Bcl-2 immunostaining: A way to finding unresponsive postmenopausal N+*breast cancer patients

Background. Bcl-2 staining positivity has shown limited prognostic value. H owever, we have decided to study this issue in the era of mammography scree ning, and adjuvant treatment protocols. Methods. Paraffin sections of 414 b reast cancers were stained for bcl-2 and staining intensity graded. Associa tion of bcl-2 with established prognosticators was analysed with chi(2) tes t and odds ratios in 2x2 tables. Kaplan-analysed Mayer analysis and Cox's r egression were used to evaluate the prognostic value of bcl-2 and other pro gnosticators. Results. Bcl-2 immunostaining was associated with tumor size, lymph node status histological type, multivariate prognostic index, standa rdized mitotic index, Ki-67 fraction, DNA-index, proportion of cells with D NA above 5c, estrogen receptor status, and histological grade. ER status sh owed the best association with bcl-2 positivity (odds ratio 11.3, 95 % CI 5 .6 - 22.7). In the whole group of patients bcl-2 positivity was not an inde pendent prognosticator. However, among N+ patients bcl-2 staining was signi ficant, and among postmenopausal N+ patients bcl-2 immunostaining was a str onger independent prognosticator than tumor size. Conclusions. The prognosi s of N+ breast cancers can potentially be evaluated with bcl-2 positivity, in association with tumor size, and mitotic activity. Among postmenopausal N+ patients, most of whom have received anti-estrogen therapy, bcl-2 positi vity is an independent prognosticator. Also, the close association of bcl-2 positivity with ER status supports the view that bcl-2 negativity reveals a patient group which might benefit from additional treatment in associatio n with anti-estrogen therapy Bcl-2 expression in breast cancer signifies le ss aggressive breast cancer types (1) but the general prognostic significan ce may be limited (2). We have recently finished the collection of a large breast cancer material from the years 1988-1991. This material is from the period of mammographic breast cancer screening and represents smaller cance rs than earlier prognostic materials studied. For the physician, such mater ial is immediately interesting for evaluation of patient prognosis and also from the standpoint of the adjuvant therapy which was given to the patient s. We have now analyzed the prognostic value of bcl-2 expression by using C ox regression applied to this group of patients.