乳腺微钙化促进乳腺癌骨转移的研究进展

乳腺癌是女性发病率最高的癌症,在过去的十年中,全球发病率持续上升,死亡率高居不下.最新的统计学研究表明,仅2018年,全球范围内检测出约210万乳腺癌病例,其中近63万患者死亡,因而也是女性死亡率最高的癌症[1].然而,许多癌症患者的死亡并非由于肿瘤在原发部位生长,而是在于肿瘤侵袭或转移至其他部位,其中乳腺癌最容易发生...     

PET/CT对小动物前列腺癌骨转移的观察研究

目的　探讨小动物PET/CT扫描在小鼠前列腺癌骨转移检测中的可行性。 方法　裸鼠23只,随机分为对照组2只,前列腺原位注射组、左心室注射组、胫骨腔内注射组每组各7只。分别采用前列腺原位注射、左心室内注射、胫骨腔内注射的方法建立前列腺癌骨转移动物模型。建模成功后饲养40天,原位注射及左心室注射组采用PET/CT扫描检测,胫骨腔注射组采用小动物高分辨率CT检测,对可疑的骨转移灶行解剖学观察及HE染色明确。 结果　前列腺原位注射组肿瘤细胞聚集腹腔软组织内生长,均未发现明显骨质破坏（0/7）;左心室注射组均发生皮下等软组织转移（7/7）, PET/CT检测出一例胫骨上端骨质破坏,组织学检测证实为骨转移灶(1/7);胫骨腔注射组所有动物均形成明显骨质破坏（7/7）且高分辨率CT检测见骨破坏分级良好。 结论　小动物PET/CT扫描能够良好的显示转移灶在小鼠体内的定位,且能良好的显示骨破坏情况,因此该技术在检测小动物骨转移上有着良好的可行性。     

Inhibition of RANKL blocks skeletal tumor progression and improves survival in a mouse model of breast cancer bone metastasis

Bone metastases cause severe skeletal morbidity including fractures and hypercalcemia. Tumor cells in bone induce activation of osteoclasts, which mediate bone resorption and release of growth factors from bone matrix, resulting in a “vicious cycle” of bone breakdown and tumor proliferation. Receptor activator of NF-κB ligand (RANKL) is an essential mediator of osteoclast formation, function, and survival, and is blocked by a soluble decoy receptor, osteoprotegerin (OPG). In human malignancies that metastasize to bone, dysregulation of the RANK/RANKL/OPG pathway can increase the RANKL:OPG ratio, a condition which favors excessive osteolysis. In a mouse model of bone metastasis, RANKL protein levels in MDA-MB-231 (MDA-231) tumor-bearing bones were significantly higher than tumor-free bones. The resulting tumor-induced osteoclastogenesis and osteolysis was dose-dependently inhibited by recombinant OPG-Fc treatment, supporting the essential role for RANKL in this process. Using bioluminescence imaging in a mouse model of metastasis, we monitored the anti-tumor efficacy of RANKL inhibition on MDA-231 human breast cancer cells in a temporal manner. Treatment with OPG-Fc in vivo inhibited growth of MDA-231 tumor cells in bony sites when given both as a preventative (dosed day 0) and as a therapeutic agent for established bone metastases (dosed day 7). One mechanism by which RANKL inhibition reduced tumor burden appears to be indirect through inhibition of the “vicious cycle” and involved an increase in tumor cell apoptosis, as measured by active caspase-3. Here, we demonstrate for the first time that OPG-Fc treatment of mice with established bone metastases resulted in an overall improvement in survival.     

