Identification of a functional genetic variant at 16q12.1 for breast cancer risk: results from the Asia Breast Cancer Consortium

Genetic factors play an important role in the etiology of breast cancer. We carried out a multi-stage genome-wide association (GWA) study in over 28,000 cases and controls recruited from 12 studies conducted in Asian and European American women to identify genetic susceptibility loci for breast cancer. After analyzing 684,457 SNPs in 2,073 cases and 2,084 controls in Chinese women, we evaluated 53 SNPs for fast-track replication in an independent set of 4,425 cases and 1,915 controls of Chinese origin. Four replicated SNPs were further investigated in an independent set of 6,173 cases and 6,340 controls from seven other studies conducted in Asian women. SNP rs4784227 was consistently associated with breast cancer risk across all studies with adjusted odds ratios (95% confidence intervals) of 1.25 (1.20−1.31) per allele (P = 3.2×10⁻²⁵) in the pooled analysis of samples from all Asian samples. This SNP was also associated with breast cancer risk among European Americans (per allele OR  = 1.19, 95% CI  = 1.09−1.31, P = 1.3×10⁻⁴, 2,797 cases and 2,662 controls). SNP rs4784227 is located at 16q12.1, a region identified previously for breast cancer risk among Europeans. The association of this SNP with breast cancer risk remained highly statistically significant in Asians after adjusting for previously-reported SNPs in this region. In vitro experiments using both luciferase reporter and electrophoretic mobility shift assays demonstrated functional significance of this SNP. These results provide strong evidence implicating rs4784227 as a functional causal variant for breast cancer in the locus 16q12.1 and demonstrate the utility of conducting genetic association studies in populations with different genetic architectures.

Breast cancer is one of the most common malignancies among women worldwide. Genetic factors play an important role in the etiology of breast cancer. To identify genetic susceptibility loci for breast cancer, we performed a genome-wide association study in 15,468 breast cancer cases and 13,001 controls. A single nucleotide polymorphism (SNP) rs4784227 located on chromosome 16q12.1, a previously-reported region for breast cancer risk, was found to be associated with breast cancer risk. The association of this SNP with breast cancer risk remained highly significant in Asians after adjusting all previously-reported SNPs in this region. In vitro biochemical experiments using both luciferase reporter and electrophoretic mobility shift assays confirmed the functional importance of this SNP. Our results demonstrate the importance of conducting genetic association studies in populations with different genetic backgrounds to identify functional variants.

Abstract LB-262: Mesenchymal stem cell-like characteristics of human phyllodes tumors

Phyllodes tumor which contains heterologous stromal elements, can transform into rhabdomyosarcoma, liposarcoma and osteosarcoma. These versatile properties of phyllodes tumor are reminiscent of mesenchymal stem cells (MSCs). We hypothesized that malignant phyllodes tumor may possess MSC-like properties. Forty-four paraffin-embedded malignant phyllodes tumors and two fresh tumor specimens were examined. by immunohistochemical staining for six MSC markers including CD44, CD29, CD106, CD166, CD105, CD90 and one cancer stem cell marker, Aldehyde dehydrogenase activity (ALDH). All MSC markers, except CD105, were detected in phyllodes tumors, with the following frequencies: CD166 (ALCAM; 76.1%), CD90 (76.1%), CD44 (HCAM, 66.6%), CD106 (VCAM-1, 30.1%), and CD29 (23.9%). ALDH was detected in all tumors with varying extent of expression, ranging from 3% to >90%. In addition, we successfully established 2 xenografts of primary human phyllodes tumors in NOD- SCID mice. Flow cytometric analysis of one of the xengrafted tumor revealed 12.6% of the cells to be highly positive for ALDEFLUOR. In vitro, the sorted ALDEFLUOR-high cells grew as spindle-shaped cells with spontaneous formation of colonies, which persisted upon serial passages. Immunofluorescent staining revealed that CD44-positive cells appeared to be distributed near the colony periphery; meanwhile CD10, CD29 and CD166 were localized at the center of the colonies. In vivo, freshly sorted ALDH-positive cells displayed greater engraftment capacity in mice than ALDH-negative cells. As few as 100 ALDH-positive cells were sufficient to form tumor, whereas a minimum of 2×104 ALDH-negative cells were needed for engraftment. It has been shown that neural ganglioside GD2 was expressed on MSC. ALDH/GD2 double positive cells (1.9%) sorted from tumor xenograft were readily engrafted into mice. Such tumor xenografts showed neuron-like histology in HE staining. Notably, only 50 ALDH/GD2 double positive cells were sufficient for engraftment. In vitro culture of ALDH / GD2 double positive cells sorted from the original tumor xenograft yielded rapidly growing spindle-shaped cells, forming numerous colonies. Between day 14 and 21, these cells could be induced by exogenous cAMP to differentiate into neural cells of various lineages, which expressed nestin (neuron stem/progenitors cell marker), ßIII-tubulin (immature neuronal progenitor cells) or GFAP(glial fibrillary acidic protein, marker for astrocytes) as shown by immunofluorescent staining. On the other hand, cultured ALDH-positive cells could be induced by isobutylmethylxanthine or beta-glycerophosphate to differentiate into adipocytes or osteocytes, utilizing Oil Red O and Alizarin Red staining, respectively. In conclusion, our findings revealed that malignant phyllodes tumor might possess many characteristics of MSC, as reflected by their phenotypic markers and ability to differentiate into various lineages of tissue/cell types.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-262.

