Shining a light on HPV: an Interview with Dr Carlos Sousa, Unilabs Lab IVD

HPV is the most prevalent sexually transmitted infection affecting both men and women.

Often, individuals can carry HPV without showing symptoms, making it challenging to avoid infection. Fortunately, in many cases, HPV resolves spontaneously or with treatable symptoms, reducing the risk of cervical cancer and other associated conditions when detected and managed early.

On International HPV Awareness Day, we're speaking with Dr Carlos Sousa, one of our molecular biologists, to get his expert insights into this topic.

Dr Sousa, could you explain HPV and its impact on individuals?

HPV affects an estimated 75 to 80% of men and women worldwide during their lifetimes. While many HPV infections resolve spontaneously, some can lead to severe health issues, including various cancers – cervix, vagina, vulva, anus, and penis – and genital warts. 

What genotypes exist, and how do they influence subsequent treatment?

HPV types are classified into high-risk and low-risk variants, with each category posing distinct health risks. Understanding the genotype of the virus is crucial for tailoring effective treatment strategies and interventions.

What tests are used in the laboratory to detect HPV?

The HPV DNA test stands as the gold standard for identifying HPV strains relevant to cancer risk. Ensuring the validity and accuracy of these tests is paramount in guiding clinical decisions and patient care. The used tests must be validated to identify cancer-risk patients and not the virus itself (clinical validation).

What diagnosis alternatives are there? How do they differ depending on the sex?

Diagnosis methods vary depending on sex. In women, HPV tests are typically conducted in the same manner as Pap tests. Using the same sample, healthcare providers can perform an HPV and Pap test and screen for other STDs such as chlamydia and gonorrhea. Additionally, urine-based HPV testing has shown effectiveness in detecting HPV infection. For MSM (Men who have Sex with Men), an anal swab can be taken for HPV testing.

How can early diagnosis of the infection be beneficial in preventing different types of tumours?

Early detection and intervention play a crucial role. HPV lesions typically require several years to progress to cancer. However, if identified accurately, these lesions can be treated effectively, preventing their progression to cancer. 

How has knowledge of the disease evolved in recent years?

In 1977, Prof. Harald Zur Hausen identified HPV as the primary and sole cause of cervical cancer. His findings paved the way for significant developments, including vaccines and the HPV test. He received the Nobel Prize in 2008 for this achievement. Today, our understanding of HPV's natural history has expanded, allowing us to comprehend how it progresses to cancer, even at a molecular level.

Can you elaborate on the benefits and efficacy of the HPV vaccination?

The HPV vaccine offers protection against genital warts and most cervical cancer cases. Additionally, it provides defense against other HPV-related cancers affecting various areas such as the vagina, vulva, penis, anus, mouth, throat, head, and neck.

In clinical trials, the vaccine demonstrated high efficacy, exceeding 90%, in preventing HPV infection, genital warts, and high-grade cervical lesions among women without prior HPV infection. 

What are some ongoing areas of research or public health initiatives aimed at addressing HPV-related issues, and what impact do you hope they will have in the future?

HPV testing as part of cervical cancer screening is instrumental in identifying women at a higher risk of developing cancer. However, to enhance follow-up efficiency, an HPV-positive triage approach is necessary. HPV triage aims to identify patients who would benefit most from colposcopy, thus preventing over-treatment for those who may not require it. Recent developments include the emergence of new biomarkers, like DNA changes and proteins called p16 and ki67, which offer promising avenues for improving screening accuracy.

Additionally, scientists are studying how the microbiome might be involved in the path from infection to cancer. It's a fascinating area of research that could help us understand more about how our own “personal flora” can either help our body to fight HPV or in other hand, possibly enable cancer development when deregulated.