A Rare Pathological Phenotype of Endometrioid Serous and Clear-Cell Ovarian Cancer with PIK3CA Mutations in Relation to The Excellent Response of Alpelisib.

Patients with metastatic ovarian cancer who develop resistance to standard therapy with or without platinum need to search for other therapeutic choices. Therefore, identifying genetic alterations and selecting an approach to treatment using precision medicine techniques are important. In a patient diagnosed with mixed-type ovarian cancer after surgery, adjuvant therapy was applied with a combination of carboplatin and taxane, but the disease recurred. Upon evaluation of the patient as having platinum-sensitive epithelial ovarian cancer (EOC), combination therapy with bevacizumab was initially successful. However, disease progression was again observed, and molecular analysis revealed the presence of an E545K mutation in the PIK3CA gene; therefore, a selective PI3K inhibitor, alpelisib, was used as a treatment under the compassionate-use protocol. The patient's complications improved after receiving the alpelisib medication. The patient has been in complete remission for over two years. This case serves as a rare example that confirms the utility of alpelisib in managing mixed-type ovarian cancer.