A microfluidic 3D in vitro model for specificity of breast cancer metastasis to bone

Cancer metastases arise following extravasation of circulating tumor cells with certain tumors exhibiting high organ specificity. Here, we developed a 3D microfluidic model to analyze the specificity of human breast cancer metastases to bone, recreating a vascularized osteo-cell conditioned microenvironment with human osteo-differentiated bone marrow-derived mesenchymal stem cells and endothelial cells. The tri-culture system allowed us to study the transendothelial migration of highly metastatic breast cancer cells and to monitor their behavior within the bone-like matrix. Extravasation, quantified 24 h after cancer cell injection, was significantly higher in the osteo-cell conditioned microenvironment compared to collagen gel-only matrices (77.5 ± 3.7% vs. 37.6 ± 7.3%), and the migration distance was also significantly greater (50.8 ± 6.2 μm vs. 31.8 ± 5.0 μm). Extravasated cells proliferated to form micrometastases of various sizes containing 4 to more than 60 cells by day 5. We demonstrated that the breast cancer cell receptor CXCR2 and the bone-secreted chemokine CXCL5 play a major role in the extravasation process, influencing extravasation rate and traveled distance. Our study provides novel 3D in vitro quantitative data on extravasation and micrometastasis generation of breast cancer cells within a bone-like microenvironment and demonstrates the potential value of microfluidic systems to better understand cancer biology and screen for new therapeutics.     

Roles of osteoclasts and bone-derived IGFs in the survival and growth of human breast cancer cells in human adult bone implanted into nonobese diabetic/severe combined immunodeficient mice

Human breast cancer frequently metastasizes to bone, and effective therapies for patients with bone metastasis are required. However, the molecular mechanism for the bone metastasis of human breast cancer has not yet been fully elucidated. The present study aimed to evaluate the importance of active osteoclasts and bone-derived insulin-like growth factors (IGFs) for the survival and growth of breast cancer cells in bone. Human breast cancer cell line MCF-7 cells were injected into human adult bone (HAB) implanted into nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. The mice were then treated with recombinant human osteoclastogenesis inhibitory factor/osteoprotegerin (rhOCIF/OPG), a decoy receptor for receptor activator of NF-kappaB ligand (RANKL), or an anti-human IGF monoclonal antibody. Histomorphometric analyses revealed that both treatments significantly decreased the tumor area of MCF-7 cells in cross-sections of the implanted HAB to about 30% of the tumor area in control mice, but had no effect on the growth of subcutaneously injected MCF-7 cells. Consistent with the results for the tumor area in HAB, there were fewer osteoclasts in the implanted HAB in rhOCIF/OPG-treated mice than in vehicle-treated mice. However, treatment with the anti-human IGF monoclonal antibody had no effect on the number of osteoclasts in HAB. The results indicate that the active osteoclasts induced by RANKL and the IGFs released as a result of bone resorption by these osteoclasts play crucial roles in the survival and growth of human breast cancer cells in bone and suggest that neutralization of bone-derived IGFs will be effective in preventing the development of bone tumors in breast cancer patients.     

TPINP和ICTP检测及SPECT和CT显像在乳腺癌骨转移中的应用

目的 比较血清TPINP和ICTP检测及SPECT和CT显像对乳腺癌术后骨转移的诊断价值.方法 选取2012年1月至2014年12月经手术病理确诊的乳腺癌患者252例,进行全身骨显像扫描.SPECT使用低能高分辨准直器,患者取全身前位和后位显像,并结合常规CT扫描进行分析.检测TPINP 和ICTP采用RIA药盒,计算采用log-logit或四参数数据处理模式.结果 乳腺癌术后SPECT骨转移率为19.4%(48/252),48例骨转移患者发现病灶123个;乳腺癌术后CT骨转移率为11.9%(30/252),30例骨转移患者发现病灶53个.SPECT和CT的转移率、病灶数比较差异均有统计学意义(χ2=4.914、P<0.05和χ2=41.386、P<0.01).血清TPINP和ICTP水平在SPECT阳性组明显高于SPECT阴性组,两者比较差异均有统计学意义(t=4.609、P<0.01和t=8.799,P<0.01).结论 99Tcm-MDP全身骨显像与CT显像比较对乳癌术后骨转移有有重要的临床应用价值,具有灵敏度高、早期发现、全身成像不易漏诊的优点.TPINP作为骨形成标志物、ICTP作为骨吸收标志物能在早期出现变化,对乳腺癌术后骨转移有重要的临床应用价值.全身显像与骨转换生化标志物相互补充,乃肿瘤诊断和治疗的趋势.     

