Human Papillomavirus

Human papillomavirus (HPV) is the most common sexually transmitted infection (STI), and more than 40 million people are affected by HPV in the United States alone. Most HPV infections (whether caused by low-risk or high-risk types of the virus) are usually self-limiting and asymptomatic. Some infections cause mild symptoms (eg, anogenital warts or lesions), and certain strains of HPV (eg, high-risk HPV types 16 and 18) have been linked to an increased risk for specific cancers. High-risk HPV types are often implicated in cervical cancer but can also cause oropharyngeal cancer, anal cancer, vulvar cancer, penile cancer, and primary urethral squamous cell carcinoma.

Testing recommendations and options vary by anatomic site, and in some sites or presentations, guidelines recommend against testing. Cervical cancer is the only disease for which preemptive screening is currently recommended.

Quick Answers for Clinicians

For which human papillomavirus (HPV)-associated diseases is testing for HPV status recommended?

Currently, cervical cancer is the only human papillomavirus (HPV)-mediated disease for which preemptive screening is recommended.

Additionally, HPV testing may inform the prognosis for specific HPV-mediated diseases, including:

Oropharyngeal squamous cell carcinoma
Vulvar squamous cell carcinoma
Penile squamous cell carcinoma
Anal carcinoma

Can human papillomavirus testing be performed on blood specimens?

No, blood is not an appropriate sample type to test for human papillomavirus (HPV) status. Collection, preservation, and transport requirements for other sample types, such as tissue or cells (eg, cervical cells), vary by type. Refer to individual tests for specific requirements before specimen collection.

How often should cervical cancer screening occur in individuals at average risk?

In general, recommended screening intervals vary based on age and clinical history. The 2020 American Cancer Society (ACS) guidelines state that primary human papillomavirus (HPV) testing is appropriate every 5 years for individuals 25-65 years of age who have a cervix and are at average risk. More frequent testing is recommended if an alternative test is used. Other acceptable screening options include cotesting every 5 years or cytology alone every 3 years.

Can human papillomavirus testing be used as an alternative to cytology in cervical cancer screening?

In general, clinical guidelines support the use of primary human papillomavirus (HPV) testing (ie, testing approved by the U.S. Food and Drug Administration [FDA] to detect high-risk HPV types in a cervical sample) as an alternative to cytology for initial screening. However, the recommended age at which primary HPV testing can be performed varies amongst guidelines. For age-specific recommendations, refer to the Screening Guidelines for Individuals With a Cervix section.

What is the difference between SurePath and ThinPrep testing?

SurePath and ThinPrep tests are both liquid-based cytology evaluations for cervical cancer screening that have largely replaced the conventional pap smear, each featuring its own collection kit and sample preparation process. When comparing SurePath to ThinPrep, one study found that using SurePath tests resulted in significantly lower rates of unsatisfactory slides and lower rates of inadequate residual volume for subsequent human papillomavirus (HPV) testing. Another study found that excessive mucus in a specimen may impact cell retrieval when using a ThinPrep test.

Do human papillomavirus primary tests and cotests detect all high-risk genotypes?

As of July 2020, the U.S. Food and Drug Administration (FDA) has approved seven human papillomavirus (HPV) tests for cotesting and two primary HPV tests for standalone use in cervical cancer screening. The test options differ in terms of which specific high-risk genotypes they target, although all FDA-approved options can detect HPV 16 and 18, the most carcinogenic and prevalent types. Additional high-risk types tested may include 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68.

Should testing for human papillomavirus be considered in newborns?

There are currently no clinical guidelines that discuss human papillomavirus (HPV) testing in newborns. Transmission of HPV is possible during labor, delivery, and regular caretaking activities (eg, bathing and diapering). There is a very low risk that HPV infection in neonates can lead to respiratory papillomatosis. However, the majority of HPV infections remain asymptomatic and resolve spontaneously.

