DNA flow cytometry and prognostic factors in 1331 frozen breast cancer specimens

Interactome Analysis of KIN (Kin17) Shows New Functions of This Protein

KIN (Kin17) protein is overexpressed in a number of cancerous cell lines, and is therefore considered a possible cancer biomarker. It is a well-conserved protein across eukaryotes and is ubiquitously expressed in all cell types studied, suggesting an important role in the maintenance of basic cellular function which is yet to be well determined. Early studies on KIN suggested that this nuclear protein plays a role in cellular mechanisms such as DNA replication and/or repair; however, its association with chromatin depends on its methylation state. In order to provide a better understanding of the cellular role of this protein, we investigated its interactome by proximity-dependent biotin identification coupled to mass spectrometry (BioID-MS), used for identification of protein-protein interactions. Our analyses detected interaction with a novel set of proteins and reinforced previous observations linking KIN to factors involved in RNA processing, notably pre-mRNA splicing and ribosome biogenesis. However, little evidence supports that this protein is directly coupled to DNA replication and/or repair processes, as previously suggested. Furthermore, a novel interaction was observed with PRMT7 (protein arginine methyltransferase 7) and we demonstrated that KIN is modified by this enzyme. This interactome analysis indicates that KIN is associated with several cell metabolism functions, and shows for the first time an association with ribosome biogenesis, suggesting that KIN is likely a moonlight protein.

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.

Src and ROCK Kinases Differentially Regulate Mineralization of Human Osteosarcoma Saos-2 Cells

Osteoblasts initiate bone mineralization by releasing matrix vesicles (MVs) into the extracellular matrix (ECM). MVs promote the nucleation process of apatite formation from Ca²⁺ and P_i in their lumen and bud from the microvilli of osteoblasts during bone development. Tissue non-specific alkaline phosphatase (TNAP) as well as annexins (among them, AnxA6) are abundant proteins in MVs that are engaged in mineralization. In addition, sarcoma proto-oncogene tyrosine-protein (Src) kinase and Rho-associated coiled-coil (ROCK) kinases, which are involved in vesicular transport, may also regulate the mineralization process. Upon stimulation in osteogenic medium containing 50 μg/mL of ascorbic acid (AA) and 7.5 mM of β-glycerophosphate (β-GP), human osteosarcoma Saos-2 cells initiated mineralization, as evidenced by Alizarin Red-S (AR-S) staining, TNAP activity, and the partial translocation of AnxA6 from cytoplasm to the plasma membrane. The addition of 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo [3,4-d] pyrimidine (PP2), which is an inhibitor of Src kinase, significantly inhibited the mineralization process when evaluated by the above criteria. In contrast, the addition of (R)-(+)-trans-4-(1-aminoethyl)-N-(4-pyridyl) cyclohexane carboxamide hydrochloride (Y-27632), which is an inhibitor of ROCK kinase, did not affect significantly the mineralization induced in stimulated Saos-2 cells as denoted by AR-S and TNAP activity. In conclusion, mineralization by human osteosarcoma Saos-2 cells seems to be differently regulated by Src and ROCK kinases.

Flow Cytometric Analysis of Brain Tumor Stem Cells

As a useful biotechnology, flow cytometry has revolutionized the field of cell analysis through its dynamic system that employs fluidics, optics, and electronics. It was first used to analyze DNA, but is often used to determine biomarker expression, as well as to characterize and sort cells, in accordance with various parameters. A common application of flow cytometry is the identification and isolation of a distinct cancer cell population, known as cancer stem cells (CSCs). Various biomarkers have been used to elucidate this proportion of cells within the brain, termed brain tumor initiating cells (BTICs). Here, we discuss methodology to prepare BTICs for flow cytometric analysis that includes the expression of markers.

Cell Kinetics of Solid Tumors with Time and Its Clinical Implication

The proliferative rate has been evaluated for several human tumor types as the fraction of cells in S-phase. The methodologies most often used are autoradiographic determination of 3H-thymidine incorporation and flow cytometric evaluation of DNA content. Cell kinetics determined on various solid primary tumors at the time of diagnosis is not related to pathologic stage but it is an indicator of clinical evolution of the disease similar or superior to other biologic and pathologic prognostic factors. In early disease, submitted to loco-regional treatment as a first-line therapy, the rate of cell proliferation provides prognostic information on relapse-free and overall survival. In this clinical situation, a different metastatic potential can be attributed to tumors with different proliferative rates. In more extensive disease, submitted to systemic treatment, proliferation indices generally influence overall survival, eventhough in responsive tumors a fast proliferative activity could be indicative of higher aggressiveness and remarkable chemosensitiveness. Proliferation indices of the metachronous metastatic lesions is increased over those of the primary tumors as a further evidence of the association between proliferative activity and disease progression.

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.

Elevated 80K-H Protein in Breast Cancer: A Role for FGF-1 Stimulation of 80K-H

An increase in fibroblast growth factor-1 (FGF-1) is established as part of the cause of several important cancers including breast cancer, but the mechanisms by which it induces malignant behavior are not known. We now report that the protein 80K-H, a substrate for PKC, appears to be part of this mechanism and that it is increased in breast cancer and localizes to the nucleus as part of the mechanism. Our conclusion is based on an examination of a total of 58 biopsy specimens from human breast cancer patients for the presence of relationships between the 80K-H protein and the following: fibroblast growth factor receptor-1 (FGFR-1), tumor grade, microvessel counts (MVC), estrogen receptor (ER) and progesterone receptor (PgR) status. Based on histological grading and immunohistochemical (IHC) assays, we found strong direct relationships between 80K-H and FGFR-1 (r=0.49, p=0.003) and tumor grade (r=0.42, p=0.006). A trend for a direct relationship was observed with PgR (r=0.27, p=0.087). Notably, 80K-H immunostaining was largely limited to the epithelial cells of the mammary ducts.

Subsequently, we studied the effects of FGF-1 on 80K-H in cultured human mammary carcinoma epithelial cells in order to establish a more direct relationship between these two molecules. We observed that FGF-1 treatment of MCF-7 cells stimulated translocation of 80K-H protein to the cell nucleus, as demonstrated by subcellular fractionation studies. Maximal intranuclear 80K-H was observed approximately 30 minutes following FGF-1 treatment. In addition, FGF-1 treatment of MCF-7 cells increased growth and invasion of MCF-7 cells, as demonstrated by cell proliferation and a modified Boyden chamber assay, respectively. Further support for 80K-H nuclearization was provided by the immunostaining of human breast cancer specimens and computer-assisted identification of a putative nuclear localization signal (NLS) near the amino terminus of 80K-H protein structure.

These data support the existence of a previously unrecognized FGF-1/80K-H nuclear pathway in progression of human breast cancer and suggest that 80K-H may be useful for the assessment of breast tumor progression.

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.

