An integrated model for prognosis in vulvar squamous cell carcinoma

Abstract

Background Vulvar squamous cell carcinoma (VSCC) is a relatively rare gynecologic cancer. Unlike cervical squamous cell carcinoma (CSCC), in which nearly all cases are caused by HPV infection, most VSCCs are HPV-independent. Patients with VSCC also have worse overall survival (OS) than those with CSCC. Unlike CSCC, the risk factors of VSCC have not been extensively studied. Here, we investigated the prognostic values of clinicopathological parameters as well as biomarkers in patients with VSCC. Methods In total, 69 cases of VSCC accessions were selected for analysis between April 2010 and October 2020. The risk factors of VSCC were screened using Cox models to establish nomograms for predicting survival outcomes. Results Following the multivariate COX model for OS, independent predictors including advanced age (hazard ratio [HR] 5.899, p = 0.009), HPV positivity (HR 0.092, p = 0.016), high Ki-67 index (HR 7.899, p = 0.006), PD-L1-positivity (HR 4.736, p = 0.077), and CD8 + tumor-infiltrating lymphocytes (TILs) (HR 0.214, p = 0.024) were included in the nomogram for OS; multivariate COX model for progression-free survival (PFS) was used to screen prognostic factors including advanced age (HR 2.902, p = 0.058), lymph node metastasis (HR 5.038, p = 0.056), HPV positivity (HR 0.116, p = 0.011), high Ki-67 index (HR 3.680, p = 0.042), PD-L1-positivity (HR 5.311, p = 0.045), and CD8 + TILs (HR 0.236, p = 0.014) to establish the PFS nomogram model. Based on the C-index (0.754 for OS and 0.754 for PFS) from our VSCC cohort and the corrected C-index (0.699 for OS and 0.683 for PFS) from an internal validation cohort, the nomograms demonstrated good predictive and discriminative ability. Kaplan-Meier curves also supported the excellent performance of the nomograms. Conclusion Our prognostic nomograms suggested that (1) shorter OS and PFS were associated with PD-L1-positivity, high Ki-67 index, and low CD8 + TILs; (2) HPV-independent tumors were associated with poorer survival outcome, and mutant p53 status showed no prognostic significance.