Cervical Cancer

Indications for Testing

Asymptomatic individuals who have a cervix and are at average risk should be routinely screened for cervical cancer, regardless of history or HPV vaccination status. The American Cancer Society (ACS) recommends routine screening starting at 25 years of age, whereas the U.S. Preventive Services Task Force (USPSTF), the American Society for Colposcopy and Cervical Pathology (ASCCP), the Society of Gynecologic Oncology (SGO), and the American College of Obstetricians and Gynecologists (ACOG) recommend beginning screening at 21 years of age. Preferred testing methods also vary by guideline. Refer to the Screening Guidelines for Individuals With a Cervix section for additional details.

Age-based screening recommendations do not apply to those at increased risk for cervical cancer (eg, individuals with a solid organ or stem cell transplantation, HIV-infected individuals, individuals with immunosuppression, or individuals who were exposed to diethylstilbestrol in utero), who may require earlier or more frequent testing.

Laboratory Testing

Screening for high-grade precancerous cervical lesions and cervical cancer can be performed using cervical cytology, primary HPV testing for multiple oncogenic types, or both (ie, cotesting). High-risk HPV genotypes are associated with cervical cancer, whereas low-risk HPV types are unrelated to cervical cancer.

HPV types 16 and 18 are the most prevalent and carcinogenic genotypes and account for a majority of cervical cancer cases. Additional high-risk HPV genotypes include 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68.

Screening Guidelines for Individuals With a Cervix

Population	Recommendations (Assuming Average Risk)^a	Related ARUP Testing Algorithm
21-24 yrs old	USPSTF, ASCCP, ACOG, and SGO: Cervical cytology every 3 yrs ACS: Do not screen	Cervical Cancer Screening: 21 to 24 Years of Age
25-29 yrs old	USPSTF: Cervical cytology every 3 yrs ASCCP, ACOG, and SGO: Cervical cytology every 3 yrs (acceptable) Primary HPV testing every 5 yrs (acceptable) ACS: Primary HPV testing every 5 yrs (preferred) Cotesting every 5 yrs (acceptable) Cervical cytology every 3 yrs (acceptable)	Cervical Cancer Screening: 25 to 29 Years of Age
30-65 yrs old	USPSTF, ASCCP, ACOG, and SGO: Cervical cytology every 3 yrs (acceptable) Primary HPV testing every 5 yrs (acceptable) Cotesting every 5 yrs (acceptable) ACS: Primary HPV testing every 5 yrs (preferred) Cotesting every 5 yrs (acceptable) Cervical cytology every 3 yrs (acceptable)	Cervical Cancer Screening: 30 to 65 Years of Age
>65 yrs old^b	USPSTF, ASCCP, ACOG, SGO, and ACS: Do not screen	Cervical Cancer Screening: >65 Years of Age
Posthysterectomy^c	USPSTF, ASCCP, ACOG, SGO, and ACS: Do not screen	—
Post-HPV vaccination	USPSTF, ASCCP, ACOG, SGO, and ACS: Refer to age-based screening recommendations	—
^aRecommendations vary for individuals with a previous diagnosis of precancerous cervical lesions or cervical cancer, a compromised immune system (eg, HIV), or a history of in utero exposure to diethylstilbestrol. ^bSpecifically, individuals older than 65 years who have 2 consecutive cotests or 3 consecutive cytologic screens within the last 10 years with no abnormal results. ^cSpecifically, individuals who have undergone a hysterectomy with removal of the cervix and have no history of a CIN2+ or more serious result. CIN2+, cervical squamous intraepithelial neoplasia grade 2 or more severe disease Sources: Fontham, 2020; ACOG, 2021; Marcus, 2021; USPSTF, 2018; Saslow, 2012

Oropharyngeal Cancer

Indications for Testing

Testing for a high-risk HPV-disease association is recommended in individuals diagnosed with or suspected of having oropharyngeal squamous cell carcinoma (OPSCC). Those who have head and neck cancer of unknown primary with squamous cell or undifferentiated histology should also be tested.