Unique features of breast cancer in Asian women--breast cancer in Taiwan as an example

Breast carcinoma is one of the most common cancers in women and is known to arise from a multifactorial process, the effect of reproductive risk factors strongly supporting a hormonal role in its etiology. Breast cancer in Asia is characterized by a lower incidence than in Western populations, but is still the leading type of cancer in Asian women, and a significant increasing tread indicates that it is an issue of particular public health importance. Asian breast cancer is characterized by early tumor onset, showing a relatively younger median age at diagnosis. Recently, scientists began to explore the tumorigenic mechanisms underlying breast cancer formation at the molecular level. Both a candidate-gene approach and genome-wide association studies have yielded crucial insights into breast cancer susceptibility genes initiating breast tumorigenesis. As expected, ethnic/racial variation in the genotypic frequency of these genes results in differences in breast cancer incidence in different populations. Furthermore, the question of how important these genes are in Asian breast cancer remains to be explored. It has been demonstrated that gene expression profiles and gene sets are prognostic and predictive for patients with breast cancer. Originally, due to its early onset, it was speculated that Asian breast cancer would have a higher frequency of the basal-like subtype of breast cancer, a molecular subtype characterized by poor differentiation, resulting in a relatively poor progression; however, recent findings do not support this speculation. The frequency of the luminal-A subtype of breast cancer, characterized by estrogen receptor expression, is similar to that in breast cancer in Caucasian, supporting the usefulness of hormone-based therapy in Asian breast cancer.

Predictive and prognostic values of tau and ERCC1 in advanced breast cancer patients treated with paclitaxel and cisplatin

OBJECTIVE

We studied tau and excision repair cross-complementing 1 expression to evaluate their predictive values in advanced breast carcinoma patients.

METHODS

Patients treated with paclitaxel and cisplatin as the first-line chemotherapy for locally advanced or metastatic breast cancer were enrolled. The expression levels of tau and excision repair cross-complementing 1 were assessed by immunohistochemistry and examined for their associations with treatment response and survival.

RESULTS

Fifty-four patients were included in this study. Despite the strong association between tau expression and lower histological grade and estrogen receptor expression, tau expression remained an independent predictor for a lower response rate in multivariate analysis (odd ratio = 0.24, P = 0.02). However, tau expression was a predictor for longer overall survival in both univariate analysis (median, 57.5 vs. 30.4 months, P = 0.02) and multivariate analysis (hazard ratio = 0.36, P = 0.008). Excision repair cross-complementing 1 was not associated with treatment response or overall survival.

CONCLUSIONS

Tau expression but not excision repair cross-complementing 1 in advanced breast cancer predicts poor response to combination chemotherapy of paclitaxel and cisplatin. However, tau expression is significantly associated with longer overall survival.

Breast density analysis for whole breast ultrasound images

Breast density has been established as an independent risk factor associated with the development of breast cancer. The terms mammographic density and breast density are often used interchangeably, since most breast density studies are performed with projection mammography. It is known that increase in mammographic density is associated with an increased cancer risk. A sensitive method that allows for the measurement of small changes in breast density may provide useful information for risk management. Despite the efforts to develop quantitative breast density measurements from projection mammograms, the measurements show large variability as a result of projection imaging, differing body position, differing levels of compression, and variation of the x-ray beam characteristics. This study used two separate computer-aided methods, threshold-based and proportion-based evaluations, to analyze breast density on whole breast ultrasound (US) imaging and to compare with the grading results of three radiologists using projection mammography. Thirty-two female subjects with 252 images per case were included in this study. Whole breast US images were obtained from an Aloka SSD-5500 ultrasound machine with an ASU-1004 transducer (Aloka, Japan). Before analyzing breast density, an adaptive speckle reduction filter was used for removing speckle noise, and a robust thresholding algorithm was used to divide breast tissue into fatty or fibroglandular classifications. Then, the proposed approaches were applied for analysis. In the threshold-based method, a statistical model was employed to determine whether each pixel in the breast region belonged to fibroglandular or fatty tissue. The proportion-based method was based on three-dimensional information to calculate the volumetric proportion of fibroglandular tissue to the total breast tissue. The experimental cases were graded by the proposed analysis methods and compared with the ground standard density classification assigned by a majority voting of three experienced breast radiologists. For the threshold-based method, 28 of 32 US test cases and for the proportion-based density classifier, 27 of 32 US test cases were found to be in agreement with the radiologist "ground standard" mammographic interpretations, resulting in overall accuracies of 87.5% and 84.4%, respectively. Moreover, the concordance values of the proposed methods were between 0.0938 and 0.1563, which were less than the average interobserver concordance of 0.3958. The experiment result showed that the proposed methods could be a reference opinion and offer concordant and reliable quantification of breast density for the radiologist.

Analysis of elastographic and B-mode features at sonoelastography for breast tumor classification

The purpose of this study was to evaluate the accuracy of neural network analysis of elastographic features at sonoelastography for the classification of biopsy-proved benign and malignant breast tumors. Sonoelastography of 181 solid breast masses (113 benign and 68 malignant tumors) was performed for 181 patients (mean age, 47 years; range, 24-75 years). After the manual segmentation of the tumors, five elastographic features (strain difference, strain ratio, mean, median and mode) and six B-mode features (orientation, undulation, angularity, average gradient, gradient variance and intensity variance) were computed. A neural network was used to classify tumors by the use of these features. The Student's t test and receiver operating characteristic (ROC) curve analysis were used for statistical analysis. Area under ROC curve (Az) values of the three elastographic features- mean (0.87), median (0.86) and mode (0.83)-were significantly higher than the Az values for the six B-mode features (0.54-0.69) (p < 0.01). Accuracy, sensitivity, specificity and Az of the neural network for the classification of solid breast tumors were 86.2% (156/181), 83.8% (57/68), 87.6% (99/113) and 0.84 for the elastographic features, respectively, and 82.3% (149/181), 70.6% (48/68), 89.4% (101/113) and 0.78 for the B-mode features, respectively, and 90.6% (164/181), 95.6% (65/68), 87.6% (99/113) and 0.92 for the combination of the elastographic and B-mode features, respectively. We conclude that sonoelastographic images and neural network analysis of features has the potential to increase the accuracy of the use of ultrasound for the classification of benign and malignant breast tumors.

Molecular subtypes of breast cancer emerging in young women in Taiwan: evidence for more than just westernization as a reason for the disease in Asia

BACKGROUND

In the past two decades, the incidence of breast cancer in young Taiwanese females has been rapidly increasing, approaching the risk level of western countries. As a first step to investigate the possible etiology, we examined the molecular subtypes of female breast cancer in Taiwan.