Inhibition of autophagy and tumor growth in colon cancer by miR-502

Autophagy is a catabolic process that allows cellular macromolecules to be broken down and recycled as metabolic precursors. The influence of non-coding microRNAs in autophagy has not been explored in colon cancer. In this study, we discover a novel mechanism of autophagy regulated by hsa-miR-502-5p (miR-502) by suppression of Rab1B, a critical mediator of autophagy. A number of other miR-502 suppressed mRNA targets (for example, dihydroorotate dehydrogenase) are also identified by microarray analysis. Ectopic expression of miR-502 inhibited autophagy, colon cancer cell growth and cell-cycle progression of colon cancer cells in vitro. miR-502 also inhibited in-vivo colon cancer growth in a mouse tumor xenografts model. In addition, the expression of miR-502 was regulated by p53 via a negative feedback regulatory mechanism. The expression of miR-502 was downregulated in colon cancer patient specimens compared with the paired normal control samples. These results suggest that miR-502 may function as a potential tumor suppressor and therefore be a novel candidate for developing miR-502-based therapeutic strategies.

The clinical usefulness of oestrogen-receptor and other markers of hormone dependence

There is an increasing trend to administer adjuvant therapy to patients with all stages of primary breast cancer. However, since only about half of these patients will eventually relapse, it would be useful to have a set of factors that could predict which patients are at high risk for recurrence and which patients are probably cured by local therapy alone.

Using tumour specimens from our San Antonio Tumour Bank, we have confirmed the prognostic significance of axillary nodal status for predicting disease-free and overall survival. Among patients with node-positive disease, both oestrogen-receptors (ER) and progesterone-receptors (PgR) are predictive of patient outcome, but PgR is the more powerful factor. Using multivariate techniques, we have found that amplification and/or expression of the HER-2/neu oncogene provides additional prognostic information for node-positive patients.

Among patients with node-negative disease, ER and tumour size comprise a powerful set of prognostic factors. But ploidy status and S-phase fraction, as measured by flow cytometry, provide additional independent information for predicting disease-free and overall survival. Using these factors, sub-groups of node-negative patients with low risk of recurrence who will probably not benefit from adjuvant systemic therapy might be identified.

A rapid and optimization-free procedure allows the in vivo detection of subtle cell cycle and ploidy alterations in tissues by flow cytometry

Cell cycle alterations are fundamental to many physiological processes but their detection has proven difficult when cells are in the context of a tissue structure. Here we describe an easy, rapid and optimization-free procedure for obtaining high resolution cell cycle profiles from nearly all tissue types derived from mouse, human and sheep. Using a standardized and non-enzymatic procedure that is universally suitable for soft, solid and epithelial tissues alike, we reproducibly obtain cell cycle profiles of highest quality with half peak coefficients of variation below 2.0. We are able to reduce preparation-derived debris to almost zero and efficiently exclude doublets, but retain multinucleated cells and apoptotic subG1-fragments. Applying this technique, we determine DNA-indices as small as 1.09 in tumor samples containing large necrotic areas and follow ploidy changes within different sections of individual tumors. Moreover, we examine tissue-specific cell cycle arrest and apoptosis as an in vivo stress response caused by radiation of mice. This method significantly improves the quality of DNA content analysis in tissues and extends the spectrum of applications. It allows assessing changes in ploidy, cell cycle distribution and apoptosis/necrosis in vivo and should be instrumental in all research that involves experimental animal models and/or patient biopsies.

Mechanism of chemoresistance mediated by miR-140 in human osteosarcoma and colon cancer cells

In this study, high-throughput microRNA (miRNA) expression analysis revealed that the expression of miR-140 was associated with chemosensitivity in osteosarcoma tumor xenografts. Tumor cells ectopically transfected with miR-140 were more resistant to methotrexate and 5-fluorouracil (5-FU). Overexpression of miR-140 inhibited cell proliferation in both osteosarcoma U-2 OS (wt-p53) and colon cancer HCT 116 (wt-p53) cell lines, but less so in osteosarcoma MG63 (mut-p53) and colon cancer HCT 116 (null-p53) cell lines. miR-140 induced p53 and p21 expression accompanied with G(1) and G(2) phase arrest only in cell lines containing wild type of p53. Histone deacetylase 4 (HDAC4) was confirmed to be one of the important targets of miR-140. The expression of endogenous miR-140 was significantly elevated in CD133(+hi)CD44(+hi) colon cancer stem-like cells that exhibit slow proliferating rate and chemoresistance. Blocking endogenous miR-140 by locked nucleic acid-modified anti-miR partially sensitized resistant colon cancer stem-like cells to 5-FU treatment. Taken together, our findings indicate that miR-140 is involved in the chemoresistance by reduced cell proliferation through G(1) and G(2) phase arrest mediated in part through the suppression of HDAC4. miR-140 may be a candidate target to develop novel therapeutic strategy to overcome drug resistance.

Matrix vesicles originate from apical membrane microvilli of mineralizing osteoblast-like Saos-2 cells

In bone, mineralization is tightly regulated by osteoblasts and hypertrophic chondrocytes which release matrix vesicles (MVs) and control extracellular ionic conditions and matrix composition. MVs are the initial sites of hydroxyapatite (HA) mineral formation. Despite growing knowledge about their morphology and function, their biogenesis is not well understood. The purpose of this work was to determine the source of MVs in osteoblast lineage, Saos-2 cells, and to check whether MVs originated from microvilli. Microvilli were isolated from the apical plasma membrane of Saos-2 cells. Their morphology, structure, and function were compared with those of MVs. The role of actin network in MV release was investigated by using microfilament perturbing drugs. When examined by electron microscopy MVs and microvillar vesicles were found to exhibit similar morphology with trilaminar membranes and diameters in the same range. Both types of vesicles were able to induce HA formation. Their electrophoretic profiles displayed analogous enrichment in alkaline phosphatase, Na(+)/K(+) ATPase, and annexins A2 and A6. MVs and microvillar vesicles exhibited almost the same lipid composition with a higher content of cholesterol, sphingomyelin, and phosphatidylserine as compared to plasma membrane. Finally, cytochalasin D, which inhibits actin polymerization, was found to stimulate release of MVs. Our findings were consistent with the hypothesis that MVs originated from cell microvilli and that actin filament disassembly was involved in their biogenesis.

Low SAFB levels are associated with worse outcome in breast cancer patients

The scaffold attachment factors SAFB1 and SAFB2 have been shown to function as estrogen receptor (ERalpha) co-repressors in breast cancer cells, and to affect many cellular processes such as stress response, RNA processing, and apoptosis. SAFB1 and SAFB2 have also been implicated in breast tumorigenesis: Their shared chromosomal locus at 19p13 is frequently lost in breast cancer, mutations have been identified, and overexpression results in growth inhibition. The purpose of this study was to determine SAFB1/SAFB2 protein expression in human breast tumors, to correlate their expression with either natural progression ("prognostic factor") or with response to Tamoxifen ("predictive factor"), and to analyze potential correlations with tumor characteristics. SAFB1/SAFB2 protein were measured by immunoblotting using a pan-SAFB antibody in tumor extracts from patients with long-term clinical follow-up (n = 289), a subset of whom had received no adjuvant systemic therapy after breast cancer surgery (n = 117) and another subset of whom were treated with adjuvant Tamoxifen (n = 172). SAFB levels were correlated with clinico-pathological variables and patient outcome. SAFB levels varied widely, with 25 tumors not expressing detectable levels of SAFB. SAFB expression was significantly correlated with ERalpha, HER-2, bcl-2 and with expression of other ERalpha coregulators such as SRC-3. There was no association between SAFB expression and disease free survival, however, low SAFB expression was significantly associated with worse overall survival in patients who did not receive adjuvant therapy. This study shows that low SAFB protein levels predict poor prognosis of breast cancer patients, suggesting critical functions of SAFB1 and SAFB2 in breast cancer cells.

