The role of estrogen and progesterone receptors in the rotator cuff disease: a retrospective cohort study

Background: Rotator cuff (RC) tears represent a common cause of shoulder pain and dysfunction in adults. The disease affects primarily women and occurs mainly in the postmenopausal period. This study aimed to investigate immunohistochemically the presence of estrogen receptor-alpha (ER-alpha), estrogen receptor-beta (ER-beta) and progesterone receptor (PR) in the supraspinatus tendon of patients with RC tendinopathy, searching for gender differences of expression. A secondary aim was to evaluate potential links between their expression and the typical histopathological findings of the ailment. Methods: Biopsies of the supraspinatus tendon were collected intraoperatively from 15 postmenopausal women and 9 men undergoing RC surgery. Specimens were stained with Haematoxylin/Eosin, Masson-Goldner Trichrome, Alcian Blu and immunohistochemical stainings for ER-alpha, ER-beta and PR were performed. Tendon alterations were evaluated with the Bonar histopathological scale. Statistical tests used in this study were the Spearman correlation coefficient and the Mann-Whitney U test. Results: In the supraspinatus tendon, cells expressed ER-alpha (p = 0.043), ER-beta (p = 0.048) and PR (p = 0.004) with statistically significant differences related to age and sex of patients. Immunoreactivity was seen in the nuclei of tenocytes and vascular cells. Postmenopausal women's samples showed a markedly higher expression of these receptors compared to their male counterpart. There was a positive correlation between the expression of ER-alpha and ER-beta (r = 0.59; p = 0.02) and between ER-beta and PR (r = 0.72; p = 0.002) in women's samples. Furthermore, in postmenopausal women the PR expression decreased with age (r = - 0.56; p = 0.027). Only in women, the ER-beta expression positively correlated with the total Bonar histopathological score (p = 0.019) and the ER-beta vascular expression positively correlated with ground substance alterations (p = 0.029). Conclusions: These results reveal that ERs and PR are present in the supraspinatus tendon of patients with RC tears, suggesting a role of sex hormones in the pathogenesis of the disease.

Automated summary

This study investigated the presence of estrogen receptors and progesterone receptor in the supraspinatus tendon of patients with RC tears, finding significantly higher expression in postmenopausal women compared to men. There were positive correlations between ER expression and age in women, as well as between ER expression and histopathological findings. The results suggest a potential role of sex hormones in the pathogenesis of RC tears.