Prognostic marker profile to assess risk in stage I-III hormone receptor-positive breast cancer patients

An exploratory study of host polymorphisms in genes that clinically characterize breast cancer tumors and pretreatment cognitive performance in breast cancer survivors

PURPOSE

Inspired by the hypothesis that heterogeneity in the biology of breast cancers at the cellular level may account for cognitive dysfunction symptom variability in survivors, the current study explored relationships between host single-nucleotide polymorphisms (SNPs) in 25 breast cancer-related candidate genes (AURKA, BAG1, BCL2, BIRC5, CCNB1, CD68, CENPA, CMC2, CTSL2, DIAPH3, ERBB2, ESR1, GRB7, GSTM1, MELK, MKI67, MMP11, MYBL2, NDC80, ORC6, PGR, RACGAP1, RFC4, RRM2, and SCUBE2), identified from clinically relevant prognostic multigene-expression profiles for breast cancer, and pretreatment cognitive performance.

PATIENTS AND METHODS

The sample (n=220) was comprised of 138 postmenopausal women newly diagnosed with early stage breast cancer and 82 postmenopausal age- and education-matched healthy controls without breast cancer. Cognitive performance was assessed after primary surgery but prior to initiation of adjuvant chemotherapy and/or hormonal therapy using a comprehensive battery of neuropsychological tests encompassing eight cognitive function composite domains: attention, concentration, executive function, mental flexibility, psychomotor speed, verbal memory, visual memory, and visual working memory. In total, 131 SNPs were included in the analysis. Standard and robust multiple linear regression modeling was used to examine relationships between each domain and the presence or absence of one or more minor alleles for each SNP. Genetic risk/protection scores (GRSs) were calculated for each domain to evaluate the collective effect of possession of multiple risk/protective alleles.

RESULTS

With the exception of CMC2, MMP11, and RACGAP1, significant (P<0.05) SNP main effect and/or SNP by future prescribed treatment group interactions were observed for every gene between at least one domain and one or more SNPs. All GRSs were found to be significantly (P<0.001) associated with each respective domain score.

CONCLUSION

Associations between host SNPs and computed GRSs and variability in pretreatment cognitive function performance support the study hypothesis, and warrant further investigations to identify biomarkers for breast cancer-related cognitive dysfunction.

Maintenance of S-nitrosothiol homeostasis plays an important role in growth suppression of estrogen receptor-positive breast tumors

Introduction

Protein denitrosylation by thioredoxin reductase (TrxR) is key for maintaining S-nitrosothiol (SNO) homeostasis, although its role in tumor progression is unknown. Therefore, the present study aimed to assess the role of altered SNO homeostasis in breast cancer cells.

Methods

The impairment of SNO homeostasis in breast cancer cells was achieved with the highly specific TrxR inhibitor auranofin and/or exposure to S-nitroso-L-cysteine. S-nitrosylated proteins were detected using the biotin switch assay. Estrogen receptor (ER) alpha knockdown was achieved using RNA silencing technologies and subcellular localization of ERα was analyzed by confocal microscopy. The Oncomine database was explored for TrxR1 (TXNRD1) expression in breast tumors and TrxR1, ER and p53 expression was analyzed by immunohistochemistry in a panel of breast tumors.

Results

The impairment of SNO homeostasis enhanced cell proliferation and survival of ER+ MCF-7 cells, but not of MDA-MB-231 (ER-, mut p53) or BT-474 (ER+, mut p53) cells. This enhanced cell growth and survival was associated with Akt, Erk1/2 phosphorylation, and augmented cyclin D₁ expression and was abolished by the ER antagonist fulvestrant or the p53 specific inhibitor pifithrin-α. The specific silencing of ERα expression in MCF-7 cells also abrogated the growth effect of TrxR inhibition. Estrogenic deprivation in MCF-7 cells potentiated the pro-proliferative effect of impaired SNO homeostasis. Moreover, the subcellular distribution of ERα was altered, with a predominant nuclear localization associated with phosphorylation at Thr311 in those cells with impaired SNO homeostasis. The impairment of SNO homeostasis also expanded a cancer stem cell-like subpopulation in MCF-7 cells, as indicated by the increase of percentage of CD44⁺ cells and the augmented capability to form mammospheres in vitro. Notably, ER+ status in breast tumors was significantly associated with lower TXNDR1 mRNA expression and immunohistochemical studies confirmed this association, particularly when p53 abnormalities were absent.