METHODS

This study included 1,028 consecutive patients with breast cancer diagnosed in National Taiwan University Hospital between 2004 and 2006. Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2, cytokeratin 5/6, and epidermal growth factor receptor expression and/or gene amplification were analyzed.

RESULTS

Younger (<or=50 years) breast cancer patients had a higher prevalence of luminal A (67% versus 57%; P < 0.001) and a lower prevalence of basal-like subtype (9% versus 17%; P < 0.001) compared with older (>50 years) patients. The higher prevalence of luminal A subtype was mainly attributed to a higher ER (75% versus 63%; P < 0.001) and PR (47% versus 33%; P < 0.001) expression rate in younger patients than older patients. Tumors with histologic grade 3 were less prevalent in younger patients than in older patients (23% versus 30%; P = 0.01). For very young (<35 years) patients, the molecular subtype distribution, ER and/or PR expression rate, and histologic grade were not significantly different from those of less young (35-50 years) patients.

CONCLUSIONS

Young breast cancer patients in Taiwan are characterized by a high prevalence of luminal A subtype and low prevalence of histologic grade 3 tumor and/or basal-like subtype. These features are distinct from young breast cancer patients in western countries.

Dynamic seizure-related changes in extracellular signal-regulated kinase activation in a mouse model of temporal lobe epilepsy

Extracellular signal-regulated kinase (ERK) is highly sensitive to regulation by neuronal activity and is critically involved in several forms of synaptic plasticity. These features suggested that alterations in ERK signaling might occur in epilepsy. Previous studies have described increased ERK phosphorylation immediately after the induction of severe seizures, but patterns of ERK activation in epileptic animals during the chronic period have not been determined. Thus, the localization and abundance of phosphorylated extracellular signal-regulated kinase (pERK) were examined in a pilocarpine model of recurrent seizures in C57BL/6 mice during the seizure-free period and at short intervals after spontaneous seizures. Immunolabeling of pERK in control animals revealed an abundance of distinctly-labeled neurons within the hippocampal formation. However, in pilocarpine-treated mice during the seizure-free period, the numbers of pERK-labeled neurons were substantially decreased throughout much of the hippocampal formation. Double labeling with a general neuronal marker suggested that the decrease in pERK-labeled neurons was not due primarily to cell loss. The decreased ERK phosphorylation in seizure-prone animals was interpreted as a compensatory response to increased neuronal excitability within the network. Nevertheless, striking increases in pERK labeling occurred at the time of spontaneous seizures and were evident in large populations of neurons at very short intervals (as early as 2 min) after detection of a behavioral seizure. These findings suggest that increased pERK labeling could be one of the earliest immunohistochemical indicators of neurons that are activated at the time of a spontaneous seizure.

The CYP19 TTTA repeat polymorphism is related to the prognosis of premenopausal stage I-II and operable stage III breast cancers

PURPOSE

Given the critical role of the CYP19 gene, encoding aromatase, in estrogen synthesis and the association of the estrogen level with its TTTA repeat polymorphism, the potential influence of this polymorphism on breast cancer survival, and hence management, deserves further study.

METHODS

Genotyping for the CYP19 TTTA repeat polymorphism was performed on 482 stage I-II and operable stage III Taiwanese breast cancer patients. Patients with more than seven TTTA repeats in either allele of CYP19 were defined as having the long allele. We correlated clinical variables and CYP19 genotypic polymorphism with outcome.

RESULTS

In hormone receptor (HR)-positive breast cancers, premenopausal patients with the long allele of the CYP19 polymorphism had a significantly higher overall survival (OS) rate (8-year, 89% versus 68%; p= .003) than those without it. This difference was further demonstrated by a multivariate analysis (OS hazard ratio, 1.53; p= .041). In postmenopausal women or patients with HR-negative breast cancer, there was no significant difference in OS between patients with or without the long allele. In premenopausal women with HR-positive cancers, adequate intensity adjuvant chemotherapy did not achieve a greater OS rate than suboptimal chemotherapy in patients with the long allele, but it resulted in a significantly higher OS rate (p= .011) than suboptimal chemotherapy in women without the long allele.

