David J. Horsfall

Clinical significance of HER-2/neu oncogene amplification in primary breast cancer. The South Australian Breast Cancer Study Group.

PURPOSE To determine prospectively the prognostic significance of HER-2/neu oncogene amplification in the primary tumors of breast cancer patients. METHODS HER-2/neu amplification in tumor DNA was determined by the slot-blot technique in 1,056 patients with breast cancer (stage I to III) diagnosed between 1987 and 1990. Parameters such as estrogen receptor (ER) and progesterone receptor (PgR) levels, tumor size, axillary nodal involvement, tumor grade, and time to relapse were prospectively obtained. RESULTS HER-2/neu oncogene amplification, > or = 2, > or = 3, and > or = 5 copy number, was detected in 21%, 11%, and 7% of patients, respectively. In a test set of 529 patients, Cox multivariate analysis showed HER-2/neu copy number > or = 3 or > or = 5 was associated with shorter disease-free survival (DFS) duration. HER-2/neu copy number > or = 3 correlated significantly with pathologic stage of disease, number of axillary nodes with tumor, histologic type, and absence of ER and PgR. For all patients, after a median follow-up duration of 39 months, Kaplan-Meier univariate analysis indicated that tumor oncogene copy number > or = 3 correlated with shorter DFS in both node-negative and node-positive patients. In Cox multivariate analysis, HER-2/neu copy number > or = 3 was associated with shorter DFS, independent of nodal status, ER level, and tumor size. CONCLUSION Although the follow-up duration of this study is relatively short, we conclude that HER-2/neu amplification is an independent predictor of shorter DFS in both node-negative and node-positive patients.

Androgens induce divergent proliferative responses in human breast cancer cell lines

Although the majority of primary human breast cancers express the androgen receptor (AR), the role of androgens in breast cancer growth and progression is poorly understood. We have investigated the effects of the naturally occurring androgen, dihydrotestosterone (DHT), and a synthetic non-metabolizable androgen, mibolerone, on the proliferation of six human breast cancer cell lines. The anti-proliferative and proliferative effects of androgens were only observed in cell lines that expressed the AR. Two of the AR-positive cell lines, T47-D and ZR-75-1 were growth inhibited in the presence of either DHT or mibolerone, while the proliferation of MCF-7 and MDA-MB-453 cells was increased by both androgens. Co-incubation of cultures with 1 nM DHT and a 100-fold excess of the androgen receptor antagonist, hydroxyflutamide, resulted in reversal of both inhibitory and stimulatory effects of DHT on T47-D, MCF-7 and MDA-MB-453 cell proliferation, indicating that DHT action is mediated by the AR in these lines. Hydroxyflutamide only partially reversed the DHT-induced growth inhibition of ZR-75-1 cultures, which suggests that growth inhibition of these cells may be mediated by non-AR pathways of DHT (or DHT metabolite) action. Mibolerone action on breast cancer cell growth was similar to that of DHT, with the exception that growth stimulation of MCF-7 and MDA-MB-453 cells was only partially reversed in the presence of a 100-fold excess of hydroxyflutamide. Anandron, another androgen receptor antagonist, was able to reverse all inhibitory and stimulatory actions of the androgens. AR antisense oligonucleotides reduced the level of immunoreactive AR expression in MDA-MB-453 and ZR-75-1 cells by more than 60%, but only reversed the growth inhibitory action of mibolerone in ZR-75-1 cultures. The results suggest that androgen action in breast cancer cell lines may not be solely mediated by binding of androgen to the AR. For example, metabolites of DHT with oestrogenic activity, or androgen binding to receptors other than the AR, may explain the divergent responses to androgens observed in different breast cancer cell lines.

