Clinically Occult Breast Cancer

Mammography as an adjunct to physical examination has led to the detection of a significant number of clinically occult, nonpalpable cancers. In a climate of increasing criticism of radical surgery for any breast malignancy, it is tempting to consider these “earliest” breast cancers as prime candidates for conservative therapy. Sixty-two such nonpalpable tumors have been encountered in a series of 232 breast biopsies performed for radiographically suspicious findings. These included 30 invasive ductal cancers, seven minimally invasive ductal cancers, 20 noninvasive ductal cancers, and five lobular carcinomas-in situ. When the mastectomy specimens were examined for evidence of multifocal cancer, 39.6% of the breasts examined demonstrated the presence of foci of invasive or noninvasive ductal or lobular carcinoma in another quadrant of the breast. Additionally, 27.6% of the invasive cancers were accompanied by axillary node metastases in those patients undergoing axillary dissection. Any therapeutic procedure for invasive or noninvasive ductal cancer which does not include total mastectomy may leave behind foci of cancer in the breast, and any procedure for invasive ductal cancer which does not include axillary dissection, regardless of the small size of the cancer, may leave behind microscopic deposits of metastatic cancer in axillary nodes.