CONCLUSIONS

The CYP19 TTTA repeat polymorphism is associated with survival in premenopausal women, but not in postmenopausal women, with HR-positive breast cancers. Premenopausal women with the long allele have a greater survival rate and may not gain benefit from adjuvant chemotherapy.

Dose variation and regimen modification of adjuvant chemotherapy in daily practice affect survival of stage I-II and operable stage III Taiwanese breast cancer patients

To assess the effect of a non-standard dose and regimen of adjuvant chemotherapy on the clinical outcome in stage I-II and operable stage III Taiwanese breast cancer patients. Variables studied included treatment variation (regimen and dose of adjuvant therapy), lymph node status, tumor size, histologic grade, and hormone receptor status. Cox's multivariate regression analyses were used to select prognostic factors significant for disease-free survival (DFS) and overall survival (OS). In the multivariate analysis, lymph node-positive, a tumor size greater than 5 cm, grade III, hormone receptor-negative status, and non-standard adjuvant chemotherapy were independent prognostic factors for DFS and/or OS. Node-positive patients treated with standard adjuvant chemotherapy had a significantly better DFS (HR=0.6; P=0.032) and OS (HR=0.54; P=0.025) than those treated with non-standard adjuvant chemotherapy. Breast cancer patients receiving standard adjuvant chemotherapy have a better DFS and OS than those receiving non-standard adjuvant chemotherapy.

Antioxidant and pro-oxidant properties of chlorhexidine and its interaction with calcium hydroxide solutions

AIM

To evaluate the antioxidant and pro-oxidant properties of chlorhexidine (CHX).

METHODOLOGY

The scavenging and generation of reactive oxygen species (ROS) by CHX in the presence or absence of saturated Ca(OH)(2) solutions was evaluated. The reaction emitted chemiluminescence in the presence of lucigenin thus was determined by a luminometer to evaluate the levels of ROS production. Changes in DNA conformation were analysed by agarose gel electrophoresis. Paired Student's t-test was used to compare the difference between groups.

RESULTS

Chlorhexidine (0.00002-0.02%) effectively scavenged 56-88% of the superoxide radicals generated by the xanthine/xanthine oxidase reaction. Through analysis of PUC18 DNA conformation changes, CHX was shown to be a mild scavenger of hydroxyl radicals generated by H(2)O(2) plus FeCl(2). However, CHX (>0.083%) decreased the mobility of PUC18 plasmid DNA with potential production of DNA-DNA cross-link and severe DNA breaks (presence of DNA smear) at further higher concentrations. Furthermore, CHX induced ROS production including H(2)O(2) and superoxide radicals in 0.1N NaOH (pH = 12.76) or Ca(OH)(2) (pH = 12.5) solutions.

CONCLUSION

Chlorhexidine exhibited both antioxidant and pro-oxidant properties under different conditions. These events are possibly involved in the killing of root canal and periodontal microorganisms when CHX and Ca(OH)(2) were used in combination or separately. Potential genotoxicity and tissue damage when extruded into the periradicular tissue and at higher concentrations should be considered during periodontal and endodontic practice.

Polymorphism of cytosolic serine hydroxymethyltransferase, estrogen and breast cancer risk among Chinese women in Taiwan

