Breast cancer grading.

Histological sections of the primary tumour from 496 women with operable breast cancer have been examined for purposes of histological grading by two observers working independently. Each found a similar distribution of grade through the series, and a virtually identical influence of grade on prognosis. This close agreement occurred despite a 30% disagreement as to grade in individual cases. It is suggested therefore, that this technique while of relevance to analysis of groups of cases is of very limited reliability in individual patient prognosis.