Бас және мойын аймағының қатерті және оның белгілері

Cancer arises in the head or neck region

Head and neck cancer develops from tissues in the lip and oral cavity (mouth), larynx (throat), salivary glands, nose, sinuses, or skin of the face. The most common types of head and neck cancer occur in the lips, mouth, and larynx. The majority of head and neck cancer is caused by the use of alcohol or tobacco, including smokeless tobacco, with increasing cases linked to the human papillomavirus (HPV). The diagnosis is confirmed by a tissue biopsy. This is because oropharyngeal cancer typically presents in the 4th–6th decade of life, and this is a relatively new vaccine. While screening in the general population does not appear to be useful, screening high risk groups by examination of the throat might be useful. The 2017 worldwide figure cites head and neck cancers as representing 5.3% of all cancers (not including non melanoma skin cancers). The usual age at diagnosis is between 55 and 65 years old.

Symptoms predominantly include a sore on the face or oral cavity that does not heal, trouble swallowing, or a change in voice. In those with advanced disease, there may be unusual bleeding, facial pain, numbness or swelling, and visible lumps on the outside of the neck or oral cavity. Head and neck cancer often begins with benign signs and symptoms of the disease, like an enlarged lymph node on the outside of the neck, a hoarse sounding voice, or a progressive worsening cough or sore throat. In the case of head and neck cancer, these symptoms will be notably persistent 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 difficulty or pain in swallowing. Speaking may become difficult. There may also be a persistent earache. Other symptoms can include: a lump in the lip, mouth, or gums; ulcers or mouth sores that do not heal; bleeding from the mouth or numbness; bad breath; discolored patches that persist in the mouth; a sore tongue; and slurring of speech if the cancer is affecting the tongue. There may also be congested sinuses, weight loss, and some numbness or paralysis of facial muscles.

Squamous cell cancers are common in areas of the mouth, including the inner lip, tongue, floor of the mouth, gums, and hard palate. Cancers of the mouth are strongly associated with tobacco use, especially the use of chewing tobacco or dipping tobacco, as well as heavy alcohol use. Cancers of this region, particularly the tongue, are more frequently treated with surgery than other head and neck cancers. Lip and oral cavity cancers are the most commonly encountered types of head and neck cancer.

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 head and neck squamous cell carcinomas (HNSCCs), "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.

Most oropharyngeal cancers are squamous cell carcinomas that begin 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 outcome than HPV negative disease, with a 54% better survival rate, but this advantage for HPV associated cancer applies only to oropharyngeal cancers. People with oropharyngeal carcinomas are at high risk of developing a second primary head and neck cancer.

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.

Laryngeal cancer begins in the larynx, or "voice box", and is the second most common type of head and neck cancer encountered. Most tumors of the salivary glands differ from the common squamous cell 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.

Around 75% of cases are caused by alcohol and tobacco use. Acrylonitrile appears to indirectly cause DNA damage by increasing oxidative stress, leading to increased levels of 8 oxo 2' deoxyguanosine (8 oxo dG) and formamidopyrimidine in DNA. (see image). Both 8 oxo dG and formamidopyrimidine are mutagenic. DNA glycosylase NEIL1 prevents mutagenesis by 8 oxo dG and removes formamidopyrimidines from DNA. However, cigarette smokers have a lifetime increased risk for head and neck cancer that is 5 to 25 times higher than the general population. The ex smoker's risk of developing head and neck cancer begins to approach the risk in the general population 15 years after smoking cessation. Smokeless tobacco is a cause of oral cancer and oropharyngeal cancer. Smokeless tobacco (including products where tobacco is chewed) is associated with a higher risk of developing head and neck cancer; this link has been established in the United States as well as in East Asian countries. Cigar smoking is also an important risk factor for oral cancer. The use of electronic cigarettes may also lead to the development of head and neck cancers due to the substances like propylene glycol, glycerol, nitrosamines, and metals contained therein, which can cause damage to the airways. Vitamin E was not found to prevent the development of leukoplakia, the white plaques that are the precursor for carcinomas of the mucosal surfaces, in adult smokers. Another study examined a combination of vitamin E and beta carotene in smokers with early stage cancer of the oropharynx and found a worse prognosis in vitamin E users.

