Correlation between 18F FDG uptake with histopathological prognostic factors in breast carcinoma

Objectives Although FDG PET/CT is widely used as breast tumor imaging,usage of FDG uptake as prognostic factor is controversial.FDG uptake of tumor is biological indicator and related with prognostic factors.Aim for this study is searching relationship between primary tumor FDG uptake and histopathological prognostic factors.

Methods 136 women and 4 men which has proven breast carcinoma received FDG PET/CT imaging for initial staging.Maximum standardized uptake values and tumor to background SUVmax ratios were calculated and compared with prognostic factors.The calculation of SUVmax for men and statistics considered in their own group and properties.

Results For women, high tumor SUVmax was significantly correlated with histologic type, tumor size, histologic grade, pleomorphism, mitotic count, lymphatic invasion, necrosis, ER negativity, Ki67 level, axillary involvement and triple negativity. PR status, cerbB2 overexpression, perineural invasion, calcification, degree of desmoplasia, tubular formation, age did not correlate with FDG uptake. Also there was significant relationship between tumor to background SUVmax ratios and tumor size, histologic grade, pleomorphism, lymphatic invasion, necrosis,Ki67 level, axillary involvement. There was no significant relationship between tumor to contralateral breast SUVmax ratio and histologic type, mitotic count, ER status, triple negativity. Between other tumor to background ratios have significant relationship with these prognostic parameters. For men, mean SUVmax was calculated and properties were studied particularly.

Conclusions Primary tumor FDG uptake showed correlation with tumor histologic type, tumor size, histologic grade, pleomorphism, mitotic count, lymphatic invasion, necrosis, ER negativity, Ki67 level, axillary involvement and triple negativity. Also it has been proven that Ki67 level and tumor size were decisive factors for the high FDG uptake values. In conclusion FDG uptake may determine tumor biological behaviour as a prognostic factor in breast cancer.