Mammography for screening high-risk patients for cancer: value of including a lateral projection

Patients who have had a mastectomy are at increased risk for cancer in the contralateral breast. Annual mammographic follow-up of these patients usually consists of a two-view screening study. We examined the value of adding a 90 degrees mediolateral view to the standard examination.

During a 2-year period, three-view film-screen mammograms of the contralateral breast were obtained in 750 consecutive patients who had had a unilateral mastectomy. A retrospective review was undertaken to determine the value of the third projection.

The study group consisted of 710 women. Findings were abnormal on 82 mammograms in 69 patients. All 82 abnormalities (100%) were seen on the mediolateral oblique view, 73 (89%) were seen on the craniocaudal view, and 76 (93%) were seen on the 90 degrees mediolateral view. Three abnormalities were seen only on the mediolateral oblique view; none were seen only on the 90 degrees mediolateral view. Seventeen patients had biopsy because of mammographic evidence of an abnormality. Twelve (71%) had biopsy-proved malignant tumor.

Inclusion of the 90 degrees mediolateral view in the standard screening examination does not increase cancer detectability.