Prognostic indicators in ovarian serous borderline tumours.

There have been great strides in our understanding of the serous group of borderline and malignant pelvic epithelial neoplasms in the past decade. While most serous borderline tumours have a favourable prognosis, recurrences and progression to carcinoma occur, often following a protracted clinical course. Clinical and pathological risk factors tend to co-vary, but the presence and type of extraovarian disease is the most important predictor for progression. Progression usually takes the form of low-grade serous carcinoma, although transformation to high-grade carcinoma is occasionally seen. A serous borderline - low-grade serous carcinoma pathway analogous to neoplastic transformation pathways seen in other organ systems has been proposed, based on global gene expression profiling, shared mutations in KRAS or BRAF, and in most cases, the presence of serous borderline tumour in de novo low-grade serous carcinoma. This discussion focuses on the key prognostic factors that predispose to disease progression and/or transformation to carcinoma in serous borderline tumours.