Diagnosis of minimal breast cancers in the BCDDP: the 66 questionable cases.

Of 1,810 breast cancers detected in the NCI/ACS Breast Cancer Detection Demonstration Projects, 592 were less than 1 cm in diameter and considered minimal; and tissue slides from 506 of them were available for retrospective review by a panel of pathologists. The initial report of this review indicated that in 66 cases the pathologic features of the presented slides were not sufficient for diagnosis of cancer. Subsequent investigation revealed that, through computer error, the slides submitted in 2 of these 66 cases were not from the lesions in question but from blind biopsy of the contralateral breast. Further review by the pathology panel of tissue from 38 of the 64 remaining cases determined that 16 of the remaining lesions were indeed cancers or borderline malignant lesions. This then left 48 cases in doubt. Only biopsy had been performed in 11 of them, and some form of mastectomy in the other 37. The original pathologic opinion had been divided in 30 of these, and the mastectomy had been delayed for 1 day to 7 months after the biopsy. In only 7 of the 48 questionable cases was definitive treatment carried out at the time of biopsy. All in all, these findings reflect sound, responsible surgical judgment.