Prognostic significance of tumor margins in mammary carcinoma.

The previously suggested favorable prognostic significance of pushing tumor margins in mammary carcinoma is denied by the present report. Although tumors with margins of this sort are less likely to be associated with extensive axillary lymph nodal metastases, the ultimate prognosis for survival is no better in these cases, and is actually somewhat worse when medullary and colloid carcinomas are excluded. Since the tumors with pushing margins appear to be comparable in other respects to those with infiltrating margins, the reason for these findings remains unclear.