In the UK clinical pathway, testing for the Human Papillomavirus HPV is a standard procedure for patients diagnosed with oropharyngeal squamous cell carcinoma. This specific type of throat cancer affects the tonsils and the base of the tongue. Because HPV positive cancers often respond better to treatment than those caused by smoking or alcohol, identifying the viral status of a tumour is essential for determining the prognosis and the most appropriate treatment plan.
The testing process is not done through a blood test but rather through the analysis of tissue already collected during a biopsy. Pathologists look for specific proteins and viral genetic material within the cancer cells. In most NHS hospitals, a two tier approach is used to ensure the highest level of accuracy, starting with a sensitive screening test followed by a more specific confirmatory test.
What we will discuss in this article
- The difference between screening for p16 and direct HPV testing
- How biopsy samples from the throat or neck lumps are used
- The role of immunohistochemistry in identifying surrogate markers
- Why confirmatory DNA or RNA tests are performed in the UK
- Understanding discordant results where tests do not match
- How HPV status influences the clinical staging of throat cancer
- The timeline for receiving HPV results after a diagnosis
The two tier testing process
- First Tier p16 Staining: The most common initial test is p16 immunohistochemistry. The p16 protein acts as a surrogate marker; its levels rise significantly when high risk HPV is causing cancerous changes in a cell. If a sample shows strong and diffuse p16 staining in more than 70 percent of the cells, it is considered positive.
- Second Tier Confirmatory Testing: Because p16 can occasionally be high for other reasons, a second test is often performed. This typically involves In Situ Hybridisation or PCR to look directly for HPV DNA or RNA. This confirms that the virus is physically present within the tumour cells.
Sample collection for testing
HPV testing does not require a separate procedure. It is performed on the tissue samples that have already been taken to diagnose the cancer.
- Incisional Biopsy: Small pieces of tissue taken from the tonsil or tongue base during an outpatient appointment or a pan endoscopy.
- Fine Needle Aspiration: If the cancer has spread to a lymph node in the neck, a small needle can be used to pull out cells. These cells can also be tested for HPV.
- Surgical Resection: If the tumour is removed through surgery, the entire specimen can be analysed to provide a definitive HPV status.
Why HPV status matters for staging
In the UK and internationally, the staging system for throat cancer was updated to reflect the fact that HPV positive cases behave differently.
- Prognosis: Patients with HPV related throat cancer generally have a significantly better long term outlook compared to those with HPV negative disease.
- Staging: An HPV positive tumour may be classified as a lower stage even if it has spread to a local lymph node, because the body response to treatment is typically much more effective.
- Future Treatment: Clinical trials in the UK are currently investigating whether HPV positive patients can receive less intensive treatment to reduce long term side effects while maintaining high cure rates.
Comparison: p16 Testing vs HPV DNA Testing
| Feature | p16 Immunohistochemistry | HPV DNA or RNA Testing |
| Test Type | Protein surrogate marker | Direct viral detection |
| Sensitivity | Very high: catches almost all cases | High: very specific to the virus |
| Method | Lab staining of tissue slides | Molecular analysis or hybridisation |
| Role in UK | Initial screening test | Confirmatory second line test |
| Cost | Relatively low and widely available | More expensive and specialised |
| Key Indicator | Over 70 percent diffuse staining | Presence of viral genetic material |
To Summarise
HPV testing is a critical component of a modern throat cancer diagnosis in the UK. It involves a sophisticated lab analysis of biopsy tissue, usually starting with p16 protein staining and followed by a confirmatory viral DNA test. Knowing whether a cancer is HPV related allows your medical team to provide a more accurate prognosis and ensures that you are placed in the correct staging category. While waiting for these specialised results can take an additional few days after the initial cancer diagnosis, the information provided is vital for tailoring your treatment plan to your specific type of disease.
If you have recently had a biopsy for suspected throat cancer, you can ask your consultant if your samples will be tested for p16 and HPV status as part of the standard workup.
Is there a blood test for throat HPV?
No. In the UK, there is currently no blood test used to diagnose HPV related throat cancer. Testing must be performed directly on the tumour tissue or cells from a lymph node.
What does it mean if my result is discordant?
A discordant result occurs when one test is positive (usually p16) and the other is negative (HPV DNA). In these cases, the specialist multidisciplinary team will review the pathology and clinical features to decide how to classify the cancer.
Can I have HPV testing on a neck lump?
Yes. If you have a firm lump in your neck, a fine needle aspiration can collect enough cells to check for both cancer and HPV status at the same time.
Does an HPV positive result mean I am contagious?
The HPV virus is very common and most adults have been exposed to it. Having HPV related cancer does not mean you are a risk to others through casual contact, though the virus itself is sexually transmitted.
How long do HPV test results take?
While a standard cancer diagnosis from a biopsy may take 7 to 10 days, the specialised HPV and p16 staining can sometimes add a few extra days to the final pathology report.
Is HPV testing done for all throat cancers?
In the UK, it is primarily performed for oropharyngeal cancers. It is not routinely done for cancers of the larynx or other parts of the throat unless the specialist has a specific reason to check.
Authority Snapshot
This article was reviewed by Dr. Stefan Petrov, a UK trained physician with an MBBS and postgraduate certifications including Basic Life Support BLS, Advanced Cardiac Life Support ACLS, and the UK Medical Licensing Assessment PLAB 1 and 2. Dr. Petrov has extensive clinical experience in general medicine and surgery, performing diagnostic and therapeutic procedures across hospital wards and intensive care units. He has contributed to medical education by creating patient focused health content and teaching clinical skills to junior doctors within the NHS.
