DNA ploidy, S-phase, and steroid receptors in more than 127,000 breast cancer patients

BCAR4 Expression as a Predictive Biomarker for Endocrine Therapy Resistance in Breast Cancer

BACKGROUND

Breast cancer, particularly the estrogen receptor positive (ER+) subtype, remains a leading cause of cancer-related death among women. Endocrine therapy is the most effective treatment for ER+ breast cancer; however, the development of resistance presents a significant challenge. This study explored the role of the breast cancer antiestrogen resistance 4 (BCAR4) gene as a potential driver of resistance and a pivotal biomarker in breast cancer.

PATIENTS AND METHODS

The researchers undertook a comprehensive analysis of 1743 patients spanning 6 independent cohorts. They examined the association of BCAR4 expression with patient outcomes across all breast cancer types and the PAM50 molecular subtypes. The relationship between elevated BCAR4 expression and resistance to endocrine therapy including AIs, the prevailing standard-of-care for endocrine therapy, was also investigated.

RESULTS

This meta-analysis corroborated the link between BCAR4 expression and adverse outcomes as well as resistance to endocrine therapy in breast cancer. Notably, BCAR4 expression is clinically significant in luminal A and B subtypes. Additionally, an association between BCAR4 expression and resistance to AI treatment was discerned.

CONCLUSION

This study expands on previous findings by demonstrating that BCAR4 expression is associated with resistance to newer therapies. The identification of patients with intrinsic resistance to hormone therapy is crucial to avoid ineffective treatment strategies. These findings contribute to our understanding of endocrine therapy resistance in breast cancer and could potentially guide the development of more effective treatment strategies.

Current concepts in breast cancer genomics: An evidence based review by the CGC breast cancer working group

BACKGROUND

Genomic abnormalities in breast cancer have been described according to diverse conceptual frameworks, including histologic subtypes, clinical molecular subtypes, intrinsic DNA, RNA, and epigenetic profiles, and activated molecular pathways.

METHODS

The Cancer Genomics Consortium (CGC) Breast Cancer Workgroup performed an evidence based literature review to summarize current knowledge of clinically significant genomic alterations in breast cancer using CGC levels of evidence. Targetable or disease-defining alterations were prioritized.

RESULTS

We summarized genomic alterations in breast cancer within a framework of existing clinical tools for diagnosis, risk stratification, and therapeutic management. Using CGC levels of evidence, we catalog copy number profiles, gene expression profiles, and mutations in clinically significant genes. We also describe emerging molecular markers such as methylation profiling and immunotherapy biomarkers.

CONCLUSION

A summary of currently available information on breast cancer genomics will enhance precision medicine by serving as an interpretive resource for clinical laboratory geneticists, providing a foundation for future practice guidelines, and identifying knowledge gaps to address in future research.

Overcoming Tamoxifen Resistance by Regulation of Del-1 in Breast Cancer

BACKGROUND

Hormone receptor-positive breast cancer accounts for nearly two-thirds of breast cancer cases; it ultimately acquires resistance during endocrine treatment and becomes more aggressive. This study evaluated the role of developmental endothelial locus (Del)-1 in tamoxifen-resistant (TAM-R) breast cancer.

METHODS

Del-1 expression in recurrent TAM-R breast cancer tissue was evaluated and compared to that in the original tumor tissue from the same patients. Del-1 expression was also evaluated in TAM-R cells by quantitative real-time PCR, western blotting, and enzyme-linked immunosorbent assay. The effects of Del-1 knockdown on the proliferation, migration, and invasion of TAM-R cells was assessed with wound-healing and Matrigel transwell assays.

RESULTS

Del-1 was more highly expressed in recurrent breast cancer as compared to the original tumor tissues before initiation of endocrine treatment. Del-1 mRNA was upregulated in TAM-R and small interfering RNA-mediated knockdown of Del-1 suppressed the migration and proliferation of TAM-R cells while partly restoring TAM sensitivity. And the TAM resistance was recovered by knockdown of Del-1.

CONCLUSIONS

TAM-R breast cancer is characterized by Del-1 overexpression and tumor progression can be inhibited by Del-1 depletion, which restores TAM sensitivity. Thus, therapeutic strategies that target Del-1 may be effective for the treatment of hormone-resistant breast cancer.

Feasibility of a Cell Kinetic-Based Adjuvant Chemotherapy Trial in Axillary Node-Negative Breast Cancer

Aims and background

Accumulated information on biologic prognostic indicators and predictors of response to different types of treatment in patients with different tumor characteristics has made it possible to design clinical protocols on biologic bases. Among cell proliferation indices, the thymidine labelling index (TLI) has proved to be an independent and consistent prognostic indicator over time. Moreover, experimental and retrospective analyses of clinical studies have revealed a direct relation between TLI and response to chemotherapy. On the basis of the results, a prospective clinical protocol on axillary node-negative breast cancer was activated in Italy in 1989.

Methods

Patients with low TLI tumors were treated with local-regional therapy alone, whereas patients with high TLI tumors were randomized to receive local-regional therapy followed or not by adjuvant chemotherapy consisting of 6 cycles of CMF.

Results and Conclusions

The present paper reports on the feasibility of a prospective clinical protocol based on a subgroup of patients with specific pathologic (node negative) and biologic (rapidly proliferating) breast cancers. However, patient eligibility was only 11%.

A Lysosomal Pepstatin-Insensitive Proteinase as a Novel Biomarker for Breast Carcinoma

Lysosomal proteinases play an important role in the turnover of intracellular proteins, and acidic proteinases such as cathepsin D are known to be increased in breast carcinoma. In the present study the activity of a newly discovered acidic lysosomal pepstatin-insensitive proteinase (CLN2p) was measured in breast tissues by the most sensitive and highly specific assay that we had developed for the diagnosis of late-infantile neuronal ceroid lipofuscinosis (LINCL) (2). Samples from eight normal subjects undergoing reductive mammoplasty and 200 patients with primary breast carcinoma were analyzed. The results suggest a two- to seventeen-fold higher CLN2p activity in tumors, which was significantly and positively correlated with already known breast cancer biomarkers such as levels of cathepsin D, estrogen receptor and progesterone receptor. These results suggest a diagnostic and prognostic potential for this novel acid proteinase in breast cancer.

Synergy between Androgen Receptor Antagonism and Inhibition of mTOR and HER2 in Breast Cancer

The androgen receptor (AR) is widely expressed in breast cancer, and evidence suggests dependence on AR signaling for growth and survival. AR antagonists such as enzalutamide and seviteronel have shown success in preclinical models and clinical trials of prostate cancer and are currently being evaluated in breast cancer. Reciprocal regulation between AR and the HER2/PI3K/mTOR pathway may contribute to resistance to HER2- and mTOR-targeted therapies; thus, dual inhibition of these pathways may synergistically inhibit breast cancer growth. HER2+ and triple-negative breast cancer cell lines were treated with AR antagonist plus anti-HER2 mAb trastuzumab or mTOR inhibitor everolimus. Apoptosis, cell proliferation, and drug synergy were measured in vitro Pathway component genes and proteins were measured by qRT-PCR, Western blot, and reverse phase protein array. In vivo, HER2+ breast cancer xenografts were treated with enzalutamide, everolimus, trastuzumab, and combinations of these drugs. AR antagonists inhibited proliferation of both HER2+ and TNBC cell lines. Combining AR antagonist and either everolimus or trastuzumab resulted in synergistic inhibition of proliferation. Dihydrotestosterone caused increased phosphorylation of HER2 and/or HER3 that was attenuated by AR inhibition. Everolimus caused an increase in total AR, phosphorylation of HER2 and/or HER3, and these effects were abrogated by enzalutamide. Growth of trastuzumab-resistant HER2+ xenograft tumors was inhibited by enzalutamide, and combining enzalutamide with everolimus decreased tumor viability more than either single agent. AR antagonists synergize with FDA-approved breast cancer therapies such as everolimus and trastuzumab through distinct mechanisms. Treatment combinations are effective in trastuzumab-resistant HER2+ breast cancer cells in vivoMol Cancer Ther; 16(7); 1389-400. ©2017 AACR.

