Head and Neck Cancers

Dr Healthism
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  • 25 Feb, 2019 3:58 pm
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Head and neck cancer is a group of cancers that starts in the mouth, nose, throat, larynx, sinuses, or salivary glands. Symptoms for head and neck cancer may include a lump or sore that does not heal, a sore throat that does not go away, trouble swallowing, or a change in the voice. There may also be unusual bleeding, facial swelling, or trouble breathing.

About 75% of head and neck cancer is caused by the use of alcohol or tobacco. Other risk factors include betel quid, certain types of human papillomavirus, radiation exposure, certain workplace exposures, and Epstein-Barr virus. Head and neck cancers are most commonly of the squamous cell carcinoma type. The diagnosis is confirmed by tissue biopsy. The degree of spread may be determined by medical imaging and blood tests.

Not using tobacco or alcohol can reduce the risk for head and neck cancer. While screening in the general population does not appear to be useful, screening high risk groups by examination of the throat might be useful. Head and neck cancer often is curable if it is diagnosed early; however, outcomes are typically poor if it is diagnosed late. Treatment may include a combination of surgery, radiation therapy, chemotherapy, and targeted therapy. Following treatment of one head and neck cancer, people are at higher risk of a second cancer.

In 2015, head and neck cancers globally affected more than 5.5 million people (mouth 2.4 million, throat 1.7 million, and larynx 1.4 million), and it has caused over 379,000 deaths (mouth 146,000, throat 127,400, larynx 105,900). Together, they are the seventh most frequent cancer and the ninth-most-frequent cause of death from cancer. In the United States, about 1% of people are affected at some point in their life, and males are affected twice as often as females. The usual age at diagnosis is between 55 and 65 years old. The average 5 year survival following diagnosis in the developed world is 42-64%.

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
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
Earache
Unusual bleeding or numbness in the mouth
Lump in the lip, mouth or gums
Enlarged lymph glands in the neck
Slurring of speech (if the cancer is affecting the tongue)
Hoarse voice which persists for more than six weeks
Sore throat which persists for more than six weeks
Difficulty swallowing food
Change in diet or weight loss
Mouth
Squamous cell cancers are common in the mouth, including the inner lip, tongue, floor of mouth, gingivae, and hard palate. Cancers of the mouth are strongly associated with tobacco use, especially use of chewing tobacco or “dip”, as well as heavy alcohol use. Cancers of this region, particularly the tongue, are more frequently treated with surgery than are other head and neck cancers.

Surgeries for oral cancers include

Maxillectomy (can be done with or without orbital exenteration)
Mandibulectomy (removal of the mandible or lower jaw or part of it)
Glossectomy (tongue removal, can be total, hemi or partial)
Radical neck dissection
Mohs procedure
Combinational e.g., glossectomy and laryngectomy done together.
The defect is typically covered/improved by using another part of the body and/or skin grafts and/or wearing a prosthesis.

Nasopharynx
Nasopharyngeal cancer arises in the nasopharynx, the region in which the nasal cavities and the Eustachian tubes connect with the upper part of the throat. While some nasopharyngeal cancers are biologically similar to the common HNSCC, “poorly differentiated” nasopharyngeal carcinoma is lymphoepithelioma, which is distinct in its epidemiology, biology, clinical behavior, and treatment, and is treated as a separate disease by many experts.

Throat
Oropharyngeal squamous cell carcinomas (OSCC) begins in the oropharynx (throat), the middle part of the throat that includes the soft palate, the base of the tongue, and the tonsils. Squamous cell cancers of the tonsils are more strongly associated with human papillomavirus infection than are cancers of other regions of the head and neck. HPV-positive oropharyngeal cancer generally has a better outcomes than HPV-negative disease with a 54% better survival, but this advantage for HPV associated cancer applies only to oropharyngeal cancers.

People with oropharyngeal carcinomas are at high risk of developing second primary head and neck cancer.

Hypopharynx
The hypopharynx includes the pyriform sinuses, the posterior pharyngeal wall, and the postcricoid area. Tumors of the hypopharynx frequently have an advanced stage at diagnosis, and have the most adverse prognoses of pharyngeal tumors. They tend to metastasize early due to the extensive lymphatic network around the larynx.

Larynx
Laryngeal cancer begins in the larynx or “voice box.” Cancer may occur on the vocal folds themselves (“glottic” cancer), or on tissues above and below the true cords (“supraglottic” and “subglottic” cancers respectively). Laryngeal cancer is strongly associated with tobacco smoking.

