Biomimetic synthesis of multilayered aragonite aggregates using alginate as crystal growth modifier

Polysaccharides were believed to play an important role in the mineralization process of many organisms. As the source of continuously and uniformly releasing alginate molecules and Ca(2+), alginate/Ca nanospherical gel was employed in the solution to induce the nucleation and growth of CaCO(3). Time-resolved transmission electron microscopy (TEM) was applied to study the crystallization at a very early stage. It was found that the initially formed lens-like vaterite particles gradually dissolved from the middle of the particle and released alginate molecules and Ca(2+) back into the system. As reaction time increased, the released substances were involved in the next stage of crystallization of CaCO(3), in the form of needle-like and shuttle-like aragonite particles sequentially depending on the concentration of alginate molecules and Ca(2+). "Egg-box" conformation of alginate and Ca(2+) was considered a skeleton for the growth of such aragonite particles. Notably, shuttle-like aragonite particles were composed of "bricks" of several hundred nanometers in size, which were very similar to biogenetic nacreous layers in shells.

Diffusion-Weighted MRI in Predicting the Efficacy of Neoadjuvant Chemotherapy of Breast Cancer

Objective: To approach the apparent diffusion coefficient(ADC) obtained on diffusion weighted imaging (DWI) in predicting the response of breast cancer to neoadjuvant chemotherapy.Methods: 53 locally advanced breast cancer patients participated in this prospective study on neoadjuvant chemotherapy. All patients were treated with weekly neoadjuvant paclitaxel plus carboplatin for 4 cycles. DWI and ADC value were examined before chemotherapy(the first time point), after the first and the forth cycle of chemotherapy(the second and the third time point). Patients were categorized as high responders if their ADC at the second time point were higher by 2 times the standard deviation than the mean pre-chemotherapy ADC, and otherwise the patients were considered as low responders. Logistic regression was conducted to examine the independent factors predictive of clinical complete response(CR) and pathologic complete response(pCR).Results: CR was documented in 13 patients (24.5%); partial response in 36 patients (67.9%); stable disease in 4 patients (7.5%) and no patient had progressive disease. 11 patients(20.8%) have achieved pCR. There was a strong positive correlation between the percentage changes in ADC value at the third time points and the degree of the tumor reduction. A significant increase in ADC value was observed at the second time point compared with the first time point (1.104±0.117×10-3mm2/s, 1.220±0.158×10-3mm2/s, P<0.001), while the decrease of the longest diameter of the tumors measured by physical examination, ultrasound or MRI or the tumor volumn measured by MRI were not (P>0.05). Logistic regression revealed that percentage changes of ADC value at the second time point were significantly associated with CR(P=0.022, hazard ratio[HR] =1.08, 95% confidence interval[CI]: 1.01∼1.16) and pCR(P=0.022, HR =1.11, 95%CI: 1.02∼1.21). The AUC value of the receiver operating characteristic curve were 0.721(95%CI: 0.512∼0.931, P=0.017) and 0.775(95%CI: 0.598∼0.952, P=0.005) in the two diagnostic tests for CR and pCR, and the sensitivity and specificity were 76.9%, 63.6% and 77.5%, 90.5%, respectively. According to categorizing system described above, 10 patients(18.9%) were considered as high responders and 43 patients(81.1%) low responders. 7 patients(70%) of the high responders have achieved clinical CR and pCR while for the low responders there were only 6 patients(14.0%) and 4 patients (9.3%) proven to have CR and pCR. The difference have both reached statistical significance(P=0.001, P<0.001). Logistic regression confirmed that the categorizing system was independently predictive of CR(P=0.006, HR=42.26, 95%CI: 2.86∼624.08) and pCR(P=0.013, HR=25.19, 95%CI: 2.00∼318.91). Taking this categorizing system as a dignostic test, the sensitivity and specificity were 53.8% and 92.5% for CR and 63.6% and 92.9% for pCR, respectively.Conclusions: The change of ADC value obtained on DWI after the first cycle of neoadjuvant chemotherapy occured prior to the morphologic changes of the tumor and at this time ADC value could to some extent predict the efficacy of neoadjuvant chemotherapy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4025.