Conclusion

The ER status in breast cancer may dictate tumor response to different nitrosative environments. Impairment of SNO homeostasis confers survival advantages to ER+ breast tumors, and these molecular mechanisms may also participate in the development of resistance against hormonal therapies that arise in this type of mammary tumors.

Breast carcinomas with hyperprolactinemia at the time of diagnosis-clinico-biological association

AIM

To analyse association between preoperative hyperprolactinemia serum levels and clinical and biological features of breast tumors.

METHODS

Serum levels of prolactin were measured in 253 women with invasive breast cancer. Clinical and biological parameters analysed were age, size, lymph node involvement, distant metastasis and immunohistochemical expression of estrogen receptor, progesterone receptor, androgen receptor, bcl-2, p53 and Ki67.

RESULTS

In ductal carcinomas hyperprolactinemia were associated with high age (p = 0.017), and with bcl-2 + + + expression (p = 0.017). Furthermore, serum prolactin values were significantly higher in bcl-2 +++ cases vs negative (p = 0.029); the same happened when we considered the positivity threshold of 25 ng/mL (p = 0.015).

CONCLUSION

Is possible to detect in 6% of infiltrating ductal breast carcinomas hyperprolactinemia (>25 ng/mL), being associated only with increasing age, but not with other clinical or biological factors; and 2) the most surprising data was the association between prolactinemia (qualitative (>25 ng/mL) and quantitative) and intense bcl-2 tissue expression, which suggests that, probably, this (prolactinemia) is not a sign of worse prognosis and evolution.

Clinical outcomes and correlates of TP53 mutations and cancer

The initial observation that p53 accumulation might serve as a surrogate biomarker for TP53 mutation has been the cornerstone for vast translational efforts aimed at validating its clinical use for the diagnosis, prognosis, and treatment of cancer. Early on, it was realized that accurate evaluation of p53 status and function could not be achieved through protein-expression analysis only. As our understanding of the p53 pathway has evolved and more sophisticated methods for assessment of p53 functional integrity have become available, the clinical and molecular epidemiological implications of p53 abnormalities in cancers are being revealed. They include diagnostic testing for germline p53 mutations, and the assessment of selected p53 mutations as biomarkers of carcinogen exposure and cancer risk and prognosis. Here, we describe the strengths and limitations of the most frequently used techniques for determination of p53 status in tumors, as well as the most remarkable latest findings relating to its clinical and epidemiological value.

Association of GATA3, P53, Ki67 status and vascular peritumoral invasion are strongly prognostic in luminal breast cancer

INTRODUCTION

Breast cancers are traditionally divided into hormone-receptor positive and negative cases. This classification helps to guide patient management. However, a subgroup of hormone-receptor positive patients relapse irrespective of hormonal therapy. Gene expression profiling has classified breast tumours into five major subtypes with significant different outcome. The two luminal subtypes, A and B, show high expression of ESR1, GATA3 and FOXA1 genes. Prognostic biomarkers for oestrogen receptor (ER)-positive cases include progesterone receptor (PR) and androgen receptor (AR), and proteins related to proliferation or apoptotic resistance. The aim of this study was to identify the best predictors of success of hormonal therapy.

METHODS

By immunohistochemistry we studied 10 markers in a consecutive series of 832 cases of breast carcinoma treated at the Paoli-Calmettes Institute from 1990 to 2002 and deposited onto tissue microarrays (TMA). These markers were luminal-related markers ER, PR, AR, FOXA1 and GATA3 transcription factors, proliferation-related Ki67 and CCND1, ERBB2, anti-apoptotic BCL2 and P53. We also measured vascular peritumoural invasion (VPI), size, grade and lymph node involvement. For 143 cases, gene expression profiles were available. Adjuvant chemotherapy and hormonal therapy were given to high- and low-risk patients, respectively. The 162 events observed and taken into account were metastases.

RESULTS

Molecular expression of the 10 parameters and subtype with ER status were strongly correlated. Of the 67 luminal A cases of this series, 63 were ER-positive. Multivariate analyses showed the highly significant prognostic value of VPI (hazard ratio (HR) = 2.47), Ki67 (HR = 2.9), P53 (HR = 2.9) and GATA3 (HR = 0.5) for the 240 patients who received hormonal therapy.

CONCLUSIONS

A panel of three antibodies (Ki67, P53 and GATA3) associated with VPI can significantly improve the traditional prognosticators in predicting outcome for ER-positive breast cancer patients receiving hormonal therapy.