DNA aneuploidy and breast cancer: a meta-analysis of 141,163 cases

BACKGROUND & AIMS

DNA ploidy, a DNA flow cytometry parameter, reflects tumor cell cycle. In breast cancer (BC), ploidy status characterizes genotypic stability and potential metastatic capacity. It is suggested that aneuploidy is an independent prognosticator for BC patients and could aid for individualized medicine. There are extensive studies concerning the prognostic significance of DNA aneuploidy, however, its clinical utility remains controversial. Herein we conducted a meta-analysis to determine the correlation between DNA ploidy status and BC characteristics and survival.

METHODS

The electronic databases PubMed, EMBASE, and Web of Science were searched for relevant studies. The major investigated parameters were the BC aneuploidy rates in relation to tumor stage, size, lymph node metastasis, grading, estrogen receptor (ER) status, disease-free survival (DFS), and overall survival (OS). Hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) for DFS and OS were extracted from each study before meta-analyzed. Risk ratios (RRs) were computed using the fixed-effect or random-effects model according to data heterogeneity, and the Mantel-Haenszel or the inverse-variance method was adopted where appropriate to obtain pooled estimates using RevMan 5.3. The Egger's test was conducted with Stata 11.

RESULTS

Pooled analyses of data from 29 studies involving a total of 141,163 cases showed that BC patients with more advanced tumors (stage I vs. stages II-IV, RR=0.84; 95% CI, 0.74 to 0.96; P=0.01), larger tumors (≤2 cm vs. >2 cm: RR=0.82; 95% CI, 0.77 to 0.87; P<0.00001), lymph node metastasis (pN0 vs. pN1-3: RR=0.85; 95% CI, 0.83 to 0.87, P<0.00001), poorer tumor proliferation (G2 vs. G1: RR=1.58; 95% CI, 1.40 to 1.79; P<0.00001; G3 vs. G1: RR=2.17; 95% CI, 1.77 to 2.67; P<0.00001; G3 vs. G2: RR=1.41; 95% CI, 1.25 to 1.60; P<0.00001), and ER- status (ER-vs. ER+: RR=1.32; 95% CI, 1.22 to 1.43; P<0.00001) were significantly more frequently aneuploid. BC patients with diploid tumors had better clinical outcomes than those with aneuploid cancers. The pooled HR estimates were0.73 (P<0.0001) for DFS and 0.72 (P=0.0001) for OS, respectively.

CONCLUSION

This meta-analysis implies that DNA aneuploidy is a significant predictor for BC progression and survival, and should be focused on in the therapeutic planning.

Cell cycle synchronization and flow cytometry analysis of mammalian cells

Analysis of cellular DNA content and measurement of pulse-labeled newly replicated DNA by flow cytometry are useful techniques for cell cycle studies. In this chapter, we describe the protocols for cell cycle synchronization of mammalian cells, including time course designs and consideration of cell types to achieve successful experiments, along with the methods for detection of DNA. Some selected applications dealing with siRNA-mediated knockdown are also presented.

Understanding the implications of the breast cancer pathology report: a case study

Case Study A.K. is a 50-year-old Caucasian female who was recently diagnosed with breast cancer and is presenting for an opinion regarding adjuvant therapy following a right segmental mastectomy and sentinel lymph node biopsy. The advanced practitioner (AP) in the outpatient oncology treatment center will be expected to participate in the discussion regarding the patient's care plan. In her review of the final pathology, the AP notes that the breast tumor is infiltrating ductal carcinoma, the most common type of invasive breast cancer. It starts in the cells that line the milk ducts in the breast, grows outside the ducts, and often spreads to the lymph nodes. Infiltrating ductal carcinoma represents 65% to 85% of all breast cancer cases (College of American Pathologists, 2011). The breast tumor measures 1.2 × 0.9 × 1.0 cm(3) (T1), is estrogen receptor positive with an H score of 280, is progesterone receptor negative with an H score of 0, and is HER2 equivocal 2+ by immunohistochemistry with a fluorescence in situ hybridization ratio of 1.9 with a copy number of 5. The Ki-67 proliferation rate is 60%, and the nuclear grade is 2/3, with a Nottingham score of 5/9. The surgical margins from the segmental mastectomy are clear by 0.4 mm. There is lymphovascular invasion present. Of two sentinel lymph nodes, none is positive (N0). There has been no workup for metastatic disease. Additionally, the AP notes that the patient is premenopausal and that A.K.'s family history is positive for a maternal aunt diagnosed with a stage I breast cancer at age 75. What is the recommended plan of care for A.K.?

Clinical and biologic features of triple-negative breast cancers in a large cohort of patients with long-term follow-up

Studies on well characterized, large populations of estrogen receptor (ER)/progesterone receptor (PgR)/HER2-negative [triple-negative (TN)] breast cancer (BC) patients with long-term follow-up are lacking. In this study, we analyze clinical outcomes of TN BC and implications of epidermal growth factor receptor (EGFR) expression. Clinical and biologic features, time to first recurrence (TTFR), and overall survival (OS) were compared in 253 TN versus 1,036 ER positive, PgR positive, HER2-negative [estrogen-driven (ED)] BC. Compared to ED, TN tumors were larger (p = 0.02), more proliferative (high S-phase 54 vs. 17 %, p < 0.0001), more aneuploid (64 vs. 43 %, p < 0.0001) and more likely EGFR positive (≥10 fmol/mg by radioligand-binding assay, 49 vs. 7 %, p < 0.0001). Among TN, EGFR-positive BC were larger (p = 0.0018), more proliferative (p < 0.0001), and more aneuploid, (p < 0.0001) than EGFR-negative BC. Adjuvant-treated TN patients had shorter TTFR (p = 0.0003), and OS (p = 0.0017), than ED patients. However, in untreated patients, no differences in TTFR and OS were observed at 8 years median follow-up. Among TN patients, EGFR expression was not associated with worse outcome. TN tumors have a worse outcome in systemically treated patients but not in untreated patients. EGFR expression, does not predict for worse long-term survival.

Placental weight and mortality in premenopausal breast cancer by tumor characteristics

Placental weight may be regarded as an indirect marker of hormone exposures during pregnancy. There is epidemiological evidence that breast cancer mortality in premenopausal women increases with placental weight in the most recent pregnancy. We investigated if this association differs by tumor characteristics, including expression of estrogen and progesterone receptors. In a Swedish population-based cohort, we followed 1,067 women with premenopausal breast cancer diagnosed from 1992 to 2006. Using Cox regression models, we estimated hazard ratios for the association between placental weight and risk of premenopausal breast cancer mortality. In stratified analyses, we estimated mortality risks in subjects with different tumor stages, estrogen receptor (ER) or progesterone receptor (PR) status. Compared with women with placental weight less than 600 g, women with a placental weight between 600 and 699 g were at a 50 % increased risk of mortality, however, not significant change in risk was observed for women with placental weight ≥ 700 g. Mortality risks associated with higher placental weight were more pronounced among ER(-) and PR(-) breast cancer tumors, where both a placental weight 600-699 g and ≥ 700 g were associated with a more than doubled mortality risks compared with tumors among women with placental weight less than 600 g. Moreover, stratified analyses for joint receptor status revealed that a consistent increased mortality risk by placental weight was only apparent in women with ER(-)/PR(-) breast cancer. The increased mortality risk in premenopausal breast cancer associated with higher placental weight was most pronounced among ER(-) and PR(-) tumors.

Prognostic value of proliferation markers: immunohistochemical ki-67 expression and cytometric s-phase fraction of women with breast cancer in libya

Background: We evaluated the association of the immunohistochemical Ki-67 expression, and S-phase fraction with clinicopathological variables and patient outcome.

Patients and methods: Histological samples from 100 primary Libyan breast carcinoma patients were retrospectively studied with monoclonal antibody to Ki-67. S-phase fraction was determined by DNA image cytometry.