Estrogen Receptor Expression: Possible Predictor of Pathological Complete Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer Patients

BackgroundEstrogen receptor(ER) status has been found to correlate inversely to pathologic complete response (pCR) rates of neoadjuvant chemotherapy(NAC) of breast cancer. However, not all ER-positive breast cancer respond equally to NAC. The present study aimed to determine the relationship between different ER expression level with pCR in locally advanced breast cancer(LABC) patients who have received NAC.MethodsA retrospective study of 332 female unilateral LABC patients undergoing NAC was performed. All patients were confirmed as invasive breast cancer before treated with NAC, including VE (vinorelbine, epirubicin), CEF (cyclophosphamide, epirubicin, fluorouracil) and PCb regimen (paclitaxel, carboplatin). All patients underwent radical surgery and pCR was defined as the absence of invasive breast cancer in both breast and axillary lymph nodes. ER status were checked using the established immunohistochemical(IHC) method and defined as negative, weakly positive(1+), medium positive(2+) and strongly positive(3+). Binary logistic regression was performed to determine the independent predictors of pCR.ResultsER negativity, 1+, 2+ and 3+ were found in 156, 108, 37 and 31 patients, of which 42(26.9%), 21(19.4%), 3(8.1%) and 1 patients(3.2%) have achieved pCR. Binary logistic regression showed that different ER expression level(P=0.021) and HER2 status(P=0.007, hazard ratio[HR] =2.557, 95% confidence interval[CI]: 1.297∼5.038) were significantly associated with the pCR rates. pCR was much more likely to occur in patients with ER-negative(P=0.024, HR =13.119, 95% CI: 1.402∼122.774) or ER 1+(P=0.025, HR=12.928, 95% CI: 1.388∼120.390) tumors than those with ER 3+ tumors.ConclusionER weekly positive patients also gain considerable benefit from NAC, which is probably less effective in ER strongly positive patients in terms of pCR.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1104.

Coexpression and Synergistic Role of Multiple Atypical Chemokine Binders in Breast Cancer

Background: The expression and role of Duffy antigen receptor for chemokine (DARC), D6 and ChemoCentryx chemokine receptor (CCX-CKR) in breast cancer have already been studied independently in the past several years. However, the relationship and importance of these atypical chemokine binders (ACB) are still unclear. In this large scale clinical study, we invastigated the characteristics of multiple ACB simultaneously. Material and Methods: The protein levels of DARC, D6 and CCX-CKR were analyzed by immunohistochemistry in 517 patients with invasive breast cancer, 29 patients with noninvasive breast cancer. All of these cases come from the Cancer Hospital of Fudan University during 2001-2006, with complete clinicopathological data and follow-up data, including survival information. Results: In the invasive breast cancer patients, triple, double and single positive expression of these ACB were 135 cases (26.1%), 154 cases (29.8%) and 121 cases (23.4%), respectively. On the other hand, 107 cases (20.7%) were complete negative. The triple positive staining was significantly conversely correlated with lymph node metastasis, disease stage, relapse-free survival (RFS) as well as overall survival (OS). DARC, D6, and CCX-CKR were independent factors that influenced lymph node metastasis and their coexpression was favorable prognostic factor for RFS and OS. Discussion: Our results confirmed that DARC, D6, and CCX-CKR play a negative role in breast cancer. Furthermore, their triple or double high coexpression is more favorable for the patients, suggesting that multiple ACB may provide better protection against metastasis and relapse by synergistically regulating chemokine network in breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4166.

Genetic Contribution of GADD45A to Susceptibility to Sporadic and Non-BRCA1/2 Familial Breast Cancers: A Systemic Evaluation in Chinese Populations

GADD45A is a candidate breast cancer susceptibility gene because its product participates in DNA repair and it is a downstream gene of p53 and BRCA1, both of which are breast cancer susceptibility genes. The genetic contribution of GADD45A to sporadic and familial breast cancer is still ambiguous. We screened germline mutation of GADD45A in 185 non-BRCA1/2 familial breast cancer patients, but no deleterious mutation was found. Seven single-nucleotide-polymorphisms were identified in a sub-sample. Five common variants (minor allele frequency (MAF)>10%) were genotyped for association analyses to scrutinize the relationship between breast cancer and polymorphisms in GADD45A in two independent population sets. In the first case-control study, a comparison of genotype frequencies between sporadic breast cancer patients and controls indicated the CT/TT-genotypes of +1506C>T and CG/CC-genotypes of +3204G>C were associated with decreased breast cancer risk (adjusted odds ratio (OR), 0.77; 95% confidence interval (CI), 0.62-0.96; and adjusted OR, 0.71; 95%CI, 0.57-0.88, respectively) compared with their wild-type homozygotes. A common hyplotype CGTCC was also associated with reduced risk (P=1.0×10-4). In a second familial breast cancer patient-based case-control study, although +1506C>T and +3204G>C failed to be validated, the haplotype CGTCC showed a borderline significance. Notably, the combined P-values were robust for +3204G>C (P=3.1×10-4) and CGTCC (P=1.6×10-5). Moreover, CGTCC was correlated with a higher GADD45A expression in normal breast tissues. In conclusion, although germline mutation of GADD45A is not common in familial breast cancer patients, polymorphisms/haplotypes in GADD45A contribute to breast cancer risk, at least to sporadic breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5163.

