23P Pre-diagnostic imaging reveals rapid emergence and progression of small cell carcinoma of the ovary hypercalcemic type (SCCOHT): Implications for monitoring carriers of SMARCA4 germline pathogenic variants (GPVs)

Conclusions: Pembrolizumab either alone or in combination with chemotherapy conferred a benefit to 7 out of 10 patients with SCC arising from mature teratoma.Evaluation in a larger cohort and comparison of responders vs. non-responders is warranted to help future patient selection for this active treatment.