Association between estrogen receptor alpha 36 expression and the risk of deep infiltrating endometriosis.

Background: Deep infiltrating endometriosis (DIE) is a severe subtype of endometriosis, often associated with dysmenorrhea and significant diagnostic challenges. Conventional biomarkers, such as cancer antigen 125 (CA125), lack sufficient specificity for accurate DIE diagnosis. Estrogen receptor α36 (ERα36) is a novel isoform of the estrogen receptor, distinct from the classic estrogen receptor α66 (ERα66), and has been implicated in the pathogenesis of several gynecologic disorders, including breast and endometrial cancer. However, the expression pattern of Methods: A case-control study was conducted between 2014 and 2016, enrolling 80 DIE patients as the case group and 132 healthy women as the control group. The expression of ERα36 was evaluated at both the mRNA and protein levels: reverse transcription-polymerase chain reaction was used for mRNA expression and immunohistochemistry was performed for protein detection. Statistical analyses were performed using SPSS version 26.0, and receiver operating characteristic curve analysis was employed to assess the diagnostic performance of ERα36 for DIE. Results: No significant differences were observed between control and endometriosis groups in demographic or reproductive characteristics (all Conclusion: ERα36 is highly expressed in DIE tissues and exhibits good diagnostic performance with high sensitivity and specificity. These findings suggest that ERα36 may serve as a novel tissue-level biomarker for DIE, representing a potential target for future therapeutic strategies.