PET/CT Imaging in Breast Cancer Patients Under 40 Results in Changed Diagnosis

Researchers found that PET/CT imaging of patients younger than 40 who were initially diagnosed with stage I–III breast cancer resulted in a change of diagnosis. As reported in the October issue of The Journal of Nuclear Medicine, while guidelines recommend FDG PET/CT imaging only for women with stage III breast cancer, it can also help physicians more accurately diagnose young breast cancer patients initially diagnosed with earlier stages of the disease.

National Comprehensive Cancer Network (NCCN) guidelines currently consider systemic FDG PET/CT staging for only stage III breast cancer patients. More recently it has been debated whether factors other than stage should be considered in this decision. One such factor is patient age, as young breast cancer patients often have more aggressive tumors. In this study, a team of researchers from Memorial Sloan Kettering Cancer Center in New York evaluated for the first time the impact of FDG PET/CT staging specifically in a young patient cohort. The study suggests that breast cancer patients under the age of 40 may benefit from systemic staging with FDG PET/CT at earlier stages than NCCN guidelines suggest.

"Proper staging right after the breast cancer has first been diagnosed will help doctors make the right treatment decisions. And figuring out which breast cancer patients will benefit most from this 'advanced staging' with FDG PET/CT helps us to improve patient care while avoiding unnecessary tests," says Christopher Riedl, MD, one of the team's lead researchers. "Our data suggest that women younger than 40 may benefit from PET/CT staging at earlier stages than doctors previously believed."

The study included 134 patients with initial diagnoses of stage I to IIIC breast cancer; those with signs of distant metastases or with prior malignancy were excluded. PET/CT findings lead to upstaging to stage III or IV in 28 patients (21%). Unsuspected extra-axillary regional nodes were found in 15 out of 134 patients (11%) and distant metastases were found in 20 out of 134 (15%), with seven out of 134 (5%) demonstrating both. PET/CT revealed stage IV disease in one out of 20 (5%) patients with initial clinical stage I, two out of 44 (5%) with stage IIA, eight out of 47 (17%) with stage IIB, four out of 13 (31%) with stage IIIA, four out of eight (50%) with IIIB, and one out of two (50%) with stage IIIC. All 20 patients upstaged to stage IV were histologically confirmed. Four synchronous thyroid and one rectal malignancies were identified.

"Future NCCN guidelines for initial staging of breast cancer patients may need to consider other factors in addition to clinical stage. This study provides further evidence that molecular imaging and nuclear medicine can help us make better cancer staging and treatment decisions," says Gary Ulaner, MD, PhD, an assistant professor at Memorial Sloan Kettering.