Surgery can include laser excision of small vocal cord lesions, partial laryngectomy (removal of part of the larynx) or total laryngectomy (removal of the whole larynx). If the whole larynx has been removed the person is left with a permanent tracheostomy. Voice rehabilitation in such patients can be achieved through 3 important ways – esophageal speech, tracheoesophageal puncture or electrolarynx. One would likely require the help of intensive teaching and speech therapy and/or an electronic device.

Trachea
Cancer of the trachea is a rare cancer which can be similar to head and neck cancer, and is sometimes classified as such.

Most tumors of the salivary glands differ from the common carcinomas of the head and neck in cause, histopathology, clinical presentation, and therapy. Other uncommon tumors arising in the head and neck include teratomas, adenocarcinomas, adenoid cystic carcinomas, and mucoepidermoid carcinomas. Rarer still are melanomas and lymphomas of the upper aerodigestive tract.

Prevention
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. As of 2017 it was not known if existing HPV vaccines can help prevent head and neck cancer.

Management
Improvements in diagnosis and local management, as well as targeted therapy, have led to improvements in quality of life and survival for people with head and neck cancer.

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, concomitant health problems, social and logistic factors, previous primary tumors, and the person’s preference. Treatment planning generally requires a multidisciplinary approach involving specialist surgeons and medical and radiation oncologists.

Surgical resection and radiation therapy are the mainstays of treatment for most head and neck cancers and remain the standard of care in most cases. For small primary cancers without regional metastases (stage I or II), wide surgical excision alone or curative radiation therapy alone is used. More extensive primary tumors, or those with regional metastases (stage III or IV), planned combinations of pre- or postoperative radiation and complete surgical excision are generally used. More recently, as historical survival and control rates are recognized as less than satisfactory, there has been an emphasis on the use of various induction or concomitant chemotherapy regimens.

Surgery
Surgery as a treatment is frequently used in most types of head and neck cancer. Usually the goal is to remove the cancerous cells entirely. This can be particularly tricky if the cancer is near the larynx and can result in the person being unable to speak. Surgery is also commonly used to resect (remove) some or all of the cervical lymph nodes to prevent further spread of the disease.

CO2 laser surgery is also another form of treatment. Transoral laser microsurgery allows surgeons to remove tumors from the voice box with no external incisions. It also allows access to tumors that are not reachable with robotic surgery. During the surgery, surgeon and pathologist work together to assess the adequacy of excision (“margin status”), minimizing the amount of normal tissue removed or damaged. This technique helps give the person as much speech and swallowing function as possible after surgery.

Radiation therapy
Radiation therapy is the most common form of treatment. There are different forms of radiation therapy, including 3D conformal radiation therapy, intensity-modulated radiation therapy, particle beam therapy and brachytherapy, which are commonly used in the treatments of cancers of the head and neck. Most people with head and neck cancer who are treated in the United States and Europe are treated with intensity-modulated radiation therapy using high energy photons. At higher doses, head and neck radiation is associated with thyroid dysfunction and pituitary axis dysfunction.

Chemotherapy
Chemotherapy in throat cancer is not generally used to cure the cancer as such. Instead, it is used to provide an inhospitable environment for metastases so that they will not establish in other parts of the body. Typical chemotherapy agents are a combination of paclitaxel and carboplatin. Cetuximab is also used in the treatment of throat cancer.

Docetaxel-based chemotherapy has shown a very good response in locally advanced head and neck cancer. Docetaxel is the only taxane approved by US FDA for head and neck cancer, in combination with cisplatin and fluorouracil for the induction treatment of inoperable, locally advanced squamous cell carcinoma of the head and neck.

While not specifically a chemotherapy, amifostine is often administered intravenously by a chemotherapy clinic prior to IMRT radiotherapy sessions. Amifostine protects the gums and salivary glands from the effects of radiation.

Photodynamic therapy
Photodynamic therapy may have promise in treating mucosal dysplasia and small head and neck tumors. Amphinex is giving good results in early clinical trials for treatment of advanced head and neck cancer.

Targeted therapy
Targeted therapy, according to the National Cancer Institute, is “a type of treatment that uses drugs or other substances, such as monoclonal antibodies, to identify and attack specific cancer cells without harming normal cells.” Some targeted therapy used in squamous cell cancers of the head and neck include cetuximab, bevacizumab and erlotinib.

The best quality data are available for cetuximab since the 2006 publication of a randomized clinical trial comparing radiation treatment plus cetuximab versus radiation treatment alone. This study found that concurrent cetuximab and radiotherapy improves survival and locoregional disease control compared to radiotherapy alone, without a substantial increase in side effects, as would be expected with the concurrent chemoradiotherapy, which is the current gold standard treatment for advanced head and neck cancer. Whilst this study is of pivotal significance, interpretation is difficult since cetuximab-radiotherapy was not directly compared to chemoradiotherapy. The results of ongoing studies to clarify the role of cetuximab in this disease are awaited with interest.

