How Are HPV Precancerous Lesions Detected and Treated?

HPV precancerous lesions are detected through a layered process that starts with screening, moves to diagnostic confirmation when something abnormal turns up, and ends with treatment choices tailored to the severity and location of the lesion. The most common pathway begins with an HPV test or Pap smear (or both), followed by colposcopy and biopsy if results are concerning. Treatment ranges from outpatient procedures that take minutes to more involved surgical excisions, depending on how advanced the changes are and whether the person plans future pregnancies. The process is well-established but evolving, with newer triage tools, self-sampling options, and even therapeutic vaccines reshaping how clinicians and patients approach each step.

Screening Is the First Layer

Detection begins before any symptoms appear, because precancerous cervical changes rarely cause noticeable signs. Two main tools are used: the Pap smear (cervical cytology), which looks for abnormal cells under a microscope, and the HPV test, which checks for the presence of high-risk HPV DNA or RNA. Both can be performed during a routine pelvic exam, and results are reported using the Bethesda System, a standardized framework that sorts findings into categories with clear clinical implications.

Over the past decade, HPV primary testing has gained ground as the preferred screening strategy in many guidelines. A large population-based study found that HPV testing alone had roughly 96% sensitivity for detecting significant precancerous changes (called CIN2 or worse), while cytology alone caught only about 48% of the same lesions.¹ That gap matters: cytology misses a substantial share of precancerous lesions at the point where intervention can still prevent cancer.

Co-testing, which combines an HPV test and a Pap smear at the same visit, catches slightly more cases than HPV testing alone. But the marginal gain is small, and it comes with a cost: more colposcopy referrals, more lab work, and more false alarms. Data from the National Cancer Institute found that the extra cases of high-grade disease immediately detected by co-testing versus HPV testing alone shrank as the underlying disease prevalence dropped, leading the authors to conclude that co-testing offers an unfavorable benefit-to-harm ratio compared with HPV primary testing in most screened populations.² In practice, the trend is moving toward HPV-first strategies with cytology reserved as a secondary step.

What Happens After a Positive HPV Test

A positive HPV result does not mean you have precancer. Most HPV infections clear on their own within a year or two. The challenge is figuring out which positive results actually indicate a lesion that needs attention and which are transient infections that will resolve without intervention. This sorting step is called triage, and it is where the system tries to avoid flooding colposcopy clinics with people who do not need them.

The most widely studied triage tools include HPV genotyping (checking whether the specific type is HPV 16 or 18, which carry higher risk), cytology (a reflex Pap smear on the same sample), and a newer lab test called p16/Ki-67 dual staining. The dual-stain test looks for two proteins that together suggest the virus is actively driving abnormal cell growth rather than just passing through. A clinical trial called IMPACT found that using dual staining alone to triage HPV-positive women had higher sensitivity than a strategy combining HPV 16/18 genotyping with cytology triage of other types, along with better risk stratification and strong reassurance against precancers at both baseline and one-year follow-up.³ In short, dual staining is proving to be a reliable gatekeeper, though its availability varies by healthcare setting.

Colposcopy and Biopsy Confirm the Diagnosis

When triage flags a person as high-risk, the next step is colposcopy: a close-up examination of the cervix using a magnifying instrument, often after applying a dilute acetic acid solution that makes abnormal areas turn white. The clinician then takes small tissue samples (biopsies) from any suspicious-looking spots. The biopsy results, graded as CIN 1, CIN 2, or CIN 3, determine what happens next.

Taking multiple biopsies of visible lesions improves accuracy. In cases where the junction between different types of cervical tissue is not fully visible (common in older women or after menopause), the clinician may also perform an endocervical curettage (ECC), a scraping of the inner cervical canal. Among women with high-grade cytology results, ECC had a yield of about 26% for detecting CIN2 or worse in the endocervix.⁴ However, when multiple directed biopsies of visible lesions had already been taken, ECC added only about 4% more detections beyond what the biopsies found. A separate study of over 13,000 colposcopy-guided exams calculated that 99 ECC specimens were needed to detect one additional case of CIN2 or worse that biopsy would have missed, though the procedure was most useful in women 46 and older with high-grade cytology.⁵

Accuracy also depends on factors outside the clinician’s control. A meta-analysis found that diagnostic mistakes during colposcopy-directed biopsy were more common in women over 50, in postmenopausal women, and when the transformation zone was difficult to see.⁶ These limitations are one reason guidelines call for more aggressive sampling in older patients or when the colposcopic view is incomplete.

Not Every Precancerous Lesion Needs Immediate Treatment

One of the most important things to understand is that many precancerous changes go away on their own, especially in younger women. A systematic review and meta-analysis tracking the natural history of untreated lesions found that about 60% of CIN 1 lesions regressed without treatment, and roughly 55% of CIN 2 lesions did the same.⁷ CIN 3 was a different story: only about 28% regressed, while the majority persisted.

