INT-2 ONCOGENE AMPLIFICATION AND PROGNOSIS IN NODE-NEGATIVE BREAST-CARCINOMA

The role of int-2 oncogene amplification on the prognosis of breast ca ncer patients was investigated in 128 patients with node-negative prim ary breast cancers given first-line local-regional treatments until re lapse and with a median follow-up of 65 months, Tumours had been previ ously characterised for oestrogen (ER) and progesterone receptor (PgR) status and proliferative activity (H-3-thymidine labelling index), Am plification of the int-2 oncogene occurred in 18% of cases and was sig nificantly related to the presence of hormone receptors and to menopau sal status or age, but not to proliferative status, Patients with tumo urs exhibiting int-2 amplification had a lower probability of disease- free survival than patients with non amplified tumours and frequently developed local-regional recurrence, Disease-free survival analysis, a djusted for the prognostic contribution provided by tumour size, stero id receptors and proliferative rate, indicated that the association be tween int-2 amplification and risk of relapse was maintained and remai ned constant even in the presence of the other co-variates, Interestin gly, int-2 amplification was a further prognostic discriminant within subsets of patients with a putatively good (i.e., tumour size <20 mm, ER+ and PgR(+)) or poor prognosis (i.e., high labelling index), Our ex ploratory study suggests that within node-negative patients, int-2 amp lification could be a valuable and independent prognosticator, useful to identify patients at high risk of local-regional recurrence. (C) 19 97 Wiley-Liss, Inc.