Short-term follow up is a reasonable alternative to biopsy of palpable breast lesions with benign imaging features, particularly for young women with probable fibroadenoma, according to a study published in the December edition of the American Journal of Roentgenology.
Jennifer A. Harvey, MD, professor of radiology at the University of Virginia in Charlottesville, Va., and colleagues said that the study showed an acceptably low prevalence of breast cancer (0.3 percent)--so low that short-term follow up is a reasonable alternative to biopsy.
The study selected 320 women with an average age of 34 years, presenting with 375 round, oval or lobular palpable masses with circumscribed margins and benign features for which short-term follow-up was recommended between July 1997 and December 2003.
Lesions that were characteristically benign, including simple cysts, oil cysts and lymph nodes, were not included in the study. Additionally, lesions that were found to be irregular shaped or had ill-defined margins were excluded from the study, because the short-term follow up of these lesions, even if nonpalpable, would be controversial, said the authors.
Evaluation was by ultrasound and/or mammography and focused clinical examination in which the aforementioned methods were selected based on the patients’ age. Outcomes were assessed with imaging or clinical follow-up lasting at least 12 months.
The researchers evaluated 186 lesions with mammography and ultrasound and 189 by ultrasound alone. The masses that were typically identified only with ultrasound (68.8 percent) were oval (73.3 percent) of equal density to normal breast tissue on mammograms (81.2 percent) hypoechoic (reflecting relatively few ultrasound waves, 90.3 percent) and believed to be fibroadenoma (81.1 percent).
Short-term follow up consisted of 85 lesions (22.7 percent) being biopsied and one 1.5-mm ductal carcinoma in situ was diagnosed. At the 2.7 year mark, 26 lesions (6.9 percent) had grown in which 24 were biopsied, with no cancer being diagnosed.
The cancer incidence for palpable lesions was compared with that for nonpalpable lesions recommended for short-term follow-up and found to have similar results, with less than one percent for palpable and approximately one percent for nonpalpable masses.
The cost of follow up compared with immediate core needle biopsy was evaluated with current Medicare reimbursement values, with the current cost for breast ultrasound at $86.06, $81.68 for unilateral diagnostic mammography, $103.39 for bilateral diagnostic film-screen mammography, $2,174 for excisional biopsy and $617.45 for ultrasound-guided core needle biopsy. The cost of biopsy of lesions that increased in size or level of suspicion was taken into account.
"Application of the results of our study may reduce the number of biopsies that result in benign findings," said Harvey. “There is also significant cost savings associated with using short-term follow-up rather than immediate biopsy.”
The study’s limitations included the exclusion of palpable lesions for which short-term follow-up was recommended but had descriptors that were not benign, such as irregular shape or ill-defined margins and that the study was based on a 12-month follow-up period rather than the typical 24-month period and the use of clinical, as well as imaging assessment of stability.
“The results of our study show that because of an acceptably low incidence of breast cancer,” concluded Harvey. “Short-interval follow up of palpable masses with benign imaging features is a reasonable alternative to immediate biopsy.”