Frequency of PIK 3CA Mutations in Chinese HER2+ Metastatic Breast Cancer Patients and Association with Clinical Benefit to Lapatinib and Capecitabine Treatment

Background: Activating mutations in PIK3CA are frequent in breast cancer (Campbell et al. Cancer Res 2004;64:7678-7681). Previous analyses suggest that the presence of PIK3CA activating mutations were associated with poor clinical outcome (Li et al. Breast Can Res Treat 2006;96:91-95) and could confer resistance to treatment with trastuzumab (T) (Berns et al. Cancer Cell 2007;12:395-402). Lapatinib (L) is an oral tyrosine kinase inhibitor targeting EGFR and HER2 pathways. L plus capecitabine (C) has demonstrated efficacy in women with HER2+ metastatic breast cancer (MBC) previously treated with T (Geyer et al. N Engl J Med 2006;355(26):2733-2743). EGF109491 evaluated the efficacy of L+C in 52 Chinese HER2+ MBC patients. The clinical benefit rate (CBR) was 57.7% (PR 44% and SD 44%) and median progression free survival (PFS) was 6.3 months. The purpose of this analysis was to establish the frequency of PIK3CA mutations in this small cohort of Chinese patients and to determine if the presence of a PIK3CA mutation has any impact on clinical benefit to L+C.Methods: 38/52 patients provided tumor samples for biomarker analysis. Briefly, DNA was extracted from these tumor samples, amplified by PCR and sequenced by Pyrosequencing methods to identify the presence of frequent activating mutations in exons 9 and 20 in PIK3CA. Mutation status was tested for association with CBR and PFS using contingency table analysis and proportional hazards analysis respectively.Results:11/38 (29%) patients harbored a mutation in the PIK3CA gene, consistent with published frequencies. 9/11 mutations reside in the catalytic domain and 2/11 mutations reside in the accessory domain of the gene. There was no statistical association with CBR (p=0.639) or PFS (HR=1.01, p=0.989) in PIK3CA wildtype patients vs. PIK3CA mutant patients. PIK3CA wildtype n=27 (%)PIK3CA Mutation n=11 (%)CR0 (0)0 (0)PR12 (44%)4 (36%)SD13 (48%)5 (45%)PD1 (4%)1 (9%)Unknown1 (4%)1 (9%)HR1.01 (p=0.989) Conclusion: The frequency of PIK3CA mutations in this small cohort of Chinese HER2+ MBC patients is consistent with published frequencies. There was no statistically significant association between the presence of a PIK3CA mutation and clinical benefit to L+C in these patients. These results are in agreement with previous reports that mutations in PIK3CA do not seem to impact clinical outcome following L-containing treatment regimens.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1140.

Intermittent Hypoxia: Potential Factor of Resistance to Endocrine Therapy

Background: It has been reported that intermittent hypoxia, which is likely more prevalent than acute hypoxia in breast cancers, can cause persistent depression of estrogen receptor alpha (ER-α) expression in breast cell lines. However, it remains suspension whether intermittent hypoxia may be associated with resistance to endocrine therapy.Material and methods: The role of intermittent hypoxia in resistance to endocrine therapy was investigated in ER-α positive breast cell lines and animal models.Results: We observed that intermittent hypoxia promoted cancer cell proliferation in vitro and in vivo compared with normoxia. At both mRNA and protein levels, intermittent hypoxia induced down-regulation of ER-α and factor inhibiting HIF-1 (FIH) as well as up-regulation of hypoxia inducible factor-1 alpha (HIF-1α) and carbonic anhydrase IX (CA-IX). ER-α positive breast cancer cells under normoxic condition were capable of an intact response to ICI 182,780 (Tocris), whereas the inhibitory effect of ICI 182,780 (Tocris) was significantly reduced in those after intermittent hypoxia. Such effect was further validated with fulvestrant (Astrazeneca) in the animal models. To clarify whether intermittent hypoxia was associated with resistance to endocrine therapy, the expression of HIF-1α, a critical regulator of hypoxia-related pathway, was blocked by a reformed type of small interfering RNA (siRNA), stealth RNAi (Invitrogen), which can reduce the cytotoxic interferon response unlike conventional siRNA. Interestingly, knock-down of HIF-1α did result in the restoration of not only the ER-α expression but also the response to endocrine therapy, which was reproducible with administration of Bortezomib, a proteasome inhibitor of HIF-1α.Discussion: These data provide functional evidence that intermittent hypoxia may confer resistance to endocrine therapy in breast cancers through the crosstalk between HIF-1α and ER-α signaling, which holds a promise to overcome endocrine resistance.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5148.