For young women under 25, regression rates can be even more striking. A study tracking women in that age group found that 88% of CIN 2 lesions regressed, though CIN 3 regression was lower at 29%.⁸ Clearance of the HPV infection itself was a strong predictor of regression, and women who had been vaccinated against HPV showed significantly higher regression rates. Because of these high regression rates, many guidelines now recommend watchful waiting for CIN 2 in young women rather than jumping straight to surgery, with close follow-up to catch the minority of cases that progress.

Excisional Treatments Remove the Abnormal Tissue

When treatment is needed, the two main excisional options are the loop electrosurgical excision procedure (LEEP) and cold knife conization (CKC). LEEP uses a thin, electrically heated wire loop to cut away a cone-shaped piece of cervical tissue. It is usually done in an office setting under local anesthesia and takes about 15 to 20 minutes. CKC uses a scalpel in an operating room, typically under general or regional anesthesia, and removes a deeper cone of tissue.

For most cervical precancers (CIN), older meta-analyses found no significant differences between the two procedures in recurrence, residual disease, or complications like bleeding and cervical narrowing, though CKC consistently removed deeper tissue specimens.⁹ However, a large recent study from Sweden complicated this picture. It found that CKC was associated with a meaningfully lower risk of recurrent cervical lesions compared with LEEP, and that HPV clearance rates were consistently higher after CKC at three, six, and twelve months.¹⁰

For adenocarcinoma in situ (AIS), a glandular precancer that behaves differently from the more common squamous precancers, the picture is clearer. A meta-analysis found that LEEP had a 44% positive margin rate compared to 29% for CKC, a significant difference. But residual disease and recurrence rates did not differ between the two procedures.¹¹ That said, many experts favor CKC for AIS because clearer margins make follow-up decision-making easier.

Ablative Options for Lower-Resource Settings

Excisional procedures require pathology labs, trained surgeons, and follow-up infrastructure. In many parts of the world, those resources are scarce. Two ablative methods destroy abnormal tissue without removing a specimen: cryotherapy (freezing) and thermal ablation (heat). Neither produces tissue for a pathologist to examine, which means they work best when the lesion has already been visually assessed and the clinician is confident there is no invasion.

Cryotherapy has been the traditional workhorse in low-resource settings, but thermal ablation devices are increasingly replacing it because they are smaller, cheaper, do not need compressed gas, and run on battery power. A pooled analysis from three large randomized trials comparing the two approaches found that about 61% of treated women tested HPV-negative at follow-up, with no significant difference between the methods.¹² A meta-analysis looking specifically at cure rates found that both approaches were effective for CIN 1 and CIN 2-3, with pooled cure proportions above 80% for higher-grade lesions regardless of which method was used.¹³ Thermal ablation also had the practical advantage of being associated with less postoperative pain and vaginal discharge.¹⁴

These ablative approaches are central to the “screen-and-treat” model used in many low-income countries, where women are screened with an HPV test (or visual inspection) and treated on the same day if eligible. Pilot programs have demonstrated that this single-visit approach dramatically increases the number of women who actually complete treatment, because it eliminates the drop-off that happens when women are told to come back for a second appointment.¹⁵

The Preterm Birth Question

For women who plan to become pregnant after treatment, the most studied concern is preterm birth. A systematic review and meta-analysis found that LEEP was associated with an overall preterm birth rate of about 9% compared to 5% in untreated women.¹⁶ But the picture is more nuanced than that headline figure suggests. When women who had LEEP were compared specifically to women who had a history of cervical dysplasia but were never treated surgically, the increased risk was not statistically significant. The elevated risk appeared mainly when treated women were compared to the general population, raising the possibility that the dysplasia itself, or factors associated with it, contributes to preterm birth risk.

Depth of excision matters. A large meta-analysis found that techniques removing more tissue were associated with worse obstetric outcomes, including higher rates of severe preterm birth (before 32 to 34 weeks) and extreme preterm birth (before 28 to 30 weeks).¹⁷ This is one reason clinicians try to remove the minimum tissue necessary and why watchful waiting for moderate lesions in young women is preferred when the evidence supports it.