Multimodal imaging and treatment of bone metastasis

The role of molecular imaging in pre-clinical research is continuously evolving. Particularly in small animal models in biomedical research, optical imaging technologies are frequently used to visualize normal as well as aberrant cellular processes at a molecular-genetic or cellular level of function. Also in cancer metastasis research, whole body bioluminescent and fluorescent imaging techniques have become indispensable tools that allow non-invasive and real-time imaging of gene expression, tumor progression and metastasis, and response to therapeutic intervention. In this paper, we discuss the use of optical imaging strategies—either alone or in combination with CT- to study intrabone tumor growth, tumor progression and to monitor efficacy of therapeutic agents in metastatic bone disease.     

Bone metastasis: evaluation of 1100 patients with breast cancer

The aim of this study is to determine the relationship between the demographics and the clinical characteristics of breast cancer (BC) patients with bone metastasis (BM). The study included 1100 BC patients, of whom 174 had BMs and 926 had no BMs. Immunohistochemical methods were employed to understand estrogen receptor (ER)/progesterone receptor (PgR) receptor levels, Ki-67 protein levels and human epidermal growth factor receptor 2 (HER2) expression levels. Data were collected based on the hospital records of these patients, and ultrasonography or magnetic resonance imaging (MRI) results were employed for tumor localization. Positron emission tomography (PET)-computed tomography (CT) data were employed for the BM evaluation. The mean age (P = 0.067) and tumor diameter (P = 0.022) of BC cases who showed BM were significantly different from those who did not show BM. In addition, a significant relationship between the tumor diameter (P = 0.001) and axillary lymph node (ALN) number (P = 0.000) and BM was observed. The percentages of ER and PgR (r = 0.639; P = 0.000) were positively correlated, while the percentage of ER and Ki-67 protein levels (r = -0.505; P = 0.000) were negatively correlated. However, these correlations were not significant between the groups. The tumor diameter and positive ALNs may have an important role in BM of BC. There was no significant effect of ER/PgR receptor levels, Ki-67 protein levels, or HER2 expression levels in BMs of BC.     

Automated CT-based analysis to detect changes in the prevalence of lytic bone metastases from breast cancer

The spinal column is the most frequent site of bone metastasis in patients with breast cancer. It is important to understand how the pattern of vertebral lesions may be affected by the introduction of modern cancer therapies. The purpose of this study was to characterize changes in the radiological appearance of spinal column metastases over the past decade using highly automated Computed Tomography (CT) based computational analysis methods. Two case series studies were performed using CT scans of patients with confirmed spinal metastases secondary to breast cancer: Cohort A with CT scans acquired between 1998 and 2001 and Cohort B with CT scans acquired between 2004 and 2007. Diseased vertebrae were classified as lytic, blastic, or mixed based on CT scan intensity through an automated 3D computer algorithm. The relative incidence of lytic vertebral metastases decreased in comparing Cohort B to Cohort A (12% vs. 49%) with a corresponding increase in mixed lesions (51% vs. 18%) Significant associations were found between the percentage of lytic lesions in number of diseased vertebrae measured per patient and lack of bisphosphonate use (RR = 2.6) and for membership in Cohort A vs. Cohort B (RR = 5.9). This work highlights a change in the CT appearance of vertebral metastases from breast cancer during the past decade toward a lower proportion of lytic disease. Observation of patient therapies suggests that differences in radiological assessment may be linked, at least in part, to bisphosphonate use. These findings have important implications for both clinical practice and research strategies involving vertebral metastases.     