Another study evaluated the impact of adding cetuximab to conventional chemotherapy (cisplatin) versus cisplatin alone. This study found no improvement in survival or disease-free survival with the addition of cetuximab to the conventional chemotherapy.

However, another study which completed in March 2007 found that there was an improvement in survival.

A 2010 review concluded that the combination of cetuximab and platin/5-fluorouracil should be considered the current standard first-line regimen.

Gendicine is a gene therapy that employs an adenovirus to deliver the tumor suppressor gene p53 to cells. It was approved in China in 2003 for the treatment of head and neck squamous cell carcinoma.

The mutational profile of HPV+ and HPV- head and neck cancer has been reported, further demonstrating that they are fundamentally distinct diseases.

Prognosis
Although early-stage head and neck cancers (especially laryngeal and oral cavity) have high cure rates, up to 50% of people with head and neck cancer 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-cell 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.

Problem of second primaries
Survival advantages provided by new treatment modalities have been undermined by the significant percentage of people cured of head and neck squamous cell carcinoma (HNSCC) who subsequently develop second primary tumors. The incidence of second primary tumors ranges in studies from 9% to 23% at 20 years. Second primary tumors are the major threat to long-term survival after successful therapy of early-stage HNSCC. Their high incidence results from the same carcinogenic exposure responsible for the initial primary process, called field cancerization.

Digestive system
As it can impair a person’s ability to swallow and eat, throat cancer affects the digestive system. The difficulty in swallowing can lead to a person to choke on their food in the early stages of digestion and interfere with the food’s smooth travels down into the esophagus and beyond.

The treatments for throat cancer can also be harmful to the digestive system as well as other body systems. Radiation therapy can lead to nausea and vomiting, which can deprive a body of vital fluids (although these may be obtained through intravenous fluids if necessary). Frequent vomiting can lead to an electrolyte imbalance which has serious consequences for the proper functioning of the heart. Frequent vomiting can also upset the balance of stomach acids which has a negative impact on the digestive system, especially the lining of the stomach and esophagus.

Respiratory system
In the cases of some throat cancers, the air passages in the mouth and behind the nose may become blocked from lumps or the swelling from the open sores. If the throat cancer is near the bottom of the throat it has a high likelihood of spreading to the lungs and interfering with the person’s ability to breathe; this is even more likely if the person is a smoker, because they are highly susceptible to lung cancer.

Others
Like any cancer, metastasization affects many areas of the body, as the cancer spreads from cell to cell and organ to organ. For example, if it spreads to the bone marrow, it will prevent the body from producing enough red blood cells and affects the proper functioning of the white blood cells and the body’s immune system; spreading to the circulatory system will prevent oxygen from being transported to all the cells of the body; and throat cancer can throw the nervous system into chaos, making it unable to properly regulate and control the body.

Treatment side effects
Depending on the treatment used, People with head and neck cancer may experience the following symptoms and treatment side effects:

Eating problems
Pain associated with lesions
Mucositis
Nephrotoxicity and ototoxicity
Xerostomia
Gastroesophageal reflux
Radiation-induced osteonecrosis of the jaw

Epidemiology
The number of new cases of head and neck cancers in the United States was 40,490 in 2006, accounting for about 3% of adult malignancies. 11,170 people died of their disease in 2006. The worldwide incidence exceeds half a million cases annually. In North America and Europe, the tumors usually arise from the oral cavity, oropharynx, or larynx, whereas nasopharyngeal cancer is more common in the Mediterranean countries and in the Far East. In Southeast China and Taiwan, head and neck cancer, specifically nasopharyngeal cancer is the most common cause of death in young men.

In 2008, there were 22,900 cases of oral cavity cancer, 12,250 cases of laryngeal cancer, and 12,410 cases of pharyngeal cancer in the United States.
In 2002, 7,400 Americans were projected to die of these cancers.
More than 70% of throat cancers are at an advanced stage when discovered.
Men are 89% more likely than women to be diagnosed with, and are almost twice as likely to die of, these cancers.
African Americans are disproportionately affected by head and neck cancer, with younger ages of incidence, increased mortality, and more advanced disease at presentation. Laryngeal cancer incidence is higher in African Americans relative to white, Asian and Hispanic populations. There is a lower survival rate for similar tumor states in African Americans with head and neck cancer.
Smoking and tobacco use are directly related to oropharyngeal (throat) cancer deaths.
Head and neck cancer increases with age, especially after 50 years. Most people are between 50 and 70 years old.

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