Cytosolic serine hydroxymethyltransferase (cSHMT) is key to intersection of folate-metabolic pathway, participating in the pyrimidine synthesis for DNA repair. Based on the hypothesis that variants of the cSHMT C1420T together with methionine synthase (MS A2756G) and 5,10-methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) are associated with breast cancer, we performed a multigenic case-control study of the effects to breast cancer risk of four polymorphisms of folate-metabolizing genes against duration of estrogen exposure. Support of our hypothesis came from the following observations: (i) Allelic frequency of cSHMT C1420T was higher in the controls than in the cases, manifesting a 0.56-fold risk reduction in breast cancer (95%CI = 0.39-0.80); and this association was more significant in those women are susceptible to time of estrogen exposure. (ii) A joint effect of the cSHMT and MS polymorphisms significantly reduced susceptibility to breast cancer (aOR = 0.55; 95%CI = 0.34-0.88). (iii) There was a trend toward a reduced risk of breast cancer in women carrying a greater number of putative low-risk genotypes (Ptrend = 0.048). (iv) This synergistic effects on risk reduction was significantly interacted with length of estrogen exposure, exhibiting a longer time of estrogen exposure (> or =30 years), menarche-to-FFTP interval (>11 years), age at the first full-term pregnancy (< or =25 years), and body mass index (< or =24). In conclusion, our study provides support to account for the preferential role of cSHMT polymorphism to lower risk of female breast cancer, and such reduced risk would be more significant in carriers with the polymorphisms of MS and MTHFR genes.

Increased expression of SRp40 affecting CD44 splicing is associated with the clinical outcome of lymph node metastasis in human breast cancer

BACKGROUND

During the malignant transformation of breast tissues, the pre-mRNA precursor splicing of specific genes can be flexibly regulated, leading to the formation of different forms or amounts of mRNA in response to the cellular microenvironment, and is frequently associated with cell tumorigenesis and may even cause tumor metastasis. Regulation of pre-mRNA splicing by serine-arginine (SR)-rich phosphoprotein is hypothesized to be associated with tumor cell metastasis.

METHODS

We enrolled 55 breast cancer patients (32 with lymph node metastasis; LNM) with paired tissue samples consisting of cancerous and tumor-adjacent normal portions and assayed these tissues for gene expression of the SR family using quantitative real-time RT-PCR (qRT-PCR), then evaluated an association with LNM of breast cancer. Furthermore, we examined whether increased expression of a specific SR gene was associated with the presence of specific CD44 spliced variants using qualitative reverse-transcription PCR (RT-PCR).

RESULTS

Support for our hypothesis came from the observations that breast tumor tissues displayed higher level of SRp40 expression as compared with the paired non-cancerous tissues, which manifested the significant association between increased SRp40 expression and LNM (OR=4.48, 95% CI, 1.08-19.50, P=0.018). In addition, the primary tumors of breast with increased expression of SRp40 gene were associated with the presence of the large CD44 inclusion variants, CD44v2, CD44v3, CD44v5, and CD44v6 (P<0.05).

CONCLUSION

Increased expression of SRp40 can be detected in breast tumor tissues with a high degree of sensitivity, and that higher expression of SRp40 closely correlates with alternative pre-mRNA splicing of CD44, which may serve as an earlier marker in predicting the risk to breast cancer patients of developing LNM.

Breast ultrasound computer-aided diagnosis using BI-RADS features

RATIONALE AND OBJECTIVES

Based on the definitions in mass category of Breast Imaging Reporting and Data System developed by American College of Radiology, eight computerized features including shape, orientation, margin, lesion boundary, echo pattern, and posterior acoustic feature classes are proposed.

MATERIALS AND METHODS

Our experimental database consists of 265 pathology-proven cases including 180 benign and 85 malignant masses. The capacity of each proposed feature in differentiating malignant from benign masses was validated by Student's t test and the correlation between each proposed feature and the pathological result was evaluated by point biserial coefficient. Binary logistic regression model was used to relate all proposed features and pathological result as a computer-aided diagnosis (CAD) system. The diagnostic value of each proposed feature in the CAD system was further evaluated by the feature selection methods. Additionally, the likelihood of malignancy for each individual feature was also estimated by binary logistic regression.

RESULTS

On each proposed feature, the malignant cases were significantly different from the benign ones. The correlation between the angular characteristic and pathological result was indicated as very high. Three substantial correlations appear in features irregular shape, undulation characteristic, and degree of abrupt interface, but the relationship for orientation feature is low. For the constructed CAD system, the performance indices accuracy, sensitivity, specificity, PPV, and NPV were 91.70% (243 of 265), 90.59% (77 of 85), 92.22% (166 of 180), 84.62% (77 of 91), and 95.40% (166 of 174), respectively, and the area index in the ROC analysis was 0.97. Compared with the significant contribution of angular characteristic, the diagnostic values of posterior acoustic feature and orientation feature were relatively low for the CAD system. When three or more angular characteristics are discovered or the degree of abrupt interface is lower than 18, the likelihood of malignancy could be predicted as greater than 40%.

