- HPV 16 and 18 cause about 70% of cervical cancer.
- Ask for subtype-specific reporting where possible.
- The 9-valent vaccine still protects even after infection with one strain.
The 14 high-risk strains
High-risk (oncogenic) HPV includes types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68. Together they cause virtually all cervical cancers and most vaginal, vulval, anal and oropharyngeal cancers.
HPV 16 and HPV 18 are responsible for around 70% of cervical cancers. Persistence of 16 or 18 for more than 24 months carries the highest risk of progression to CIN 3 or cancer.
The low-risk strains
Types 6 and 11 cause more than 90% of genital warts but do not cause cancer. Warts are cosmetically distressing but not dangerous. They are typically treated with topical therapy, cryotherapy or minor excision.
How to read your HPV test
Modern HPV tests report separately: HPV 16 positive, HPV 18 positive, or 'other high-risk positive'. The distinction matters because HPV 16 carries a higher risk than the pooled others, and doctors escalate faster.
If your result is HPV positive but you cannot see the subtype, ask your clinician. Some UK NHS laboratories only report pooled results; private labs and clinics in Turkey typically provide the full breakdown.
Frequently asked questions
Is HPV 16 always cancerous?
No, but it carries the highest risk of persistence and progression. Careful follow-up matters more than with other strains.
Can I have more than one strain?
Yes, co-infection is common and slightly increases risk of persistence.
Does the vaccine cover all strains?
The 9-valent Gardasil covers 16, 18, 31, 33, 45, 52 and 58 (high-risk) plus 6 and 11 (warts) — about 90% of cancer-causing strains.
Could a doctor-led plan help you?
A 30-minute video consultation with Dr Berra Önsoy — reviewing your test results and giving you a clear, personalised next step.
Request a video consultation