Mucinous borderline ovarian tumors with BRAFV600E mutation may have low risk for progression to invasive carcinomas

Purpose Mucinous ovarian carcinomas (MOCs) are relatively rare. It has been proposed that a subset of mucinous cystadenomas (MCAs) may progress to mucinous borderline tumors (MBTs), and then to MOCs. KRAS is the predominantly mutated gene in MOC; however, other associated mutations and the mechanism underlying carcinogenesis in MOC remain unclear. Here, we assessed molecular genetic alterations in mucinous ovarian tumors and constructed mutation profiles. Methods Using the Sanger sequencing method, we assessed genetic mutations (KRAS, BRAF, TP53, and PIK3CA) in 16 cases of MOC, 10 cases of MBT, and 12 cases of MCA. Results Among MOC cases, the prevalence of G12D and G13D KRAS mutations was 43.8% (7/16). No MOC cases showed V600E BRAF and TP53 mutations. Among MBT cases, the prevalence of G12D KRAS mutation was 20.0% (2/10), those of TP53 and PIK3CA mutations were nil, and that of V600E BRAF mutation was 40% (4/10). None of the genetic mutations assessed were detected among MCA cases. Conclusion These results suggest that MBT with V600E BRAF mutation may rarely progress to MOC, while MBT with G12D or G13D KRAS mutation may more commonly progress to MOC.