High human papillomavirus viral load and local immune dysregulation are associated with poor clinical outcomes in patients with cervical cancer.

Objective: Human papillomavirus (HPV) infection is the primary cause of cervical cancer. Higher viral load, that is, a greater abundance of HPV DNA in a tumor, has been associated with poorer clinical outcomes, and may play a role in the more accurate prediction of (non-) responders to treatment. In this study, we investigated the correlation between HPV viral load, clinical outcomes, and immune parameters related to HPV infection.

Methods: HPV viral load was quantified using quantitative polymerase chain reaction on biopsies from a prospective cohort of women diagnosed with cervical cancer. Patients were categorized into 2 HPV viral load groups based on the optimal fit of a non-linear piecewise regression model. Immunohistochemical staining was used to measure tumor cell characteristics (Ki67, p16^INK4a, Pan-CK), as well as local tumor immune parameters (CD3, CD4, CD8, FOXP3) and immune checkpoint expression (PD-1, PD-L1). Kaplan-Meier curves were generated to compare recurrence-free and overall survival.

Results: In the 44 women included in our study, high HPV viral load was significantly associated with shorter overall and recurrence-free survival (p = .045 and p = .046, respectively; 2-sided) and positively correlated with an increased risk of lymph node and distant metastasis. In addition, a high HPV viral load was linked to lower percentages of tumor-infiltrating lymphocytes and reduced expression levels of PD-1 and PD-L1.

Conclusions: The viral load of HPV in cervical cancer correlates positively to metastasis and recurrence and negatively to survival rates, potentially because of local immune suppression. These results might indicate a lower response to immune checkpoint inhibition in the high viral load group and that other treatment options should still be explored.