Calcium- and pH-dependent localization of annexin A6 isoforms in Balb/3T3 fibroblasts reflecting their potential participation in vesicular transport

Annexin A6 (AnxA6), calcium- and membrane-binding protein, is involved in membrane dynamics. It exists in the cell in two isoforms, AnxA6-1 and AnxA6-2, varying only by the VAAEIL sequence. In most cells, AnxA6-1 predominates. A limited number of observations suggests that both isoforms differ from each other functionally. The EGF-dependent Ca(2+) influx in A431 cells is inhibited only by AnxA6-1. Moreover, AnxA6-2 was found to exhibit higher affinity for Ca(2+). In this report we addressed the potential significance of the VAAEIL deletion in AnxA6-2. For this purpose, we expressed AnxA6 isoform cDNAs in bacteria or mouse Balb/3T3 fibroblasts. The recombinant AnxA6-2 was characterized by a less extended molecular shape than that of AnxA6-1 and required a narrower [Ca(2+)] range to bind liposomes. Upon lowering pH in the presence of EGTA recombinant AnxA6-2 became less hydrophobic than AnxA6-1 as revealed by the Triton X-114 partition. Furthermore, AnxA6-2 revealed stronger F-actin binding than that of AnxA6-1. Immunofluorescence microscopy showed that the EGFP-tagged AnxA6 isoforms expressed in Balb/3T3 fibroblasts relocate in a Ca(2+)- and H(+)-sensitive manner to the vesicular structures in a perinuclear region or in cytosol. Cell fractionation showed that in resting conditions AnxA6-1 is associated with early endosomes and AnxA6-2 with late endosomes, and an increase in [Ca(2+)] and/or [H(+)] induced their opposite distribution. These findings suggest a potentially independent regulation, localization, and function of AnxA6 isoforms in Balb/3T3 fibroblasts. More generally, our findings suggest distinct functions of AnxA6 isoforms in membrane dynamics.

Nelfinavir induces liposarcoma apoptosis and cell cycle arrest by upregulating sterol regulatory element binding protein-1

"HIV protease-induced lipodystrophy syndrome" is associated with the use of HIV protease inhibitors for treatment of HIV infection. In-vitro studies suggest that alteration of sterol regulatory element binding protein-1 levels underlie its pathogenesis. We postulated that HIV protease inhibitors may represent a novel class of antiliposarcoma agents. SW872, FU-DDLS-1 and LiSa-2 liposarcoma, and HT1080 and 293 nonliposarcoma cell lines were treated with HIV protease inhibitors (nelfinavir, ritonavir, saquinavir, indinavir and amprenavir), and clonogenic assays were performed. Nelfinavir exhibited the most potent inhibition of clonogenicity, and further assays for proliferation, cell cycle and apoptosis were performed with nelfinavir. Immunoblots were performed for sterol regulatory element binding protein-1, proapoptotic and cell cycle-related protein expression after nelfinavir treatment. Finally, a sterol regulatory element binding protein-1-inducible SW872 cell line was developed to examine the phenotype resulting from upregulated sterol regulatory element binding protein-1. Nelfinavir selectively inhibited clonogenicity and proliferation, and induced G1 cell cycle block and induced apoptosis in a dose-dependent manner in SW872 and LiSa-2 cells, whereas it had minimal or no effect on these parameters in FU-DDLS-1 or nonliposarcoma cells. Nelfinavir induced significant sterol regulatory element binding protein-1 expression in a dose-dependent and time-dependent fashion in sensitive SW872 and LiSa-2 cells, modestly in HT1080 cells, but not in nelfinavir-insensitive FU-DDLS-1 and 293 cells without inducing adipocytic differentiation. Forced expression of sterol regulatory element binding protein-1 in inducible-SW872 cells led to the induction of proapoptotic and antiproliferative proteins, and consequent reduction of cellular proliferation. Our data indicate that nelfinavir represents a novel class of antiliposarcoma agent that acts by selectively upregulating sterol regulatory element binding protein-1 expression in liposarcomas.

Primary breast cancer phenotypes associated with propensity for central nervous system metastases

BACKGROUND

There is anecdotal evidence that the incidence of central nervous system (CNS) metastases in breast cancer patients is increasing. It is unclear whether specific tumor biological properties or the use of systemic therapies influence this risk.

METHODS

Using a database of 10,782 patients, 2685 patients were identified who experienced recurrence distantly. Clinical and biological features were analyzed in 2 ways: (1) patients who ever had versus those who never had CNS metastases, and (2) CNS metastases as the first site of recurrence versus those who had other sites. Correlations of survival after CNS metastasis with clinical and biologic features were also analyzed.

RESULTS

In the ever versus never analysis, CNS metastases were significantly associated with younger age, premenopausal status, infiltrating ductal carcinoma histology (IDC), estrogen receptor (ER) and progesterone receptor (PR) negativity, low Bcl-2, high S-phase, aneuploidy, and altered p53. Tumor size, lymph node status, and use of adjuvant systemic therapy played little role. HER-2 overexpression was not associated with an increased risk in these patients (none of whom were treated with trastuzumab) (P = .91). However, epidermal growth factor receptor (EGFR) overexpression was associated with increased risk (P = .02). A multivariate analysis revealed ER negativity (odds ratio [OR] 2.8, P < .001), IDC histology (OR 2.5, P = .02), and young age (P < .001) as independent factors for CNS metastases. The clinical and biologic profiles of primary tumors with CNS metastases at first recurrence did not differ from those with CNS metastases after recurrence to other sites, except for HER-2 status. HER-2-positive tumors were not more likely to undergo recurrence initially in the CNS (P =.04). The median survival after CNS metastases was 5.5 months and HER-2-positive patients had a shorter survival.

CONCLUSIONS

Younger patients with hormone receptor-negative, highly proliferative, genomically unstable, and p53-altered tumors were at increased relative risk for CNS metastases. HER-2 expression and adjuvant systemic therapies did not increase this risk.

Prognostic/Predictive Factors in Breast Cancer

This can be an exciting time for pathologists and cytopathologists as we refine or knowledge of prognostic/predictive factors in breast cancer. We can become more visible in our role as consultants to the other physicians, and more engaged in our role as re-searchers. Recent advances in computer science, coupled with the availability of new biological markers, now provide unique opportunities for us to expand our diagnostic abilities and also predict the biologic behavior of a given tumor. Thus, we must become more familiar with emerging concepts and technologies in different disciplines.

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.

Biennial Versus Annual Mammography and the Risk of Late-Stage Breast Cancer

BACKGROUND

Mammography screening may reduce breast cancer mortality by detecting cancers at an earlier stage. However, certain questions remain, including the ideal interval between mammograms.

METHODS

We conducted an observational study using information collected by seven mammography registries across the United States to investigate whether women diagnosed with breast cancer after having screening mammograms separated by a 2-year interval (n = 2440) are more likely to be diagnosed with late-stage disease (positive lymph nodes or metastases) than women diagnosed with breast cancer after having screening mammograms separated by a 1-year interval (n = 5400). Analyses were stratified by age and breast density to clarify whether groups that have the poorest mammography sensitivity (i.e., women under age 50 years and those with mammographically dense breasts) would benefit most from annual screening. The subjects were women diagnosed with breast cancer between 1996 and 2001 who were 40-89 years old at their index mammographic examination (i.e., the most recent screen at or before breast cancer diagnosis). Data were analyzed by logistic regression, adjusting for race, ethnicity, family history of breast cancer, and mammography registry.

