FDG PET/CT not useful in staging newly diagnosed stage III invasive lobular breast cancer

Although National Comprehensive Cancer Network (NCCN) guidelines consider 18F-PET/CT (FDG PET/CT) appropriate for systemic staging of newly diagnosed stage III breast cancer, the technique may not be equally valuable for all breast cancer histologies. Researchers at the Memorial Sloan Kettering Cancer Center found that while FDG PET/CT is valuable for systemic staging of stage III ductal breast cancer, it adds little to the systemic staging of ILC.

"We are evaluating patient and disease factors that affect the value of FDG PET/CT for systemic staging of locally advanced breast cancer," said study coauthor Molly Parsons. "Our ongoing work suggests that the histology of the primary breast malignancy may be one such factor."

The researchers found that, at best, only 3% of newly diagnosed patients with stage III ILC would have benefited from systemic staging with FDG PET/CT, as compared to conventional CT and bone scan. The results suggest that ILC be staged with CT and bone scan, rather than FDG PET/CT.

The study was presented at the ARRS 2014 Annual Meeting in Toronto.