CONCLUSION

The computerized BI-RADS sonographic features conform to the sign of malignancy in the clinical experience and efficiently help the CAD system to diagnose the mass.

Radio-guided sentinel lymph node biopsy using periareolar injection technique for patients with early breast cancer

BACKGROUND/PURPOSE

Sentinel lymph node (LN) biopsy has been widely adopted in the axillary staging of clinical node-negative breast cancer patients. This study aimed to evaluate the accuracy of radio-guided sentinel LN (SLN) biopsy (SLNB) using the periareolar injection technique for predicting the histopathologic status of axillary LNs in early breast cancer patients.

METHODS

Between November 2003 and November 2004 in the National Taiwan University Hospital, radio-guided SLNB using the periareolar injection technique was consecutively performed in 213 female patients with early breast cancer (stage T1 and T2) but without clinically palpable axillary LN and previous chemotherapy. Two mCi of filtered (0.22 microm) (99m)Tc-sulfur colloid were injected in the afternoon 1 day before surgery (2-day protocol) or 1 mCi of the same radiopharmaceutical was injected on the morning of the surgery (1-day protocol). During surgery, a handheld gamma probe was used to identify the LNs with radioactivity in the axilla. A node was deemed a SLN if its radioactivity was >10% of the hottest node. All the SLNs identified were removed for histology.

RESULTS

Radioactive SLN was identified at surgery in 207 patients. The SLN identification rate was 97.2% (207/213). Of these 207 patients, 163 patients had received both SLNB and axillary LN dissection. Among these 163 patients, 77 patients had LN metastases and four had negative SLN but positive non-SLN. The false-negative rate of SLNB for the detection of axillary LN metastases was 5.2% (4/77). There were no statistical differences between false-negative and SLN positive groups for all factors.

CONCLUSION

Our study suggests that SLNB with periareolar injection of radiocolloid provides valuable information on the axillary nodal status in patients with early breast cancer.

B-group vitamins, MTHFR C677T polymorphism and carotid intima-media thickness in clinically healthy subjects

OBJECTIVE

Plasma B-group vitamins and age may affect the carotid intima-media thickness (IMT) in subjects with different 677TT genotype of the methylenetetrahydrofolate reductase (MTHFR) gene.

DESIGN

A hospital-based cross-study.

SETTING

Genomic and Vascular Center, Changhua Christian Hospital, Changhua, Taiwan.

SUBJECTS

Five hundred and forty-one clinically healthy subjects.

INTERVENTION

Fasting plasma, homocysteine (Hcy), vitamin B(6), vitamin B(12), folate and B-mode carotid ultrasound.

RESULTS

MTHFR genotype, plasma concentrations of folate, vitamin B(6) and vitamin B(12) and age were significantly correlated to the plasma Hcy concentration. MTHFR 677TT carriers had higher concentrations of Hcy than did subjects with the CC and CT genotypes. Age, sex, body mass index and plasma Hcy were independent contributors to increase carotid IMT. However, with stratification by mean value of age and B-group vitamins concentrations, we found that at advanced age, lower plasma folate and vitamin B(12) were three risk factors involved in the enhancing effect of the MTHFR 677TT genotype on the increase of plasma Hcy and carotid IMT.

CONCLUSION

MTHFR 677TT-related carotid atherosclerosis was only identified in healthy elderly subjects with lower level of plasma folate and vitamin B(12).

SPONSORSHIP

Changhua Christian Hospital.

A phase II trial of weekly paclitaxel and high-dose 5-fluorouracil plus leucovorin in patients with chemotherapy-pretreated metastatic breast cancer

BACKGROUND

Weekly paclitaxel and infusional high-dose 5-fluorouracil/leucovorin (HDFL) are both effective regimens for metastatic breast cancer (MBC) patients.