Failure of primary breast cancer neoangiogenesis to predict pattern of distant metastasis

In the present study, the primary tumor angiogenesis characteristics of 81 stage IV previously untreated breast cancers with synchronous metastasis to different distant sites (10 patients with soft tissue metastases, 31 with bone metastases, and 40 with visceral metastases) were analyzed. The primary intratumor microvessel density was assessed by immunohistochemical assay on paraffin-embedded primary tumor samples, using a monoclonal anti-CD34 antibody. The mean primary intratumor microvessel density (at 400× fields) was 78±39 (SD) microvessels per field. The microvessel density was not significantly related to the main clinical/pathological features of the tumor (age, cytohistological grade, DNA ploidy, diameter, and receptor status). The percentage of tumor cases with high primary intratumor microvessel density (cut-off median value of the series 73±39 microvessels/field) did not significantly differ in patients with bone, soft tissue, or visceral metastatic disease. Aanalysis of clinical outcome showed a significantly shorter time to progression and overall survival for patients with visceral metastases (P<0.001 and P<0.0002 by log-rank, respectively). Presence of visceral metastases was confirmed to be the only independent prognostic factor related to a worse TTP (hazard risk 2.15, 95% confidence interval 1.14–4.03, P<0.02) and overall survival (hazard risk 1.81, 95% confidence interval 0.98–3.35, P<0.06) by multivariate analysis. In conclusion, the assessment of neoangiogenesis of primary breast cancer by CD34 expression does not provide information predictive of different distant sites of metastasis. Received: 15 June 2001 / Accepted: 12 September 2001     

Identification of estrogen-responsive genes involved in breast cancer metastases to the bone

Bone metastasis is the most common metastasis in breast cancer patients. Clinical observations propose strong association between estrogen receptor (ER)-positive tumors and the development of bone metastases. We hypothesized of biologically diverse sets of hormone-dependent tumors predisposed to bone metastases and of possible role of ER-signaling pathways in the development and progression of bone metastases. We developed a novel in vitro estrogen (E2)-responsive model system, in which breast cancer cells and bone cells express high levels of either ERα or ERβ. Using co-culture approach and gene array technology we identified E2-responsive genes involved in the interaction between cancer cells and bone cells. We detected 13 genes that were altered solely by ERα and 11 genes that were regulated solely by ERβ in cancer cells. Only 5 genes were modified by both ERα and ERβ. Interestingly, the majority of genes in bone cells were altered through ERβ. Two genes, namely MacMarcks and Muc-1, whose changes in expressions in cancer cells in response to E2 were highly significant, were selected for immunohistochemical analysis using tissue microarrays of 59 infiltrating ductal carcinomas. Our results indicated that both MacMarcks and Muc-1 were expressed at high frequency in ER-positive tumors. The correlation between ERα- and ERβ-status of hormone-dependent tumors with combined expression of these two markers might suggest a more aggressive tumor phenotype associated with bone metastases. Further analysis of tissues with clinicopathological characteristics and known bone metastatic disease will indicate potential prognostic values of these and other markers in the development of bone metastases in a subgroup of “bad” hormone-dependent breast cancer. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Formation of vasculogenic mimicry in bone metastasis of prostate cancer: Correlation with cell apoptosis and senescence regulation pathways

Vasculogenic mimicry (VM) has been found in prostate cancer (PCa) as an independent marker of poor prognosis. To investigate the correlation between VM and bone metastasis in PCa, a total of 80 cases were analyzed by CD31 and PAS dual-staining as well as the follow-up data. All cases were divided into two groups: VM-positive and VM-negative (VM-pos/VM-neg). Immunohistochemical staining for investigating the expression of Casepase-3, Bcl-2/Bax, and SA-β-gal was performed. 28 of the 80 PCa cases exhibited VM structure (35.0%). The incidence of bone metastasis in the VM-pos and VM-neg was 67.9% (19/28) and 38.5% (20/52), respectively. The positive rate of Casepase-3 and Bcl-2 expression was significantly different of the two groups (Caspases-3: VM-pos 71.4%, 20/28 vs VM-neg 42.3%, 22/52; Bcl-2: VM-pos 35.7%, 10/28 vs VM-neg 65.4%, 34/52). Bcl-2/Bax ratio of the VM-pos (0.71 ± 0.22) was lower than that of the VM-pos (0.89 ± 0.13). In addition, a higher frequency of SA-β-gal was detected in VM-pos (64.29 ± 86.42) than in VM-neg (25.37 ± 72.21). Taken together, our findings demonstrate that PCa with VM has the tendency to develop bone metastasis. Activations of cell apoptosis and senescence regulation pathways may play important roles in the formation process of VM structure.     

