Characterization of node-negative breast cancer by clinico-pathologic and biologic factors.

About 30% of node-negative breast cancer (NNBC) patients relapse and about 20-25% die after local treatment. This is a heterogenous disease and at present no single factor completely distinguishes those patients destined to have a recurrence and to die, for whom an adjuvant treatment seems indicated. With the objective of subdividing NNBC into different prognostic groups, we studied the expression and relationship of eight factors related both to the clinico-pathologic characteristics and to the tumor biology in 78 consecutive patients: menopausal status, tumor size, grading (G), intratumoral vascular invasion (IVI) steroid hormonal receptors, proliferative rate and epidermal growth factor receptor (EGFr) expression. The frequencies of the risk factors examined were: pre- or perimenopausal status in 29.5%, tumor size greater than 2 cm (pT2) in 28%, GIII in 45%, IVI in 13% estrogen receptor (ER)-negative in 43% and progesterone receptor (PgR)-negative in 60%. There were 23% high proliferating (Ki-67 antibody greater than 20%) and 54% EGFr positive tumors. The distribution of the above risk factors in each tumor were: no factor in 4%; one in 15%; two in 30%; three in 23%; four in 14%; five in 8%; six in 2%; seven in 4% and no case had the sum of all the factors. The mean distribution value was of two per case. Twenty-eight percent of patients had more than the sum of four factors. A significant correlation was observed among: premenopausal status with G III (61% vs 45% in postmenopausal status; p less than 0.05), premenopausal status with ER-negative tumors (65 vs 29% in postmenopasual; p less than 0.05) and between the lack of expression of the two hormonal receptors (overall agreement of 77; p less than 0.05). The prognostic value of these findings needs to be verified with an adequate follow-up.