HEAD AND NECK CANCERS
Head and neck cancer as a disease that affects the upper aerodigestive tract (UADT). They normally arise from the epithelium or covering of these structures and for this reasons are mostly squamous cell carcinomas. Structures that are commonly affected are the oral cavity, pharynx, larynx, nasal cavity & paranasal sinuses, and salivary glands.
How frequent is head and neck cancers?
Head and neck cancer account for approximately 4% of all cancers in the United States. The estimated incidence of head and neck cancer in 2017 was 65,000.
The overall frequency of head and neck cancer is quite high and accounts for more than 550, 000 cases annually worldwide.
Males are affected significantly more than females with a ratio ranges from 2: 1 to 4: 1.
What are the causes and risk factors for head and neck cancers?
Head and neck cancer is considered a multifactorial entity but the most common causes and risk factors include:
1. Smoking: E heavy cigarette smokers, there is a 5- to 25 fold increase of cancer compared to with non-smokers. 75% of all cases of head and neck cancer in the United States are associated with smoking and alcohol.
- Alcohol: Alcohol consumption independently increases the risk of cancer in the upper digestive tract.
- Viral infections
- Epstein-Barr virus: Large body of evidence supports the role of Epstein-Barr virus as the primary etiology agent in the pathogenesis of nasopharyngeal carcinoma.
- human papillomavirus, HPV: HPV now causes most oropharyngeal cancers in the U.S. Immunologic molecular evidence has established a causal role for HPV, primarily type 16, in patients with head and neck cancer particularly those arising in the base of the tongue and tonsils. HPV associated oropharyngeal cancers are typically seen in younger men who are nonusers of the tobacco. In the United States, the incidence of oropharyngeal cancer caused by HPV infection is increasing, while the incidence of oropharyngeal cancer related to other causes is falling. Over 20 million Americans have some type of genital or oral HPV infection. HPV is a sexually transmitted infection that can infect the oropharynx (tonsils and back of the throat), anus, and genitals. In some people with oral HPV infection, leads to HPV-OSCC (HPV-positive oropharyngeal squamous cell cancer) after many years. It is recommended that oropharyngeal tumors be tested for HPV. HPV is transmitted to your mouth by oral sex. It may also be possible to get oral HPV in other ways. Performing oral sex and having many oral sex partners can increase your chances of oral HPV infection. Around 10% of men and 3.6% of women in the U.S. have HPV in their mouths and HPV infection is more commonly found with older age. Most people clear the infections on their own within a year or two, but in some people, HPV infection persists. Oropharyngeal cancer patients with HPV in their tumor live longer, on average than people without HPV (i.e. HPV-positive tumors usually respond well to therapy). However, patients who currently smoke tobacco or have smoked for a long time in the past do not live as long as patients who never smoked. Patients who are current smokers should consider quitting.
- Human immunodeficiency virus: There is an approximately 2-3 fold increase in the incidence of a squamous cell carcinoma of the head and neck in HIV- infected patients
- Occupational exposure: Exposure to dry cleaning agent perchloroethylene, asbestos, pesticides, polycyclic aromatic hydrocarbons, textile workers, woodworkers, metals, ceramics, food industry, and login
- The formaldehyde is associated with nasal and possible cancers of the nasal cavity or paranasal sinuses.
- Squamous cell carcinoma of the larynx and base of the tongue has also been associated with exposure to agent orange.
- Genetic and hereditary factors can be associated with throat and mouth cancer. The analysis of the genes in head and neck cancer was based on public currently available gene expression data and clinical made at data from the Cancer Genome Atlas, consisting of 499 patients. According to the analysis, 792 genes were associated with prognostic outcome, out of which 341 images were associated with unfavorable prognosis and 451 with a favorable prognosis. The LIMA 1 gene, a cytoskeletal-associated protein is associated with an unfavorable prognosis. CALM L5, calcium binding protein that may be implicated in different deviation of keratinocytes, shown to be associated with a favorable prognosis. The NOTCH is a common mutation found
In squamous cell carcinoma of the head and neck; this is a genetic mutation has also been previously implicated in a number humans tumor type, including colon, breast, and pancreatic cancers.
other risk factors for cancer of the head and neck include the following:
PAAN (Betelquit). The immigrant from South East Asia to use PAAN in the mouth should be aware that he should have it has been strongly associated with an increased risk of oral cancer.
Preserve or salty foods. Consumption of certain preserve of salty foods during childhood is a risk factor for nasopharyngeal cancer.
How are head and neck cancers classified?
Head and neck cancers arise from a variety of locations of the structures within the head and neck region. This region is normally divided into 5 sites by which cancers are classified:
- Oral cavity, which includes the lips, buccal mucosa, anterior tongue, the floor of the mouth, hard palate, upper gingiva, lower gingiva, and retromolar trigone.
- Pharynx, which is divided into the nasopharynx, the oropharynx, and the hypopharynx.
The nasopharynx, the narrow tubular passage behind the nasal cavity, is the upper part of the pharynx.
The oropharynx, the middle part of the pharynx, includes the tonsillar area, the tongue base, the soft palate, and the posterior pharyngeal wall.
