EXTENSIVE AND PREDOMINANT IN-SITU COMPONENT IN BREAST-CARCINOMA - THEIR INFLUENCE ON TREATMENT RESULTS AFTER BREAST-CONSERVING THERAPY

Intramammary tumour recurrence is one of the most important problems i n breast-conserving therapy. We reviewed a series of 957 patients trea ted with breast-conserving therapy for primary invasive breast carcino mas between 1 January 1985 and 31 December 1992 at the University of H eidelberg. All histological slides were re-evaluated for risk factors with special emphasis on the extent and subclassification of the in si tu tumour and the margin status. Six parameters were identified as sig nificant risk factors for intramammary recurrence in the univariate an alysis, including extensive or predominant in situ component (EIC, wit h at least twice the greatest dimension of the invasive tumour compone nt), histological grade, angioinvasion, lobular tumour type, involved resection margin and lymph node status. The presence of an EIC was sta tistically correlated with low tumour grade, tumour at the resection m argins and in re-excision specimens and with multifocal tumour invasio n. Multivariate logistic regression analysis revealed that EIC (relati ve risk (RR)=1.9), tumour grade (RR=1.76), angioinvasion (RR=1.34), lo bular tumour type (RR=1.65) and young age (less than or equal to 40 ye ars, RR=1.39) were independent predictors of local recurrence. When co mbining these factors in a Linear model, the simultaneous presence of at least two of the five risk factors predicted a 5-year risk of intra mammary recurrence of 20.9% compared with a risk of only 1-5% when non e or one of these risk factors were identifiable. We conclude that the risk of subsequent intramammary recurrence after breast-conserving th erapy can be estimated from a scoring system that includes four histol ogical risk factors and the patient's age. (C) 1998 Published by Elsev ier Science Ltd. All rights reserved.