The role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18f-Fdg Pet/Ct) in staging breast cancers of different clinical stages and subtypes

Abstract

Aim: Positron Emission Tomography with Computed Tomography (PET/CT) technology has the ability to detect clinically unsuspected nodal or distant metastases, but international guidelines discourage the use of PET/CT in localized breast cancers of stage IIIA or below. Our study aimed to evaluate the role of PET/CT in staging both early and locally advanced breast cancers. Method: We retrospectively studied 622 consecutive breast cancer patients who presented at clinical stages I–III and underwent pre-treatment PET/CT. Each patient's clinical staging was compared with the corresponding PET/CT results to assess the rates of distant metastasis and disease upstaging. Results: The detection rate of distant metastasis by PET/CT for clinical stages I, II and III were 0.7%, 6.7% and 27.5% respectively. Distant metastasis was identified most frequently in clinically localized breast cancers of the HER2-enriched subtype (11.8%), followed by luminal B (11.7%), basal (6.0%), and luminal A subtypes (5.6%). The upstaging rates for clinical stages I, II and III by PET-CT were 30.1%, 30.0% and 34.9% respectively. Basal breast cancer subtype showed the highest upstaging rate (38.8%), followed by HER2-enriched (37.7%), luminal B (34.8%), and luminal A subtypes (20.6%). Conclusion: PET/CT technology is effective in detecting distant metastasis particularly in clinical stage III, HER2-enriched and luminal B breast cancers. In addition, PET/CT leads to high rates of disease upstaging in all clinical stages and breast cancer subtypes. Our results suggest that more judicial use of PET/CT for more accurate staging of clinically localized breast cancers may be warranted to improve patient outcomes.