Bone resorption increases tumour growth in a mouse model of osteosclerotic breast cancer metastasis

Osteosclerotic metastases account for 20% of breast cancer metastases with the remainder osteolytic or mixed. In mouse models, osteolytic metastases are dependent on bone resorption for their growth. However, whether the growth of osteosclerotic bone metastases depends on osteoclast or osteoblast actions is uncertain. In this study, we investigate the effects of high and low bone resorption on tumour growth in a mouse model of osteosclerotic metastasis. We implanted human breast cancer, MCF-7, cells into the tibiae of mice. Low and high levels of bone resorption were induced by osteoprotegerin (OPG) treatment or calcium deficient diet respectively. We demonstrate that OPG treatment significantly reduces tumour area compared to vehicle (0.42 +/- 0.06 vs. 1.27 +/- 0.16 mm2, P < 0.01) in association with complete inhibition of osteoclast differentiation. In contrast, low calcium diet increases tumour area compared to normal diet (0.90 +/- 0.30 vs. 0.58 +/- 0.20 mm2, P < 0.05) in association with increased osteoclast numbers (84.44 +/- 5.18 vs. 71.11 +/- 3.56 per mm2 bone lesion area, P < 0.05). Osteoblast surfaces and new woven bone formation were similarly increased within the tumour boundaries in all treatment groups. Tumour growth in this model of osteosclerotic metastasis is dependent on ongoing bone resorption, as has been observed in osteolytic models. Bone resorption, rather than bone formation, apparently mediates this effect as osteoblast surfaces in the tumour mass were unchanged by treatments. Treatment of breast cancer patients through correction of calcium deficiency and/or with anti-resorptive agents such as OPG, may improve patient outcomes in the adjuvant as well as palliative settings.     

Preventive effects of zoledronic acid on bone metastasis in mice injected with human breast cancer cells

Bisphosphonates are used routinely to reduce bone-related events in breast cancer patients with bone metastasis. We evaluated the effects of zoledronic acid, a third generation, nitrogen-containing bisphosphonate, to prevent bone metastasis in breast cancer. Zoledronic acid or vehicle alone was administered to nude mice either simultaneously or after intracardiac injection of human breast cancer MDA-MB-231 cells. Nude mice treated with zoledronic acid at early time points showed a lower incidence of bone metastases than did vehicle-treated nude mice, but these differences were not statistically significant. Only 37.5% of mice treated with zoledronic acid at the time of tumor cell inoculation developed bone metastases compared to over 51.8% of mice receiving vehicle alone (P = 0.304). Cell count of apoptosis confirmed by immunohistochemical staining in metastatic bone tissue significantly increased in the zoledronic acid-treated groups compared to non-treated group (1,018.3 vs 282.0; P = 0.046). However, metastatic tumor cells, which invade soft tissue around the bone, did not show extensive apoptosis; there were no differences between the zoledronic acid-treated and control groups. These results suggest that zoledronic acid increases apoptosis of metastatic breast tumor cells in the bone and could therefore reduce metastatic tumor burden. These results support the use of zoledronic acid to reduce the incidence of bone metastasis in breast cancer.     

Species-specific homing mechanisms of human prostate cancer metastasis in tissue engineered bone

The development of effective therapeutic strategies against prostate cancer bone metastases has been impeded by the lack of adequate animal models that are able to recapitulate the biology of the disease in humans. Bioengineered approaches allow researchers to create sophisticated experimentally and physiologically relevant in vivo models to study interactions between cancer cells and their microenvironment under reproducible conditions. The aim of this study was to engineer a morphologically and functionally intact humanized organ bone which can serve as a homing site for human prostate cancer cells. Transplantation of biodegradable tubular composite scaffolds seeded with human mesenchymal progenitor cells and loaded with rhBMP-7 resulted in the development of a chimeric bone construct including a large number of human mesenchymal cells which were shown to be metabolically active and capable of producing extracellular matrix components. Micro-CT analysis demonstrated that the newly formed ossicle recapitulated the morphological features of a physiological organ bone with a trabecular network surrounded by a cortex-like outer structure. This microenvironment was supportive of the lodgement and maintenance of murine haematopoietic cell clusters, thus mimicking a functional organ bone. Bioluminescence imaging demonstrated that luciferase-transduced human PC3 cells reproducibly homed to the humanized tissue engineered bone constructs, proliferated, and developed macro-metastases. This model allows the analysis of interactions between human prostate cancer cells and a functional humanized bone organ within an immuno-incompetent murine host. The system can serve as a reproducible platform to study effects of therapeutics against prostate cancer bone metastases within a humanized microenvironment.     

