Head And Neck Cancer
Head and Neck Cancer
- The term head and neck cancer refers to a group of biologically similar cancers originating from the upper aerodigestive tract, including the lip, oral cavity (mouth), nasal cavity, paranasal sinuses, pharynx, and larynx. Most head and neck cancers are squamous cell carcinomas (SCCHN), originating from the mucosal lining (epithelium) of these regions. Head and neck cancers often spread to the lymph nodes of the neck, and this is often the first (and sometimes only) manifestation of the disease at the time of diagnosis. Head and neck cancer is strongly associated with certain environmental and lifestyle risk factors, including tobacco smoking, alcohol consumption, UV light and occupational exposures, and certain strains of viruses, such as the sexually transmitted human papillomavirus. These cancers are frequently aggressive in their biologic behavior; patients with these types of cancer often develop a second primary tumor. Head and neck cancer is highly curable if detected early, usually with some form of surgery although chemotherapy and radiation therapy may also play an important role. The 2009 estimated number of head and neck cancer in the US is of 35,720 new cases.
Signs and symptoms
- Throat Cancer usually begins with symptoms that seem harmless enough, like an enlarged lymph node on the outside of the neck, a sore throat or a hoarse sounding voice. However, in the case of throat cancer, these conditions may persist and become chronic. There may be a lump or a sore in the throat or neck that does not heal or go away. There may be difficult or painful swallowing. Speaking may become difficult. There may be a persistent earache. Other possible but less common symptoms include some numbness or paralysis of the face muscles.
Presenting symptoms include
> Mass in the neck
> Neck pain
> Bleeding from the mouth
> Sinus congestion, especially with nasopharyngeal carcinoma
> Bad breath
> Sometimes a sore tongue
> Painless ulcer or sores in the mouth that do not heal.
> White, red or dark patches in the mouth that will not go away.
> Unusual bleeding or numbness in the mouth.
> A lump in your lip, mouth or gums.
> Enlarged lymph glands in the neck.
- Alcohol and tobacco use are the most common risk factors for head and neck cancer in the United States. Alcohol and tobacco are likely synergistic in causing cancer of the head and neck. Smokeless tobacco is an etiologic agent for oral and pharyngeal cancers. Cigar smoking is an important risk factor for oral cancers as well. Other potential environmental carcinogens include marijuana and occupational exposures such as nickel refining, exposure to textile fibers, and woodworking. Cigarette smokers have a lifetime increased risk for head and neck cancers that is 5- to 25-fold increased over the general population. The ex-smoker’s risk for squamous cell cancer of the head and neck begins to approach the risk in the general population twenty years after smoking cessation. The high prevalence of tobacco and alcohol use worldwide and the high association of these cancers with these substances makes them ideal targets for enhanced cancer prevention.
- A patient usually presents to the physician complaining of one or more of the above symptoms The patient will typically undergo a needle biopsy of this lesion, and a histopathologic information is available, a multidisciplinary discussion of the optimal treatment strategy will be undertaken between the radiation oncologist, surgical oncologist, and medical oncologist.
Throat cancers are classified according to their histology or cell structure, and are commonly referred to by their location in the oral cavity and neck. This is because where the cancer appears in the throat affects the prognosis – some throat cancers are more aggressive than others depending upon their location. The stage at which the cancer is diagnosed is also a critical factor in the prognosis of throat cancer
Squamous Cell Carcinoma
Squamous cells are the epithelium (tissue layer) that is the surface cells of much of the body. Skin and mucous membranes are squamous cells. This is the most common form of larynx cancer, accounting for over 90% of throat cancer. Squamous Cell Carcinoma is most likely to appear in males over 40 years of age with a history of heavy alcohol use coupled with smoking.
Adenocarcinoma is a cancer of the columnar epithelium typical of the lower esophagus. It is typical of Barrett’s Esophagus but may be at another location. Adenocarcinoma is thought of as a product of Barrett’s Oesophagus.
Avoidance of recognised risk factors (as described above) is the single most effective form of prevention. Regular dental examinations may identify pre-cancerous lesions in the oral cavity.
When diagnosed early, oral, head and neck cancers can be treated more easily and the chances of survival increase tremendously.
Improvements in diagnosis and local management, as well as targeted therapy, have led to improvements in quality of life and survival for head and neck cancer patients since 1992.
After a histologic diagnosis has been established and tumor extent determined, the selection of appropriate treatment for a specific cancer depends on a complex array of variables, including tumor site, relative morbidity of various treatment options, patient performance and nutritional status, concomitant health problems, social and logistic factors, previous primary tumors, and patient preference. Treatment planning generally requires a multidisciplinary approach involving specialist surgeons and medical and radiation oncologists.
Patients with head and neck cancer can be categorized into three clinical groups: those with localized disease, those with locally or regionally advanced disease, and those with recurrent and/or metastatic disease. Comorbidities (medical problems in addition to the diagnosed cancer) associated with tobacco and alcohol abuse can affect treatment outcome and the tolerability of aggressive treatment in a given patient.
Surgery as a treatment is sometimes used in cases of throat cancer. In such cases an attempt is made to remove the cancerous cells. This can be particularly tricky if the cancer is near the larynx and can result in the patient being unable to speak. Surgery is more commonly used to resection (remove) some of the lymph nodes to prevent further spread of the disease.
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). Bladder cancer may be treated with intravesical (into the bladder through a tube inserted into the urethra) chemotherapy. The way the chemotherapy is given depends on the type and stage of the cancer being treated.
Although early-stage head and neck cancers (especially laryngeal and oral cavity) have high cure rates, up to 50% of head and neck cancer patients present with advanced disease. Cure rates decrease in locally advanced cases, whose probability of cure is inversely related to tumor size and even more so to the extent of regional node involvement. Consensus panels in America (AJCC) and Europe (UICC) have established staging systems for head and neck squamous cancers. These staging systems attempt to standardize clinical trial criteria for research studies, and attempt to define prognostic categories of disease. Squamous cell cancers of the head and neck are staged according to the TNM classification system, where T is the size and configuration of the tumor, N is the presence or absence of lymph node metastases, and M is the presence or absence of distant metastases. The T, N, and M characteristics are combined to produce a “stage” of the cancer, from I to IVB.