How would you treat a recurrent, metastatic invasive Paget's disease of the vulva?

Just to clarify, this is a recurrence within the radiated groin, and that recurrent groin node has been resected so there is no gross disease currently?

Any treatment for metastatic, recurrent invasive vulvar Paget’s disease will be non-curative/palliative, so at this post, if there is no gross disease, I would favor observation. The risk of distant or locoregional recurrence is obviously high, so I would send for HER2 testing (30-60% HER2 overexpression in vulvar Paget’s) and NGS to see if you have any targeted therapy options for when she recurs. If nothing targetable, there are a few case reports or series that show variable responses (not typically durable) to different chemo regimens, but I would save systemic therapy for a recurrence...