Basaler und myoepithelialer Phänotyp des invasiven Mammakarzinoms

Abstract

AimsThe aim of the present study was to evaluate the prognostic impact of basal and myoepithelial phenotype in breast carcinomas (BBC and MBC) in the palliative situation.MethodsParaffin-embedded material from 244 primary breast carcinomas of patients with subsequent metastatic disease was stained immunohistochemically for CK 5/6, CK14, smooth-muscle actin, p63, estrogen receptor and progesterone receptor. BBC was defined as positive for CK5/6 and/or CK14 and MBC as positive for SMA and/or p63. Clinical and pathological data were available for all patients and follow-up data for 96.3% (range 5 days-151 months).ResultsUntil the end of the follow-up period 90.2% of patients died and 6.1% are still alive. Of the tumours 28.7% could be classified as BBC and 8.2% as MBC. Kaplan Meier analysis revealed a trend for reduced survival after first diagnosis of metastasis (OASM) for BBC and MBC. Differences in survival were significant for BBC (log-rank =5.0; p=0.025), but not for MBC. CK5/6+ and CK14+ double positive tumours (n=18; 7.4%) were identified as a subgroup of BBC associated with reduced OASM (log-rank=8,6; p=0.003). This subgroup, but not BBC or MBC was an independent negative prognostic factor in a multivariate analysis including age, typing, tumour size, grading, axillary nodes, HR, Her2/neu, site of first metastasis and disease-free interval.ConclusionThe association of BBC and MBC with reduced OASM in metastatic breast carcinomas is not independent from established prognostic factors. CK5/6+ CK14+ double positive tumours may be a subgroup of BBC with particularly unfavourable outcome.