RESULTS

Among women age 40-49 years at the index mammogram, those with a 2-year screening interval were more likely to have late-stage disease at diagnosis than those with a 1-year screening interval (28% versus 21%; odds ratio [OR] = 1.35, 95% confidence interval [CI] = 1.01 to 1.81). There was no increase in late-stage disease for women 50 years or older with a 2-year versus a 1-year screening interval (women age 50-59 years at index mammogram: OR = 0.97, 95% CI = 0.75 to 1.25; women age 60-69 years at index mammogram: OR = 0.99, 95% CI = 0.72 to 1.35; women age 70 years or older at index mammogram: OR = 0.88, 95% CI = 0.64 to 1.19). There was no indication that women with dense breasts would benefit more from a 1-year versus 2-year screening interval than women with fatty breasts.

CONCLUSION

These findings may be useful for policy decisions about appropriate screening intervals and for use in statistical models that estimate the costs and benefits of mammography by age and screening interval.

Hormonal Factors and Breast Tumor Proliferation: Do Factors that Affect Cancer Risk also Affect Tumor Growth?

BACKGROUND

Tumor cell proliferation is one of the most significant predictors of prognosis for women with breast cancer. Personal characteristics that affect hormonal exposure have been implicated in breast tumor etiology, and it is possible that they may also influence tumor cell proliferation. We examined the association between hormone-related breast cancer risk factors and breast tumor proliferation, as reflected in two proliferation measures, Ki-67 and mitotic count.

METHODS

The study population was 484 women 40 years of age and older, who were members of a managed care organization's breast cancer screening program and were diagnosed with invasive breast cancer between 1988 and 1995. The percent of Ki-67 positive tumor cells averaged over four high powered fields (Ki-67) was log transformed and analyzed in a linear regression model. Mitotic count was dichotomized into high versus low (<or=10), and analyzed in an unconditional logistic regression model with the odds ratio (OR) as the measure of association.

RESULTS

Consistent with other studies, there was a significant trend of decreased tumor cell proliferation with increasing age ( p for trend <0.05 for both measures). Higher body weight was associated with higher Ki-67 ( p for trend <0.05), but not with higher mitotic count. We found no significant associations between any reproductive factors (age at menarche, parity, age at first birth, menopausal status and age at menopause) and either measure of tumor cell proliferation. We observed an association between reduced tumor proliferation, as measured by mitotic count and former/current use of hormone replacement therapy (HRT) in comparison to never use (adjusted OR's: former HRT use: 0.40 (95% CI 0.19-0.85); current HRT use: 0.52 (95% CI 0.26-1.04).

CONCLUSION

Certain factors related to hormonal exposure that influence breast tumor etiology, for example, age, also appear to increase tumor growth. Conversely HRT use, which clearly increases breast cancer risk, may not adversely affect, and possibly may diminish cell proliferation once tumors are established.

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.

Gadd153 restores resistance to radiation-induced apoptosis after thiol depletion

It has been demonstrated that depletion of cellular thiols in lymphoma cells leads to an increased susceptibility of the cells to radiation-induced apoptosis. To elucidate the responsible mechanisms we used cDNA array hybridization to screen for differences in gene expression induced by thiol depletion. Among other genes we found the transcription factor Gadd153 to be upregulated after exposing the cells to cystine/methionine free culture medium. To study the functional consequences of this upregulation, cells constitutively expressing high levels of Gadd153 were generated by transfection. We found that overexpression of Gadd153 slightly reduced the amount of radiation-induced apoptosis in cells kept in normal medium but very significantly reduced apoptosis (from 55% to 18%) in cells which were treated with cystine/methionine free culture medium. The observed protective effect of Gadd153 against radiation-induced apoptosis in thiol depleted lymphoma cells argues for an anti-apoptotic function of Gadd153 after perturbation of the cellular redox state.

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.

Cyclo-oxygenase-2 (COX-2) mRNA expression correlates with progesterone receptor positivity in human breast cancer

BACKGROUND

We previously presented evidence showing that cyclo-oxygenase 2 (COX-2) plays an important role in mammary carcinogenesis and angiogenesis in human breast cancer. The present study aims to compare COX-2 mRNA expression with hormone receptor status, S-phase fraction, telomerase activity, and DNA ploidy in human breast cancer.

METHODS

Total cellular RNA was extracted from frozen breast tissue samples according to standard methodology. The mRNA copy numbers for COX-2 were determined in 18 infiltrating carcinomas using quantitative RT-PCR and TaqMan methodology. The oestrogen receptor (ER) and progesterone receptor (PgR) status was determined using the ligand-binding technique (ER+ = > 3 fmol/mg, PgR+ = > 5 fmol/mg). We also determined DNA ploidy status (diploid or aneuploid), S-phase fraction (< 6% = low, 6-10% = intermediate, > 10% = high), and telomerase activity (total protein generated by TRAP assay).

RESULTS

The median COX-2 mRNA copy number per micro g of RNA was 126 713 (range = 15 717-2 022 050). COX-2 expression was significantly associated with PgR positivity (p = 0.013). The association between COX-2 and DNA diploidy failed to reach a statistical significance (p = 0.085). No significant association was detected between COX-2 and S-phase fraction, ER status, or telomerase activity.

CONCLUSIONS

COX-2 mRNA expression is associated with PgR positivity in human breast cancer. This observation is consistent with the hypothesis that COX-2 upregulates aromatase activity.

Flow cytometry in primary breast carcinomas: prognostic impact of multiploidy and hypoploidy

BACKGROUND

The aims of the present work were to study the prognostic impact of multiploidy and/or hypoploidy in breast cancers and their relation to other classic clinicopathologic prognostic factors (T, grade, receptors, and lymph node status).

METHODS

From 3 January 1990 to 7 January 1999, 1984 previously untreated, invasive breast carcinoma samples were snap frozen for flow-cytometry.

RESULTS

Multiploid tumors had the same prognosis as the aneuploid ones, and those with one hypoploid peak had a better prognosis than did the other aneuploid tumors. However, the presence of both multiploid and hypoploid peaks was correlated with a poor outcome, even after multivariate analysis. In this series after quality control, 93.4% of the histograms could be evaluated concerning ploidy; of these 81.6% could be assessed concerning S-phase fraction (SPF) in the entire population and 77.1% in the multiploid population. In the entire population, we performed a multivariate analysis including all relevant prognostic factors remaining after monovariate analysis by using a compound factor (proliferative activity) regrouping SPF and mitotic activity. This analysis showed that lymph node status and proliferative activity correlates with every type of survival, whereas receptor status correlates with all types of survival except recurrence free survival size, correlated with non-metastasis and overall survival. Grade and age correlated only with overall survival and vascular permeations only with disease-free survival.

CONCLUSIONS

SPF is a valuable predictor of survival, can be confidently assessed in multiploid histograms, and thus improves the yield of flow cytometry. When combined with mitotic activity, the prognostic impact of SPF is the same as that of lymph node status. Tumors that are hypoploid and multiploid have a significantly worse prognosis.

