Relationship between the expression of oestrogen receptor and progesterone receptor and (18)F-FDG uptake in endometrial cancer

Background: Progestogens have been widely used for the treatment of inoperable endometrial cancer or younger patients with endometrial cancer. Identifying markers that are predictive of a response to progestogens is critical for successful therapy. Molecular imaging with (18)F(-)fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) can provide metabolic phenotypic information of many malignancies. We investigated whether estrogen receptor (ER)/progestogen receptor (PR) status is correlated with (18)F-FDG uptake, and whether (18)F-FDG PET/CT could be useful for predicting ER/PR status in endometrial cancer. Results: Endometrial cancers in the ER-positive group had lower SUVmax than those in the ER-negative group (12.3 ± 6.2 vs. 19.9 ± 6.6, respectively; P = 0.003). Endometrial cancers in the PR-positive group also had lower SUVmax than those in the PR-negative group (12.4 ± 6.2 vs. 20.0 ± 6.9, respectively; P = 0.005). Multivariate analysis indicated that SUVmax and tumour differentiation grade were significantly associated with both ER and PR status (P = 0.027 and P = 0.044, respectively). ER expression was predicted with an accuracy of 74.2% when a SUVmax value of 15.3 was used as a cutoff point for analysis. Similarly, PR expression was predicted with an accuracy of 74.2%, when a SUVmax value of 15.95 was used as the threshold for analysis. Conclusion: Higher (18)F-FDG accumulation in endometrial cancers is correlated with negative ER/PR expression. (18)F-FDG PET/CT may be used to predict the status of ER/PR and thus aid in optimal treatment decision in endometrial cancers. Methods: We carried out a retrospective analysis on 62 endometrial cancer patients who underwent (18)F-FDG PET/CT before radical treatment. The maximum of standardized uptake value (SUVmax) was calculated from the (18)F-FDG accumulation of the primary tumor. The relationship between SUVmax and ER/PR status was analyzed.