c-erbB-2 expression in primary breast cancer.
c-erbB-2 is an oncoprotein which is overexpressed in up to 40% of primary breast cancers. c-erbB-2 overexpression is a bad prognostic factor in patients with lymph node-positive disease. Unfortunately, there has been no agreement to date on whether c-erbB-2 overexpression is of prognostic significance in patients with lymph node-negative disease. c-erbB-2 overexpression is correlated with the absence of estrogen receptor expression in a number of publications. Correlation between c-erbB-2 overexpression and hormone sensitivity in the clinical setting is less well established and is the focus of ongoing studies. Both preclinical and clinical studies support an association between c-erbB-2 receptor overexpression and resistance to alkylating agents. In contrast, the data for c-erbB-2 and anthracyclines should be viewed in a slightly different manner. Anthracyclines appear to have a greater therapeutic effect in c-erbB-2-positive disease which may be dose sensitive. In c-erbB-2-negative disease not only is the therapeutic effect reduced but there does not appear to be any improved response to higher doses of anthracyclines. The data for c-erbB-2 and the taxanes is still not clear enough to provide any definite conclusions. If there is a correlation it would at present appear to be between paclitaxel and response rates, but this needs to be confirmed in larger studies. Few studies have looked at changes in c-erbB-2 on therapy. Those that have seem to show no significant change on either tamoxifen or chemotherapy.
Tagliabue
E
E
Division of Experimental Oncology E, Istituto Nazionale Tumori, Milan, Italy. tagliabue@istitutotumori.mi.it
Ménard
S
S
Robertson
J F
JF
Harris
L
L
D001943:Breast Neoplasms / Q000378:metabolism*; D005260:Female; D005784:Gene Amplification; D006801:Humans; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis* / Q000235:genetics; D011960:Receptors, Estrogen / Q000378:metabolism
D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen