In the study, the researchers used a specialized form of PET imaging called "estrogen receptor expression imaging" for 22 patients with endometrial adenocarcinoma and nine patients with endometrial hyperplasia (a thickening of the uterine lining that is a risk factor for developing endometrial cancer) to evaluate diagnostic accuracy. All patients underwent preoperative PET scans with 18F-fluoroestradiol (18F-FES)-a tracer that has been successfully used in diagnosing breast cancer-and 18F-fluorodeoxyglucose (18F-FDG) to compare differences in tracer accumulation.

The researchers confirmed that endometrial carcinoma reduces estrogen dependency with accelerated glucose metabolism as it progresses to a higher stage or grade. By combining the two tracers, researchers were able to use a new index of uptake ratio that can better predict pathologic stages and aggressiveness of tumors. The results of the study were encouraging, with the combined techniques having 86% accuracy.

For endocrine-related tumors (including endometrial cancer), tumors vary from well-differentiated and close in character to the tissue of origin to poorly differentiated tumors, which are aggressive and bear less resemblance to the tissue of origin. The well-differentiated tumors tend to be more slow-growing and less aggressive than poorly differentiated tumors. They also retain their endocrine function and/or responsiveness.

For endometrial cancer, estrogen receptor expression is related to endocrine responsiveness and indicated by FES uptake. Poorly differentiated tumors often have increased and abnormal breakdown of glucose, indicated by FDG. The combination of the two, as indicated by the study, was better than either alone at indicating the aggressiveness of the tumor.

Personalized cancer therapy involves treatment that is individualized for patients based on patient characteristics and the tumor's biology. By studying the tumor's properties, physicians can predict the tumor's path and formulate the best strategy for treating the disease.

Source: Society of Nuclear Medicine