A Phase I/II Clinical Trial of Accelerated Partial Breast Irradiation Using External Beam and Image-Guidance in Early-Stage Breast Cancer Patients Treated with Breast Conservative Surgery

Purpose: To evaluate the early therapeutic outcome of accelerated partial breast irradiation(APBI) in low-risk breast cancer patients treated with breast conservative surgery(BCS) in a Chinese population, to analyze the intra-fractional and residual error with image-guidance.Material and methods: Eligible patients were age ≥18 years, unicentric Stage I invasive carcinoma or ductal carcinoma in situ(DCIS), treated with BCS with margin>2mm. Sixteen patients were enrolled between June 2008 and April 2009, with median age 53 ys (46-71). Clinical target volume(CTV) is defined by surgical cavities plus 1.5cm margin, another 1cm is expanded to form the planning target volume(PTV), with edition to no closer than 5 mm to the skin surface and no deeper than the anterior chest wall. Three-dimensional treatment plannings with field in field technique were generated with dose of 38.5Gy/10F, bid with interval≥6 hours. Two online cone beam CTs (CBCT) was acquired for each fraction, using Elekta Synergy, X- Ray Imaging system. One is after setup with skin-markers and the other at the end of fraction. Three different registrations: bony structure, grey and grey with manual adjustment(gmanual) were compared. The clip box included: whole breast, ipsilateral lung and part of the vertebras. The registration results of each fraction were recorded. The mean shifts and standard deviation (SD) were calculated on the CBCT pre and post-treatment.Results: The ratio of APBI PTV/whole breast PTV was 25%-40% (median 29.3%). 6MV photon with median fields of 4(3-6) was used. Grade I skin toxicity was found in all the 16 patients after 15-20(median 17) days of treatment, grade II skin reaction occured in 2 patients.The setup errors detected by the initial CBCT are 7mm in lateral(X), 10mm in longitudinal(Y) and 7mm in vertical directions(Z).Table 1 Setup errors detected by the differences between pre-treatment CBCT with skin marker and planning CT  grey  gmanual  x (cm)y(cm)z(cm)x (cm)y(cm)z(cm)Mean-0.010.14-0.1 0.15-0.13SD0.260.370.290.280.370.28system error0.210.320.230.210.310.23random error0.180.190.180.180.230.2margin0.650.930.700.650.940.72 The bony algorithm showed statistical difference with grey or gmanual algorithms (p<0.05). Shift was applied when the registration result by gmanual was >3mm in any directions. The residual error and intra-fraction error was then analyzed after on-line shift and the post-fraction CBCT, which resulted in 6.9mm(X)l, 6.4mm(Y)and 7.3mm (Y) directions, see Table 2.Table 2 The summary of residual errors and intra-fraction errors after shift alignment x (cm)y (cm)z (cm)mean0.010.00-0.07SD0.260.290.29system error0.210.200.23random error0.230.200.22margin0.690.640.73 Conclusion: APBI with 3-D conformal external beam and image guidance is a feasible technique. Grey registration with manual adjustment is recommended for clinical application. The initial set-up error data confirmed the safety of 1cm margin from CTV to PTV. With online shift of any error above 3mm, the combination of residual error and intra-fraction error is 6.9mm, 6.4mm and 7.3mm in X, Y and Z directions, which might provide potential for margin reduction with image guidance.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4111.

Overexpression or Lack of beta 2-Adrenergic Receptor Correlate with Progression of Breast Cancer