SPECT/CT 双时相99mTc- MIBI断层显像 在乳腺癌诊断中的应用

目的 探讨SPECT/CT双时相 99mTc-MIBI断层显像在乳腺癌临床中的诊断价值。 方法 选取2015 年 1 月~2017 年 5月广西柳州市中医院胸外科收治的女性乳腺疾病患者 98 例进行了术前两种检查方法的诊断,并将诊断结果记录,与术后的病理结果进行比对。结果 SPECT/CT双时相 99mTc-MIBI断层显像的敏感性94.80%、特异性90.00%、准确性93.90%,高于钼靶 X 线检查的敏感性82.10%、特异性60.00%、准确性77.60%,SPECT/CT双时相 99mTc-MIBI断层显像和钼靶 X 线检查对腋窝淋巴结转移灶的检出率分别为84.30%和59.40%,两种检查方法对乳腺癌的诊断比较均有统计学差异（P＜0.05）。 结论 99mTc- MIBI双时相断层显像对乳腺癌的诊断效能优于钼靶X线检查,有较高的实用价值。     

RANKL-induced CCL22/macrophage-derived chemokine produced from osteoclasts potentially promotes the bone metastasis of lung cancer expressing its receptor CCR4

Chemokines are now known to play an important role in cancer growth and metastasis. Here we report that differentiating osteoclasts constitutively produce CCL22 (also called macrophage-derived chemokine) and potentially promote bone metastasis of lung cancer expressing its receptor CCR4. We first examined expression of chemokines by differentiating osteoclasts. CCL22 was selectively upregulated in osteoclast-like cells derived from RAW264.7 cells and mouse bone marrow cells upon stimulation with RANKL (receptor activator of nuclear factor-κB ligand). In addition, a human lung cancer cell line SBC-5 that efficiently metastasized to bone when intravenously injected into NK cell-depleted SCID mice was found to express CCR4. Stimulation of SBC-5 cells with CCL22 induced cell migration and also enhanced phosphorylation of protein kinase B/Akt and extracellular signal-regulated kinase (ERK). Furthermore, immunohistochemical analysis of bone metastasis lesions demonstrated close co-localization of tartrate-resistant alkaline phosphatase (TRAP)-positive osteoclasts expressing CCL22 and SBC-5 cells expressing CCR4. Collectively, these results suggest that osteoclasts may promote bone metastasis of cancer cells expressing CCR4 in the bone marrow by producing its ligand CCL22.This study was supported in part by a Grant-in-Aid for Young Scientists (B) (No. 15790089), Grant-in-Aids for Cancer Research (No. 16022224 and 16023225) and a Grant-in-Aid for the 21st Century COE Program from Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, and by Solution Oriented Research for Science (SORST) of Japan Science and Technology Corporation (JST) and High-Tech Research Center Project for Private Universities: matching fund subsidy from MEXT, 2002–2006.     

