Vulvar squamous cell carcinoma arising on human papillomavirus-independent precursors mimicking high-grade squamous intra-epithelial lesion: a distinct and highly recurrent subtype of vulvar cancer.

AIMS: Each category of vulvar squamous cell carcinoma (VSCC), human papillomavirus (HPV)-associated and HPV-independent, arises on a specific intra-epithelial precursor: high-grade squamous intra-epithelial lesions (HSIL) and differentiated vulvar intra-epithelial neoplasia (dVIN), respectively. However, a subset of HPV-independent VSCC arises on an intra-epithelial precursor closely mimicking HSIL. We aimed to explore the clinicopathological features of the HPV-independent tumours with HSIL-like lesions and compare them with HPV-independent VSCC with dVIN and HPV-associated tumours with HSIL. METHODS AND RESULTS: We retrospectively identified 105 cases of surgically treated VSCC with adjacent intra-epithelial precursors. The cases were classified into three groups based on the HPV status and the adjacent precursor identified: (i) HPV-associated VSCC with HSIL (n = 26), (ii) HPV-independent VSCC with dVIN lesions (n = 54) and (iii) HPV-independent VSCC with HSIL-like lesions (n = 25). We analysed the histological and clinical features including the recurrence-free survival and disease-specific survival in the three groups. Patients with HPV-independent VSCC with HSIL-like lesions and with dVIN were older than patients with HPV-associated VSCC (76 and 77 versus 66 years, respectively, P < 0.001). HPV-independent VSCC with HSIL-like lesions recurred more frequently [hazard ratio (HR) = 3.87; P < 0.001] than HPV-independent VSCC with dVIN (HR = 2.27; P = 0.1) and HPV-associated VSCC (HR = 1). In the multivariate analysis, HPV-independent VSCC with HSIL-like lesions remained significant for recurrence. No differences in disease-specific survival were observed between the three groups. CONCLUSIONS: Even though VSCC with HSIL-like lesions are not associated with higher mortality, they are more likely to recur and might benefit from more intensive treatment strategies and closer surveillance after treatment.

Human papillomavirus and p53 status define three types of vulvar squamous cell carcinomas with distinct clinical, pathological, and prognostic features.

INTRODUCTION: Based on their etiological relationship with human papillomavirus (HPV), the 2020 WHO classification has divided vulvar squamous cell carcinomas (VSCC) into two distinct types, HPV-associated and HPV-independent, and HPV-independent tumours have recently been divided according to p53 status. Nevertheless, the clinical and prognostic significance of this classification has not been clearly established. We analysed the differential clinical, pathological, and behavioural characteristics of these three types of VSCC in a large series of patients. METHODS AND RESULTS: VSCC samples from patients who underwent primary surgery at the Hospital Clinic of Barcelona, Spain, during a 47-year period (January 1975 to January 2022) were analysed (n = 190). HPV detection, p16, and p53 immunohistochemical staining were evaluated. We also analysed recurrence-free survival (RFS) and disease-specific survival (DSS). Thirty-three tumours (17.4%) were HPV-associated and 157 (82.6%) HPV-independent. Of these, 20 showed normal and 137 abnormal p53 expression. The two types of HPV-independent tumours showed worse RFS in the multivariate analysis (hazard ratio [HR] = 3.63; P = 0.023 for the HPV-independent p53 normal VSCC and HR = 2.78; P = 0.028 for the HPV-independent p53 abnormal VSCC). Although the differences were not significant, HPV-independent VSCC had worse DSS than HPV-associated VSCC. Although patients with HPV-independent p53 normal tumours had worse RFS than patients with HPV-independent p53 abnormal tumours, the DSS was better for the former group. Only advanced FIGO stage was associated with worse DSS in multivariate analysis (HR = 2.83; P = 0.010). CONCLUSION: The association of HPV and p53 status have prognostic implications, reinforcing a three-tier molecular classification of VSCC (HPV-associated VSCC, HPV-independent VSCC with normal p53, HPV-independent VSCC with abnormal p53).

Analysis of Local Recurrence Risk in Ductal Carcinoma In Situ and External Validation of the Memorial Sloan Kettering Cancer Center Nomogram.

BACKGROUND: Adjuvant radiotherapy and hormonotherapy after breast-conserving surgery (BCS) in ductal carcinoma in situ (DCIS) have been shown to reduce the risk of local recurrence. To predict the risk of ipsilateral breast tumor relapse (IBTR) after BCS, the Memorial Sloan Kettering Cancer Center (MSKCC) developed a nomogram to analyze local recurrence (LR) risk in our cohort and to assess its external validation. METHODS: A historical cohort study using data from 296 patients treated for DCIS at the Hospital Clínic of Barcelona was carried out. Patients who had had a mastectomy were excluded from the analysis. RESULTS: The mean age was 58 years (42-75), and the median follow-up time was 10.64 years. The overall local relapse rate was 13.04% (27 patients) during the study period. Actuarial 5- and 10-year IBTR rates were 5.8 and 12.9%, respectively. The external validation of the MSKCC nomogram was performed using a multivariate logistic regression analysis on a total of 207 patients, which did not reach statistical significance in the studied population for predicting LR (p = 0.10). The expression of estrogen receptors was significantly associated with a decreased risk of LR (OR: 0.25; p = 0.004). CONCLUSIONS: In our series, the LR rate was 13.4%, which was in accordance with the published series. The MSKCC nomogram did not accurately predict the IBTR in this Spanish cohort of patients treated for DCIS (p = 0.10).