Evidence-Based Medicine Matters

Professor Sir Colin Berry

Emeritus Professor of Pathology

As a medical student I assisted at many radical mastectomies. This mutilating operation was carried out in the belief that the best hope of cure for cancer of the breast was to “get ahead of the tumour”. It should thus be excised with an adequate margin; this might necessitate the removal of the entire breast, underlying muscles and even part of the chest wall. As the tumour was known to spread by lymphatics to local lymph nodes, these were usually removed. In terms of our understanding of the disease in the late 1950’s, this was not unreasonable therapy even if the left the woman with a swollen arm and the inability to use that arm effectively. What was unreasonable was that no-one, until around that time, had looked to see if it was good treatment – in particular, whether this degree of surgical aggression was necessary. Could more conservative treatment be as effective? A better understanding of tumour biology (the realisation that getting ahead of the tumour is unrealistic since some tumours would have metastasised via the blood when at a very early clinical stage) and moves to conserve the breast, to look critically at the pattern of lymph node involvement and to be selective about what might be done together with the advent of highly selective chemotherapy has transformed the situation for most women. It is surprising, in retrospect, that for perhaps 30 years the radical solution was assumed to be the best one. It was the development of the clinical trail that enabled surgeons to be confident that they could do the best for their patients on the basis of carefully collected data on survival and quality of life – the old mantra could not be abandoned without evidence.