Background: Human Papilloma Virus (HPV) DNA tests are highly sensitive and can triage women with mild lesions, improving the prognosis and diagnosis of cervical lesions. However, additional efficient strategies should be developed to improve the specificity of these tests.
Methods: This study aimed to evaluate the clinical value of HPV DNA load in improving the diagnosis and prognosis of cervical lesions by p16/Ki-67 testing. Histological samples were collected from 350 women with HR-HPV genotyping and analyzed by qRT-PCR. Immunohistochemical staining was used to assess p16 and Ki-67 expression and clinical performance characteristics were calculated.
Results: Of the cases, 271 had detectable HR-HPV infection, in which HPV-16 was most prevalent (52.0%), followed by HPV-58 (22.5%). P16/Ki-67-positivity increased with histological severity but not for HR-HPV infection. Amongst the 13 HR-HPV genotypes, only HPV-16 (P = 0.016) and HPV-58 (P = 0.004) viral loads significantly correlated with lesion severity. The P16/Ki-67/HPV DNA load co-test indicated an increased sensitivity for the detection of cervical intraepithelial neoplasia (CIN) lesions compared to p16/Ki-67 staining in HPV-16 and/or 58 positive cases. Viral load did not improve the sensitivity of p16/Ki-67 co-test in non-HPV-16 or 58 positive cases. The clinical performance of the p16/Ki-67/HPV DNA load co-test was limited for the prediction of the outcome of CIN1 lesions. However, amongst the 12 HPV-16 and/or 58 positive CIN2 cases in which return visit results were obtained, the behavior of the lesions could be predicted, with a sensitivity, specificity, positive prediction rate (PPV), and negative prediction rate (NPV) of 0.667, 1, 1 and 0.5, respectively.
Conclusion: Combination of the assessment of HPV DNA load with the intensity of p16 and Ki-67 staining could increase the sensitivity of CIN lesion diagnosis and predict the outcome of CIN2 in patients with a HPV-16 and/or 58 infection.
Keywords: Diagnosis and prognosis; HPV DNA load; Immunohistochemistry; p16/Ki-67/HPV DNA load co-test.