Can Visual Inspection with Acetic Acid (VIAC) be used to rule out cancer in patients with genital warts?

VIAC Cannot Be Used to Rule Out Cancer in Patients with Genital Warts

Visual inspection with acetic acid (VIAC) is not recommended for ruling out cancer in patients with genital warts because acetowhitening is not a specific test for HPV infection or malignancy, and biopsy remains the definitive method for excluding squamous cell carcinoma when clinical concern exists. 1

Why VIAC Is Inadequate for Cancer Exclusion

Lack of Specificity

• The CDC explicitly states that acetic acid application is not a specific test for HPV infection, causing many false-positives particularly in low-risk populations. 1
• The specificity and sensitivity of acetowhitening have never been adequately defined for diagnostic purposes. 1
• Research demonstrates that VIA has extremely poor sensitivity (20%) for detecting precancerous lesions when compared to HPV testing (100% sensitivity), making it unreliable for excluding malignancy. 2

Clinical Guideline Recommendations

• The CDC guidelines from 1998 and 2010 explicitly state that routine use of acetic acid soaks and examination with magnification as a screening test is not recommended. 1
• The 2010 CDC guidelines emphasize that acetic acid application "is not a specific test for HPV infection" and therefore "the routine use of this procedure for screening to detect mucosal changes attributed to HPV infection is not recommended." 1

When Biopsy Is Mandatory

Biopsy should be performed in the following clinical scenarios to rule out malignancy: 1, 3

• The diagnosis is uncertain
• Lesions do not respond to standard therapy
• Disease worsens during therapy
• The lesion is atypical in appearance
• The patient is immunocompromised
• The warts are pigmented, indurated, fixed, bleeding, or ulcerated 1, 3

Special Risk in Immunosuppressed Patients

• Squamous cell carcinomas arising in or resembling genital warts occur more frequently among immunosuppressed persons (including HIV-infected patients), requiring more frequent biopsy for confirmation of diagnosis. 1, 3
• These patients may not respond well to standard therapy and have higher recurrence rates. 1

The Correct Diagnostic Approach

Visual Inspection Alone

• Diagnosis of genital warts is typically made by visual inspection without acetic acid application. 1
• The FDA drug label for podofilox emphasizes that "although genital warts have a characteristic appearance, histopathologic confirmation should be obtained if there is any doubt of the diagnosis." 4

When Malignancy Must Be Excluded

• Differentiating warts from squamous cell carcinoma (including Bowenoid papulosis) is of particular concern and requires biopsy, not VIAC. 4
• Squamous cell carcinoma may be associated with HPV but presents with concerning features that warrant tissue diagnosis. 4

Critical Pitfalls to Avoid

• Do not rely on negative VIAC results to exclude cancer—the test lacks the sensitivity and specificity needed for this purpose. 1, 2
• Do not use HPV DNA testing to rule out genital warts or cancer—negative HPV testing does not exclude the diagnosis of genital warts, and management decisions should not be based on HPV tests alone. 1, 3
• Do not assume all acetowhite lesions are benign warts—this finding is nonspecific and can occur with dysplasia or normal tissue. 1, 5
• In immunocompromised patients, maintain a lower threshold for biopsy given the increased risk of malignant transformation. 1, 3

Evidence Quality Note

The WHO recommended in 2021 "using HPV DNA detection as the primary screening test rather than VIA or cytology" for cervical cancer screening, further undermining the utility of acetic acid-based visual inspection methods. 2 Research consistently demonstrates that VIA-based screening may not be acceptable for detecting precancerous lesions. 2