Results: The median Ki-67 percentage for all tumors was 27.5%, ranging from 1 to 80% and the median S-phase fraction (SPF) was 11%, ranging from 0 to 62 %. Tumors with high Ki-67 expression were found in 76% of patients and with high SPF values in 56%. Ki-67 expression was more frequent in tumors with high SPF than low SPF. High Ki-67 and high SPF were associated with advanced stages, poor differentiation of tumors, positive lymph nodes, and distant metastasis. The Ki-67 was associated with hormone receptor negative tumors. The SPF was higher in young patients (<50 years) than in older patients. In the overall population (median follow-up 49 months), patients with high Ki-67 and high SPF had shorter survival time and predicted recurrence than patients with low Ki-67 and low SPF. In a Cox multivariate analysis, high SPF (p= 0.007), hormonal status (p= 0.001) and clinical stage (p=0.005) were independent predictors of disease-specific survival. The Ki-67 (p=0.065) in borderline significance proved to be independent predictor of disease-free survival. The SPF showed more statistically significance with a high grade of malignancy and survival time than Ki-67.

Conclusions: The SPF value is useful cell proliferation marker to assess tumor prognosis. These markers may reflect the aggressive behavior of Libyan breast cancer and predict of the recurrence. It is therefore important to take these markers into consideration to select a high risk subgroup of the patients for intensive treatment.

Biological mechanisms and clinical implications of endocrine resistance in breast cancer

Endocrine therapy represents the first and most efficacious targeted treatment for women with estrogen receptor-positive (ER+) breast cancer. In the last four decades several hormonal agents have been successfully introduced in clinical practice as both palliative therapy for advanced disease and adjuvant treatment for prevention of tumor relapse. Nevertheless, the intrinsic and acquired resistance occurs in a significant proportion of patients, limiting the efficacy of endocrine treatments. Several molecular mechanisms have been proposed to be responsible for endocrine resistance. Loss of ER expression, altered activity of ER coregulators, deregulation of apoptosis and cell cycle signaling, and hyperactive receptor tyrosine kinase (RTK) and stress/cell kinase pathways can collectively orchestrate the development and sustenance of pharmacologic resistance to endocrine therapy. Preclinical and clinical evidence documents the plasticity in ER expression levels and signaling. As such, ER can either drive gene transcription and tumor progression directly or crosstalk with alternate RTK and cellular kinase signaling pathways, resulting in modulation of its own expression levels and transcriptional program. For this reason a therapeutic approach based on the combination of agents targeting both ER and RTK signaling represents a promising strategy to be tested. Among many RTKs, EGFR, HER2, and PI3K have been found to be viable targets for the combination therapy strategy, at least in the preclinical setting. However, early results from clinical trials testing combination strategies have been discordant, suggesting the need for better approaches to simultaneously inhibit multiple escape pathways and to select the patients who may benefit the most from these strategies.

Prognostic significance of DNA image cytometry in Libyan breast cancer

BACKGROUND

We evaluated the relation of nuclear DNA content and clinicopathological features and prognosis in primary breast cancer of female Libyan patients with variable stage and grade and different treatment regimes.

PATIENTS AND METHODS

Histological samples from 104 patients of breast carcinoma were retrospectively studied by computerized nuclear DNA cytometry. Isolated nuclei from paraffin sections were stained with Feulgen stain and DNA was measured using a computer-assisted image analysis cytometry system. In each case, 200 nuclei were measured and the DNA histograms, S phase fraction (SPF) and number of cells above 5c and 9c were determined. We applied different approaches in the analysis of DNA to compare the DNA histograms with different clinicopathological features and survival.

RESULTS

The mean of DNA ploidy mode for all tumors was 3.43; 82.7% of tumors were aneuploid and 17.3% were diploid. The median SPF was 3.5% for DNA diploid and 13.5% for DNA aneuploid tumors. DNA aneuploid tumors and high SPF were associated with advanced stage, distant metastasis, high histological grade and lymph node involvement. The SPF was also associated with large tumor size and with younger patients (<50 years). In the overall population (median follow-up 51 months), patients with aneuploid DNA histograms and high SPF values had shorter survival times than those with diploid DNA histograms and low SPF values (p = 0.001, p < 0.0001, respectively). Also, short survival was associated with a multiploid DNA histogram and with DNA aneuploid cells ≥5 cells (p < 0.0001, p = 0.001, respectively). In a Cox multivariate analysis, DNA ploidy (p = 0.010), age (p = 0.038) and clinical stage (p = 0.001) were independent predictors of overall survival, and DNA ploidy (p = 0.018) and clinical stage (p = 0.001) also proved to be independent predictors of disease-specific survival. The SPF cutoff point of 11% might be applied to separate patients into good and poor prognosis groups.

CONCLUSIONS

DNA image cytometry with careful analysis of the histograms may provide valuable prognostic information in Libyan breast cancer, with potential clinical implications in patient management, particularly in predicting the patients at high risk for metastasis and recurrence who should be considered as candidates for combined adjuvant therapy.

Mechanisms of endocrine resistance in breast cancer

The estrogen receptor (ER) pathway plays a pivotal role in breast cancer development and progression. Endocrine therapy to block the ER pathway is highly effective, but its usefulness is limited by common intrinsic and acquired resistance. Multiple mechanisms responsible for endocrine resistance have been proposed and include deregulation of various components of the ER pathway itself, alterations in cell cycle and cell survival signaling molecules, and the activation of escape pathways that can provide tumors with alternative proliferative and survival stimuli. Among these, increased expression or signaling of growth factor receptor pathways, especially the EGFR/HER2 pathway, has been associated with both experimental and clinical endocrine therapy resistance. New treatment combinations targeting both ER and growth factor receptor signaling to block the crosstalk between these pathways and eliminate escape routes have been proven highly effective in preclinical models. Results of recent clinical studies, while partly supporting this approach, also highlight the need to better identify a priori the patients whose tumors are most likely to benefit from these specific cotargeting strategies.

Evaluation of hormone receptor expression for use in predicting survival of female dogs with malignant mammary gland tumors

OBJECTIVE

To evaluate the prognostic potential of expression of hormone receptors in malignant mammary gland tumors of dogs. Design-Cohort study.

ANIMALS

89 female dogs with malignant mammary gland tumors and 24 female dogs with benign mammary gland tumors.

PROCEDURES

Female dogs with malignant (n = 89 dogs) and benign (24) mammary gland tumors were evaluated to determine the prognostic value of the expression of estrogen receptor (ER)A or the progesterone receptor (PR), as determined by use of immunohistochemical methods.

RESULTS

In this study, 68 (60.2%) and 88 (77.9%) of the 113 dogs with mammary gland tumors had expression of ERA and PR, respectively. Expression of ERA and PR was detected proportionately more frequently in benign tumors (23/24 [95.8%] and 24/24 [100%], respectively) than in malignant tumors (45/89 [50.6%] and 64/89 [71.9%]). Percentage of tumors with positive results for ERA and PR was significantly higher in tumors < 5 cm in diameter; as clinical stage I, II, or III; and without metastasis to lymph nodes or distant metastasis. However, only PR expression in tumor cells was significantly associated with 1-year survival after surgical removal of the tumor. Moreover, dogs with malignant tumors expressing ERA and PR had a significantly higher survival rate, compared with the rate for dogs with malignant tumors expressing ERA but not PR.

CONCLUSIONS AND CLINICAL RELEVANCE

These findings strongly suggested that expression of PR could be used as a prognostic factor for survival, especially in female dogs with malignant mammary gland tumors with ERA expression.

