If you’ve been diagnosed with cancer of the throat, tonsils, or back of the tongue, you may have seen “p16-positive” or “p16-negative” on your pathology report. This one result can tell your care team a lot about your cancer: what likely caused it, how it’s staged, and how it may respond to treatment.
This guide explains what HPV and p16 testing are, how HPV-positive and HPV-negative head and neck cancers differ, and what your result may mean for you.
What is HPV, and how is it linked to throat cancer?
HPV (human papillomavirus) is a very common virus that spreads through intimate skin-to-skin contact. Most sexually active people will have it at some point, and the body usually clears it without any problems. In a small number of people, a high-risk type, most often HPV16, stays in the body for years and can slowly cause cells to transform into cancer.
In the head and neck, HPV causes cancer almost only in the oropharynx: the tonsils, the base of the tongue, and the soft palate. About three out of four oropharyngeal cancers in the U.S. are caused by HPV, and these cases are increasing while cancers from other causes are falling.
HPV-negative head and neck cancers are usually linked to tobacco and alcohol use. They can occur in the oropharynx as well as in the mouth, voice box, and lower throat.
What is a p16 test?
p16 is a protein inside your cells. When high-risk HPV takes over a cell, the cell makes much more p16 than usual. A pathologist stains a sample of your tumor to look for it, using a lab method called immunohistochemistry (IHC).
The test doesn’t detect the virus itself. Instead, it shows the effect HPV has on the cell, which is why p16 is called a surrogate (stand-in) marker for HPV. For cancers of the oropharynx, p16 is a reliable, widely used way to tell whether HPV is driving the cancer.
A few things to know:
- p16 works best for the oropharynx. In other parts of the head and neck, like the mouth or voice box, p16 alone is less reliable, and extra HPV tests may be needed.
- Other HPV tests exist. Your team may also test the tumor directly for HPV DNA or RNA to confirm the result, especially if p16 is unclear.
- This is a tumor test, not a blood or swab test. It tells you about your cancer, not whether you currently have an active HPV infection elsewhere.
HPV-positive vs. HPV-negative at a glance
HPV-positive and HPV-negative head and neck cancers are now understood as two different diseases that tend to affect different people and behave differently.
| HPV-positive (p16-positive) | HPV-negative (p16-negative) |
Main cause | Long-lasting high-risk HPV infection | Mostly tobacco and alcohol |
Where it starts | Almost always the oropharynx (tonsils, base of tongue) | Anywhere in the head and neck |
Who it affects most | Often younger, with little or no smoking history | Often older, with a history of smoking or drinking |
Common first sign | A painless lump in the neck | A sore, pain, trouble swallowing, or voice change |
Response to treatment | Usually responds well | Can be harder to treat |
Outlook | Generally more favorable | Generally less favorable |
Trend in the U.S. | Rising | Falling |
Sources: JAMA review, 2026; NCI fact sheet.
These are general patterns. Anyone can develop either type, and your own situation may look different.
What your result means for your outlook and stage
If your cancer is p16-positive, this is generally reassuring news. HPV-positive oropharyngeal cancers have a better prognosis and are less likely to come back than HPV-negative ones. Even when the cancer is locally advanced, more than 80% of people with HPV-positive oropharynx cancer are alive five years later.
If your cancer is p16-negative, it may be harder to treat, but many people are still cured, especially when the cancer is found early. Your care team will build a plan based on your specific stage and health.
Your result also changes how your cancer is staged. Because the two types behave so differently, doctors now use a separate staging system for HPV-positive oropharyngeal cancer. HPV-positive cancer often spreads to neck lymph nodes early, yet still does well with treatment. So the same tumor may be given a lower stage number if it’s HPV-positive. Don’t be surprised if your stage seems lower than you expected, and ask your doctor if you have questions.
What your result means for treatment
For now, outside of clinical trials, standard treatment for oropharyngeal cancer is the same whether or not it’s HPV-positive. Depending on your stage, it may include surgery (often robotic surgery through the mouth), radiation, chemotherapy, or a combination. Most locally advanced oropharyngeal cancers, whether HPV-positive or negative, are treated with chemoradiation.
Why researchers are studying “less” treatment. These treatments work very well for HPV-positive cancer, but they can cause lasting side effects like dry mouth, trouble swallowing, and taste changes. Because many people with HPV-positive cancer are younger and live for decades after treatment, researchers are testing whether gentler treatment can work just as well. This is often called de-escalation.
Early results are encouraging. For example, a 2025 Mayo Clinic study found that a shorter, lower-dose course of radiation and chemotherapy after surgery caused fewer side effects while keeping cancer control similar for selected patients.
Important: De-escalated treatment is not yet standard care. It’s mainly available through clinical trials, for carefully selected patients. If you’re p16-positive, ask whether a trial might be right for you, but don’t reduce treatment on your own.
If you’re p16-negative, your team may recommend standard full-strength treatment. Clinical trials, including immunotherapy studies, may also be an option.
Common worries about an HPV-positive result
Learning that a virus caused your cancer can bring up hard questions. Here are answers to a few of the most common.
“Is my cancer contagious?” No. Cancer itself can’t be passed to another person.
“Is my partner at risk?” Research is reassuring here. A Johns Hopkins study found that long-term partners of people with HPV-positive throat cancer were no more likely to have oral HPV than the general population, and their cancer risk stayed low. Couples who have been together for years have likely already shared any infections, so most don’t need to change their intimate life. The researchers noted the study was small and early, so talk with your doctor about any specific concerns.
“Does this mean someone was unfaithful?” No. HPV can stay hidden in the body for many years, even decades, before causing cancer. There’s no way to know when or from whom it was acquired.
“Did I do something wrong?” No. HPV is extremely common, and most people who have it never develop cancer. An HPV-positive diagnosis is not a reflection of your choices or character.
If your partner is female, her doctor may suggest routine cervical cancer screening, which is a good idea for everyone anyway.
Questions to ask your care team
- Was my tumor tested for p16? What was the result?
- Was any additional HPV testing done to confirm it?
- How does my HPV status affect my stage and outlook?
- Does my HPV status change my treatment options?
- Am I eligible for any clinical trials, including ones testing less intensive treatment?
- What long-term side effects should I expect, and how can we reduce them?
- Does my partner need any testing or precautions?
Disclaimer: The information provided in this article is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Outcomes4Me is not acting as your caregiver, and any suggestions or guidance offered should not replace the advice of your healthcare provider or qualified medical professional. Always seek the guidance of your physician or other qualified health provider with any questions you may have regarding a medical condition.