Background: Recent studies showed that stress can modulate biological behavior of ovarian carcinoma through adrenergic receptors. Since both nonselective beta-adrenergic receptor antagonist propranolol and selective beta 2-adrenergic receptor (b2AR) antagonist ICI 118,551 instead of b1AR antagonist atenolol could eliminate most of the effects, b2AR is accordingly regarded as the key molecule. In this study, we investigated the role of b2AR in breast cancer. Material and Methods: Gene expression of b2AR was analyzed by RT-PCR in human breast cancer cell lines MDA-MB-231, MDA-MB-435, MDA-MB-468, MCF-7, T47D, BT-549, HCC1937, BCaP-37 and normal mammary epithelial-like cell line HBL-100. b2AR cDNA was transfected into MDA-MB-435 cells. Protein level of b2AR was analyzed by immunohistochemistry in clinical samples, including 25 normal human breast or benign disease breast tissues and 202 breast cancer tissues. Results: b2AR was detected in majority of breast cancer cell lines, except for MDA-MB-435, MCF-7 and T47D, and all of normal or benign disease breast tissues. Both nonselective beta-adrenergic receptor agonist norepinephrine (NE) and selective b2AR agonist terbutaline promoted proliferation and invasion of spontaneous b2AR-positive MDA-MB-231 cells and transfectant MDA-MB-435-b2AR cells, these effects were completely inhibited by selective b2AR antagonist ICI 118,551. In the breast cancer patients, 125 samples (61.9%) expressed b2AR weakly or moderately just as normal breast or benign diseases tissue, and 43 (21.3%) presented significantly stronger b2AR expression, while no b2AR staining was found in other 34 samples (16.8%). Higher expression or lack of b2AR were associated with axillary lymph nodes metastasis and poor disease free survival (DFS). Discussion: Based on our preliminary results, the breast cancer patients could be classified into three subgroups: b2AR “normal”, high expression and negative groups. Overexpression or lack of b2AR associated with metastasis and clinical prognosis in breast cancer. Obviously, abnormal expression of b2AR may influence the outcome of breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4165.

Changing Patterns and Present Status of Female Breast Cancer in China over 30 Years

Introduction: As a metropolis with rapid social and economic development over the past three decades, Shanghai has a breast cancer incidence that surpasses all other cancer registries in China.Methods: In order to estimate the regular changing patterns of female breast cancer in urban Shanghai, population-based incidence data from 1975 to 2004 were studied. In addition, a one-hospital-based in-patient database of 9709 female breast cancer patients treated surgically between Jan-1990 and Dec-2008 were reviewed, retrospectively.Results: We observed that breast cancer incidence increased dramatically over the past 30 years and documented a peak incidence represented by the middle-age group (45-59 yrs), which emerged in the last 20 years. The incidence peak moved from the 40-44 year group in the previous two decades to the 50-54 year group in the most recent decade. Median age at diagnosis was earlier in Shanghai than in the western countries, although it increased from 47.5-yr in 1990 to 51-yr in 2008. Considerably higher exposure to reproductive risk factors and relatively fewer hormone-dependent cases were observed- only 49.2% of breast cancers were estrogen receptor(ER) positive, 46.1% were progesterone receptor positive. The proportion of asymptomatic cases detected by screening gradually increased, as well as that of early-stage cases (from 78.6% in 1990 to 87.9% in 2008 and carcinoma in situ (14.9% in 2008). Analysis of surgical treatment patterns suggested a trend of less-invasive options.Conclusions: Rapid socioeconomic growth and birth-control policies have revealed some unique risk factors, which pushed the pattern of breast cancer in Shanghai towards that of the western countries. Age of peak incidence as well as median age at diagnosis increase with time, which suggests that increased incidence trending along with increasing age will be observed in the future. The middle-age group born after 1950s would be involved in current birth-control policies and they are also the cohorts related to the incidence boom. Thus specific screening protocols should be refined for the Chinese population, considering not only increasing age but also birth cohorts. Improvements in breast cancer detection provide patients with more opportunities for less invasive treatment options.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2058.

Epidemiology of Triple Negative Breast Cancer in China

Background:The classification of tumors based on the gene expression may define intrinsic breast cancer subtypes in which the effect of risk factors could be more obvious. We sought to assess the risk factors for triple negative breast cancer on Chinese population.Methods: A retrospective study of 5761 patients was carried out from a large database of breast cancer patients undergoing surgery between January 1, 1991 and June 31, 2008 in Cancer Hospital, Fudan University, Shanghai, China. Univariate analyses were performed by chi-square test of Student's t test and multivariate analyses by logistic regression.Results: A total of 1108 women were identified as having triple negative breast cancer and were compared with the 4653 women with non-triple negative. Regardless the pathological discrepancy, women with triple negative breast cancers were significantly more likely to be younger age(P=0.001; OR=1.615, 95%CI=1.207-2.160), premenopausal (P = 0.003; OR = 1.570, 95% CI = 1.171-2.106) and parous women (P = 0.001; OR = 1.741, 95% CI = 1.269-2.387).There seems no associations with increasing risk of triple negative breast cancer for breastfeeding (P=0.126), younger age at menarche (P=0.129), first degree family history (P=0.111) and oral contraceptive usage (P=0.251).Conclusion:Based on this large population study in Chinese breast cancer patients, the risk factors for triple negative phenotype may be somewhat different from those for Western women. Therefore, a better knowledge of this issue is warranted due to it may have impact on clinical outcomes and may offer some insight into the process of carcinogenesis and therapeutic efficacy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2065.