Pseudoprogression and improvement of quality of life in a patient with advanced endometrial cancer treated with immunotherapy: a case report

Until recently, treatment options for patients with recurrent or metastatic endometrial cancer (EC) were limited. First-line treatment is usually based on carboplatin and paclitaxel and there was no standard second-line therapy following platinum failure. However, the introduction of immunotherapy has expanded both first-line and later-line options for EC and made determination of mismatch repair status essential. We describe the case of a 56-year-old woman with deficient mismatch repair/microsatellite instability EC who did not respond to first-line treatment with carboplatin and paclitaxel but had a high response to subsequent immunotherapy with dostarlimab. There was initial pseudoprogression of one target lesion but marked improvement in quality of life.