BREAST-CANCER - 2 MICROMETASTATIC VARIANTS IN THE AXILLA THAT DIFFER IN PROGNOSIS

Measurement of the area of the tumour deposits present in routine sect ions from the axillary nodes from a series of 1069 breast cancer patie nts showed that 138 cases had a single micrometastasis (0.2 cm(2) or l ess), while in 29 a similar load was spread over two or more nodes. Th ese 167 cases represent 15% of the patients in the series, Twenty-five of them had died of breast cancer within a mean follow-up of 6 years. They had smaller micrometastases than those surviving (P < 0.0025). H istological examination in the 138 with single micrometastases showed that two variants were present, In one, tumour growth was confined to the capsular lymphatics and/or the subcapsular sinus, In the other, tu mour growth was present in the nodal lymphoid tissue, and, on occasion , at the other sites as well, Those with growth in the lymphoid tissue had a better prognosis than those without (P < 0.0035), Prognosis in the former was comparable to that in the node-negative cases, while in those lacking such growth it was similar to that in the node-positive , The presence of these two variants could explain divergent reports i n the literature on prognosis in cases with micrometastases, While the mechanisms behind this apparent paradox remain speculative, the obser vation can be of diagnostic interest in routine surgical pathology.