Surgical margin status and recurrence pattern in invasive vulvar Paget's disease: A Japanese Gynecologic Oncology Group study

Objective: To examine the association between surgical margin status and recurrence pattern in invasive vulvar Paget's disease.

Methods: This is a preplanned secondary analysis of a previously organized nationwide retrospective study in Japan (JGOG-1075S). Women with stage I-IV invasive vulvar Paget's disease who received surgical treatment from 2001-2010 were examined (n=139). Multivariable analysis was performed to assess local-recurrence, distant-recurrence, and all-cause mortality based on surgical margin status.

Results: The median age was 70 years. The majority had stage I disease (61.2%), and the median tumor size was 5.0cm. Nodal metastasis was observed in 15.1%. Simple vulvectomy (46.0%) was the most common surgery type followed by radical vulvectomy (28.1%). More than half received vulvar reconstructive surgery (59.0%). Positive surgical margin was observed in 35.3%, and close margin <1cm was observed in 29.5%. Vulvectomy type was not associated with surgical margin status (P=0.424). The median follow-up was 5.8 years. Positive surgical margin was associated with increased local-recurrence (5-year cumulative rates for positive versus negative margin: 35.8% versus 15.0%, P=0.010) but not distant-recurrence (18.3% versus 16.0%, P=0.567). Positive surgical margin was also associated with increased all-cause mortality (5-year overall survival rates for positive versus negative margin: 72.6% versus 88.2%, P=0.032). In multivariable analysis, positive surgical margin remained an independent factor associated with increased risk of local-recurrence (hazard ratio 2.80, 95% confidence interval 1.18-6.63) and all-cause mortality (hazard ratio 2.87, 95% confidence interval 1.20-6.83).

Conclusion: Positive surgical margin appears to be common in invasive vulvar Paget's disease that is associated with increased local-recurrence and all-cause mortality risks. Role of alternative surgical technique or adjuvant therapy merits further investigation to improve local disease control.