The biological role and regulation of versican levels in cancer

Increased expression of the proteoglycan, versican is strongly associated with poor outcome for many different cancers. Depending on the cancer type, versican is expressed by either the cancer cells themselves or by stromal cells surrounding the tumor. Versican plays diverse roles in cell adhesion, proliferation, migration and angiogenesis, all features of invasion and metastasis. These wide ranging functions have been attributed to the central glycosaminoglycan-binding region of versican, and to the N-(G1) and C-(G3) terminal globular domains which collectively interact with a large number of extracellular matrix and cell surface structural components. Here we review the recently identified mechanisms responsible for the regulation of versican expression and the biological roles that versican plays in cancer invasion and metastasis. The regulation of versican expression may represent one mechanism whereby cancer cells alter their surrounding microenvironment to facilitate the malignant growth and invasion of several tumor types. A greater understanding of the regulation of versican expression may contribute to the development of therapeutic methods to inhibit versican function and tumor invasion.

Expression of Extracellular Matrix Components Versican, Chondroitin Sulfate, Tenascin, and Hyaluronan, and Their Association with Disease Outcome in Node-Negative Breast Cancer

Purpose: The purpose is to determine whether the levels of expression of extracellular matrix components in peritumoral stroma are predictive of disease outcome for women with node-negative breast cancer. Experimental Design: Tumor tissue from 86 patients with node-negative breast cancer was examined by immunohistochemical staining for the expression of versican, chondroitin sulfate (CS), tenascin, and hyaluronan (HA). With the exception of HA, the expression of the extracellular matrix components was measured by video image analysis. Statistical correlation of the immunohistochemical data with clinicopathological characteristics and disease outcome was performed. Results: All of the extracellular matrix components were present in the peritumoral stroma of the entire study cohort. In contrast, immunoreactivity within the cancer cell was observed in 82% of tumors for HA, 12% for CS, and 4% for tenascin; no immunostaining of cancer cells for versican was observed for any of the tumors. Cox regression and Kaplan-Meier analyses indicated that elevated expression of stromal versican predicted increased risk and rate of relapse in this cohort. Elevated expression of tenascin was predictive of increased risk and rate of death only. Although neither CS nor HA were predictive of disease outcome in this cohort, tumor size was predictive of increased risk and rate of both relapse and survival. Conclusions: Elevated expression within peritumoral stromal matrix of versican and tenascin was predictive of relapse-free and overall survival, respectively, in women with node-negative breast cancer.

Standard Preanalytical Coding for Biospecimens: Defining the Sample PREanalytical Code

Background: Management and traceability of biospecimen preanalytical variations are necessary to provide effective and efficient interconnectivity and interoperability between Biobanks. Methods: Therefore, the International Society for Biological and Environmental Repositories Biospecimen Science Working Group developed a “Standard PREanalytical Code” (SPREC) that identifies the main preanalytical factors of clinical fluid and solid biospecimens and their simple derivatives. Results: The SPREC is easy to implement and can be integrated into Biobank quality management systems and databases. It can also be extended to nonhuman biorepository areas. Its flexibility allows integration of new novel technological developments in future versions. SPREC version 01 is presented in this article. Conclusions and Impact: Implementation of the SPREC is expected to facilitate and consolidate international multicenter biomarker identification research and biospecimen research in the clinical Biobank environment. Cancer Epidemiol Biomarkers Prev; 19(4); 1004–11. ©2010 AACR.

Formation of Hyaluronan- and Versican-rich Pericellular Matrix by Prostate Cancer Cells Promotes Cell Motility

Previous studies have demonstrated that high levels of hyaluronan (HA) and the chondroitin sulfate proteoglycan, versican in the peritumoral stroma are associated with metastatic spread of clinical prostate cancer. In vitro integration of HA and versican into a pericellular sheath is a prerequisite for proliferation and migration of vascular smooth muscle cells. In this study, a particle exclusion assay was used to determine whether human prostate cancer cell lines are capable of assembling a pericellular sheath following treatment with versican-containing medium and whether formation of a pericellular sheath modulated cell motility. PC3 and DU145, but not LNCaP cells formed prominent polarized pericellular sheaths following treatment with prostate fibroblast-conditioned medium. The capacity to assemble a pericellular sheath correlated with the ability to express membranous HA receptor, CD44. HA and versican histochemical staining were observed surrounding PC3 and DU145 cells following treatment with prostatic fibroblast-conditioned medium. The dependence on HA for integrity of the pericellular sheath was demonstrated by its removal following treatment with hyaluronidase. Purified versican or conditioned medium from Chinese hamster ovary K1 cells overexpressing versican V1, but not conditioned medium from parental cells, promoted pericellular sheath formation and motility of PC3 cells. Using time lapse microscopy, motile PC3 cells treated with versican but not non-motile cells exhibited a polar pericellular sheath. Polar pericellular sheath was particularly evident at the trailing edge but was excluded from the leading edge of PC3 cells. These studies indicate that prostate cancer cells recruit stromal components to remodel their pericellular environment and promote their motility.

