Variation in the use of percutaneous biopsy for diagnosis of breast abnormalities in Ontario.

BACKGROUND: Preoperative diagnosis of breast abnormalities is currently the standard of care. A population-based study to determine the use of percutaneous needle biopsy for breast diagnosis in Ontario was performed.
METHODS: A total of 17,068 women undergoing breast tissue sampling (percutaneous needle biopsy or surgical excision) for diagnosis between April 1, 2002, and December 31, 2002, and without a previous cancer diagnosis were identified. Univariate and multivariate analyses examined the association of age, residence in a particular local health integration network (LHIN), income quintile, urban or rural residence, primary care provider, any prior mammogram, and prior regular screening mammography, as well as whether the biopsy was initiated by a screening mammogram with different methods of tissue diagnosis.
RESULTS: A total of 10,459 women (61%) underwent percutaneous biopsy for diagnosis. A total of 10,131 women underwent surgery, of whom 6,637 received a benign diagnosis and 3,494 had cancer, for a benign-to-malignant ratio of 1.9:1. Women with cancer were slightly more likely to undergo percutaneous biopsy than women without (64.7% vs. 60.3%). There was variation among LHINs in the use of percutaneous biopsy (range, 24%-72%). Women with the highest incomes, urban residence, a primary care provider, or history of any prior mammography were more likely to receive percutaneous biopsy. On multivariate analysis, age 50 to 69 years, LHIN, urban residence, primary care provider, and screen-initiated evaluation were associated with percutaneous biopsy.
CONCLUSIONS: Variation in the use of percutaneous biopsy by factors unrelated to indications for biopsy indicate that strategies to identify and overcome barriers to its use are needed.