Head and neck cancer refers to a group of cancers that originate in the head and neck region. These malignancies can develop in various locations, including the oral cavity, throat (pharynx), voice box (larynx), nasal cavity, and salivary glands.
Understanding Head and Neck Cancer Occurrence
Head and neck cancers account for approximately 4% of all new cancer cases annually in the United States, with an estimated 66,000 new diagnoses each year. While these cancers can affect individuals of any age, they are more frequently diagnosed in older adults, with the average age at diagnosis typically around 60 to 70 years. Men are diagnosed with head and neck cancers at a rate two to three times higher than women, reflecting differing exposure patterns to certain risk factors. Geographical variations also exist, with certain regions showing higher incidence rates.
The oral cavity and oropharynx (the middle part of the throat behind the mouth) are among the most common sites for these cancers to develop. Squamous cell carcinoma, which originates from the flat cells lining these areas, accounts for over 90% of all head and neck cancers.
Survival and Prognosis
The prognosis for individuals with head and neck cancer varies significantly depending on the cancer’s location, stage at diagnosis, and the patient’s overall health. The overall 5-year survival rate for head and neck cancers combined is approximately 60%.
Survival rates improve considerably when the cancer is detected at an early stage, before it has spread extensively. For localized head and neck cancers, where the tumor is confined to its original site, the 5-year survival rate can be as high as 84%. However, if the cancer has spread to regional lymph nodes, the survival rate decreases to around 65%, and for distant metastases, where the cancer has spread to other parts of the body, the survival rate drops to approximately 40%.
Mortality and Trends
Head and neck cancers contribute significantly to cancer-related mortality each year. In the United States, these cancers are responsible for over 15,000 deaths annually. While this number is substantial, it is lower than the mortality rates for more prevalent cancers such as lung, colorectal, and breast cancer.
Mortality trends for head and neck cancers have shown some shifts over time. Death rates for oral cavity and pharyngeal cancers generally decreased from 2000 to 2019, with an average decline of 1.7% per year. This decline is partly attributed to reduced tobacco use in many populations and improvements in treatment approaches. However, mortality rates for oropharyngeal cancers linked to Human Papillomavirus (HPV) infection have shown a different trend, with some studies indicating a stabilization or slight increase in certain demographics, reflecting the changing epidemiology of the disease.
Key Risk Factors and Their Impact
Several factors are strongly linked to the development of head and neck cancers, with tobacco and alcohol consumption being historically dominant. Tobacco use, whether smoking cigarettes, cigars, pipes, or using smokeless tobacco, is a major cause, accounting for an estimated 85% of head and neck cancers. The risk increases significantly with the duration and intensity of tobacco use. Similarly, heavy alcohol consumption independently increases the risk, and combining tobacco and alcohol poses a synergistic effect, elevating the risk even further than either factor alone.
Human Papillomavirus (HPV) infection, particularly HPV type 16, has emerged as a growing risk factor, especially for oropharyngeal cancers. HPV-positive oropharyngeal cancers now account for an estimated 70% of all oropharyngeal cancer cases in the United States, and this proportion has been increasing. The presence of HPV infection changes the biological characteristics of these tumors and often leads to a better prognosis compared to HPV-negative cancers. Other less common risk factors include exposure to certain industrial chemicals, occupational exposures to wood dust, and poor nutrition.