Breast cancer incidence and mortality in a Caribbean population: comparisons with African-Americans

We describe breast cancer incidence and mortality in the predominantly African-origin population of Barbados, which shares an ancestral origin with African-Americans. Age-standardized incidence rates were calculated from histologically confirmed breast cancer cases identified during a 45-month period (July 2002-March 2006). Mortality rates were estimated from death registrations over 10-years starting January 1995. There were 396 incident cases of breast cancer for an incidence rate of 78.1 (95% confidence interval (CI) 70.5-86.3), standardized to the US population. Breast cancer incidence in African-Americans between 2000 and 2004 was 143.7 (142.0-145.5) per 100,000. Incidence peaked at 226.6 (174.5-289.4) per 100,000 among Barbadian women aged 50-54 years, and declined thereafter, a pattern in marked contrast to trends in African-American women, whose rates continued to increase to a peak of 483.5 per 100,000 in those aged 75-79 years. Incidence rate ratios comparing Barbadian and African-American women showed no statistically significant differences among women aged>or=55 years (p<or=0.001 at all older ages). The age-standardized mortality rate in Barbados was 32.9 (29.9-36.0) per 100,000; similar to reported US rates. The pattern of diverging breast cancer incidence between Barbadian and African-American women may suggest a greater contribution from genetic factors in younger women, and from environmental factors in older women. Studies in intermediate risk populations, such as Barbados, may assist the understanding of racial disparities in breast cancer.

Expression of androgen, estrogen and progesterone receptors in mucinous carcinoma of the breast

Hormone receptors play important roles in breast cancer. We investigated the expression of hormone receptors in breast cancer to evaluate the importance of hormone receptors in the clinicopathology of breast cancer. Androgen receptor (AR), estrogen receptor (ER) and progesterone receptor (PR) expression characteristics were evaluated using immunohistochemistry stain, comparing patient age, tumor size and axillary lymph node status for 23 pure mucinous and 105 non-mucinous infiltrating ductal carcinomas in the human female breast. Mucinous carcinoma with axillary lymph node metastasis occurred less frequently than non-mucinous carcinoma (11.8% vs. 55.2%; p = 0.01). Compared with the non-mucinous type, mucinous carcinoma specimens showed less AR expression (21.7% vs. 51.4%; p = 0.01) but more ER expression (78.3% vs. 52.4%; p = 0.02). In addition, AR expression was also associated with ER and/or PR coexpression (37/74, 50%) in infiltrating ductal carcinoma. But only three of 20 (15%) mucinous carcinoma specimens with AR expression had associated ER and/or PR coexpression. Our findings revealed that mucinous carcinoma samples from the breast show distinct clinicopathologic and hormone receptor expression features compared to non-mucinous carcinoma.

The role of surgery in the management of older women with breast cancer

Standard treatment for early breast cancer usually involves multi-modality treatment with a combination of surgery and one or more adjuvant therapies. These may include chemotherapy, radiotherapy, endocrine therapy and Trastuzumab. The treatment schedule for an individual patient may be complex, prolonged and associated with significant morbidity. The benefits of such regimens are clear to see in the improving mortality statistics for this breast cancer. However, such protocols may not appropriate for all women. Older women (over 70 years) have increasing rates of co-morbidities, reduced life expectancy and generally have more favourable breast cancer disease biology. Competing causes of death mean that they are less likely to die of their breast cancer, stage for stage, than a younger woman. In addition, their tolerance to some of the therapies is reduced which increases treatment related morbidity and reduces the risk to benefit ratio. It may therefore be appropriate to modify treatment protocols in selected older women. This should be done in consultation with the multi-disciplinary team with input from specialists in Medicine for the Elderly. The views and wishes of the patient should be respected during these discussions. This article reviews these issues.

Age interacts with the expression of steroid and HER-2 receptors in operable invasive breast cancer

BACKGROUND

The negative association between the oestrogen receptor (ER) and the human epidermal growth factor receptor 2 (HER-2) in breast cancer travels in both directions. ER+ tumours are less likely HER-2+ and HER-2+ tumours are less likely ER+.

METHODS

We studied the age-related immunohistochemical (IHC) expression of ER, progesterone receptor (PR) and HER-2 in 2,227 tumours using age as a continuous variable. Steroid receptors were considered positive for any nuclear staining of invasive cancer cells and for HER-2, either for strong expression by IHC (score 3+) or gene amplification by fluorescence in situ hybridisation (FISH). Based on nonparametric regression, the age-related association between steroid receptors and HER-2 was presented as likelihood curves.

RESULTS

The association between ER or PR and HER-2 is age-related. The age-related expression of ER and PR is HER-2 dependent. In HER-2(-) cases, the odds ratio (OR) for being ER+ was 2.594 (95% CI = 1.874-3.591) up to age 50 and age-independent thereafter; for PR-expression the OR was 2.687 (95% CI = 1.780-4.057) up to age 45 and 0.847 (95% CI = 0.761-0.942) thereafter. In HER-2+ cases, the OR was 0.806 (95% CI = 0.656-0.991) to be ER+ and 0.722 (95% CI = 0.589-0.886) to be PR+. The age-related OR for breast cancers to be HER-2+ is steroid receptor dependent. Taking together, ER+PR+HER-2+ breast cancers appear on average 5.4 years earlier than breast cancers of any other ER/PR/HER-2 phenotype (95% CI = 3.3-7.5; P < 0.0001).

CONCLUSION

There is a qualitative interaction between age and expression of steroid and HER-2 receptors. Our findings suggest a strong age-related selective growth advantage for breast tumour cells belonging to the ER+PR+HER-2+ subgroup.

The aged breast

There is a clear association between the development of breast cancer and increasing age, with 80% of cancers occurring in women more than 50 years of age and one-third in women over 70 years. Following the menopause the breast undergoes involution, with the main changes affecting the terminal ductal lobular unit. There is an increase in oestrogen receptor alpha (ERalpha)-positive cells, a decrease in proliferation but, in comparison to premenopausal breasts, a greater number of ERalpha-proliferating cells. The breast cancers that occur in women >/= 75 years are more likely to be ER-positive, with a low growth rate and limited expression of HER-2 and p53. It is proposed that uneven involution of the breast, the persistence of at-risk lesions, the presence of ERalpha-proliferating cells and local oestrogen metabolism in breast adipose tissue are factors in the development of breast cancers with a well-differentiated phenotype.

Analysis of gene expression profiles in the offspring of rats following maternal exposure to xenoestrogens

Many environmental chemicals are known endocrine disruptors (EDs). These have the potential to alter endocrine systems via various mechanisms that include binding to hormone receptors, thereby either mimicking or blocking the hormone actions and causing abnormal gene expression. Here, to elucidate the molecular mechanism(s) underlying the detrimental effects associated with the estrogenicity of these chemicals, we determined whether gene profiles were altered in rats exposed to 4-tert-octyphenol (OP) and diethylstilbestrol (DES) in utero. Pregnant rats were treated with a high dose of OP (600 mg/kg BW per day) or DES (500 microg/kg BW per day) at gestational days (GD) 17, 18 and 19. Both dams and neonates were euthanized at lactation day (LD) 5. The transcript profiles of uterine tissue were compared in treated versus control in both maternal and neonatal sites using cDNA microarray to determine the expression levels of approximately 13,000 genes and expressed sequence tags (ESTs). The expression levels of some known estrogen-responsive genes, i.e., complement component 3, epidermal growth factor receptor or c-fos oncogene and calbindin 3, as well as some other randomly selected genes, including general transcription factor IIa, transcription factor 4 and lymphocyte specific 1, were increased by OP and/or DES treatment in the uteri of both maternal and neonate groups. However, the magnitude of these alterations in gene expression differed markedly between dams and neonates, most likely reflecting the temporal susceptibility of the reproductive tract to estrogenic chemicals. Importantly, the altered gene patterns identified by microarray analysis were confirmed by RT-PCR and real-time RT-PCR. Fifteen primers were designed to amplify specific altered genes. These genes were selected for validation because of their markedly increased expression levels and they were classified on the basis of gene ontology. Overall, a high correlation was observed between microarray and real-time PCR data. Taken together, these results indicate that placental exposure to OP or DES may cause temporal changes in gene expression in the uteri of dams and neonates. Moreover, these findings may provide useful indicators of the adverse effects of EDs and prove particularly important in elucidating the effects of xenoestrogens on estrogen-responsive tissues, such as the developing reproductive tract.

