Immediate biopsy versus observation for abnormal findings on mammograms: an analysis of potential outcomes and costs

The increased usage of screening mammography has led to an increase in the number of needle localized breast biopsies. The perceived low yield of the biopsies has caused concern about the costs and effectiveness of this procedure. Arguments have centered on what is the appropriate true-positive rate for screening mammography, and which abnormal findings may be observed rather than tested immediately.

A decision analysis was done to help answer these questions. Factors evaluated included age of patient at discovery of abnormal finding, the rate of follow-up mammograms eventually requiring biopsy, the potential effects of tumor-doubling time on increasing the stage of disease, quality-of-life issues, and costs.

For an average 50-year-old woman the quality-adjusted life expectancy (QALE) was longer for immediate biopsy by 0 to 3 years, depending on the assumptions on tumor-doubling time; however, immediate biopsy increased the cost per patient from $700 to $900. The QALE was also superior for immediate biopsy if more than 30% of follow-up mammograms required biopsy, and immediate biopsy was more cost effective if more than 36% of follow-up mammograms required biopsy. Patient age did not affect the superiority of immediate biopsy over observation, although quality-of-life issues did.

Those lesions with a greater than 20% to 30% probability of being malignant, or lesions with potentially short doubling times, should undergo immediate biopsy. Lesions judged to be at lower risk may be observed for 6 months. Either of these recommendations should be adjusted depending on an individual patient's quality-of-life concerns.