BACKGROUND: The authors examined the relevance of S-phase fraction (SPF) and multidrug resistance (MDR) phenotype as predictive tests of breast cancer response in a series of patients treated by conventional doses of neoadjuvant chemotherapy with (FAC) or without (FTC) doxorubicin. METHODS: Fine needle samplings of tumors were used to measure SPF by flow cytometry before treatment (Day 0), and to assess the MDR phenotype using semiquantified reverse transcriptase polymerase chain reaction and immunocytochemistry, before and after (Days 8 and 28) the first cycle of chemotherapy. RESULTS: Measurement of SPF before treatment was significantly associated with clinical response, but sequential assessment of MDR phenotype identified three groups of tumors with distinct outcomes: (1) tumors with a positive and constant expression of MDR1, in which prediction of resistance was restricted to patients treated by FAC; (2) tumors without any detectable expression, in which resistance to FAC or FTC treatments was rarely observed; and (3) tumors with an early (Day 8) acquired or increased MDR1 gene expression, which were always resistant to therapy to both treatment regimens. These results were confirmed at the protein level. CONCLUSIONS: Sequential assessment of MDR phenotype is a relevant tool for monitoring breast cancer response in neoadjuvant chemotherapy.
RCT Entities:
BACKGROUND: The authors examined the relevance of S-phase fraction (SPF) and multidrug resistance (MDR) phenotype as predictive tests of breast cancer response in a series of patients treated by conventional doses of neoadjuvant chemotherapy with (FAC) or without (FTC) doxorubicin. METHODS: Fine needle samplings of tumors were used to measure SPF by flow cytometry before treatment (Day 0), and to assess the MDR phenotype using semiquantified reverse transcriptase polymerase chain reaction and immunocytochemistry, before and after (Days 8 and 28) the first cycle of chemotherapy. RESULTS: Measurement of SPF before treatment was significantly associated with clinical response, but sequential assessment of MDR phenotype identified three groups of tumors with distinct outcomes: (1) tumors with a positive and constant expression of MDR1, in which prediction of resistance was restricted to patients treated by FAC; (2) tumors without any detectable expression, in which resistance to FAC or FTC treatments was rarely observed; and (3) tumors with an early (Day 8) acquired or increased MDR1 gene expression, which were always resistant to therapy to both treatment regimens. These results were confirmed at the protein level. CONCLUSIONS: Sequential assessment of MDR phenotype is a relevant tool for monitoring breast cancer response in neoadjuvant chemotherapy.
Authors: Francisco S Chung; Jayson S Santiago; Miguel Francisco M De Jesus; Camille V Trinidad; Melvin Floyd E See Journal: Am J Cancer Res Date: 2016-08-01 Impact factor: 6.166
Authors: R Lacave; F Coulet; S Ricci; E Touboul; A Flahault; J G Rateau; D Cesari; J P Lefranc; J F Bernaudin Journal: Br J Cancer Date: 1998-03 Impact factor: 7.640
Authors: Julia Leemput; Christel Masson; Karine Bigot; Abdelmounaim Errachid; Anouk Dansault; Alexandra Provost; Stéphanie Gadin; Said Aoufouchi; Maurice Menasche; Marc Abitbol Journal: Mol Vis Date: 2009-02-20 Impact factor: 2.367
Authors: J Y Pierga; M Jouve; B Asselain; A Livartowski; P Beuzeboc; V Diéras; S Scholl; T Dorval; T Palangié; E Garcia-Giralt; P Pouillart Journal: Br J Cancer Date: 1998-05 Impact factor: 7.640