Using array-comparative genomic hybridization to define molecular portraits of primary breast cancers

We analysed 148 primary breast cancers using BAC-arrays containing 287 clones representing cancer-related gene/loci to obtain genomic molecular portraits. Gains were detected in 136 tumors (91.9%) and losses in 123 tumors (83.1%). Eight tumors (5.4%) did not have any genomic aberrations in the 281 clones analysed. Common (more than 15% of the samples) gains were observed at 8q11-qtel, 1q21-qtel, 17q11-q12 and 11q13, whereas common losses were observed at 16q12-qtel, 11ptel-p15.5, 1p36-ptel, 17p11.2-p12 and 8ptel-p22. Patients with tumors registering either less than 5% (median value) or less than 11% (third quartile) total copy number changes had a better overall survival (log-rank test: P=0.0417 and P=0.0375, respectively). Unsupervised hierarchical clustering based on copy number changes identified four clusters. Women with tumors from the cluster with amplification of three regions containing known breast oncogenes (11q13, 17q12 and 20q13) had a worse prognosis. The good prognosis group (Nottingham Prognostic Index (NPI) <or=3.4) tumors had frequent loss of 16q24-qtel. Genes significantly associated with estrogen receptor (ER), Grade and NPI were used to build k-nearest neighbor (KNN) classifiers that predicted ER, Grade and NPI status in the test set with an average misclassification rate of 24.7, 25.7 and 35.7%, respectively. These data raise the prospect of generating a molecular taxonomy of breast cancer based on copy number profiling using tumor DNA, which may be more generally applicable than expression microarray analysis.

Factors correlating with lymph node metastases in patients with T1 ductal invasive breast cancer

BACKGROUND: Identification of reliable predictors of axillary lymph node metastases (ALNM) may be useful in selecting appropriate management for patients with T1-size breast cancer. This study was undertaken to determine the association between ALNM and several variables, including age, tumor size, grade, estrogen receptor status, progesterone receptor status, p53 and c-erbB2 protein expression, and Ki-67 proliferative index. METHODS: In a retrospective study, 74 patients with pT1b and pT1c ductal invasive breast carcinoma and with known nodal status were analyzed. The size of the infiltrating tumor was microscopically evaluated. The histological grading was performed using the modified criteria of Bloom and Richardson, as described by Elston and Ellis. The immunophenotype of the tumor was determined as: the expression of estrogen (ER) and progesterone (PR) receptors, p53, c-erbB2 and Ki-67. The patients were grouped by age as follows: <50, 50-70, and >70 years old. RESULTS: Twenty six patients (35%) were node positive. Tumor size was related directly to nodal positivity. Nodal positivity was significantly related to negative PR status, p53 protein overexpression and high Ki-67 index (p<0.05). No significant association was found between nodal positivity and patient age, tumor grade, ER status, and c-erbB2 expression. CONCLUSION: These data suggest that PR status, Ki-67 proliferation index, and p53 protein expression might provide additional information to the lymph node status in T1 ductal breast carcinomas.

Hormonal influences on cancer progression and prognosis

Cell differentiation, proliferation, apoptosis, and cell motility are induced and regulated by a host of growth factors, vitamins, and hormones. The mode of function of these modifiers of biological response, the signaling pathways that they activate, and the interacting pathways that can influence the biological outcome have been the focus of attention. Especially recognized and discussed in this review is the deregulation of their function, leading to abnormalities in cell proliferation, alteration of intercellular adhesive cohesion, remodeling of the extracellular matrix, and invasive behavior and metastatic deposition that are so characteristic of tumor development and progression, which strongly underscores the concept of molecular progression of cancer constructed on the basis of the relationship between genetic changes and the biological events associated with cancer progression. The molecular changes associated with hormone- and vitamin-driven responses and the deregulation of the expression and function of their target genes seem to correlate with specific biological events linked with cancer invasion and progression, and these findings could lead to the establishment of new markers of progression and to the development of new strategies for patient management. The scope of this work has been restricted by design and is dictated by the field of interest of the author's laboratory, but it is hoped that this field would be regarded adequately to reflect the wide genre of scientific interest in this field of human disease.

Proliferative markers as prognostic and predictive tools in early breast cancer: where are we now?

In the last few decades, proliferative markers have been broadly evaluated as prognostic and predictive factors for early stage breast cancer patients. Several papers evaluating one or more markers have been published, often with contradictory results. As a consequence, there is still uncertainty about the role of these proliferative markers. The present paper critically reviews the current knowledge about the following markers: thymidine labeling index, S phase fraction/flow cytometry, Ki 67, thymidine kinase (TK), cyclins E, cyclin D, the cyclin inhibitors p27 and p21, and topoisomerase IIalpha. For each marker, the prognostic and predictive role was separately analyzed. Only papers published in English in peer-reviewed journals before June 2004 that include at least 100 evaluable patients were selected. In addition, the prognostic and predictive role of the proliferative markers had to be assessed through multivariate analyses. One hundred and thirty-two papers fulfilled these criteria and 159 516 patients were analyzed. Unfortunately, several methodological problems in the research to date prevent us from including any one of these proliferative markers among the standard prognostic and predictive factors. Early incorporation of translational research and new technologies with clinical trials are needed to prospectively validate biological markers and allow their use in clinical practice.

The importance of temporal effects in evaluating the prognostic impact of joint ERPR expression in premenopausal women with node-positive breast cancer

Although there is abundant information about the independent effects of estrogen receptor (ER) and progesterone receptor (PR) on outcomes of breast cancer, comparatively little is known about the impact of joint (ER+PR+, ER+PR-, ER-PR+ and ER-PR-) ERPR expression. The purpose of this study was to evaluate the prognostic relevance of joint ERPR expression to progression free survival (PFS). Data from 710 patients with a median follow-up of 119 months has been analyzed retrospectively. Our results indicate that the effect of the ER+PR+ phenotype on PFS was significantly time-dependent (p<0.0001); favorable in the first 3 years of follow-up (HR=0.67, p=0.0175) compared to ER-PR- phenotype, but unfavorable during the later follow-up period (HR=2.89, p=0.0006). Similar patterns were also observed for ER+PR- and ER-PR+ phenotypes, but the effect did not reach statistical significance. In the tree-based analysis, we found that, among patients with more than 4 positive nodes and age greater than 40, those with ER-PR+ tumors had the worst PFS ( p=0.025), and among patients with 1--3 positive nodes and stage of T1 and T2, those with ER+PR- had the worst outcome ( p=0.006). Our results demonstrate that failure to recognize the time-varying effect of the steroid hormonal receptors can obscure their role in the prognosis of breast cancer. We also provide more evidence to support the concept that ER-PR+ is a real group representing a distinct clinical entity.

Immunohistochemical study of androgen receptors in breast carcinoma. Evidence of their frequent expression in lobular carcinoma

Androgens and androgen receptors (AR) are involved in the pathogenesis of breast cancer. Epidemiological studies have shown a significant association between the risk of breast cancer and androgens. However, the functional role and clinical value of AR expression in breast carcinoma have still not been clearly defined. The present study was set up to investigate the prevalence of ARs in a series of consecutive invasive breast carcinomas (IBCs) and to evaluate the patterns of AR phenotypes in a series of selected invasive lobular carcinomas (ILCs). Among the 250 consecutive IBCs (consisting of 212 ductal and 38 lobular neoplasms), AR immunoreactivity was observed in 151/250 (60.4%) cases, being expressed in 118/212 (56%) ductal and 33/38 (87%) lobular carcinomas (a statistically significant difference, chi2=11.82). AR expression was frequently associated with ER (65.2%, chi2=14.33) and PR positivity (66.9%, chi2=7.36). Most AR positive cases showed a low proliferative index (63.7%) and a low or intermediate histological grade (G1-G2, 63.9%). Among the 80 selected ILCs, AR expression was observed in 64/80 (80%) cases. Our results confirm that ARs are expressed in most breast cancers. Moreover, we demonstrated that AR positivity is particularly marked in lobular neoplasms. In addition, AR positive carcinomas are frequently characterized by a low or intermediate grade, a low proliferative index and ER and/or PR co-expression.

