Uterine serous carcinoma.

ABSTRACT

Serous endometrial cancer represents a relative rare entity accounting for about 10% of all diagnosed endometrial cancer, but it is responsible for 40% of endometrial cancer-related deaths. Patients with serous endometrial cancer are often diagnosed at earlier disease stage, but remain at higher risk of recurrence and poorer prognosis when compared stage-for-stage with endometrioid subtype endometrial cancer. Serous endometrial cancers are characterized by marked nuclear atypia and abnormal p53 staining in immunohistochemistry. The mainstay of treatment for newly diagnosed serous endometrial cancer includes a multi-modal therapy with surgery, chemotherapy and/or radiotherapy. Unfortunately, despite these efforts, survival outcomes still remain poor. Recently, The Cancer Genome Atlas (TCGA) Research Network classified all endometrial cancer types into four categories, of which, serous endometrial cancer mostly is found within the "copy number high" group. This group is characterized by the increased cell cycle deregulation (e.g., CCNE1, MYC, PPP2R1A, PIKCA, ERBB2 and CDKN2A) and TP53 mutations (90%). To date, the combination of pembrolizumab and lenvatinib is an effective treatment modality in second-line therapy, with a response rate of 50% in advanced/recurrent serous endometrial cancer. Owing to the unfavorable outcomes of serous endometrial cancer, clinical trials are a priority. At present, ongoing studies are testing novel combinations of various targeted and immunotherapeutic agents in newly diagnosed and advanced/recurrent endometrial cancer - an important strategy for serous endometrial cancer, whereby tumors are usually p53+ and pMMR, making response to PD-1 inhibitor monotherapy unlikely. Here, the rare tumor working group (including members from the European Society of Gynecologic Oncology (ESGO), Gynecologic Cancer Intergroup (GCIG), and Japanese Gynecologic Oncology Group (JGOG)), performed a narrative review reporting on the current landscape of serous endometrial cancer and focusing on standard and emerging therapeutic options for patients affected by this difficult disease.