Body Mass Index is Negatively Associated with Endometrial Cancer Stage, Regardless of Subtype and Menopausal Status.

Objective: Obesity is one of the common risk factors for developing of endometrial cancer and is negatively associated with its survival, although this result is controversial. Endometrial cancer stages range from stage I, which has better clinical outcomes to stage IV, which has poorer clinical outcomes. Endometrial cancer traditionally divides into type 1 and type 2 dependent on histology which has different clinical outcomes. In this study we investigated whether obesity is associated with the stages of endometrial cancer taking into account subtypes of cancer and menopausal status. Methods: Data on 1,104 women with endometrial cancer were retrospectively collected from the largest women's hospital in China and analysed. Data included age at diagnosis, body mass index (BMI), histology of cancer and menopausal status. Results: The BMI in patients with stage I endometrial cancer was significantly higher than that in patients with stage II or III or IV (p=0.0001). However, there was no statistical difference in BMI between patients with stage II, and stage III endometrial cancer. This negative association was persisted with type 1 and type 2 endometrial cancer (p=0.1989) and premenopausal and post-menopausal status (p=0.4342). In addition, the proportion of over-weight or obese women in type1 endometrial cancer with stage I was not different to type 2 endometrial cancer with stage I. Conclusion: Our data demonstrate that BMI is negatively associated with endometrial cancer in early stage regardless of subtypes of cancer, menopausal status and obesity may be also a potential risk factor for developing type 2 endometrial cancer.