Update on Prognostic and Predictive Markers in Mucinous Ovarian Cancer

SIMPLE SUMMARY: Mucinous ovarian cancer (MOC) is a rare tumor that can be classified according to stage in early MOC and advanced MOC. Early MOC is characterized by a good prognosis and, in most cases, surgical treatment alone represents the mainstay of therapy. Despite the good prognosis, some early-stage MOCs can relapse and exhibit aggressive behavior, and new biomarkers are emerging to better stratify these patients. Advanced MOC, instead, is characterized by a poor prognosis. Radical surgery is still the mainstay of treatment since these tumors are chemo-resistant. New targeted therapies are being studied to improve the prognosis in this setting, but unfortunately, none of these have been approved yet. This review focuses on the most relevant clinical, pathological, and molecular features and treatment options according to prognosis. ABSTRACT: This review includes state-of-the-art prognostic and predictive factors of mucinous ovarian cancer (MOC), a rare tumor. Clinical, pathological, and molecular features and treatment options according to prognosis are comprehensively discussed. Different clinical implications of MOC are described according to the The International Federation of Gynecology and Obstetrics (FIGO) stage: early MOC (stage I-II) and advanced MOC (stage III-IV). Early MOC is characterized by a good prognosis. Surgery is the mainstay of treatment. Fertility-sparing surgery could be performed in patients who wish to become pregnant and that present low recurrence risk of disease. Adjuvant chemotherapy is not recommended, except in patients with high-risk clinical and pathological features. Regarding the histological features, an infiltrative growth pattern is the major prognostic factor of MOC. Furthermore, novel molecular biomarkers are emerging for tailored management of early-stage MOC. In contrast, advanced MOC is characterized by poor survival. Radical surgery is the cornerstone of treatment and adjuvant chemotherapy is recommended, although the efficacy is limited by the intrinsic chemoresistance of these tumors. Several molecular hallmarks of advanced MOC have been described in recent years (e.g., HER2 amplification, distinct methylation profiles, peculiar immunological microenvironment), but target therapy for these rare tumors is not available yet.