Follow-Up After Treatment

Treatment does not end when the abnormal tissue is removed or destroyed. Recurrence happens, so surveillance is essential. A register-based cohort study with a mean follow-up of nine years found a total recurrence rate of high-grade lesions of 10%, with a mean time to recurrence of 28 months.¹⁸ Post-treatment HPV testing is increasingly used as a “test of cure.” In that same study, HPV testing alone had a negative predictive value of 97% for excluding recurrent high-grade disease, and 100% for excluding cervical cancer within three years. No cervical cancer case during long-term follow-up had a result showing negative HPV but positive cytology, suggesting HPV testing may be sufficient on its own for post-treatment surveillance. A systematic review similarly found that high-risk HPV testing was generally more sensitive than cytology as a test of cure, with negative predictive values consistently above 98%.¹⁹

HPV Precancers Beyond the Cervix

The cervix gets most of the attention, but HPV can cause precancerous changes in other areas: the anus, the vulva, and the vagina. Detection and treatment differ at each site.

Anal high-grade squamous intraepithelial lesions (HSIL) are most common in people living with HIV, men who have sex with men, and anyone with a history of receptive anal intercourse. A landmark trial published in the New England Journal of Medicine established that treating anal HSIL rather than simply monitoring it reduced the risk of progression to anal cancer. Detection uses high-resolution anoscopy, a procedure similar to colposcopy but directed at the anal canal, performed at least every six months in high-risk populations.²⁰

Vulvar intraepithelial neoplasia (VIN) and vaginal intraepithelial neoplasia (VAIN) are less common than cervical precancers but are becoming more frequently recognized.²¹ No routine screening tests exist for these sites; detection relies on clinical suspicion and biopsy of visible lesions.²² Treatment typically involves surgical excision, though imiquimod, a topical cream that stimulates a local immune response, has shown promise. Complete response rates for high-grade VIN treated with imiquimod ranged widely (from 5% to 88% across studies), while early data for CIN 2-3 and VAIN showed complete response rates between 57% and 86%.²³ Imiquimod is not yet standard of care for cervical lesions, but a randomized phase II trial has been testing whether combining it with the 9-valent HPV vaccine could improve outcomes for CIN 2/3 patients, potentially offering a nonsurgical path that preserves cervical tissue.²⁴

Self-Sampling Is Expanding Who Gets Screened

One of the biggest barriers to detecting HPV precancers is that many people never get screened in the first place. Embarrassment, lack of access to a clinic, or past negative experiences with pelvic exams all play a role. Self-sampling, where a person collects their own vaginal sample at home using a swab or brush, is addressing this gap. An updated meta-analysis found that PCR-based HPV tests performed on self-collected samples were equally sensitive as clinician-collected samples for detecting CIN2 or worse, with only a tiny reduction in specificity.²⁵ Mailing self-sampling kits to a person’s home address was more than twice as effective at getting a sample taken as simply sending a reminder letter to visit a clinic.

Even urine-based HPV testing is under investigation. A study comparing HPV detection across sample types found good concordance between vaginal self-samples and clinician-collected cervical samples, with urine samples showing somewhat lower but still meaningful agreement.²⁶ These approaches are not yet universally integrated into screening programs, but they represent a meaningful shift toward meeting people where they are.

Vaccination Is Already Changing the Numbers

While detection and treatment remain essential for people already exposed to HPV, prevention through vaccination is rewriting the landscape. U.S. surveillance data from 2008 through 2022 showed that among women aged 20 to 24 (the first cohort widely vaccinated as adolescents), the incidence of CIN2 or worse dropped by about 80%.²⁷ Among women aged 25 to 29, CIN3 or worse incidence was about 37% lower in 2022 than in 2008. A meta-analysis of observational studies from multiple countries estimated that HPV vaccination was associated with roughly a 62% reduction in CIN2 or worse overall.²⁸

These gains are concentrated in younger age groups who were vaccinated before exposure. Women over 40, who were largely unvaccinated, actually saw rising rates of CIN2 or worse during the same surveillance period. Vaccination reduces the future burden of precancer dramatically, but it does not replace screening for people who are already past the optimal vaccination age or who were never vaccinated.

The Emotional Side of an HPV Diagnosis

Something that rarely makes it into clinical guidelines is the psychological toll. HPV is sexually transmitted, and finding out you carry it, or that it has caused precancerous changes, triggers a predictable set of reactions. A qualitative study found that women who tested positive described feeling stigmatized, anxious, and worried about their sexual relationships and about disclosing their result to others.²⁹ A separate study of young women found that about a third reacted to an HPV diagnosis with fear and nearly a third with anxiety, while the diagnosis was associated with higher levels of obsessive and compulsive behaviors related to hygiene.³⁰

These reactions can interfere with follow-up. A person who feels ashamed may avoid returning for colposcopy, and someone who is anxious may catastrophize about a result that has a high probability of resolving on its own. Clinicians and screening programs increasingly recognize that clear communication about HPV’s ubiquity (most sexually active people will contract it at some point), the high likelihood of clearance, and the difference between infection and cancer are all part of effective precancer management, not just the biopsy and the treatment plan.