Ultrasound proves effective for axillary staging of less common breast cancer

Both ultrasound alone and ultrasound-guided fine-needle aspiration biopsy of lymph nodes are reliable ways to stage invasive lobular carcinoma, a form of breast cancer occurring in only 10% to 15% of cases. Although preoperative assessment can be quite challenging with this cancer, research from the University of Texas M.D. Anderson Cancer Center in Houston found ultrasound to be as effective for staging invasive lobular carcinoma as it is for the more common invasive ductal carcinoma.

Invasive lobular carcinoma is often spotted at a later stage. It grows in cells lining the lobules of the breast, with a more diffuse thickening of breast tissue, instead of showing up clearly as a lump on mammograms. Researchers wanted to know if these characteristics and problems also extended to ultrasound staging and fine-needle biopsy of lymph nodes.

Dr. Judy C. Boughey and colleagues in the surgical oncology department at M.D. Anderson published their research in the October issue of the American Journal of Surgery and presented it at the 8th Annual Meeting of the American Society of Breast Surgeons in May 2007.

They studied ultrasound and fine-needle biopsy results of 217 patients with invasive lobular carcinoma. Fine-needle aspiration biopsies were performed when ultrasound findings were inconclusive or suspicious. These findings were compared with existing reports of axillary staging with ultrasound in invasive ductal carcinoma patients.

The ultrasound tests were negative in 63%, or 137, of the invasive lobular carcinoma cases and suspicious or indeterminate in 37%, or 80, cases. Fine-needle aspiration biopsies were positive in 62% of these indeterminate cases. Of 111 node-positive patients, 39% (43) were identified by preoperative ultrasound and fine-needle aspiration biopsy. The sensitivity of these tests correlated with primary tumor and nodal metastasis size and was similar to results found in invasive ductal carcinoma patients.

The researchers concluded that ultrasound is just as useful in axillary staging of invasive lobular carcinoma as it is in invasive ductal carcinoma, especially when combined with fine-needle aspiration biopsy.