Androgen receptor agonist activity of the synthetic progestin, medroxyprogesterone acetate, in human breast cancer cells

Medroxyprogesterone acetate (MPA), which is frequently used as second line hormonal therapy for the treatment of metastatic breast cancer, binds with high affinity to the progesterone receptor (PR). However, the androgenic side-effects of MPA suggest that it may also activate androgen receptor (AR) regulated pathways. Treatment of the human breast cancer cell lines MDA-MB-453, ZR-75-1 and T47-D with high dose (100 nM) MPA resulted in 26-30% inhibition of cell growth, which was partially reversed by co-treatment with a 10-fold excess of the synthetic antiandrogen, anandron. Scatchard analysis demonstrated specific, high affinity (non-PR) binding of [3H]MPA to cytosols prepared from the PR-/AR+ MDA-MB-453 and PR+/AR+ ZR-75-1, but not the PR-/AR- BT-20 breast cancer cell lines. Competition of [3H]MPA binding to MDA-MB-453 cytosols by equimolar concentrations of androgens (5alpha-dihydrotestosterone (DHT), R1881) and the antiandrogen, anandron was consistent with binding of MPA to the AR. In ZR-75-1 cell cytosol fractions, DHT, R1881 and anandron only partially competed out [3H]MPA binding, suggesting that androgens displace [3H]MPA binding to AR but not to PR. Induction by MPA of AR transactivation was demonstrated in MDA-MB-453 and ZR-75-1 cells, and in the CV-1 cell line transfected with a full-length AR. In these cell lines the increased activity of the androgen responsive reporter gene (MMTV-CAT) by 1 nM MPA was fully (MDA-MB-453, CV-1) or partially (ZR-75-1) inhibited by co-culture with 1 microM anandron. These findings indicate that MPA is an AR agonist and suggest that the in vivo effects of MPA in breast cancer patients may in part be mediated by the AR.

EMS1 amplification can occur independently of CCND1 or INT-2 amplification at 11q13 and may identify different phenotypes in primary breast cancer.

Chromosome 11q13 is amplified in about 13% of primary breast cancers. CCND1, encoding the cell cycle regulatory gene cyclin D1, and EMS1, encoding a filamentous actin binding protein, are favoured candidate onocogenes, whereas INT-2 is an unexpressed gene at this locus. In this study we tested the possibility that different regions of this large amplicon could be independently amplified and subsequently defined the phenotype of EMS1 amplified tumours in a series of 961 primary breast carcinomas. Using DNA slot blots, EMS1 was amplified in 15.2% of samples: 5.4% were coamplified for CCND1; 7.9% coamplified for INT-2 and 6.7% showed EMS1 amplification alone. The degree of amplification of CCND1 and INT-2 was highly correlated (P=0.0001). In contrast, no such relationship existed between EMS1 and CCND1 or INT-2 amplification, demonstrating independent amplification of EMS1 in 44% of amplified tumours. EMS1 amplification (⩾twofold increase in copy number) was positively correlated with patient age ⩾50 years (P=0.025), ER positivity (P=0.022), PgR positivity (P=0.018), and was negatively correlated with HER-2/neu (c-erbB2) amplification (P=0.01). In common with CCND1/INT-2, EMS1 amplification was associated with increased risk of relapse in patients with lymph node-negative disease (P=0.028). In contrast, EMS1 and CCND1/INT-2 amplification appeared to confer different phenotypes in ER positive and negative tumours. A ⩾threefold increase in EMS1 copy number was associated with an apparent increased risk of relapse and death in patients with ER negative tumours, but was without effect in ER positive tumours. In contrast, CCND1/INT-2 amplification had no effect in the patients with ER negative tumours but was associated with early relapse in ER positive patients. Thus EMS1 amplification may identify subgroups of breast cancer patients with increased probability of relapse and death distinct from those identified by CCND1/INT-2 amplification. Further studies are required to more clearly determine the functional consequences of EMS1 overexpression and a biological basis for the relationship between EMS1 amplification and phenotype in breast cancer.

