What Does HPV 16 or 18 Positive Mean?

An HPV test checks cervical cells for high-risk HPV types. NCI describes the two possible answers in plain terms. A negative result means high-risk HPV was not found. A positive result means it was.

Some tests go further and name which type. That is where 16 and 18 come from.

So your result says one thing: this virus is present in this sample now. It is a statement about today, not about the future.

NCI lists 12 high-risk HPV types: 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59.

Then it separates two of them out. HPV 16 and HPV 18 are responsible for most HPV-related cancers.

NCI also names them when explaining why some infections last. Among the factors that increase the chance an infection will persist and lead to precancerous cells, it lists having a very aggressive HPV type, particularly HPV 16 or HPV 18. The others it names are smoking, a weakened immune system, HIV, and medicines that suppress immunity.

That is the reason your report singled out a number.

This is the part that gets lost in the panic of reading the result.

NCI says most HPV infections go away on their own without causing cancer. The immune system usually controls them, and clears them within a year or two.

NCI also notes that infection with high-risk HPV causes no symptoms. Nothing about how you feel tells you whether an infection is clearing or staying.

HPV is also extremely common. NCI says around half of new infections are with a high-risk type.

NCI sets out the sequence carefully, and every step matters.

A high-risk infection that persists for many years can lead to cell changes. Those changes, if untreated, may get worse over time and become precancerous, and then cancerous.

Three conditions sit in that sentence. The infection has to persist. Many years have to pass. And the changes have to go untreated.

Screening exists to break the chain at the third step. NCI says routine screening with an HPV test or Pap test can prevent most cervical cancer, by finding and removing precancerous cells before they develop into cancer. It adds that cervical cancer is most common in women who are rarely or never screened.

This can feel confusing. The test only shows that the virus is present now.

NCI says follow-up depends on your current result and on your previous screening results. So your earlier negative tests count. Ask your care team what the change means for you.

There is no single answer that applies to everyone with a positive 16 or 18 result, and NCI explains why.

Updated guidelines take a tailored approach. Alongside your current screening result, your care team looks at your previous screening results, any previous treatment for precancerous changes, and personal factors such as your age.

Based on that individual risk, NCI lists three possible paths:

• a repeat HPV test or HPV and Pap cotest in 1 or 3 years.
• a colposcopy with a biopsy.
• treatment for high-grade cervical cell changes.

NCI describes colposcopy as an exam of the cervix with a magnifying instrument. It usually includes a biopsy so the tissue can be checked under a microscope. It is a look, not a treatment.

High-risk HPV is not only a cervical issue, and the numbers NCI publishes vary widely by site.

NCI says virtually all cervical cancer is caused by HPV. It attributes over 90% of anal cancer, 75% of vaginal cancer, 70% of oropharyngeal cancer, 69% of vulvar cancer, and 63% of penile cancer to HPV.

Those figures describe cancers that have already occurred. They are not the chance that any infection will become one.

HPV and Cancer covers the virus more broadly, Cervical Cancer Screening explains the testing schedule, and Colposcopy covers the procedure itself.

• National Cancer Institute — HPV and Cancer
• National Cancer Institute — HPV and Pap Test Results: Next Steps after an Abnormal Cervical Cancer Screening Test