In a patient with squamous vulvar cancer previously treated with cisplatin and radiotherapy and now with widely metastatic recurrence, would you initiate treatment with chemotherapy or consider immunotherapy?

This is a difficult case, and the literature on systemic treatment options in metastatic vulvar cancer is sparse. I would check for PDL1, MMR as you have done. In addition, I would also test for NTRK gene fusion. A next general sequencing panel such as CARIS or Foundation One is useful in these settings.

My approach is to give chemotherapy as first-line (platinum, taxane, bevacizumab), and then immunotherapy as second-line if the tumor is PDL1 positive or MMR high. In addition, I would have a discussion regarding the goals of care and expectations with the patient. Engaging the support of palliative medicine specialists in these cases is also key (whenever possible).

I would wait for the CPS score. If >1, then immunotherapy.