title: Ki-67 expression in operable breast cancer: a comparative study of immunostaining and a real-time RT-PCR assay.
abstract: The main purpose of this retrospective study was to compare Ki-67 expression in operable breast cancer examined by immunostaining and real-time reverse transcriptase polymerase chain reaction (RT-PCR). Relations between Ki-67 and classic prognostic factors were also investigated, and the prognostic relevance of Ki-67 expression was examined. Expression of Ki-67 was analyzed in specimens of invasive ductal breast cancer tissue obtained from 131 women during radical mastectomy. There was a significant, but weakly positive, correlation between Ki-67 expression assessed by immunostaining and real-time RT-PCR (tau=0.154, p=0.005). Higher Ki-67 expression in immunostaining and RT-PCR was more often seen in grade 3 tumors (p<0.001 and p=0.026, respectively). No significant relationship with age, disease stage, nodal involvement, estrogen receptor or HER2 status was found. In a univariate and multivariate analysis of cancer-specific survival with a median follow-up of 56 months, Ki-67 expression determined by immunostaining or real-time RT-PCR was no prognostic factor. We demonstrated that Ki-67 expression levels measured by immunostaining and real-time RT-PCR were weakly concordant, and both were related to higher tumor grade. Ki-67 expression did not influence survival.
authors: Department of Chemotherapy, Copernicus Memorial Hospital, Medical University of Lodz, 93-509 Lodz, Poland. piotrpo@mp.pl
authors: Piotr
authors: P
authors: Potemski
authors: Elzbieta
authors: E
authors: Pluciennik
authors: Andrzej K
authors: AK
authors: Bednarek
authors: Renata
authors: R
authors: Kusinska
authors: Robert
authors: R
authors: Kubiak
authors: Dorota
authors: D
authors: Jesionek-Kupnicka
authors: Cezary
authors: C
authors: Watala
authors: Radzislaw
authors: R
authors: Kordek