The hypopharynx, which is the lower part of the pharynx, includes the pyriform sinuses, the posterior surface of the larynx (post-cricoid area) and the inferoposterior, and inferolateralpharyngeal walls.
- The larynx is divided into 3 anatomic regions: The supraglottic larynx, the glottic larynx (true vocal cords and the anterior and posterior commissure) and the subglottic larynx.
- Nasal cavity and paranasal sinuses, which include the maxillary, ethmoid, sphenoid, and frontal sinuses.
- Major salivary glands (parotid, submandibular, and sublingual) and minor salivary glands, which are located throughout the submucosa in the mouth and the upper aerodigestive tract.
What are the types of cancers in the head and neck?
Squamous cell carcinomas account for 90 to 95 percent of the lesions in the head and neck. They can be categorized as well differentiated (greater than 75 percent keratinization), moderately differentiated (25 to 75 percent keratinization), and poorly differentiated (less than 25 percent keratinization) tumors. Less common histologies include verrucous carcinoma (a variant of squamous cell carcinoma), adenocarcinoma, adenoid cystic carcinoma, and mucoepidermoid carcinomas.
What are the symptoms of head and neck cancers?
Symptoms can vary according to location
Oropharyngealtumors–Presenting complaints can include pain, pain in swallowing, bleeding, or a neck mass.
Nasopharyngeal carcinoma–The most frequent presenting complaint is a neck mass due to regional lymph node metastasis, which occurs in nearly 90 percent of patients.
Symptoms due to the primary tumor may include hearing loss (associated with serous otitis media), tinnitus, nasal obstruction and pain, and its associated growth into adjacent anatomical structures, which can lead to muscle involvement and impaired function of cranial nerves II to VI.
Hypopharyngealtumors–Patients with these tumors often remain asymptomatic for a longer period and are therefore more likely to be seen in the later stages of the disease. Pain in swallowing otalgia, weight loss, and neck mass are common presenting symptoms.
Laryngeal cancer–The symptoms associated with cancer of the larynx depend upon location
Persistent hoarseness may be the initial.
the complaint in glottic cancers; later symptoms may include pain in swallowing, referred ear pain, chronic cough, hemoptysis, and stridor.
Supraglottic cancers are often discovered later and may present with airway obstruction or palpable metastatic lymph nodes.
Primary subglottic tumors are rare. Affected patients typically present with stridor or complaints of dyspnea on exertion.
Sinus tumors–Common presenting symptoms of sinus tumors include nose bleeding and unilateral nasal obstruction.
Facial and/forehead pain may be seen in later stages, due to pressure or tumor infiltration into nerves or periosteum.
How is head and neck cancer diagnosed?
A thorough physical exam is essential along with an endoscopy examination.
If your doctor sees any suspicious lesion a biopsy is performed and send for pathology examination.
Fine needle aspiration cytology—Fine needle aspiration cytology (FNA) is frequently used to make an initial tissue diagnosis of a head and neck cancer when a patient presents with a neck mass (metastatic cervical lymph node) without an obvious site.
Imaging studies—Imaging studies.
(computed tomography [CT], magnetic resonance imaging [MRI], positron emission tomography [PET], and integrated PET/CT)are important for assessing the degree of local infiltration, the involvement of regional lymph nodes, and presence of distant metastases or second primary tumors.
Staging for head and neck cancer
The tumor node metastases(TNM) staging system of the American Joint Committee on Cancer (AJCC) and the International Union for Cancer Control (UICC) is used to classify cancers of the head and neck.
T classifications indicate the extent of the primary tumor and are site-specific
Treatment for head and neck cancer is complex due to the Variety of tumor subsites and anatomic constraints of the head and neck. The Importance of maintaining organ function. A multidisciplinary approach including
EARLY STAGE: Approximately 30 to 40 percent of patients with head and neck squamous cell carcinomas (HNSCCs) present with early (stage I and II) disease.
In general, these patients are treated with either primary surgery or definitive radiation therapy(RT). Five-year overall survival in patients with stage I or stage II disease is typically 70 to 90 percent.
ADVANCED STAGE: Effective approaches for locoregionally advanced head and neck squamous cell carcinomas include
Primary surgery followed by either postoperative RT or concurrent chemoradiation
Induction chemotherapy followed by concurrent chemoradiotherapy
Neo (adjuvant –in addition to) chemotherapy the drugs may shrink the tumor and give more surgical options.
What are the side effects of treatment of head and neck cancer?
Surgery and chemoradiation have a variety of the effects on patients. It often changes the patient’s ability to swallow chew, swelling of the neck, or talk.
Redness, irritation, sores in the mouth, difficulty swallowing, changes in taste, or nausea are the changes in patients who have received radiation to the head and neck. If There are changes should be reported to the doctor and nurses so you can learn how to deal with them.
The information in this document does not replace a medical consultation. It is for personal guidance use only. We recommend that patients ask their doctors about what tests or types of treatments are needed for their type and stage of the disease.
- American Cancer Society
- The National Cancer Institute
- National Comprehensive Cancer Network
- American Academy of Gastroenterology
- National Institute of Health
- MD Anderson Cancer Center
- Memorial Sloan Kettering Cancer Center
- American Academy of Hematology