Viral Infection May Drive Squamous Cell Skin Cancer Development

Global initiatives to eradicate the human papillomavirus (HPV) might have unexpected benefits towards reducing skin cancer. Although renewed efforts targeting HPV focus on eliminating cervical cancer, a research group in Taiwan showed a long-term association between HPV and skin cancers.

The study’s results demonstrated significantly higher risks for basal cell carcinoma, squamous cell skin cancer, and melanoma among individuals infected with HPV. Among the types of skin cancers, squamous cell had the highest risk, highlighting a strong correlation to HPV.

HPV is a known causative factor for cervical, oral, anal, penile, and other cancers. However, most HPV infections resolve within a few years without leading to cancer. Since infections do not show clear symptoms, an infected individual may not be aware of their status.

The virus attacks powerful tumor-fighting proteins in the cell, essentially weakening the cell and allowing DNA corruption or mutations to pile up. Mutations or other DNA damage that is not repaired can lead to cancer. A robust immune system can stop the viral infection over time, so most infected individuals will not develop cervical, oral, or other HPV-associated cancers.

Still, the research group in Taiwan wanted to assess whether there were lingering risks of skin cancer among the population. To address this question, they accessed a national research database in Taiwan that contains medical records of 26 million people. They filtered for age, sex, HPV status, dates, and occupational sun exposure. They ultimately used a 1:2 ratio of one HPV-exposed individual to every two control individuals for a combined total of 2,819,622 people.

With the association, the incidence of squamous cell skin cancer continues to expand and multiply over time for those with HPV. At the same time, incidence increases very slowly among individuals who are not infected. The trend was similar for basal cell carcinoma, and to a lesser extent, melanoma.

The study also showed that males exhibited a higher risk of developing skin cancer when they were compared with females. The age groups indicated an increased risk for skin cancer with advancing age. Also, participants with hypertension had a higher risk of skin cancer. Multiple reports have also linked light-sensitizing, antihypertensive (such as hydralazine and hydrochlorothiazide) medications to an increased risk for skin cancer.

The results are supported by findings in other studies. Research from investigators in Greece detected HPV in biopsies of melanomas. A study on the Australian population found a link between HPV and the formation of squamous cell skin cancer.

The authors suggest that HPV may cause infected individuals to become more sensitive to damage from ultraviolet radiation (UV). An animal study treated HPV-like skin warts with UV, and the skin lesions were converted into squamous cell skin cancer.

The authors caution against overinterpreting their results and using HPV vaccines to prevent skin cancers. The study did not collect biochemical or scientific evidence, which disqualifies conclusions about vaccination.

This summary was based on:
Chen C, Luo C, Tsai SC et al. Synergistic Effect of Human Papillomavirus and Environmental Factors on Skin Squamous Cell Carcinoma, Basal Cell Carcinoma, and Melanoma: Insights from a Taiwanese Cohort. Cancers (Basel). 2024;16(12):2284. doi: 10.3390/cancers16122284.