Ductal breast carcinomas with whole chromosome gains as a particular subset of near-diploid tumors with different metastasis free survival

We recently proposed the existence of a subtype of slightly hyperdiploid ductal breast cancers with cytogenetic alterations differing from those usually observed in the majority of these tumors. We aimed to establish whether these tumors, which represent about 50% of those with a DNA index (DI) comprised between 1.1 and 1.3, correspond to a particular clinicopathological entity. A retrospective study of 1771 patients operated for ductal carcinomas was performed. Three classes of tumors constituted according to DI were compared for the usual clinicopathological factors and clinical outcome. About 690 tumors (39%) were diploid/hypodiploid (DI < 1.1), 134 (7.6%) were hyperdiploid (1.1 < or = DI < 1.3) and 947 (53.4%) were polyploid (DI > or = 1.3). Median follow-up time was 106 months (range 1-177). Polyploid tumors were significantly associated with large tumor size, advanced clinical stage, high histological grade and S-phase fraction (SPF), positive lymph nodes and loss of steroid receptors. Hyperdiploid and diploid/hypodiploid tumors were similar for all the variables except SPF which was significantly higher in hyperdiploid tumors (p < 0.001). Overall survival was similar in hyperdiploid and diploid/hypodiploid tumors in univariate and multivariate analysis, while hyperdiploid tumors were significantly related to a poorer metastasis free survival, both in univariate (p = 0.023) and multivariate analysis (p = 0.031). Despite very close initial clinicopathological and biological characteristics, hyperdiploid tumors differed from diploid/hypodiploid tumors by a higher risk of metastasis, possibly related to their increased SPF.

Exploring cancer register data to find risk factors for recurrence of breast cancer--application of Canonical Correlation Analysis

Background

A common approach in exploring register data is to find relationships between outcomes and predictors by using multiple regression analysis (MRA). If there is more than one outcome variable, the analysis must then be repeated, and the results combined in some arbitrary fashion. In contrast, Canonical Correlation Analysis (CCA) has the ability to analyze multiple outcomes at the same time.

One essential outcome after breast cancer treatment is recurrence of the disease. It is important to understand the relationship between different predictors and recurrence, including the time interval until recurrence. This study describes the application of CCA to find important predictors for two different outcomes for breast cancer patients, loco-regional recurrence and occurrence of distant metastasis and to decrease the number of variables in the sets of predictors and outcomes without decreasing the predictive strength of the model.

Methods

Data for 637 malignant breast cancer patients admitted in the south-east region of Sweden were analyzed. By using CCA and looking at the structure coefficients (loadings), relationships between tumor specifications and the two outcomes during different time intervals were analyzed and a correlation model was built.

Results

The analysis successfully detected known predictors for breast cancer recurrence during the first two years and distant metastasis 2–4 years after diagnosis. Nottingham Histologic Grading (NHG) was the most important predictor, while age of the patient at the time of diagnosis was not an important predictor.

Conclusion

In cancer registers with high dimensionality, CCA can be used for identifying the importance of risk factors for breast cancer recurrence. This technique can result in a model ready for further processing by data mining methods through reducing the number of variables to important ones.

The S-phase fraction of the aneuploid cell subpopulation is the biologically relevant one in aneuploid breast cancers

BACKGROUND

In the case of DNA-aneuploid tumors there are no clear guidelines as to which S-phase fraction is the more relevant one: that corresponding to either the diploid or the aneuploid population, or rather an average of both.

MATERIALS AND METHODS

We studied 280 breast cancer specimens from previously untreated patients. Histologically, 231 were ductal infiltrating carcinomas, 30 lobular infiltrating carcinomas and 19 corresponded to other, less frequent varieties. Postsurgically, 164 cases (58.6%) were classified as T1, 87 (31.1%) as T2 and 7 as T3. The remaining 22 cases were multifocal, diffuse tumors. Flow cytometry was performed on fresh tumor tissue, and immunohistochemistry for hormone receptors, Ki67, c-erb-B2 and p53 on paraffin-embedded material.

RESULTS

In diploid tumors, a high S-phase (above the 75th percentile) correlated significantly with Ki67 expression > or =20% (p<0.0001). In aneuploid tumors, however, this was only the case for the aneuploid fraction of tumor cells (p< 0.0001). A high S-phase of diploid tumors correlated directly and significantly with a high histologic grade (p=0.04), a high nuclear grade (p=0.01), tumor size (p=0.0008), and inversely with estrogen (p<0.0001) and progesterone (p<0.0001) receptor expression. In aneuploid tumors, the aneuploid tumor fraction showed a direct and significant correlation with a high histologic grade (p=0.005), a high nuclear grade (p=0.001), mutant p53 expression (p=0.0009), and inversely with estrogen (p<0.0001) and progesterone (p=0.0001) receptor expression. A high S-phase of the diploid cell fraction of aneuploid tumors, on the other hand, just showed an inverse correlation with high nuclear grade of the tumors (p=0.02), and none whatsoever with all other tested parameters.

Hormone receptor status of a contralateral breast cancer is independent of the receptor status of the first primary in patients not receiving adjuvant tamoxifen

PURPOSE

To determine whether the hormone receptor status of the primary breast cancer (PBC) is predictive of the hormone receptor status of the subsequent contralateral breast cancer (CBC).

PATIENTS AND METHODS

We identified patients in our database with known estrogen receptor (ER; n = 193) and/or progesterone receptor (PgR; n = 178) status in their PBC and in their subsequent CBC. One hundred twenty-six of these patients had received no adjuvant therapy, 34 had received adjuvant tamoxifen, and 33 had received adjuvant chemotherapy alone. The median interval between the first diagnosis of PBC and the development of the subsequent CBC was 3 years. ER and PgR assays were assessed biochemically in two central reference laboratories using identical quality-controlled ligand-binding methods.

RESULTS

Among systemically untreated patients (n = 126), 88% of patients with ER-positive PBC and 75% of patients with ER-negative PBC developed an ER-positive CBC (P = .11). Among the tamoxifen-treated patients, those with an ER-positive PBC were almost equally likely to develop an ER-positive (47%) or ER-negative (53%) CBC (P = .99). PgR status was similar. In the untreated group (n = 112), 59% of patients with a PgR-positive PBC and 66% with a PgR-negative PBC developed a PgR-positive CBC (P = .48). Among tamoxifen-treated patients (n = 33), 50% of patients with a PgR-positive PBC versus 27% of patients with a PgR-negative PBC developed a PgR-positive CBC (P = .28).

CONCLUSION

ER and PgR status of the primary tumor does not predict the hormone receptor status of the subsequent CBC in the absence of selective pressure of adjuvant therapy. Thus, other reasons should be considered to clarify the failure of tamoxifen to reduce the incidence of CBC in patients with a receptor-negative PBC.

Differential association of BRCA1 and BRCA2 genes with some breast cancer-associated genes in early and late onset breast tumors

BACKGROUND

Accumulating evidence indicating more aggressive features of breast carcinoma (BC) in young women than their older counterparts have raised the question of whether these differences are present at the genetic level.

METHODS

For this purpose, we performed a comparative analysis of the frequency of deletions of BRCA1, BRCA2, BRCAX, TP53, ATM, and RB1 and amplification of Cyclin D1 and also studied the interrelation and prognostic significance of these genetic alterations in 30 early onset (< or =40 years) and 33 late onset (>40 years) cases of BC. These gene alterations were also studied in 11 other types of breast lesions.

RESULTS

A differential pattern of alterations (deletion/amplification) was observed in the two age groups, with the sequence in younger women being BRCA1 (72%), TP53 (71%), ATM (64%), BRCA2 (62%), RB1 (60%), Cyclin D1 (43%), and BRCAX (24%) and that in the older group being TP53 (66%), RB1 (63%), BRCA1 (56%), ATM (53%), BRCA2 (45%), Cyclin D1 (24%), and BRCAX (23%). Similar, differential correlations were also seen with several clinicopathological parameters, prognosis, and combinations of alterations among these genes in the two age groups.

