Head and Neck Cancer

• In a global gender analysis of HPV-related head and neck cancer, it is evident that the incidence rate among males is significantly higher than that among females. In the 2018 Cancer Annual Report, the incidence rate of oropharyngeal cancer (standardized to the 2000 World Population Age Standard) in males was 8.37 per 100,000, surpassing 7.85 per 100,000 for female cervical cancer.
• According to data from The Hong Kong Cancer Registry (HKCaR), in 2020, two-thirds of head and neck cancer patients (including lip, tongue, salivary glands, oral cavity, tonsils, oropharynx, hypopharynx, other unspecified oral sites, nasal cavity, middle ear, and paranasal sinuses) were males.
• From 2010 to 2020, the incidence of new head and neck cancer cases in Hong Kong increased by 25%, and in 2020, two out of every three new cases were males. On the other hand, for local oropharyngeal cancer cases alone, 80% of the patients were males.
• Up to this day, the global incidence rate of HPV-related head and neck cancer in males remains significantly higher than in females. The composition of tonsil cells is highly similar to that of cervical cells, making them susceptible to continuous HPV infection, which can progress into tonsil cancer. Data shows that the number of HPV-related tonsil cancer cases is on the rise in China, Hong Kong, and Taiwan, with approximately 60-70% of tonsil cancer cases being HPV-related, approaching the proportions seen in Western countries.

• The symptoms of head and neck cancer vary depending on the primary site of origin:
  - If the primary site is in the oral cavity, it may present as ulcers inside the mouth that are difficult to heal and painful.
  - If it's in the oropharynx, it can lead to difficulty swallowing, bad breath, discomfort and pain in the throat.
  - If it's in the hypopharynx or throat, it might cause hoarseness, painful swallowing, difficulty swallowing, or the appearance of a lump in the neck.
   
• Enlargement of neck lymph nodes can also be a common symptom of head and neck cancer. Different primary locations of head and neck cancer may lead to enlargement of lymph nodes in different areas, and this should be closely monitored.

Because symptoms can vary depending on the primary site, it is essential to consult a doctor for an examination if you experience the above-mentioned symptoms to avoid missing the opportunity for treatment.

Infection with the Human Papillomavirus (HPV) is one of the causes of head and neck cancer:

• HPV is primarily transmitted through sexual contact, coming into contact with skin wounds, mucous membranes, or infected bodily fluids. In addition to genital areas, oral sex can lead to oral HPV infection. Prolonged HPV infection that the body cannot clear on its own may lead to head and neck cancer, affecting both men and women.
• Research in the United States has shown more cases of HPV-related oropharyngeal cancer in males than in females. This is because males engage in more relative sexual behaviour than females, increasing their chances of detecting HPV infection in the oral cavity.

There is no routine oral HPV screening for head and neck cancer, and most cases are diagnosed in later stages, significantly affecting a patient's appearance and social life after treatment. Therefore, it is advisable to receive the HPV vaccine early as a preventive measure against HPV-related head and neck cancer.

Diagnosis

When the doctor suspects a patient may have head and neck cancer, they will recommend a tissue examination to determine the presence of cancerous cell changes. This is typically performed by an otolaryngologist (ear, nose, and throat specialist) using an endoscope. Suppose the otolaryngologist deems taking a tissue sample with an endoscope is inappropriate. In that case, the doctor may arrange other relevant tests based on the severity of the patient's condition and specific needs. These additional tests may include imaging studies of the head and neck (such as CT scans or MRIs), chest examinations, abdominal examinations, and various blood tests. These tests help provide a comprehensive understanding of the patient's condition at an early stage and assess whether there is any cancer cell metastasis.

Treatments

*The treatment plan should be determined through consultation between the doctor and the patient, considering the specific circumstances of the cancer.

1. de Martel C, et al. Lancet Global Health. 2020;8:e180-e190
2, 3. Hong Kong Cancer Registry, Hong Kong Authority. Available at: https://www3.ha.org.hk/cancereg/allagesresult.asp.
4. American Cancer Society. Key Statistics for Oral Cavity and Oropharyngeal Cancers. Available at: https://www.cancer.org/cancer/oral-cavity-and-oropharyngeal-cancer/about/key-statistics.html.