Betel nut chewing is associated with an increased risk of squamous cell carcinoma of the head and neck.

The presence of gastroesophageal reflux disease (GERD) or laryngeal reflux disease can also be a major factor. Stomach acids that flow up through the esophagus can damage its lining and raise susceptibility to throat cancer.

People after hematopoietic stem cell transplantation (HSCT) are at a higher risk for oral squamous cell carcinoma. Post HSCT oral cancer may have more aggressive behavior and a poorer prognosis when compared to oral cancer in non HSCT patients. This effect is supposed to be due to continuous, lifelong immune suppression and chronic oral graft versus host disease. while other studies suggest use is not shown to be associated with oral squamous cell carcinoma or decreased squamous cell carcinoma.

A person usually presents to the physician complaining of one or more of the above symptoms. The person will typically undergo a needle biopsy of this lesion, and if histopathologic information is available, a multidisciplinary discussion of the optimal treatment strategy will be undertaken between the radiation oncologist, surgical oncologist, and medical oncologist. Most (90%) cancers of the head and neck are squamous cell derived, termed "head and neck squamous cell carcinomas".

Squamous cell carcinoma is a cancer of the squamous cell, a kind of epithelial cell found in both the skin and mucous membranes. It accounts for over 90% of all head and neck cancers,

Adenocarcinoma is a cancer of the epithelial tissue that has glandular characteristics. Several head and neck cancers are adenocarcinomas (either of intestinal or non intestinal cell types).

Avoidance of recognized risk factors (such as smoking and alcohol) is the single most effective form of prevention. Regular dental examinations may identify pre cancerous lesions in the oral cavity. After a histologic diagnosis has been established and tumor extent determined, such as with the use of PET CT, 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, medical oncologists, 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. For 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 have been recognized as less than satisfactory, there has been an emphasis on the use of various induction or concomitant chemotherapy regimens.

Surgery as a treatment is frequently used for 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, the 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 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 treatment 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. Radiation therapy for head and neck cancers can also cause acute skin reactions of varying severity, which can be treated and managed with topically applied creams or specialist films.

Chemotherapy for 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 themselves 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 the 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. There is no evidence that erythropoietin should be routinely given with radiotherapy.

Photodynamic therapy may have promise for treating mucosal dysplasia and small head and neck tumors.

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 therapies used in squamous cell carcinomas of the head and neck include cetuximab, bevacizumab, and erlotinib. Cetuximab is used for treating people with advanced stage cancer who cannot be treated with conventional chemotherapy (cisplatin). However, cetuximab's efficacy is still under investigation by researchers. 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 profiles of HPV+ and HPV head and neck cancer have been reported, further demonstrating that they are fundamentally distinct diseases.

Immunotherapy is a type of treatment that activates the immune system to fight cancer. One type of immunotherapy, immune checkpoint blockade, binds to and blocks inhibitory signals on immune cells to release their anti cancer activities. In 2016, the FDA granted accelerated approval to pembrolizumab for the treatment of people with recurrent or metastatic HNSCC with disease progression on or after platinum containing chemotherapy. Later that year, the FDA approved nivolumab for the treatment of recurrent or metastatic HNSCC with disease progression on or after platinum based chemotherapy. In 2019, the FDA approved pembrolizumab for the first line treatment of metastatic or unresectable recurrent HNSCC.

Depending on the treatment used, people with head and neck cancer may experience the following symptoms and treatment side effects: There is no clear evidence on the effectiveness of these interventions or any particular type of psychosocial program or length of time that is most helpful for those with head and neck cancer. 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. HPV associated oropharyngeal cancer has been shown to respond better to chemoradiation and, subsequently, have a better prognosis compared to non associated HPV head and neck cancer.