CONCLUSIONS

Differential frequencies and interrelationships of genetic alterations and prognoses in these two age groups indicate that the molecular pathways for the development of tumors in both age groups may not be similar, though the ultimate effect is deregulation of cell cycle checkpoints and defects in the DNA repair pathway.

Aromatase inhibitors and breast cancer: time for a change?

Aromatase inhibitors bind reversibly or irreversibly to the aromatase enzyme in peripheral fat and also in the breast, leading to undetectable plasma levels of oestrogens in postmenopausal women. These agents have been shown to be more effective than tamoxifen in first-line treatment of oestrogen receptor-positive advanced and metastatic breast cancer. Additionally, they have been demonstrated to be superior as both adjuvant and neoadjuvant treatment. It is likely that they will also be useful for breast cancer prevention but the cost/benefit ratio has yet to be determined.

Characteristics and outcome of 1755 operable breast cancers in women over 70 years of age

From 1981 to 1995, 1755 patients aged 70 years or over who had nonmetastatic unilateral breast carcinoma received curative local or regional treatment in our institute. Median follow-up was 8 years. The median age of these patients was 75 years (range: 70-94), and 86% were under 81 years of age. Tumors were classed as T3-4 in 24% of them; 18% had N1b/N2 tumors, and in 12% grade 3 disease was present. Only 19% were both ER and PR negative. The S phase fraction was <5% in 79% of patients. In 1046 patients (60%) modified radical mastectomy was performed, while 20% underwent lumpectomy and in 20% radiotherapy was the only treatment administered. Adjuvant endocrine therapy was given in 463 (26%) cases, and only 3% of patients received chemotherapy. The median overall survival time was 121 months. The overall cancer-related death rate was 49%. The 10-year disease-free survival (DFS) rate was 64%, and the 10-year local relapse rate was 14%. Prognostic factors determined on univariate analysis were tumor size, clinical nodal status (ER and PR), and grade. No significant difference in outcome was observed between mastectomy and conservative treatment. Parameters for which correlations with DFS were found on multivariate analysis were clinical nodal status (P < 0.0001), tumor size (P < 0.0001), ER (P < 0.0001), and PR (P = 0.04). Breast cancer in elderly women is frequently hormone-dependent (81%) with a low proliferation index. Prognostic factors are the same as in younger postmenopausal patients. More than 50% of these patients died from a cause other than their breast cancer.

Genotoxic stress leads to centrosome amplification in breast cancer cell lines that have an inactive G1/S cell cycle checkpoint

Centrosome amplification plays a key role in the origin of chromosomal instability during cancer development and progression. In this study, breast cancer cell lines with different p53 backgrounds were used to investigate the relationship between genotoxic stress, G(1)/S cell cycle checkpoint integrity, and the development of centrosome amplification. Introduction of DNA damage in the MCF-7 cell line by treatment with hydroxyurea (HU) or daunorubicin (DR) resulted in the arrest of both G(1)/S cell cycle progression and centriole duplication. In these cells, which carry functional p53, HU treatment also led to nuclear accumulation of p53 and p21(WAF1), retinoblastoma hypophosphorylation, and downregulation of cyclin A. MCF-7 cells carrying a recombinant dominant-negative p53 mutant (vMCF-7(DNp53)) exhibited a shortened G(1) phase of the cell cycle and retained a normal centrosome phenotype. However, these cells developed amplified centrosomes following HU treatment. The MDA-MB 231 cell line, which carries mutant p53 at both alleles, showed amplified centrosomes at the outset, and developed a hyperamplified centrosome phenotype following HU treatment. In cells carrying defective p53, the development of centrosome amplification also occurred following treatment with another DNA damaging agent, DR. Taken together, these findings demonstrate that loss of p53 function alone is not sufficient to drive centrosome amplification, but plays a critical role in this process following DNA damage through abrogation of the G(1)/S cell cycle checkpoint. Furthermore, these studies have important clinical implications because they suggest that breast cancers with compromised p53 function may develop centrosome amplification and consequent chromosomal instability following treatment with genotoxic anticancer drugs.

Relevance of breast cancer cell lines as models for breast tumours: an update

The number of available breast cancer cell (BCC) lines is small, and only a very few of them have been extensively studied. Whether they are representative of the tumours from which they originated remains a matter of debate. Whether their diversity mirrors the well-known inter-tumoural heterogeneity is another essential question. While numerous similarities have long been found between cell lines and tumours, recent technical advances, including the use of micro-arrays and comparative genetic analysis, have brought new data to the discussion. This paper presents most of the BCC lines that have been described in some detail to date. It evaluates the accuracy of the few of them widely used (MCF-7, T-47D, BT-474, SK-BR-3, MDA-MB-231, Hs578T) as tumour models. It is concluded that BCC lines are likely to reflect, to a large extent, the features of cancer cells in vivo. The importance of oestrogen receptor-alpha (gene ESR1 ) and Her-2/ neu ( ERBB2 ) as classifiers for cell lines and tumours is underlined. The recourse to a larger set of cell lines is suggested since the exact origin of some of the widely used lines remains ambiguous. Investigations on additional specific lines are expected to improve our knowledge of BCC and of the dialogue that these maintain with their surrounding normal cells in vivo.

Deletion mapping of chromosome 1 in early onset and late onset breast tumors--a comparative study in eastern India

Younger women exhibit more aggressive pathologic features of breast cancer (BC) compared to their older counterparts. Young age has been shown to be an independent predictor of adverse prognosis. These findings have raised the question of whether these differences are also present at the genetic level. Twenty-five early onset (age < or = 40 years) tumors including 4 bilateral tumors, and 26 late onset (>40 years) breast tumors, including 2 bilateral tumors, were examined for loss of heterozygosity (LOH) at chromosome 1 using 11 polymorphic microsatellite markers. A comparative study revealed high frequencies of LOH in chr. 1p36 (61%), 1p31.3 (40%), 1p21.3 (50%) and 1q22-23.2 (56%) in a younger group, and chr. 1p36 (46%), 1p34.2 (48%), and 1q22-23.2 (52%) in an older group. These differences in LOH frequency in these two age groups were significant for chr. 1p21.3 (p = 0.025) only. These data suggest that the deletion pattern in early onset breast tumors is not fully identical to late onset breast tumors. Similar differential deletion patterns of LOH in the 5 highly deleted regions were seen in premenopausal and postmenopausal groups. An association was seen between LOH at chr. 1p34.2 and chr. 1q22-23.2 and higher grade of the tumors in older women. Among the highly deleted regions, the deletion at chr. 1p36 was found to occur early in both groups because of common allelic loss in the bilateral tumors.

Infiltrating lobular carcinoma of the breast: tumor characteristics and clinical outcome

INTRODUCTION

Invasive lobular carcinoma (ILC) comprises approximately 10% of breast cancers and appears to have a distinct biology. Because it is less common than infiltrating ductal carcinoma (IDC), few data have been reported that address the biologic features of ILC in the context of their clinical outcome. In the present study we undertook an extensive comparison of ILC and IDC using a large database to provide a more complete and reliable assessment of their biologic phenotypes and clinical behaviors.

METHODS

The clinical and biological features of 4140 patients with ILC were compared with those of 45,169 patients with IDC (not otherwise specified). The median follow-up period was 87 months.

RESULTS

In comparison with IDC, ILC was significantly more likely to occur in older patients, to be larger in size, to be estrogen and progesterone receptor positive, to have lower S-phase fraction, to be diploid, and to be HER-2, p53, and epidermal growth factor receptor negative. It was more common for ILC than for IDC to metastasize to the gastrointestinal tract and ovary. The incidence of contralateral breast cancer was higher for ILC patients than for IDC patients (20.9% versus 11.2%; P < 0.0001). Breast preservation was modestly less frequent in ILC patients than in IDC patients. The 5-year disease-free survival was 85.7% for ILC and 83.5% for IDC (P = 0.13). The 5-year overall survival was 85.6% for ILC and 84.1% for IDC (P = 0.64).