Testing is not indicated for individuals with nonsquamous cell carcinoma of the oropharynx or with head and neck cancer of nonoropharyngeal primary. Testing is also not indicated in cases of locally or regionally recurrent cancers when the HPV status of the primary tumor has been previously determined.

Laboratory Testing

HPV status has been shown to have a strong prognostic significance in the context of OPSCC. Following a diagnosis of OPSCC (or another applicable head and neck cancer), the cell cycle regulator p16 is a useful surrogate biomarker for HPV status and can be assessed by immunohistochemistry (IHC) with a high level of sensitivity. For p16 to qualify as a surrogate marker for HPV status, the testing must be performed on a squamous cell carcinoma tissue block from the oropharynx or carcinoma detected in a level 2 or level 3 cervical lymph node in the setting of suspected OPSCC. The high-risk HPV types most often implicated in oropharyngeal cancer (eg, 16, 18) can also be directly detected by polymerase chain reaction (PCR) and in situ hybridization (ISH) testing.

Both tissue and fine needle aspiration (FNA) specimens may be used for testing. When an FNA sample tests negative for high-risk HPV, repeat testing with a tissue sample (if available) should be considered. Additional PCR and/or ISH testing may be indicated in p16-positive tumors.

Vulvar Cancer

Currently, clinical guidelines provide limited guidance with respect to HPV testing in the context of vulvar cancer. College of American Pathologists (CAP)/ASCCP guidelines recommend testing for p16 (a surrogate biomarker for HPV status) by IHC when the morphologic assessment of a potentially precancerous lesion is inconclusive.

According to guidelines from the National Comprehensive Cancer Network (NCCN), HPV status has prognostic significance in individuals with confirmed vulvar squamous cell carcinoma, and supplemental testing for HPV status may be considered. Testing options to determine HPV status include p16 by IHC, HPV by ISH, and HPV by PCR. Because HPV-related vulvar squamous cell carcinoma is often multifocal, cervical screening should also be considered.

Penile Cancer

Although infection with high-risk HPV types has been linked to penile cancer, clinical guidelines are limited in the discussion of HPV testing. The NCCN recommends assessing HPV status during the initial evaluation of suspected penile squamous cell carcinoma.

Typical testing includes p16 (a surrogate biomarker for HPV status) by IHC and/or high-risk HPV by PCR. When morphology is indeterminate in a potentially precancerous specimen, p16 by IHC can also be useful to inform histologic interpretation.

Anal Cancer

Due to a lack of data, guidelines do not currently recommend routine anal cancer screening by cytology, although some providers choose to offer it to individuals at increased risk of the disease (eg, those living with HIV). If screening is performed, the appropriate initial test is cytology rather than HPV testing. HPV testing is not considered useful when screening for anal carcinoma.

In cases of suspected anal carcinoma, testing for p16 (a surrogate HPV biomarker) by IHC may be helpful to inform histologic interpretation when the assessment of a possible precancerous lesion is inconclusive. In individuals with confirmed anal carcinoma, p16 by IHC and/or HPV testing for high-risk types can be considered to help determine prognosis.

Primary Urethral Cancer

Primary urethral cancer (PUC) is a very rare malignancy that can occur in men and women. Although HPV is a potential risk factor for PUC, HPV testing in the context of suspected or confirmed PUC is not currently included in clinical guidelines.

Anogenital Warts and Lesions

Most cases of anogenital warts are diagnosed clinically, and CDC guidelines recommend against the use of HPV testing (through direct or indirect methods), as results are not confirmatory and have no impact on disease management. However, when the morphology of a potentially precancerous anogenital lesion is unclear, p16 by IHC can be used to guide histologic interpretation. Biopsy and IHC may also be considered when warts or lesions are unchanged or worsened with therapy, especially in immunocompromised individuals.