Relationship between primary tumour 18F-FDG uptake and immunohistochemical and clinical prognostic parameters in breast carcinoma

Objective The objective of this study was to investigate the relationship between level of 18F-fluorodeoxyglucose (18F-FDG) accumulation in primary breast tumour assessed by positron emission tomography/computed tomography (PET/CT) and histopathological and clinical prognostic factors. Material and methods A retrospective analysis was performed using the medical records of 58 female patients (age range: 31-86 years, mean age: 56) with biopsy of proven breast carcinoma, and who had undergone 18F-FDG PET/CT examination before chemotherapy/surgery. The 18F-FDG uptake of breast tumours was calculated as tumour to background ratio (TBR), which was compared with histopathological and clinical prognostic parameters. Results The histology of the breast tumour in the 58 patients was ductal type in 52 (90%), lobular in 4 (7%), and mucinous in 2 (3%). Tumour size was ≤ 2 cm in 31 (53%) patients, and > 2 cm in 27 (47%). The levels of TBRs were not significantly different between the patients groups with tumours of 2 cm or less and greater than 2 cm (P = 0.131). No significant difference between levels of TBR was observed neither with regards to axillary lymph node involvement (P = 0.065) nor in terms of distant metastases (p = 0.123). No statistically significant difference was found in levels of TBRs between patients with c-erbB-2 receptor positive and negative ones (P = 0.107). Progesterone receptor (PR) expression was observed in 33 patients (57%), and 25 patients (43%) were PR negative. As regards progesterone receptor status, a statistically significant difference was observed in mean TBR levels between patients with and without progesterone receptor expression (P = 0.020). Oestrogen receptor expression was positive in 41 (71%) patients, and negative in 17 (29%) patients. The difference in the levels of TBRs between patients with and without oestrogen receptor expression was at the level of significancy (P = 0.050). Conclusions It is concluded that 18F-FDG uptake correlates with progesterone negativity of the tumour. However, a significant association with clinical prognostic parameters and level of 18F-FDG uptake levels could not be demonstrated.