Head and neck cancer day is observed on July 27 every year. Head and neck cancers are cancers that can occur in the squamous cells lining the mucosal surfaces of the head and neck, which include the oral cavity, throat or pharynx, and voice box or larynx, and also in the mucosal surfaces of the paranasal sinuses, and salivary glands, and nerves in the head and neck. Squamous cells are thin cells that look like fish scales, are found in the tissue that forms the surface of the skin, the lining of the respiratory and digestive tracts, and the lining of the hollow organs of the body.
Head and neck cancers are also called squamous cell carcinomas of the head and neck, and may spread locally or to the lymph nodes in the neck.
Head and neck cancers can occur due to alcohol and tobacco use, secondhand smoke exposure, infection with cancer-causing types of human papillomavirus (HPV type 16), consumption of betel liquid, radiation exposure, occupational exposure, underlying genetic disorders, and the Epstein-Barr virus infection, which is a risk factor for nasopharyngeal cancer and cancer of the salivary gland.
ABP Live spoke to Dr Kanury VS Rao, Co-Founder and Chief Scientific Officer, PredOmix, a Gurugram-based health-tech company, and Dr Vikas Talreja, Medical Oncologist, Regency Hospital, Kanpur, and asked them about the factors which determine where head and neck cancers occur.
When oral cancer occurs, a white or red patch develops on the gums, the tongue, or the lining of the mouth, there could be unusual bleeding or pain in the mouth, or the jaw may swell, according to the US National Institutes of Health (NIH). Consumption of tobacco and alcohol, HPV infection, and prolonged UV radiation are risk factors for cancers in the oral cavity, the experts said.
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In the case of cancers of paranasal sinuses and nasal cavity, chronic sinus infections do not respond to treatment with antibiotics, sinuses become blocked, bleeding may occur through the nose, or frequent headaches may happen. Occupational exposure to certain substances such as wood dust, formaldehyde, nickel and certain chemicals increase the risk of cancers in the nasal cavity and paranasal sinuses, Dr Rao said.
According to Dr Talreja, smoking and family history of head and neck cancers can also play a role in cancers of the nasal cavity and paranasal sinuses.
Cancers of the salivary glands cause swelling under the chin or around the jawbone, pain in the face, chin or neck, or numbness of the muscles in the face.
"Previous radiation treatment to the head and neck region increases the risk of salivary gland cancers. Apart from this, some hereditary conditions, like familial adenomatous polyposis and Lynch syndrome, also contribute to salivary gland cancers," Dr Rao said.
Familial adenomatous polyposis is a genetic disorder in which cancers of the large intestine and rectum occur, and multiple growths called polyps take place in the colon.
Lynch syndrome is an inherited condition that increases the risk of developing colorectal cancer.
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"The specific causes of salivary gland cancer are not entirely understood, but factors like radiation exposure, certain genetic syndromes, and previous history of head and neck cancers may contribute to the development of salivary gland cancers," Dr Talreja said.
Throat cancer is characterised by pain when swallowing, pain in the ears, neck or throat, or trouble hearing.
According to Talreja, tobacco and alcohol use are the major risk factors for pharyngeal cancer. "HPV infection, particularly with high-risk strains like HPV 16, has been associated with an increasing number of pharyngeal cancers, especially in the tonsils and base of the tongue."
Laryngeal cancer is characterised by pain when swallowing, ear pain, or difficulty breathing or speaking.
Dr Rao said that heavy tobacco and alcohol consumption are the primary risk factors for laryngeal cancers. He also said that prolonged and excessive use of the voice, especially in professions that strain the vocal cords, may contribute to laryngeal cancer development.
Dr Talreja said that chronic irritation from tobacco smoke and alcohol may lead to cellular changes that can eventually result in cancer. "Gastro-oesophageal reflux disease (GERD) may increase the risk of laryngeal cancer due to the repeated exposure of stomach acid to the larynx.”
GERD occurs when stomach acid repeatedly flows back into the oesophagus, and the backwash, or acid reflux irritates the lining of the food pipe.
Dr Rao concluded that in India and other South Asian countries, tobacco and alcohol are the major culprits for linear growth of squamous cell carcinomas among men. "Since prevention is the best cure for this nemesis, early detection, timely medical intervention, and lifestyle changes can play a vital role in reducing the risk of these cancers, and improving outcomes for individuals at risk of these cancers."
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