Progesterone receptor status significantly improves outcome prediction over estrogen receptor status alone for adjuvant endocrine therapy in two large breast cancer databases

PURPOSE

To determine whether progesterone receptor (PgR) status provides additional value to estrogen receptor (ER) status and improves prediction of benefit from endocrine treatment among patients with primary breast cancer.

PATIENTS AND METHODS

Clinical outcomes of patients in two large databases were analyzed as a function of steroid receptor status. The first database (PP), contained 3,739 patients who did not receive any systemic adjuvant therapy and 1,688 patients who received adjuvant endocrine therapy but no chemotherapy. The second database (SPORE), contained 10,444 patients who received adjuvant endocrine therapy but no chemotherapy. Biochemical ER and PgR assays were identically performed in two different central laboratories.

RESULTS

In univariate and multivariate analyses, the prognostic significance of PgR status among systemically untreated patients is modest. Among endocrine-treated patients, however, multivariate analyses, including lymph-node involvement, tumor size, and age, demonstrate that PgR status is independently associated with disease-free and overall survival. For recurrence, the reduction in relative risk (RR) was 25% for ER-positive/PgR-negative patients and 53% for ER-positive/PgR-positive patients, compared with ER-negative/PgR-negative patients (P <.0001, PP patients). Patients with ER-positive/PgR-negative tumors have a reduction in RR of death of 30% (SPORE patients) and 38% (PP patients), compared with patients with ER-negative/PgR-negative tumors (P <.0001). For ER-positive/PgR-positive tumors, the reduction of the risk of death was greater than 46% in SPORE patients and 58% in PP patients, indicating that ER-positive/PgR-positive patients derive more benefit from endocrine therapy (P <.0001).

CONCLUSION

When accurately measured, PgR status is an independent predictive factor for benefit from adjuvant endocrine therapy. Therefore, PgR status should be taken into account when discussing RR reductions expected from endocrine treatment with individual patients.

Flow cytometry and quantitative immunohistochemical study of cell cycle regulation proteins in invasive breast carcinoma: prognostic significance

BACKGROUND

Between January 11, 1991 and January 8, 1992, 104 patients with previously untreated, invasive, primitive breast carcinoma were admitted to the authors' hospital.

METHODS

For each patient, flow cytometry DNA analyses on frozen samples and on immunohistochemical staining were performed, including Ki-67, cyclin A, p53, and p21(waf1) (p21), with assessment of the percentages of positive nuclei were assessed. Correlations with classic clinicopathologic data and survival (overall, metastasis free, or recurrence free) and a multivariate analysis were performed.

RESULTS

After a multivariate analysis according to a Cox model that was stratified by age, tumor size, tumor grade, lymph node status, and receptor status, among the factors studied, the presence of p21 was the unique remaining prognostic factor for patients with invasive breast carcinoma. Because of the lack of a correlation between p21 and proliferative factors (Ki-67, S-phase, and cyclin A), the authors combined p21 with those markers and found that, for the different combinations, after statistical analysis, only p21 combined with S-phase or with cyclin A and lymph node status were salient survival prognostic factors.

CONCLUSIONS

Immunohistochemical study of proteins involved in the cell cycle and assessment of proliferative activity using flow cytometric DNA analysis aided the authors in singling out correlations of cyclin A and S-phase, along with p21, with metastasis free survival and overall survival in patients with invasive breast carcinoma. These promising results will require confirmation in a larger series of patients.

Diversity in expression and prognostic significance of G1/S cyclins in human primary lung carcinomas

Expression of cyclin A, cyclin E and cdk2 was examined immunohistochemically in 144 cases of primary non-small cell lung carcinoma to evaluate their prognostic value. Cyclin A was co-expressed with cdk2 in the proliferating cells, ie those showing positive Ki-67 staining. The labelling index (LI) of cyclin A revealed a positive correlation with the S-phase fraction and an inverse correlation with histological differentiation. Furthermore, high cyclin A LIs indicated a poor prognosis in all histological types. Cyclin E exhibited a characteristic staining pattern: in squamous cell carcinoma (SCC), differentiated cells without Ki-67 staining revealed cyclin E positivity with expression of cdk2. Conversely, in adenocarcinoma (AC), proliferating cells revealed cyclin E positivity. Cases of large cell carcinoma showed heterogeneous cyclin E staining patterns, unlike those of SCC or AC. Statistical analyses also revealed a marked contrast between SCC and AC. In AC, the LI of cyclin E was inversely correlated with histological differentiation and a high LI predicted a worse prognosis. In contrast, in SCC, the LI of cyclin E correlated positively with histological differentiation and better prognosis. However, the expression levels of cyclin E mRNA evaluated by quantitative RT-PCR were higher in poorly differentiated SCC and AC, suggesting that protein turnover plays a large role in determining cyclin E protein levels. Although the expression of cyclins was demonstrated to be diversely regulated depending on the histological type, the combined immunohistochemical analyses performed in this study on these proteins could be useful tools for evaluating patient prognosis in lung carcinomas.

Computer-generated nuclear features compared with axillary lymph node status and tumor size as indicators of breast cancer survival

The extent to which malignant cells deviate from normal is generally accepted to be a prognostic indicator. However, assessing the degree of deviation has been subjective and poorly reproducible. Our goal is to develop a computer program for objectively measuring nuclear size, shape, and texture from histologic slides and to make the program available on the Internet. We used this program to analyze 353 histologic sections obtained from patients with invasive breast cancer who were diagnosed and treated from 1981 through 1995 and who had determinable outcomes. The median follow-up was 8.3 years. We compared the relationship of survival with our computer-derived nuclear features versus axillary lymph node status and tumor size. We believe that our results are generally applicable because our patient survival, when stratified by lymph node status, was similar to that of the 24,000 breast cancer patients in the National Cancer Institute's Surveillance, Epidemiology, and End Results program. In multivariate analysis, the strongest prognostic factor was the largest nuclear area, followed by tumor size and the extent of axillary lymph node involvement. The mean area of the 3 largest nuclei when combined with tumor size identified 30% of all breast cancer patients who had an 87% 15-year breast cancer-specific survival. Inclusion of lymph node status added little to this 2-factor model. Routine axillary lymph node surgery for prognostic purposes may become unnecessary, because nuclear features may provide sufficient information.

Adjuvant chemotherapy with doxorubicin and cyclophosphamide in women with rapidly proliferating node-negative breast cancer

This prospective clinical trial was designed to assess the impact of adjuvant chemotherapy in women with rapidly proliferating node-negative breast cancer. This group has been predicted to have a 5-year disease-free survival (DFS) of 70% without adjuvant chemotherapy. In this study, 449 women with rapidly proliferating breast cancer (91% measured by S-phase fraction and 9% by histochemistry) received adjuvant chemotherapy with doxorubicin/cyclophosphamide (AC) plus tamoxifen for estrogen receptor-positive or progesterone receptor-positive cancer. The 5-year DFS was 90% (+/- 2%) and the 5-year overall survival was 94% (+/- 1%). At a median follow-up of 62 months, the strategy of administering 6 cycles of AC to women with T2 N0 cancer and 3 cycles in those with smaller T1 N0 cancers appeared to eliminate tumor size as a potential prognostic factor. Adjuvant chemotherapy with AC appears effective in reducing recurrence rates for women with rapidly proliferating node-negative breast cancer.

