Is the positivity of estrogen receptor or progesterone receptor different between type 1 and type 2 endometrial cancer?

Endometrial cancer is a major cancer in women and traditionally divided into type 1 and type 2. It is well known that type 2 endometrial cancer has a poor prognosis. Studies have suggested that estrogen receptor (ER) or progesterone receptor (PR) positive are positively associated with endometrial cancer survive. However whether the positivity of ER or PR is different between cancer types has not been investigated yet. In this retrospective study, the positivity of ER or PR was analysed in 1054 women with primary diagnosed endometrial cancer taking into account cancer types and menopausal status from the largest university teaching women's hospital in China. The positivity of ER or PR (over 90%) was significantly higher in type 1 compared to that in type 2 endometrial cancer (71% or 64%) in both premenopausal and postmenopausal women. There was no different in positivity of ER or PR in type 1 endometrial cancer between premenopausal and postmenopausal women. However, in type 2 endometrial cancer, the positivity of ER or PR in premenopausal women was significantly higher compared to that in postmenopausal women. Our data demonstrate that both ER and PR positivity are significantly higher in type 1 endometrial cancer (92%) compared to type 2 (72% ER positive, 65% PR positive). Menopausal status is not associated with the positivity of ER or PR in type 1 endometrial cancer. Our data may provide some novel insights why Asian women have better outcomes of endometrial cancer which was reported in the literature.