Immunohistochemical expression of estrogen and progesterone receptors in endometrial polyps and its relationship to clinical parameters

To investigate the differences in steroid receptor expression patterns between glandular and stromal portions in endometrial polyps among premenopausal and postmenopausal patients and the relationship between the receptor expression in endometrial polyps and clinical parameters. A total of 25 postmenopausal and 25 premenopausal patients with solitary endometrial polyp detected by office hysteroscopy were involved in the study. All patients underwent hysteroscopic polypectomy under general anesthesia or spinal anesthesia. Estrogen and progesterone expression patterns were investigated in the polyps using immunohistochemistry. The mean age was 57.6 years in postmenopausal patients and 36.9 in premenopausal patients. Average gravida, body mass index (BMI), and frequency of smokers did not differ between groups. However, the patient's age and their concomitant diseases were significantly different between premenopausal and postmenopausal patients (P = 0.01). Comparison in postmenopausal patients showed that glandular estrogen and progesterone receptor expression were both significantly greater than stromal estrogen and progesterone receptor expression (P = 0.037 and < 0.001, respectively). Proliferative phase endometrial polyps also demonstrated significantly greater expression of progesterone receptors in glandular epithelium compared with stroma (P = 0.019). However, stromal and glandular estrogen receptor expression did not differ among premenopausal patients. There was a statistically significant correlation among stromal progesterone receptor expression, plasma estrogen and FSH level (P = 0.01). A negative correlation was found between stromal progesterone receptor expression and patient's age (P = 0. 01). Estrogen and progesterone receptor expression were lower in the stromal portion of the endometrial polyp than in the glandular portion in postmenopausal patients. Stromal progesterone receptor expression was lower in older patients and there was a relation between low estrogen hormone levels and lower stromal progesterone receptor expression.