Human breast cancer cell metastasis to long bone and soft organs of nude mice: a quantitative assay

Bone is a common metastatic site in human breast cancer (HBC). Since bone metastasis occurs very rarely from current spontaneous or experimental metastasis models of HBC cells in nude mice, an arterial seeding model involving the direct injection of the cells into the left ventricle has been developed to better understand the mechanisms involved in this process. We present here a sensitive polymerase chain reaction (PCR) method to detect and quantitate bone and soft organ metastasis in nude mice which have been intracardially inoculated with Lac Z transduced HBC cells. Amplification of genomically incorporated Lac Z sequences in MDA-MB-231-BAG HBC cells enables us to specifically detect these cells in mouse organs and bones. We have also created a competitive template to use as an internal standard in the PCR reactions, allowing us to better quantitate levels of HBC metastasis. The results of this PCR detection method correlate well with cell culture detection from alternate long bones from the same mice, and are more sensitive than gross Lac Z staining with X-gal or routine histology. Comparable qualitative results were obtained with PCR and culture in a titration experiment in which mice were inoculated with increasing numbers of cells, but PCR is more quantifiable, less time consuming, and less expensive. This assay can be employed to study the molecular and cellular aspects of bone metastasis, and could easily be used in conjunction with RT-PCR-based analyses of gene products which may be involved with HBC metastasis.     

Breast carcinomas with isolated bone metastases have different hormone receptor expression profiles than those with metastases to other sites or multiple organs

Breast carcinoma (BC) is one of the most common osteotropic tumors. The subset of BC patients with isolated bone metastasis (IBM) forms a clinically distinct group and often has a favorable clinical outcome as compared to others with metastatic BC. We analyzed all BC patients with distal organ metastasis in our institution between 1997 and 2003 (N = 198) to identify the clinicopathologic features of BC with IBM and compare them to those with metastasis to other sites. We found that 63% of BC patients with advanced disease had bone metastases, and 44% of those were IBM. The proportion of cases with IBM that expressed estrogen receptor and/or progesterone receptor (47/52; 90%) was significantly higher than those with non-bone metastases (P < .0001) and than those with multiple metastases involving bone (P < .0001). The distribution of BC molecular subtypes in cases of IBM was again significantly different from that of the remainder. By univariate and multivariate analysis of the clinicopathologic factors examined, only estrogen receptor and progesterone receptor status of the primary tumor was predictive for IBM. The median survival after diagnosis of metastatic disease was significantly longer in cases with IBM than that of any other group. Our results indicate that the diversity in receptor expression patterns not only reflects the biological diversity of mammary tumors but may also predict their metastatic potential and thus could potentially be used in surveying women patients with nonmetastatic disease.     

Activin A circulating levels in patients with bone metastasis from breast or prostate cancer

Recent studies have highlighted that Activin A, a member of the transforming growth factor-β (TGF-β) superfamily, may be involved in the regulation of osteoblastic activity and in osteoclast differentiation. Therefore, we have investigated the clinical significance of its circulating levels in patients with bone metastasis. Activin A serum concentrations were determined, by a commercially available enzyme-linked immunosorbent assay kit, in 72 patients with breast cancer (BC) or prostatic cancer (PC) with (BM+) or without (BM−) bone metastases, in 15 female patients with age-related osteoporosis (OP), in 20 patients with benign prostatic hypertrophy (BPH) and in 48 registered healthy blood donors (HS) of both sex (25 female and 23 male). Activin A serum concentrations were significantly increased in BC or PC patients as compared to OP (P < 0.0001) or BPH (P = 0.045), respectively, or to sex matched HS (P < 0.0001). Additionally, these levels resulted more elevated in PC patients as compared to BC patients (P = 0.032). Interestingly, Activin A was significantly higher in BM+ patients than in BM− patients (BC, P = 0.047; PC, P = 0.016). In BC patients, a significant correlation was observed only between Activin A and number of bone metastases (P = 0.0065) while, in PC patients, Activin A levels were strongly correlated with the Gleason score (P = 0.011) or PSA levels (P = 0.0001) and, to a lessen extent, with the number of bone metastases (P = 0.056). Receiver operating characteristic curve (ROC) analysis showed a fair diagnostic accuracy of Activin A to discriminate between BM+ and BM− patients (BC: AUC = 0.71 ± 0.09, P = 0.03; PC: AUC = 0.73 ± 0.081, P = 0.005). These findings indicate that Activin A may be implicated in the pathogenesis of bone metastasis. Therefore, this cytokine may be considered a novel potential target for a more selective therapeutic approach in the treatment of skeletal metastasis and may be also useful as additional biochemical marker of metastatic bone disease.