INTRODUCTION
Guidelines for breast cancer staging exist, but adherence remains
unknown. This study evaluates patterns of imaging in early-stage breast
cancer usually reserved for advanced disease.
METHODS
Surveillance Epidemiology and End Results data linked to Medicare
claims from 1992–2005 were reviewed for stage I/II breast cancer
patients. Claims were searched for preoperative performance of CT, PET, and
bone scans, and brain MRIs (“advanced imaging”).
RESULTS
There were 67,874 stage I/II breast cancer patients; 18.8%
(n=12,740) had preoperative advanced imaging. The proportion of patients
having CTs, PET scans and brain MRIs increased from 5.7% to
12.4% (p<0.0001), 0.8% to 3.4%
(p<0.0001) and 0.2% to 1.1% (p=0.008), respectively,
from 1992–2005. Bone scans declined from 20.1% to
10.7% (p<0.0001). “Breast cancer” (174.x)
was the only diagnosis code associated with 62.1% of PET scans,
37.7% of bone scans, 24.2% of CTs, and 5.1% of brain
MRIs. ≥1 symptom or metastatic site was suggested for 19.6%
of bone scans, 13.0% of CTs, 13.0% of PET scans and
6.2% of brain MRIs. Factors associated (p<0.05) with use of
all modalities were urban setting, breast MRI and ultrasound. Breast MRI was
the strongest predictor (p<0.0001) of bone scan (OR1.63,
95%CI 1.44–1.86), Brain MRI (OR1.74, 95%CI
1.15–2.63), CT (OR2.42, 95%CI 2.12–2.76), and PET
(OR5.71, 95%CI 4.52–7.22).
CONCLUSION
Aside from bone scans, performance of advanced imaging is increasing
in early-stage Medicare breast cancer patients, with limited rationale
provided by coded diagnoses. In light of existing guidelines and increasing
scrutiny about healthcare costs, greater reinforcement of current
indications is warranted.