F-18-FDG uptake in breast cancer correlates with immunohistochemically defined subtypes

Abstract

Objectives To determine whether a correlation exists between maximum standardized uptake value (SUVmax) on F-18-fluorodeoxyglucose positron emission tomography (FDG-PET) and the subtypes of breast cancer. Methods This retrospective study involved 548 patients (mean age 51.6 years, range 21-81 years) with 552 index breast cancers (mean size 2.57 cm, range 1.0-14.5 cm). The correlation between F-18-FDG uptake in PET/CT, expressed as SUVmax, and immunohistochemically defined subtypes (luminal A, luminal B, human epidermal growth factor receptor 2 (HER2) positive and triple negative) was analyzed. Results The mean SUVmax value of the 552 tumours was 6.07 +/- 4.63 (range 0.9-32.8). The subtypes of the 552 tumours were 334 (60 %) luminal A, 66 (12 %) luminal B, 60 (11 %) HER2 positive and 92 (17 %) triple negative, for which the mean SUVmax values were 4.69+/-3.45, 6.51+/-4.18, 7.44+/-4.73 and 9.83+/-6.03, respectively. In a multivariate regression analysis, triple-negative and HER2-positive tumours had 1.67-fold (P < 0.001) and 1.27-fold (P = 0.009) higher SUVmax values, respectively, than luminal A tumours after adjustment for invasive tumour size, lymph node involvement status and histologic grade. Conclusion FDG uptake was independently associated with subtypes of invasive breast cancer. Triple-negative and HER2-positive breast cancers showed higher SUVmax values than luminal A tumours. Key Points F-18-FDG PET demonstrates increased tissue glucose metabolism, a hallmark of cancers. Immunohistochemically defined subtypes appear significantly associated with FDG uptake (expressed as SUVmax). Triple-negative tumours had 1.67-fold higher SUVmax values than luminal A tumours. HER2-positive tumours had 1.27-fold higher SUVmax values than luminal A tumours.