Adenoid cystic carcinoma of the breast: molecular markers, treatment, and clinical outcome

BACKGROUND

The objective of this study was to comprehensively characterize the clinical and biologic features of adenoid cystic carcinoma (ACC) and to assess the implications for management in a large cohort of patients.

METHODS

From a database of 50,000 patients, 28 were identified with ACC for which clinical follow-up and biologic information was available. The biologic features examined included estrogen receptor and progesterone receptor status, DNA ploidy, and S-phase fraction. Median follow-up was 83 months with a range of 29 to 144 months. Overall survival and disease free survival curves were drawn using Kaplan and Meier estimates and were compared by the log-rank test.

RESULTS

All but one patient were postmenopausal with a median age at diagnosis of 66 years (range, 40-96 years). One patient had macroscopic metastatic disease at diagnosis. Median tumor size was 1.9 cm (range, 0.5-7.0 cm). Axillary lymph node dissection was performed in 23 patients. Only 1 patient (4%) had histologic positive lymph nodes (2 of 10), and no recurrence was detected for this patient. Forty-six percent were ER positive (median, 16 fmol/mg protein; range, 5-1017 fmol/mg), and 35% were PgR positive (median, 61 fmol/mg protein; range, 6-854 fmol/mg). S-phase fraction and DNA ploidy were assessable in 24 cases. Ninety percent of tumors had low S-phase (median, 3.3%; range, 0.1-34.2%), and 92% were diploid. Simple or modified radical mastectomy was performed in 22 patients, and 6 patients were treated by lumpectomy. Five of these six patients also received radiation therapy after lumpectomy. Despite the different surgical approaches, there were no local recurrences. The 5-year disease free survival rate was 100%, and the 5-year overall survival rate was 85% (95% confidence interval, 71.7-98.6%).

CONCLUSIONS

Adenoid cystic carcinomas of the breast have very favorable biologic characteristics and, consistent with this, an excellent prognosis. Good local control can be achieved by lumpectomy with radiation or by simple mastectomy. Axillary lymph node dissection is not helpful in clinical management.

CDK-inhibitors-associated kinase activity: a possible determinant of malignant potential in smooth muscle tumors of the external soft tissue

There has been accumulating histological observation of leiomyoma and leiomyosarcoma of the external soft tissue regarding their differential diagnosis. The definitive diagnostic tools have not been established, however, nor have the pathological mechanisms of cell proliferation in these tumors been clarified. Herein, expression of the cyclin-dependent kinase inhibitors (CKIs), p21, p27 and p57 and their associated kinase activities were examined in 61 cases of soft tissue smooth muscle tumors. Immunohistochemical staining showed that all 3 inhibitor proteins were expressed in all cases of leiomyoma and leiomyosarcoma, but that the mean values of their labeling indices (LIs) were higher in the cases of leiomyosarcoma. In addition, the LIs of p21 and p27 were inversely correlated in total cases. Immunoblotting revealed that these proteins are expressed at higher levels in tumors, in particular, in leiomyosarcoma. When CKIs were immunoprecipitated from tissue extracts, cyclin/cdk protein complexes associated with, at least, 1 CKI were detectable only in tumor tissues. Furthermore, cdk2 or cdk4 kinase activity manifested by these cyclin/cdk/CKI complexes (CKI-associated kinase activity) was detectable exclusively from leiomyosarcoma, but not from leiomyoma. Among the cases of leiomyosarcoma, cdk2 activity was generally found associated either with p21 or p27, but not both. Statistical analysis indicated that p21- and p27 LIs are predictive of positive or negative clinical outcome, respectively. In conclusion, the participation of CKIs in active cyclin/cdk complexes in a reciprocal and redundant manner and subsequent CKI- associated kinase activity are the characteristic profiles of malignant phenotype in these tumors. Moreover, immunohistochemical detection of CKIs may provide a useful tool for evaluating patients' prognosis.

Doublet discrimination in DNA cell-cycle analysis

Differences in doublet analysis have the potential to alter DNA cell-cycle measurements. The techniques for doublet determination are often used interchangeably without regard for the complexity in cell shapes and sizes of biological specimens. G(0/1) doublets were identified and quantitated using fluorescence height versus area and fluorescence width versus area pulse measurements, by enumerating the proportion of G(2) + M cells that lack cyclin B1 immunoreactivity, and modeled in the DNA histograms by software algorithms. These techniques were tested on propidium iodide-stained whole epithelial cells or nuclei from asynchronous cultures, or after exposure to chemotherapeutic agents that induced cell-cycle arrest and were extended to human breast tumor specimens having DNA diploid patterns. G(0/1) doublets were easily discernible from G(2) + M singlets in cells or nuclei that are generally homogenous and spherical in shape. Doublet discrimination based on pulse processing or cyclin B1 measurements was nonconcordant in some nonspherical cell types and in cells following cell cycle arrest. Significant differences in G(0/1) doublet estimates were observed in breast tumor specimens (n = 50), with estimates based on pulse width twice those of pulse height and nearly five times greater than computer estimates. Differences between techniques are attributed to difficulties in the separation of the boundaries between G(0/1) doublets and G(2) + M singlet populations in biologically heterogeneous specimens. To improve reproducibility and enhance standardization among laboratories performing cell cycle analysis in experimental cell systems and in human breast tumors, doublet discrimination analysis should best be accomplished by computer modeling. Shape and size heterogeneity of tumor and arrested cells using pulse-processing can lead to errors and make interlaboratory comparison difficult.

Optimizing flow cytometric DNA ploidy and S-phase fraction as independent prognostic markers for node-negative breast cancer specimens

Developing a reliable and quantitative assessment of the potential virulence of a malignancy has been a long-standing goal in clinical cytometry. DNA histogram analysis provides valuable information on the cycling activity of a tumor population through S-phase estimates; it also identifies nondiploid populations, a possible indicator of genetic instability and subsequent predisposition to metastasis. Because of conflicting studies in the literature, the clinical relevance of both of these potential prognostic markers has been questioned for the management of breast cancer patients. The purposes of this study are to present a set of 10 adjustments derived from a single large study that optimizes the prognostic strength of both DNA ploidy and S-phase and to test the validity of this approach on two other large multicenter studies. Ten adjustments to both DNA ploidy and S-phase were developed from a single node-negative breast cancer database from Baylor College (n = 961 cases). Seven of the adjustments were used to reclassify histograms into low-risk and high-risk ploidy patterns based on aneuploid fraction and DNA index optimum thresholds resulting in prognostic P values changing from little (P < 0.02) or no significance to P < 0.000005. Other databases from Sweden (n = 210 cases) and France (n = 220 cases) demonstrated similar improvement of DNA ploidy prognostic significance, P < 0.02 to P < 0.0009 and P < 0.12 to P < 0.002, respectively. Three other adjustments were applied to diploid and aneuploid S-phases. These adjustments eliminated a spurious correlation between DNA ploidy and S-phase and enabled them to combine independently into a powerful prognostic model capable of stratifying patients into low, intermediate, and high-risk groups (P < 0.000005). When the Baylor prognostic model was applied to the Sweden and French databases, similar significant patient stratifications were observed (P < 0.0003 and P < 0.00001, respectively). The successful transference of the Baylor prognostic model to other studies suggests that the proposed adjustments may play an important role in standardizing this test and provide valuable prognostic information to those involved in the management of breast cancer patients.

