HPV: how vaccines and research are changing the history of the virus

The human papillomavirus (HPV) is one of the most widespread sexually transmitted viruses in the world: it is estimated that over 80% of the population will be infected at least once in their lifetime. In most cases, the infection is asymptomatic and resolves spontaneously through the immune system. However, some HPV variants – especially the high-risk strains such as 16 and 18 – can persist in the body and cause tumour-causing lesions: according to the WHO, the papillomavirus is in fact responsible for almost all cervical cancers, for an increasingly large proportion of anogenital and pharyngeal (tonsil and tongue base) cancers.

Prevention plays a crucial role in counteracting this risk: vaccination against HPV has proved highly effective in preventing infections by the most dangerous strains, significantly reducing the risk of developing precancerous lesions and tumours by as much as up to 90% thus potentially allowing us to eradicate cervical cancer and significantly reduce the incidence of other related cancers in the future.

Prevention: vaccine and screening

HPV vaccines protect against high-risk viral strains and are recommended for both girls and boys. In Italy, the vaccination is offered free of charge from the age of 11 to 26.

Despite the effectiveness of this vaccination, which is essential for both sexes, screening in the female population is equally important. The Pap test and HPV test enable early detection of the virus and any precancerous lesions. Guidelines recommend the Pap test every three years for women between the ages of 25 and 30, and the HPV test every five years for women over 30.

‘It is crucial to dispel some persistent myths about HPV vaccination: the vaccine has been widely shown to be safe and well-tolerated, and there is no scientific evidence that the vaccine encourages early initiation of sexual activity. Finally, it is important to stress that vaccination is not a substitute for regular screening in women, as it does not protect against all HPV strains,’ explain Domenica Lorusso and Paolo Bossi – both professors at Humanitas University and responsible, respectively, of Gynecological Oncology at Humanitas San Pio X and Head and Neck Tumour Oncology at IRCCS Istituto Clinico Humanitas.

The commitment of gynaecological cancer research

In addition to prevention, research plays a crucial role in improving treatments for gynaecological cancers caused by HPV. Italian research has played a fundamental role in advancing the treatment of cervical cancer, leading to results that are tangibly changing patients’ lives thanks to the combined use of chemotherapy and immunotherapy.

To cite a recent example, the international KEYNOTE-A18 study led by Prof. Lorusso showed that immunotherapy with pembrolizumab combined with chemoradiation therapy reduced the risk of death in patients with locally advanced cervical cancer by 33%. ‘This result represents a significant step forward in the treatment of a disease that, although preventable, continues to affect many women,’ says the specialist. ‘The long-term goal of complete eradication of cervical cancer remains, which as the WHO reminds us, is only possible through the combined use of vaccination, screening and access to advanced therapies.’

HPV and head and neck cancer: more awareness is needed

As already mentioned, HPV infections are not only implicated in the development of genital cancers, but also in head and neck cancers, since the virus can be transmitted during oral sex. A further reason to emphasise the importance of vaccination in men. The papillomavirus is in fact a carcinogenic agent for neoplasms of the pharynx (in particular the tonsils and base of the tongue), and the infection is responsible for 32-36% of these tumours.

‘Again, prevention through HPV vaccination is a key tool to reduce the impact of these diseases,’ explains Paolo Bossi. ‘Thanks to Research, we are now achieving fundamental progress in the identification of biomarkers for early diagnosis, also by means of liquid biopsy, and in the development of more effective therapies – I am thinking of immunotherapy or targeted radiotherapy strategies – which are significantly improving patients’ prognosis and quality of life.’