Fascin-1 expression as stratification marker in borderline epithelial tumours of the ovary

AimsTo evaluate the actin-bundling protein fascin-1 (FSCN1) as marker for borderline ovarian tumours (BOTs).MethodsWe analysed a retrospective cohort of 140 BOTs with validated diagnosis by an independent pathologist. Immunohistochemical detection of FSCN1 was quantified as combined immunoreactive score (CIS) blinded to clinical patient data. Analyses were first performed for FSCN1 positive versus negative, and then verified using three categories derived from the observed distribution (negative, weak, strong; CIS 0, 1–2, 3–9).ResultsWe detected FSCN1 positivity in 51.4%, and strong expression (CIS 3–9) in 14.3% of the samples. FSCN1 positivity was associated with serous subtype (p