Prognostic implications of different cell cycle analysis models of flow cytometric DNA histograms of 1,301 breast cancer patients: Results from the multicenter morphometric mammary carcinoma project (MMMCP)

AbstractResistance to endocrine therapy in estrogen receptor-positive (ER+) breast cancer is a major clinical problem with poorly understood mechanisms. There is an unmet need for prognostic and predictive biomarkers to allow appropriate therapeutic targeting. We evaluated the mechanism by which minichromosome maintenance protein 3 (MCM3) influences endocrine resistance and its predictive/prognostic potential in ER+ breast cancer. We discovered that ER+ breast cancer cells survive tamoxifen and letrozole treatments through upregulation of minichromosome maintenance proteins (MCMs), including MCM3, which are key molecules in the cell cycle and DNA replication. Lowering MCM3 expression in endocrine-resistant cells restored drug sensitivity and altered phosphorylation of cell cycle regulators, including p53(Ser315,33), CHK1(Ser317), and cdc25b(Ser323), suggesting that the interaction of MCM3 with cell cycle proteins is an important mechanism of overcoming replicative stress and anti-proliferative effects of endocrine treatments. Interestingly, the MCM3 levels did not affect the efficacy of growth inhibitory by CDK4/6 inhibitors. Evaluation of MCM3 levels in primary tumors from four independent cohorts of breast cancer patients receiving adjuvant tamoxifen mono-therapy or no adjuvant treatment, including the Stockholm tamoxifen (STO-3) trial, showed MCM3 to be an independent prognostic marker adding information beyond Ki67. In addition, MCM3 was shown to be a predictive marker of response to endocrine treatment. Our study reveals a coordinated signaling network centered around MCM3 that limits response to endocrine therapy in ER+ breast cancer and identifies MCM3 as a clinically useful prognostic and predictive biomarker that allows personalized treatment of ER+ breast cancer patients.

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Comparing the Prognostic Value of PTEN and Akt Expression with the Mitotic Activity Index in Adjuvant Chemotherapy-Treated Node-Negative Breast Cancer patients aged <55 years

Analytical Cellular Pathology ◽

10.1155/2007/569246 ◽

2007 ◽

Vol 29 (1) ◽

pp. 25-35

Author(s):

Emiel A. M. Janssen ◽

Håvard Søiland ◽

Ivar Skaland ◽

Einar Gudlaugson ◽

Kjell H. Kjellevold ◽

...

Keyword(s):

Breast Cancer ◽

Cell Cycle ◽

Cancer Patients ◽

Mitotic Activity ◽

Invasive Breast Cancer ◽

Prognostic Value ◽

Activity Index ◽

Breast Cancer Patients ◽

Node Negative ◽

Mitotic Activity Index

Background: The prognostic value of the PI3K/Akt/mTOR pathway and PTEN in invasive breast cancer (IBC) is controversial. Cell proliferation, especially the Mitotic Activity Index (MAI), is strongly prognostic in lymph node-negative (LNneg) invasive breast cancer. However, its prognostic value has not been compared with the value of Akt and PTEN expression. Material and Methods: Prognostic comparison of Her2Neu, p110alpha (PIK3CA), Akt, mTOR, PTEN, MAI and cell-cycle regulators in 125 LNneg patients aged <55 years with cyclophosphamide, methotrexate, and 5-fluorouracil (CMF)-based adjuvant systemic chemotherapy. Results: Twenty-one (17%) patients developed distant metastases = DMs (median follow-up: 134 months). p110alpha correlated (p = 0.01) with pAkt but only in PTEN-negatives; pAkt correlated (p = 0.02) with mTOR. PTEN-negativity correlated with high MAI, high grade and ER-negativity (p = 0.009). The MAI was the strongest prognosticator (Hazard Ratio = HR = 2.9, p = 0.01). Her2Neu/p110α/Akt/mTOR features have no additional prognostic value to the MAI. PTEN had additional value but only in MAI < 3 (39/125 = 31%; 8% DMs). 19/39 = 49% of the MAI < 3 patients have combined MAI < 3 / PTEN+ with 0% DMs, contrasting 15% DMs in MAI < 3 / PTEN− (p = 0.03). Conclusions: In T1−3N0M0 adjuvant CMF-treated breast cancer patients aged <55 years, MAI was the strongest survival predictor. The PI3K/Akt/mTOR pathway and cell-cycle regulator characteristics had no additional prognostic value, but PTEN has. Patients with combined MAI < 3 & PTEN-positivity had 100% survival. The small subgroup of MAI < 3 patients that died were PTEN-negative.

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