CONCLUSION

Despite the fact that the biologic phenotype of ILC is quite favorable, these patients do not have better clinical outcomes than do patients with IDC. At present, management decisions should be based on individual patient and tumor biologic characteristics, and not on lobular histology.

Hormone receptor status of breast cancer in India: a study of 798 tumours

The objectives of this study were to document the oestrogen and progesterone receptor (ER & PR) status of breast cancer in the Indian population (as done by immunohistochemistry on paraffin blocks), and correlate the steroid receptor status of breast cancer with all relevant patient and tumour characteristics. Our current data have been compared with previously published data from other centres. In contrast to the higher rates reported in the Western literature, only 32.6% of our tumours were ER positive and 46.1% were PR positive. Tumours were separated into four categories: ER+PR+ (25%), ER+PR- (7.4%), ER-PR+ (21.1%) and ER-PR- (46.5%). ER and PR immunoreactivity increased with advancing age, and correlated with the presence of elastosis. Infiltrating lobular carcinoma, mucinous carcinoma, and mixed tumours were more frequently ER & PR positive. High-grade infiltrating duct carcinomas, pure comedo ductal carcinoma in situ, and medullary carcinoma were predominantly ER & PR negative. The presence of necrosis and lymphovascular invasion showed an inverse relationship with ER and PR reactivity.

Flow cytometry in primary breast carcinomas: Prognostic impact of S-phase fraction according to different analysis patterns

BACKGROUND

The aim of the present work was to study the prognostic impact of ploidy and S-phase fraction (SPF) assessed according to recently described methods. These methods of analysis combine different ploidy groups and separate euploid (good) prognostic groups from noneuploid (bad) prognostic groups. The definition of euploidy varied according to the author; some of them even included aneuploid peaks with few events. A comparison was also drawn to the average SPF and the diploid peak SPF observed in aneuploid histograms.

METHODS

From January 3, 1990 to January 7, 1999, 1,984 previously untreated, invasive breast carcinoma samples were snap-frozen and processed for FCM. The present study evaluated all nondiploid and nonmultiploid histograms, using different analysis patterns and the values of the average SPF and diploid SPF.

RESULTS

SPF is a salient prognostic factor even after multivariate analysis for DFS and MFS. Using several methods of analysis of ploidy and SPF shows that the classical method of analysis involving separation of ploidy according to diploidy versus aneuploidy and analysis of SPF restricted to the aneuploid peak in nondiploid and nonmultiploid histograms is as relevant as other recently proposed patterns of analysis, and that the average SPF or the diploid SPF of aneuploid tumors does not add significant prognostic information.

CONCLUSIONS

SPF is a valuable predictor of survival and can be confidently assessed in a simple way by restricting the analysis to the peak of interest (except for multiploid tumors).

Proliferative activity in primary breast carcinomas is a salient prognostic factor

BACKGROUND

The goal of the current study was to investigate the prognostic impact of proliferative activity, together with the other classic clinicopathologic prognostic factors (tumor size, tumor grade, receptor status, ploidy, and lymph node status), in breast carcinoma by counting mitoses and evaluating S phase fraction (SPF) in fresh and frozen tumor samples.

METHODS

From March 1, 1990, to July 1, 1999, a total of 1984 previously untreated invasive breast carcinoma samples were snap-frozen for flow cytometry.

RESULTS

After multivariate analysis incorporating all classic prognostic factors, SPF combined with mitotic activity (i.e., proliferative activity) remained the sole prognostic factor in the lymph node-negative group; proliferative activity was accompanied by tumor size as a prognostic factor in patients with lymph node-positive disease and by lymph node status, lymphatic invasion, and receptor status in the overall population. The predictive value of proliferative activity was superior to that of the reference standards (classic prognostic predictors according to the guidelines of our institution [common oncology practice] and the St. Gallen classification). A review of the literature, focusing on series in which fresh material was used, allowed us to demonstrate that there is widespread agreement regarding the correlation between SPF and prognosis, even after multivariate analysis.

CONCLUSIONS

S phase fraction is a valuable predictor of survival and can confidently be assessed in approximately 80% of cases. In conjunction with mitotic activity, SPF should become a prognostic factor that is used in daily practice by oncologists for the management of breast carcinoma.

Prognostic markers in node-negative breast cancer: A prospective study

BACKGROUND

Despite years of research, it is still unclear which women with node-negative (N-) breast cancer will need adjuvant chemotherapy and which women are being treated unnecessarily. Our goal was to determine which factors best predicted disease free survival (DFS) or cancer-specific overall survival (OS) and, therefore, select the correct patients for treatment. A total of 11 parameters were measured: estrogen receptor (ER), progesterone receptor (PR), age, race, ploidy status, %G0/G1 (% non-DNA synthesis), %S (% S-phase), cathepsin D status, size, stage, and histologic grade.

RESULTS

In this prospective study, we followed 556 N- patients diagnosed between 1991 and 1996. The tumors were 56% ER+, 51% PR+, 30% diploid, with a mean %S of 8.9%. The level of cathepsin D ranged from 0.50 to 155 pmol/mg of protein with a mean of 42.9 pmol/mg of protein. There were 87 recurrences (16%) and 72 cancer deaths (13%), with a median follow-up of 7.8 years. Ploidy status (p = 0.01), S-phase activity (p = 0.003), G1 phase activity (p = 0.02) and age (p = 0.01) were able to significantly predict DFS in a univariate manner. All of the measurable factors were significant or borderline significant in predicting OS in a univariate manner except for age, race, and ER status. In multivariate analysis with S-phase included, it was the only remaining factor in DFS and OS; with S-phase excluded, age and ploidy status remained as factors for DFS in stepwise regression, while PR, size, and cathepsin D were the remaining factors that predicted cancer-specific OS. The effect of adjuvant treatment on prognosis was also analyzed.

CONCLUSIONS

Both biochemical and clinical parameters have the potential to predict prognosis for N- breast cancer. In this large prospective clinical trial, with a median follow-up of 7.8 years, no individual marker adequately predicted the prognosis for an individual patient. %S activity was the best independent marker, but only 77% of the tumors provided this value. Subset analysis provided improved prognostication, but there were limits to its utility. These data represents a definitive study starting in 1991 and ending in 2002.

Improved DNA flow cytometric, DNA ploidy, and S-phase reproducibility between 15 laboratories in analysis of breast cancer using generalized guidelines

BACKGROUND

Lack of generalized guidelines for DNA flow cytometric analysis (FCM) may be the main reason for its limited use in the clinical management of breast cancer.

METHODS

After an initial interlaboratory reproducibility study (Round I), we concluded that it was the evaluation of the DNA histograms rather than the technical performance of the analysis that was the main reason for discordant results between laboratories. Guidelines for the interpretation of DNA histograms were therefore drawn up. We present here data from a new reproducibility study (Round II) using these guidelines.

RESULTS

For 10 laboratories also participating in Round I, use of the guidelines increased the concordance in DNA ploidy status from 89% to 100% for the 46 samples used in both rounds. The concordance rate for SPF also increased; mean r(s)-value increased from 0.81 to 0.88, and mean kappa value (lower two-thirds versus upper third versus not reported) increased from 0.55 to 0.71. Five new laboratories, participating only in Round II, also agreed with the 10 original laboratories regarding DNA ploidy status. With the inclusion of all 15 laboratories, we obtained a mean r(s)-value of 0.81 and a mean kappa value of 0.72 for SPF.

CONCLUSIONS

Generalized guidelines for DNA FCM increase interlaboratory agreement, which is highly important in clinical routines and in multicenter studies. Furthermore, inexperienced FCM laboratories using generalized guidelines can produce and interpret DNA FCM data equally as well as experienced laboratories.