filedHPVIt is natural for everyone to remembercervical cancerbut do you know that as one of the top ten cancers in Hong Kong menhead and neck cancerIt also has a relationship that cannot be ignored with HPV.
Head and neck cancer is a general term for cancers of the upper respiratory tract. According to the location of the cancer, it can be divided into nasopharyngeal cancer, mouth cancer, tongue cancer, throat cancer and salivary gland cancer .About 90% of head and neck cancer tumor typessquamous cell carcinoma(squamous cell carcinoma-SCC) is formed by squamous cell lesions on the mucosal surface of the head and neck. In the past ten years, the number of new cases of head and neck cancer in Hong Kong has continued to rise every year, with an increase of up to 40%.
The Faculty of Medicine of the Chinese University of Hong Kong published a research report in 2016. The analysis showed that one in five oral and oropharyngeal cancer patients in Hong Kong were infected with HPV, and they were younger than other non-HPV oropharyngeal patients cancer, and most of them are non-smokers or alcoholics. In the global gender analysis of HPV-related head and neck cancer research published by international scholars in 2020, the incidence rate of male oropharyngeal cancer was 8.37 / per 100,000 population, which has exceeded the rate female cervical cancer of 7.85 / per 100,000 of the population.
In June of the same year, the US Food and Drug Administration (FDA) conditionally approved Merck’s nine-valent HPV vaccine for the prevention of oral and other cancers of the head and neck. Before this, the HPV vaccine was mainly promoted for the prevention of cervical and rectal cancer, and did not cover head and neck cancer. Although the protective effect of the nine-valent HPV vaccine on head and neck cancer has not been verified by large-scale studies, according to the instructions on the FDA approval letter, the authorities pre-approved the vaccine for use based on reasonable assumptions about the effectiveness of the vaccine in preventing cervical and rectal cancer Prevention of head and neck cancer. However, this approval comes with a condition, that is, if Merck can directly prove that the vaccine can effectively prevent persistent oral HPV infection in future clinical trials, otherwise the authorities have the opportunity to suspend the approval .
Head and neck cancer is very common in Taiwan, ranking fourth in the national cancer statistics, after colorectal cancer, lung cancer and liver cancer (so many head and neck surgeons like to go to Taiwan for exchange and overseas training). Local data showed that among patients with oropharyngeal cancer caused by HPV, 82.8% were HPV 16 and 7.5% were HPV 58. Both are common types that cause cervical cancer and are the types that have included in the 9-valent vaccine. In addition, an American epidemiological study found that after the HPV vaccine was launched on the market, the rate of oral infection of the corresponding HPV type decreased significantly. Even among unvaccinated men, oral HPV infection rates decreased, suggesting that vaccination has a herd protection function. Perhaps it was these epidemiological data that convinced the FDA to approve early.
It should be noted that being infected with HPV does not mean that it will definitely become cancer. Most HPV infections are asymptomatic, and the incubation period of the virus is as high as ten years, during which time it can be transmitted from person to person. HPV is mainly transmitted through sexual contact with skin wounds, mucous membranes or body fluids, and oral sex can also cause oral infections. Although the human body can clear most HPV infections automatically, if the infection persists for a long time, it can cause cancer. Unfortunately, there is currently no targeted drug to treat HPV in the body, including vaccination cannot be used to treat HPV infection. Therefore, the best time to prevent HPV is before sexual activity, for example, the World Health Organization (WHO) recommends that children receive their first dose of the HPV vaccine when they are 9-14 years old.
Currently, the application of the 9-valent HPV vaccine in Hong Kong is limited to the prevention of cervical cancer, rectal cancer and genital warts (ie cauliflower). At the same time, the discussion of head and neck cancer in Hong Kong is very low, and it is easy to ignore. It is hoped that the government will strengthen knowledge about head and neck cancer while promoting health education, and consider expanding the application of the HPV vaccine in the prevention of head and neck cancer.
Subject: Dr. Lai Yat-ling, Honorary Clinical Assistant Professor of Surgery, University of Hong Kong
