Breast cancer

Seasonal variation has been demonstrated in connection with several aspects of primary breast carcinoma. This report describes a seasonal variation in the growth of breast carcinoma in the axillary nodes that has not been reported previously and has prognostic implications. The nodes from a series of 301 node-positive breast cancer patients were investigated prospectively for the presence/absence of tumour cells in their efferent lymphatic vessels, the former being of poor prognosis. Their presence, i.e. positive EV-status, is common in nodes with established tumour growth. Many more patients coming to operation in the first 6 months of the year showed such findings, while more of negative EV-status were found in the second half (chi(2)=13, P<0.0005). Positive EV-status was, as expected, associated with poor prognosis relative to EV-negative (chi(2)=14). Its prognostic impact did not alter with season. It may be of note that seasonal variation in the arrival of micrometastases at the nodes has also been reported recently. These two phenomena may have a common pathogenesis.