Codon 89 polymorphism in the human 5 alpha-reductase gene in primary breast cancer

The enzyme human steroid 5-alpha reductase type II (SRD5A2) and androgen receptor (AR) are critical mediators of androgen action, suggesting a potential role in hormonally related cancers. The SRD5A2 gene harbours two frequent polymorphic sites, one in the coding region, at codon 89 of exon 1, where valine is substituted by leucine (V89L) and the other in the 3' untranslated region (3' UTR) where a variable number of dinucleotide TA repeat lengths exists. The V89L polymorphism is known to alter the activity of this enzyme. In the present study we examined 144 sporadic breast tumours from Italian patients for the V89L and TA polymorphisms by sequence and fragment analysis, respectively. Tumour extract prostate specific antigen (PSA) concentration as well as a number of well-established clinical and pathological parameters were evaluated. The results show that 53% of the tumours were homozygous for VV alleles, 37% were heterozygous for VL alleles and 10% were homozygous for LL alleles. TA(0) repeats were found in tumours with VV, LL and VL genotypes. TA(9) repeats were only found in VV homozygotes and were totally absent from either LL homozygotes or VL heterozygotes. PSA expression was significantly elevated in tumours with VV genotype. The presence of LL alleles in breast tumours is associated with earlier onset and shorter disease-free (RR = 2.65;P = 0.013) and overall survival (RR = 3.06;P = 0.014) rates. The VV genotype is associated with a more favourable prognosis. Our study suggests that the polymorphism in codon 89 of exon 1 of the human 5 alpha-reductase gene is related with TA repeat genotypes, PSA expression and breast cancer prognosis. More specifically, we found that the LL genotype is also associated with earlier onset and more aggressive forms of breast cancer. Long-term-outcome studies are needed to investigate the relevance of this polymorphism to breast cancer susceptibility.

Two-color, cytokeratin-labeled dna flow cytometric analysis of 332 breast cancers: lack of prognostic value with 12-year follow-up

CONTEXT

DNA flow cytometry of breast cancer is a proposed tumor marker of prognostic significance that is of controversial clinical utility because of lack of standardization and confirmatory studies.

OBJECTIVE

To evaluate the prognostic significance of the more informative technique of multiparametric 2-color DNA flow cytometry as recommended by the 1992 DNA Cytometry Consensus Conference.

DESIGN

Three hundred thirty-two breast carcinomas with 7 to 12 years of follow-up were prospectively analyzed as fresh tumors that were mechanically dissociated into whole cell suspensions. These suspensions were dual fluorescence-labeled with propidium iodide (DNA) and antibodies to cytokeratin (epithelium) and leukocyte common antigen (internal leukocyte control) for gated analysis of subpopulations. Multicycle software with histogram-dependent algorithms employing background, aggregate, and debris correction were used in DNA and cell-cycle quantitation. Data were analyzed according to the DNA Flow Cytometry Consensus Conference recommendations.

RESULTS

DNA ploidy and proliferation stratified into 3 categories were not predictive of overall or disease-free survival. Sixty-five percent of tumors were nondiploid, and 35.4% were diploid. Two hundred six tumors were able to be evaluated for synthesis-phase fraction (SPF) analysis, with 74 of 206 cases in the low range (<13.4%), 36.4% in the intermediate range (>13.5 to <25.4%), and 27.6% in the high SPF (>25.5%) category. Aneuploid tumors tended to have a higher SPF. Univariate survival analysis showed prognostic significance of the following: tumor size, stage, TNM components, vascular invasion, nuclear grade, and histologic grade. Only T classification, presence of positive axillary lymph nodes, and distant metastases were significant independent predictors of survival in multivariate Cox regression models. Age and hormone receptor status showed no prognostic significance. Synthesis-phase fraction was significantly correlated with tumor size, stage, T classification, nuclear and histologic grade, presence of estrogen or progesterone receptors, and axillary lymph node status. None of the histologic parameters showed any significant association with DNA aneuploidy, except for high nuclear and histologic grade and the absence of estrogen receptors.

CONCLUSIONS

Despite the use of state-of-the-art processing and flow cytometry analytic techniques, DNA ploidy and proliferation measurements were not predictive of survival in any stage of breast cancer. However, select histopathologic parameters and TNM stage were significant predictors of survival in univariate and multivariate analyses. We conclude that DNA ploidy and proliferation measurements do not provide significant prognostic information for clinicians to integrate into therapeutic decision making for patients with breast cancer.

MIB-1 index, S-phase fraction, mitotic figure count, and SBR histologic grading in invasive breast carcinoma: a comparative study

Proliferative activity has been proven to be of prognostic significance in breast carcinoma. This study was performed to compare the different proliferative fractions in the Egyptian population and to define the most suitable one for daily routine use in our surgical pathology laboratories. The proliferative activity of 63 invasive ductal carcinomas was evaluated by immunohistochemical staining of paraffin-embedded tissue sections with MIB-1 rabbit polyclonal antibody and the heat-induced epitope retrieval method, flow cytometric determination of the S-phase fraction (SPF) on frozen tissues, and estimation of the Scarff-Bloom-Richardson (SBR) grading and mitotic figure count (MFC) on hematoxylin and eosin-stained tissue sections. Fifty-two percent of invasive ductal carcinoma were aneuploid. The mean values of MIB-1 index, SPF, and MFC were 17.7 +/- 12.3, 4.9 +/- 3.8, and 5.2 +/- 4.5, respectively, for diploid tumors; while for aneuploid tumors, they were 58.6 +/- 31.9, 19.9 +/- 12.2, and 23.1 +/- 16.9, respectively. These values were significantly higher in aneuploid versus diploid tumors (p < 0.0001). A close correlation was found between MIB-1 index, SPF, MFC, and SBR grading (p < 0.0001). In conclusion, in surgical pathology laboratories that cannot afford the costs of flow cytometry and/or immunostaining, proper SBR grading and MFC can provide an estimation of the proliferation fraction similar to the flow cytometric SPF and MIB-1 immunostaining.

DNA ploidy analyses in 218 consecutive Pakistani breast cancer patients: does it add anything?

An analysis was made to evaluate the significance of DNA ploidy in the biology and prognosis of breast carcinoma. This was done by estimating the correlation of DNA ploidy with other established prognostic markers of breast cancer, namely tumor size, tumor grade, lymph node metastasis and S-phase fraction. From 1995 up to year 2000 ploidy analysis was performed on 218 consecutive cases of infiltrating breast carcinoma by flow cytometry using formalin fixed paraffin embedded material. From the laboratory record, data regarding other pathological variables was retrieved. No correlation could be found between DNA ploidy and tumor grade, nor could there be found a correlation with tumor size. For lymph node metastasis there was a significant difference between the proportion of aneuploids and diploids having metastasis in more than 4 lymph nodes. However, no significant difference was found in axillary lymph node positive and negative groups when number of positive lymph nodes was not taken into account. The mean value of S-phase fraction for the aneuploids and the diploids was also insignificantly different. In conclusion DNA ploidy alone did not add much to predict tumor behaviour in terms of known pathologic variables.

