Cancers of the head and neck are not common, and are tricky to treat. There are some geographic distributions, which are related to local tobacco chewing habits (India), or viral infections. The demographics are also shifting from mainly tobacco and alcohol users to otherwise younger and healthy non-users with HPV infections.
The anatomy of the head and neck region is complex. It involves the mouth cavity including the tongue, jaw, the back of the throat, tonsils, the nasal cavity with the sinuses, the bones of the jaw, the salivary glands, the voice box or the larynx, and the thyroid gland. While the thyroid gland is part of the neck, the treatment is different from the rest of the head and neck area.
Causes: mainly heavy tobacco and alcohol use. EBV or Epstein-Barr virus is associated with Nasopharyngeal cancers, and certain subtypes of Human Papilloma virus, or HPV is increasing being associated with Head and Neck cancers.
Premalignant conditions include leukoplakia from chronic irritation, erythroplakia, and carcinoma in situ (or pre-invasive cancer).
The most common pathologic finding of malignancy is a squamous cell carcinoma, or cancer of the lining of the upper aero-digestive tract.
Symptoms include pain or difficulty with swallowing, change of voice or breathing, earaches, change of hearing or balance, lumps in the neck, and sometimes no symptoms. The disease can be picked up on a routine dental examination.
Diagnosis is usually made with a fine needle aspirate or FNA of a swollen lymph gland. This will differentiate between the squamous cell carcinomas of the head and neck region from lymphomas originating in the lymphatic system itself. The path of investigation bifurcates from there. If it confirms a squamous cell carcinoma, an investigation for the primary ensues.
Investigation will involve a thorough examination of the oral cavity with punch biopsies of suspicious spots. This will include an office fiber optic examination, followed by a more thorough examination under anesthesia to include a laryngoscopy (exam of the vocal cords), bronchoscopy (the air passage) and upper endoscopy to examine the food passage. All these are in such close proximity, that it is it important to clearly delineate the extent of the tumor.
Radiology studies will include an MRI of the neck and a CT scan of the chest. Increasingly, a PET scan is being used as a way of finely delineating active areas of neck node disease, and second primaries.
A treatment plan is determined after staging is complete. It can involve
-Surgery for early stage, easily accessible tumors.
-Radiation therapy when surgery is major, and will require extensive reconstruction. Or delivered after surgery as a clean up.
-Chemotherapy, which improves radiation results by about 1/3rd
-Salvage surgery, if there is residual disease after primary treatment.
-Palliative chemotherapy, for recurrent disease, which is not amenable to repeat surgery.
Head and Neck Cancers tend to recur in the local area, and do not tend to metastasize, or spread, early. The problem is, running out of local curative treatment options. There is a lifetime total dose of radiation that can be delivered to any area, and a finite amount of surgery and reconstruction that can be done. Chemotherapy is not curative, hence the push to eradicate the disease up front, with a combination of treatments. In addition, the population is at risk for developing a second primary, for the same reason that they got the first cancer: tobacco and alcohol use.
Side effects of the treatment are significant:
-Soreness and ulcers of the inside lining of the mouth and throat
-Dryness of the mouth, because the salivary glands are often radiated
-Difficulty swallowing and breathing
-Hearing difficulty and ringing noises in the ears
-Redness and skin breakdown of the area of the neck being radiated
-Malnutrition and dehydration, because of the difficulty swallowing.
-Lymphedema, or swelling of the neck, as a delayed effect
Support and treatment of immediate and delayed side effects includes
-Nutrition and hydration support: often needs a tube by which nutrition drinks are delivered directly into the stomach, bypassing the painful areas, in addition to intravenous nutrition
-Swallowing therapy after treatment has ended to retrain the muscles.
-Oral and dental care, using mouth rinses, fluoride treatments, treatment of thrush
-Skin care of the neck, with application of aloe ointments
-Pain control with anesthetic mouth rinses
-Surveillance, post treatment, for delayed effects
-Psychotherapy, for difficulty dealing with loss of functions, vital to sense of well-being.
Recovery from curative treatments is slow, and can take up to a year.