PATIENTS AND METHODS

A study was designed using weekly paclitaxel 90 mg/m(2) 1-hour infusion followed by 2,000 mg/m(2) 5-fluorouracil plus 300 mg/m(2) leucovorin 24-hour infusion on days 1, 8 and 15, repeated every 28 days, in patients who had previously received a > or =1 regimen for MBC. The dose of paclitaxel was adjusted in each cycle according to toxicity.

RESULTS

A total of 182 cycles were given to 28 patients. The doses of paclitaxel needed to be reduced only in 22 (12%) cycles. Forty-five cycles were skipped or delayed more than 7 days, mostly due to neutropenia, infection, or neurotoxicity. Twenty-five patients were evaluable for response. Four had complete response, 13 partial response, seven stable disease, and two progressive disease. The response rate was 60.7% (95% CI: 42.6-78.8). Median survival was 18.1 months (95% CI: 11.4-24.9), and progression-free survival seven months.

CONCLUSION

Weekly paclitaxel plus infusional HDFL is an active and well tolerated regimen for pretreated MBC patients.

Should adjuvant radiotherapy to the supraclavicular fossa be routinely given in patients with breast conservative treatment?

BACKGROUND

To analyze the overall outcome, supraclavicular fossa (SCF) recurrence rate, and pattern of failure in breast cancer patients treated with conservative surgery and adjuvant radiotherapy excluding SCF treatment.

METHODS

A total of 143 patients were enrolled in the study. Ninety-two percent of patients were stages I and II, and 8% were stage III. The median age was 44 years, and 31% of patients were </=40 years old. Radiotherapy was delivered to the ipsilateral breast excluding the SCF.

RESULTS

The 5-year overall survival rate of the cohort was 95%, and disease-free survival rate was 91%. The cumulative incidence of SCF recurrence was 18% in patients with involved axillary nodes (N) >/= 4, and 0.8% in patients with N < 4. The 5-year SCF-recurrence-free survival in patients with N >/= 4 and N < 4 was 80% and 99%, respectively (P < 0.001). N >/= 4 was the only independent predictor for locoregional control (P = 0.045), disease-free survival (P = 0.001), and overall survival (P = 0.008) in multivariate analysis.

CONCLUSIONS

Women with N >/= 4 have a significantly higher risk of SCF recurrence and poorer survival. The SCF might be safely spared in patients with N < 4, but should be routinely included in the radiotherapy design for those with N >/= 4.

Non-traumatic colon perforation in children: a 10-year review

Colon perforation is an abdominal surgical emergency in the pediatric population, but is seldom reported when occurring from non-traumatic causes in children beyond the neonate. The goal of this study was to identify the clinical characteristics, management, and outcomes of non-traumatic colon perforation in children. Medical records for the 10-year period from September 1994 to September 2004 were reviewed for children beyond the neonate with non-traumatic colon perforation. Data gathered included age, gender, symptoms, duration of symptoms, physical findings, and length of postoperative hospital stay. Diagnostic information included laboratory data, radiographic imaging, and operative findings. Forty-four patients with non-traumatic colon perforation were recruited into this study. The mean age was 2.22 +/- 1.87 years; 91.4% of cases were younger than 5 years old. The most common presenting symptom was fever (97.7%); the most common sign was abdominal distention (93.1%). The mean duration of symptoms prior to admission was 6.19 days. Pneumoperitoneum was presented in 86.3% of patients by plain abdominal radiograph. Ascending and transverse colon were the most common perforation sites. Non-typhoid salmonella was the leading pathogen isolated, causing 20.4% of episodes. One case died due to Clostridium speticum infection. Non-traumatic colon perforation most commonly affects children younger than 5 years of age. It may be secondary to infection, especially non-typhoid salmonella. Plain abdominal radiograph can be an adjuvant tool for the high index of suspicion for colon perforation in children with abdominal distention and history of fever or diarrhea for more than 5 days.