Low proliferative rate of invasive node-negative breast cancer predicts for a favorable outcome: a prospective evaluation of 669 patients

This study was designed to compare outcome in terms of disease-free survival (DFS) in women with histologically negative axillary lymph nodes and documented low proliferative rate cancer to other well-defined prognostic factors including type of adjuvant treatment. Between 1988 and 1998, we studied 669 patients with invasive node-negative breast cancer up to 5 cm in size and low proliferative rate measured by flow cytometry to determine S-phase fraction (SPF) or by histochemistry (Ki67/MIB1). At a median follow-up of 53 months, 5-year DFS for the entire group was 94% and did not differ significantly by type of systemic adjuvant treatment: none (133 patients, 95% DFS), tamoxifen (441 patients, 94% DFS), or chemotherapy with doxorubicin and cyclophosphamide (95 patients, 92% DFS). In a multivariate prognostic factor analysis, only tumor size was significant; 5-year DFS was 96% for T1N0 cancer versus 89% for T2N0 cancer (P = 0.01). We have prospectively confirmed that a low rate of proliferation as measured by SPF or MIB1 determination confers an excellent prognosis in invasive node-negative breast cancer up to 5 cm in size, regardless of adjuvant treatment.

Flow cytometric analysis of primary tumors and their corresponding metastatic nodes in breast cancer

Human breast carcinoma is biologically heterogeneous, and its clinical course may vary from one which is indolent to one which rapidly progresses. Although it is the metastasis rather than the primary tumor that ultimately overwhelms the patients, studies concerning the DNA pattern have focused on the primary tumors. This study was undertaken to identify heterogeneities between primary tumors and metastases, and to evaluate the prognostic significance of the ploidy pattern and the S-phase fraction (SPF) of metastatic nodes in axillary node positive patients. Seventy-four frozen specimens of the primary and corresponding metastatic nodes from 37 patients have been analyzed by flow cytometry and the SPF calculated. The results of ploidy pattern analysis in primaries revealed 25 diploidy (67.6%) and 12 aneuploidy (32.4%), while those in metastasis showed 17 diploidy (46.0%) and 20 aneuploidy (54.0%). The aneuploidy group in metastatic nodes had the poorer histological grade (85.0% vs. 15.0%, p = 0.02), and more mean metastatic nodes (5.75 +/- 2.10 vs. 3.05 +/- 1.56, p = 0.018), and more frequent lymphatic vessel invasion (65.0% vs. 11.8%, p = 0.031) than its counterpart. Decreased expression of ER (70.6% vs. 25.0% p = 0.006) and increased expression of c-erbB2 (65.0% vs. 23.5%, p = 0.012) were observed in the aneuploidy of metastatic nodes. The group with higher SPF in metastatic nodes had more metastatic nodes (5.47 +/- 2.31 vs. 4.00 +/- 1.78, p = 0.042), and the higher incidence of lymphatic vessel invasion (57.9% vs. 22.2%, p = 0.027), and poor histological grade (71.4% vs. 37.5%, p = 0.039). In conclusion, the cell populations in metastatic nodes revealed DNA pattern which differed from that of primary tumors. The ploidy pattern and SPF in metastatic nodes might be considered as discriminate measure for risk factors in breast cancer patients with positive axillary node.

Cytogenetic analysis of invasive breast cancer: a study of 27 Asian patients

Tumor cytogenetic analysis from 27 patients with breast cancer diagnosed at the Singapore General Hospital revealed complex karyotypic aberrations in 12 cases. The study group comprised 25 women and 2 men, ranging in age from 33 to 78 years (median 52 years). Ethnic distribution consisted of 22 Chinese, 3 Malaysian, and 2 Indian patients. Pathologic assessment disclosed 24 invasive ductal, 2 invasive mucinous, and 1 mixed invasive mucinous and ductal carcinomas. Histologic grading showed 3 grade 1, 10 grade 2, and 12 grade 3 tumors; 2 cancers were not graded, because they had been subjected to prior chemotherapy. Tumor sizes ranged from 1.5 to 10 cm (median 3 cm). Eleven cases were axillary node negative, whereas the remaining 16 node-positive cancers affected as many as 3 nodes in 8 cases and 4 or more nodes in another 8. Twenty cases demonstrated estrogen-receptor positivity, and 8 cases progesterone-receptor positivity. The spectrum of cytogenetic abnormalities involved chromosomes 1, 3, 6, 7, 8, 11, 16, and 17 and ranged from gains and deletions of both long and short arms, trisomy, monosomy, and other rearrangements. There was a trend toward the presence of karyotypic abnormalities in tumors of higher grade.

Flow cytometry in primary breast carcinomas. Prognostic impact of proliferative activity

From 1990 to 1996, 607 previously untreated, node-negative, invasive breast carcinomas were sampled by a pathologist for flow-cytometric DNA analysis. The aim of the present work was to study the correlations between flow cytometric results obtained thanks to the American Consensus (AC) guidelines of 1993 and the established clinico-pathological prognostic factors (T, grade, receptors), and despite a short global follow-up (mean of 4 years), to correlate flow cytometry with the outcome of the patients. In this study S-phase fraction (SPF) correlated strongly with tumor size, histological grade, lack of steroid receptors, histological type and was together with the mitotic activity a paramount prognostic factor even after multivariate analysis. This study compared also the technical criteria proposed by the AC with our own more stringent ones and concluded that the criteria of the AC are relevant and allow, thanks to the use of tertiles in the reporting of SPF values, a comparison of values obtained by different teams. Our review of the literature, focused on series using fresh material, enabled us to show that there is a rather wide agreement concerning the relationship between SPF and prognosis most often after multivariate analysis. This despite the lack of standardization in the design of the studies (implementation of the technical steps or reporting of results). When estimated from fresh or frozen material following AC's guidelines. SPF along with mitotic activity should become a prognostic factor used in the daily practice by oncologists in the management of breast carcinomas.

Breast cancer prognostic significance of a single nucleotide polymorphism in the proximal androgen response element of the prostate specific antigen gene promoter

Prostate Specific Antigen (PSA) expression by breast epithelial cells is associated with favorable breast cancer prognosis. In preliminary studies, we found that a nucleotide variation (G-->A) at position -158 in the androgen response element (ARE-1) of the PSA promoter was present in four out of 9 breast tumors examined and in a breast carcinoma cell line. We have now determined the nucleotide composition at position -158 of DNA extracted from 148 well-characterized breast tumors and compared tumor genotype with that of controls without cancer, with tumor PSA concentration and with clinicopathological variables, overall survival and disease free survival. The G-->A base change at position -158 is a polymorphism. Allelotypes were similarly distributed in breast cancer patients and controls. The Mann-Whitney U Test showed a significantly higher tumor PSA concentration in tumors that presented a homozygous G as opposed to homozygous A genotype. Genotype at position -158 was not associated with clinicopathological variables in contingency table analysis. Univariate Cox regression models showed a 28% reduction in risk for death in patients with homozygous G genotype compared to those with homozygous A genotype (P = 0.03). However, ARE-1 genotype did not significantly add to the prognostic power in the multivariate model of overall survival. In summary, the base change at position -158 is a polymorphism that may affect breast cancer prognosis, but further studies are required to confirm this possibility and to investigate the relevance of this polymorphism in terms of breast cancer susceptibility.