Extending free vaccination to males could reduce the spread of the human papilloma virus, which is the primary cause of both cervical and oropharyngeal cancer.
The human papilloma virus (HPV) is a leading cause of several types of cancer. The World Health Organization (WHO) estimates that two types of HPV (16 and 18) cause 70% of all cervical cancer cases. According to the U.S. Center for Disease Control (CDC), HPV infection is responsible for about 70% of all oropharyngeal cancer cases in the country. Globally, oropharyngeal cancer caused by HPV infection is on the rise.
Cervical and oropharyngeal cancer are both prevalent in Taiwan. According to data compiled by the Ministry of Health and Welfare, cervical cancer is the fourth most common malignancy among women, with over 4,000 Taiwanese women afflicted annually. Those infected with HPV have a heightened risk of developing cervical cancer. Both of these cancers can be lethal, with a five-year survival rate of just 66% for cervical cancer and around 50% for cancer of the oropharynx.
The WHO has set a goal of eliminating cervical cancer globally by 2030. It estimates that to achieve that goal, all countries must reach and maintain an incidence rate of below four per 100,000 women, which requires vaccinating 90% of women under the age of 15.
Taiwan in late 2018 began a program subsidizing school-based HPV vaccination for girls entering junior high and by mid-2020 had achieved a vaccination rate of 60%.
However, due to vaccine hesitancy, getting to 90% is not easy, says Dr. Chang Chih-Long, director of the Department of Medical Research at Taipei’s Mackay Memorial Hospital and a senior gynecology oncologist. “Resistance to vaccination is a persistent challenge,” he says. “Even in the case of a disease as dangerous as COVID-19 [for which the benefits of inoculation are high], we find that reaching a 70% vaccination target is not easy in many countries.”
Chang suggests that Taiwan adjust its vaccination strategy to overcome vaccine hesitancy. Instead of focusing solely on women, he believes Taiwan should aim to vaccinate a certain percentage of the population of both sexes. In that case, it would not be essential to vaccinate such a high proportion of women. Also, men are often carriers of HPV through their sexual behavior, so vaccinating them is important for reducing the spread of the virus, he says. Inoculating men would not only help reduce the incidence of cervical cancer, but also oropharyngeal cancer, which disproportionately affects males.
“Men tend to think that HPV infection is something women need to worry about, because of the focus on its link to cervical cancer,” Chang says. “But the rise in oropharyngeal cancer caused by HPV infection in men shows that HPV is something they absolutely should be concerned about, especially as their immune systems may be less effective than women’s at fighting off the viral infection.”
A study published in April that examined records and tumor samples from 541 predominantly male (94%) Taiwanese patients treated at the Linkou Chang Gung Memorial Hospital in Taoyuan County between 1998 and 2016 for oropharyngeal squamous cell carcinoma (OPSCC) found that 28% of tumors were HPV-positive. 81% of patients used tobacco, which is another risk factor for oropharyngeal malignancies.
“As with HPV-positive OPSCC globally, HPV is an increasingly important etiological factor in Taiwanese OPSCC,” wrote the researchers of the study, which was published by the San Francisco-based non-profit PLOS.
However, there is some cause for optimism about the prospects of such patients. A University of Michigan Health Lab blog post published in April noted that HPV-positive oropharyngeal cancer “generally is more responsive to treatments and results in better outcomes than HPV-negative cancers, and that “this held true with the Taiwan patients.”
Besides persuading men to get vaccinated against a virus they may think is irrelevant to them, there is also a challenge with screening, Chang says. While Taiwan has a long-running and highly successful cervical cancer screening program, there is no equivalent for cancer of the oropharynx.
Still, free HPV vaccination for men has many clear advantages – including the potential to raise awareness of the risk HPV infection poses to men – even in the absence of an accompanying screening program, and should be seriously considered, he says. “Reducing the spread of HPV in the population is a step-by-step process.”