Relationship between p53 gene abnormalities and other tumour characteristics in breast‐cancer prognosis

The prognostic significance of p53 gene abnormalities was investigated in 919 primary breast‐cancer patients. p53 expression and tumour‐cell proliferation fraction determined by MIB‐1 count, p53 exon 5 and 6 mutations and HER‐2/neu oncogene amplification were detected by immunohistochemistry, PCR‐SSCP and slot‐blot hybridization, respectively. Increased MIB‐1 count, p53 expression, HER‐2/neu oncogene amplification and p53 mutations were detected in 33%, 29%, 10% and 8% of tumours, respectively. Statistically significant associations were observed between p53 expression or MIB‐1 count and age below 50 years, high‐grade tumours, medullary carcinomas, and absence of hormone receptors. p53 mutations were associated with increased MIB‐1 count, HER‐2/neu oncogene amplification and absence of hormone receptors, but not with age, tumour size or grade, histological subtype, or the number of axillary nodes involved. After a median follow‐up of 66 months, p53 expression was observed to be associated with significant increases in risk of both relapse and death from breast cancer, but not after adjusting for the effect of other parameters. In these analyses, MIB‐1 count, and not HER‐2/neu oncogene amplification, was an independent predictor of prognosis. In node‐negative patients, only p53 exon 5 and 6 mutations and MIB‐1 count were associated with a statistically significant increase in risk of death from breast cancer, independent of tumour size and ER concentration. We conclude that tumour‐cell proliferation fraction, as measured by MIB‐1 count, is the most useful parameter of breast‐cancer prognosis, with the exception of ER, tumour size and the number of axillary nodes involved.

Medroxyprogesterone acetate therapy in advanced breast cancer: the predictive value of androgen receptor expression.

PURPOSE To determine the predictive value of androgen receptor (AR) levels in primary tumors of women who undergo medroxyprogesterone acetate (MPA) therapy for advanced breast cancer after relapse on tamoxifen adjuvant therapy. METHODS Between 1984 and 1987 at Flinders Medical Centre, South Australia, 136 postmenopausal women received adjuvant tamoxifen therapy for lymph node-positive breast cancer. Estrogen receptor (ER), progesterone receptor (PgR), and AR levels, tumor size, and degree of axillary node involvement were determined at the time of diagnosis. The median follow-up period was 81 months; 89 women developed metastatic disease, 83 of whom subsequently received MPA (500 mg/d). The objective response rate ([RR] ie, complete response [CR] and partial response [PR]) and progression-free interval (PFI) were assessed in response to MPA therapy. Associations between RR, PFI, and primary tumor characteristics including ER, PgR, and AR levels were examined using the Mann-Whitney U test, Kaplan-Meier product-limit estimator, and Cox proportional hazards regression, as appropriate. RESULTS Thirty-two of 83 patients (38.6%) responded to MPA. RR was significantly associated with the presence of AR (P < .001), but not with other primary tumor characteristics or duration of tamoxifen therapy. After initiation of MPA treatment, PFI increased with increasing concentration of AR in the primary tumor. CONCLUSION Response to MPA after adjuvant tamoxifen treatment for lymph node-positive breast cancer was positively associated with AR level in the primary tumor. This finding suggests that MPA action in breast cancer may be mediated in part by the AR.