Vulvar Paget's disease and stromal invasion: Clinico-pathological features and survival outcomes.

Purpose: To evaluate clinico-pathological features, treatments and survival outcomes of vulvar Paget's disease (VPD).

Methods: We retrospectively reviewed VPD diagnosed between 1983 and 2018 at the Department of Surgical Sciences, Sant'Anna Hospital, Turin. Clinico-pathological characteristics and surgical treatment outcomes were investigated according to the depth of invasion.

Results: A total of 122 patients were identified. Eighty-seven patients were diagnosed with intraepithelial VPD, 22 with microinvasive (<=1 mm) VPD and 16 with invasive VPD. The median follow-up was 94.6 months (interquartile range 25th-75th, 26-120). Most of patients 95/122 (77%) were treated by surgery. Local recurrence was observed in 69/95 (73%) patients without significant difference between the 3 groups (p = 0.33), however, total vulvectomy showed better local control in microinvasive and invasive VPD than in intraepithelial tumors. At 120 months the cancer-specific survival was 100% for intraepithelial and microinvasive VPD versus 31% for invasive VPD (log-rank p = <0.0001) Age ≥65 years (OR: 4.17 CI 1.12-15.5, p = 0.03) and VPD's area ≥15 cm (OR: 5.83 CI 1.75-19.3, p = 0.004) were associated with risk of invasiveness.

Conclusion: Microinvasive VPD has an identical prognosis to intraepithelial VPD, suggesting the omission of lymphadenectomy or adjuvant treatments are safe in this subset of patients. We recommend caution to propose medical treatment in patients who are ≥65 years old and with wide tumor area, as they are at the greatest risk of invasiveness.