Prevalence and Independence of p53 Signatures and β-Catenin Signatures in Risk-Reducing Salpingo-Oophorectomy Specimens.

Clusters of epithelial cells of the fallopian tube exhibiting aberrant p53 expression, termed "p53 signatures," are detected at a relatively high frequency and have been regarded as putative precursors of high-grade serous carcinoma (HGSC). In contrast, the recently proposed "β-catenin signature" represents a distinct tubal epithelial alteration characterized by the aberrant expression of β-catenin, the biological significance of which remains unclear. To clarify the frequency and spatial relationship between the two lesions, we analyzed 30 consecutive risk-reducing salpingo-oophorectomy specimens from BRCA1/2 mutation carriers using the sectioning and extensively examining the fimbriated end protocol and performed immunohistochemical evaluation for p53, β-catenin, and Ki-67. p53 signatures and β-catenin signatures were each identified in seven cases (23%). Two cases (6.7%) harbored both lesions; however, no spatial overlap or histological continuity was observed. Neither lesion demonstrated significant associations with BRCA mutation subtype, age, body mass index, or parity. Furthermore, no cases showed serous tubal intraepithelial lesion, serous tubal intraepithelial carcinoma, or HGSC. These findings suggest that p53 signatures and β-catenin signatures may represent distinct localized epithelial alterations in the fallopian tube, although further molecular and spatial analyses are required to clarify their biological relationship.