooperation among physicians, dentists, prosthodontists, nutritionists, speech and swallowing therapists, physical and occupational therapists and psychiatrists. This is why organ preservation is an attractive option when treating malignancies of head and neck. It has been shown that cancers of larynx and hypopharynx cane be effectively treated without radical laryngectomy with preservation of voice, with radiation alone or in combination with chemotherapy.
Stopping the use of tobacco and alcohol can prevent recurrence and the development of second primary cancers. Patients with head and neck cancer often have diffused mucosal abnormalities referred to as "field carcinogenesis". Isotretinoin can cause regression of premalignant lesions like leukoplakia. However, there is recurrence when Isotretinoin is stopped. Role of these agents in chemoprevention has not been completely defined yet. Randomized trials to evaluate their roles are undergoing.