PI3K pathway protein analyses in metastatic breast cancer patients receiving standard everolimus and exemestane.

Autor: Kruger DT; Department of Medical Oncology, Amsterdam UMC, Vrije Universiteit Amsterdam/Cancer Center Amsterdam, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.; Division of Molecular Pathology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands., Opdam M; Division of Molecular Pathology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands., van der Noort V; Division of Biometrics, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands., Sanders J; Department of Pathology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands., Nieuwenhuis M; Department of Medical Oncology, Amsterdam UMC, Vrije Universiteit Amsterdam/Cancer Center Amsterdam, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands., de Valk B; Department of Internal Medicine - Oncology, Spaarne Gasthuis, Spaarnepoort 1, 2134 TM, Hoofddorp, The Netherlands., Beelen KJ; Department of Internal Medicine - Oncology Centre, Reinier de Graaf Gasthuis, Reinier de Graafweg 5, 2625 AD, Delft, The Netherlands., Linn SC; Division of Molecular Pathology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.; Department of Medical Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.; Department of Pathology, University Medical Centre Utrecht, and Utrecht University, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands., Boven E; Department of Medical Oncology, Amsterdam UMC, Vrije Universiteit Amsterdam/Cancer Center Amsterdam, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands. e.boven@amsterdamumc.nl.
Jazyk: angličtina
Zdroj: Journal of cancer research and clinical oncology [J Cancer Res Clin Oncol] 2020 Nov; Vol. 146 (11), pp. 3013-3023. Date of Electronic Publication: 2020 Jun 21.
DOI: 10.1007/s00432-020-03291-x
Abstrakt: Purpose: Everolimus plus exemestane (EVE/EXE) is a registered treatment option for ER-positive, HER2-negative (ER +/HER2-) metastatic breast cancer (MBC), but resistance mechanisms limit efficacy. We aimed to find markers that might help select patients with a higher chance on benefit from EVE/EXE.
Methods: Immunohistochemistry (IHC) of PTEN, p-AKT(Thr308), p-AKT(Ser473), p-4EBP1, p-p70S6K, p-S6RP(Ser240/244), p-ERK1/2 and p-S6RP (Ser235/236) was performed on primary tumour tissue and on biopsies immediately taken from ER +/HER2- MBC patients before the start of standard EVE/EXE (Eudract 2013-004120-11). Unsupervised hierarchical clustering was executed to create heatmaps to distinguish subgroups of preferentially activated and less-activated PI3K/MAPK proteins. Uni- and multivariate Cox models were used for associations with PFS.
Results: Primary tumour tissue from 145 patients was retrieved. Median PFS was 5.4 months. Patients without (neo)adjuvant therapy (p = 0.03) or bone only disease (p = 0.04) had longer PFS on EVE/EXE. In primary tumours, neither single proteins nor PI3K/MAPK-associated heatmap subgroups were significantly associated with PFS. In 21 patients a non-osseous biopsy obtained before dosing was useful for continuous scoring, which demonstrated upregulation of several proteins as compared to readings in corresponding primary tumour tissues. These comparisons revealed that increased expression of p-4EBP1 was significantly associated with worse PFS (multivariate HR 3.69, p = 0.05).
Conclusions: IHC of single proteins or heatmap subgroups of the differentially activated PI3K/MAPK pathways was not able to discriminate patients on EVE/EXE with poor or better PFS. Upregulation of p-4EBP1 in pre-treatment biopsies as compared to levels in primary tumours pointed towards shorter PFS.
Databáze: MEDLINE
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