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Sublethal heating can increase subsequent thermal resistance of bacteria, which may compromise the validity of thermal process validations for slow-roasted meats. Therefore, this research evaluated the accuracy of a traditional log-linear inactivation model, developed via prior laboratory-scale isothermal tests, and a novel path-dependent model accounting for sublethal injury, applied to pilot-scale slow cooking of whole-muscle roasts. Irradiated turkey breasts, beef rounds, and pork loins were inoculated with an eight-serovar Salmonella cocktail via vacuum tumble marination in a salt-phosphate marinade. The resulting initial Salmonella population in the geometric center (core) was 7.0, 6.3, and 6.3 log CFU/g for turkey, beef, and pork, respectively. Seven different cooking schedules representing industry practices were evaluated in a pilot-scale, moist-air convection oven. Core temperatures recorded during cooking were used to calculate lethality real-time via the log-linear model. The path-dependent model reduced the bias (mean residual) and root mean square error by 4.24 and 4.60 log CFU/g respectively, in turkey; however, the new model did not reduce the prediction error in beef or pork. Overall, results demonstrated that slow-cooked roasts, processed to a computed lethality at or near that required by the regulatory performance standards, as calculated with a state-dependent model, may be underprocessed. [ABSTRACT FROM AUTHOR]

Introduction: Population based studies (eg, Hershman et al. BCRT 2006 and Lohrisch et al. JCO 2006) showed poorer survival associated with long delays in adjuvant chemotherapy (CTX) initiation following definitive surgery (DS) for women with breast cancer (BC). Delays in CTX following diagnosis (DX) have not been evaluated. The ASCO/NCCN quality measures (QMs) recommend CTX <=120 days after DX for patients with stage II/III ER/PR negative disease. We sought to examine the impact of delayed CTX on survival overall and stratified by disease-specific prognostic factors. Methods: 4,608 women with stage I-III HER2 negative breast cancer diagnosed between 2000 and 2006 at 8 NCCN centers were identified using the NCCN outcomes database. Patients with T3/4 disease or who received neoadjuvant therapy were excluded. The association between CTX timing and OS was evaluated using multivariate Cox models adjusted for CTX type, age, race, BMI, residential distance, insurance, SES, comorbidity, ER/PR, LVI, grade, T stage, and N stage. The impact of CTX timing was evaluated using a >90-day (d) DS-to-CTX threshold, based on poor outcomes observed in prior studies, and a >120d DX-to-CTX threshold, based on the ASCO/NCCN QMs. Results: Median follow-up was 7.2 years and OS at 7 years was 89%. Overall, 401 (8.7%) patients received CTX >120d after DX and 113 (2.4%) patients received CTX >90d after DS. The DX-to-CTX interval was more strongly correlated with the DX-to-DS (r = 0.74) interval than DS-to-CTX (r = 0.54) interval. A >90d DS-to-CTX interval was significantly associated with poorer survival (HR: 1.65, 95% CI 1.04-2.60, p = 0.03) in adjusted analyses. Shorter DS-to-CTX thresholds of >60d (n = 636, HR: 1.13, 95% CI: 0.89-1.43, p = 0.319) or >75d (n = 273, HR: 1.05, 95% CI 0.74-1.49, p = 0.76) were not associated with OS. The association between a >120d DX-to-CTX interval and OS was not statistically significant (HR: 1.32, 95% CI 0.99-1.76, p = 0.06). Patients who received CTX >135d(n = 231, HR1.25, 95% CI: 0.87-1.81, p = 0.22)or>150d(n = 128, HR1.15, 95% CI: 0.59-2.24, p = 0.69) after DX did not display an increased risk of death. Excluding pathological staging factors from the model had no effect on the results. In subgroup analyses stratified by ER/PR, LVI, grade, T stage or N stage, a >120d delay in CTX did not display significant associations with OS. Among ER/PR negative patients, the association between a >120d delay and OS was borderline non-significant after adjusting the p-value for multiple hypothesis testing using the false discovery rate method (HR: 1.80, 95% CI: 1.16-2.79, p = 0.09). Conclusion: Consistent with previous studies, CTX delays of >90 days following surgery were associated with poorer survival. OS was not significantly compromised in patients with DX-to-CTX intervals >120 days although this analysis may have limited power to detect small effects. More variation in the DX-to-CTX interval was attributed to pre-surgery time which may explain the differences observed between the DX-to-CTX and DS-to-CTX intervals. Among patients with ER/PR negative disease, a non-significant association between OS and a >120 day DX-to -CTX interval was observed that warrants further examination. [ABSTRACT FROM AUTHOR]

Background: The results of the ACOSOG- Z0011 trial have had potential practice changing implications for the management of patients with positive sentinel lymph node (SLN) undergoing lumpectomy and radiation for breast cancer. However, some evidence suggests a shift in axillary management even prior to the initial report of data supporting sentinel lymph node biopsy (SLNB) alone in mid-2010. We analyzed data in the National Comprehensive Cancer Network (NCCN) outcomes database from NCCN centers and the Michigan Breast Oncology Quality Initiative (MiBOQI) hospitals to examine institutional practice patterns with respect to use of completion axillary dissection (CALND) for SLN positive breast cancer in the years leading up to publication of these trial results. We hypothesized that CALND would be omitted more frequently in women treated at NCCN centers compared to those treated at MiBOQI programs. Methods: We identified 2,172 women with clinical T1/T2 N0 breast cancer who underwent breast surgery and SLNB and had a positive SLN from 2007 through 2010 at one of 12 participating NCCN centers or 12 MiBOQI sites. Patient and tumor characteristics, definitive breast procedure, year of diagnosis, and institutional affiliation were analyzed as predictors of use of SLNB alone in univariate Chi-Square and multivariable logistic regression models. Results: CALND was omitted in 314 (14.5%) of the 2,172 patients. Over time, there was a dramatic increase in the use of SLNB alone (12% in 2007 to 23% in 2010). In the univariate analyses, increased patient age, later year of diagnosis, lower T stage, and lower pathologic N stage were significant predictors of use of SLNB alone (all p < .0001). There was no association between definitive breast surgery type, hormone receptor status, Her-2 Neu status, or institutional affiliation and use of SLNB alone. In the multivariable model, older age at diagnosis, later year of diagnosis, and lower pathologic N stage remained significant independent predictors of SLNB alone. There were no significant differences in rates of omission of CALND between NCCN and MIBOQI sites. Conclusions: Omission of CALND occurred frequently in women with SLN positive breast cancer cared for in both NCCN and MiBOQI institutions in advance of reporting results of ACOSOG-Z0011. This shift was seen in management of patients undergoing lumpectomy as well as mastectomy. Further study is warranted to determine the extent of durable practice changes as well as any impact on survival and local-regional control. [ABSTRACT FROM AUTHOR]

This paper presents a comparative analysis of Outpatient Parenteral Antimicrobial Therapy (OPAT) structures and delivery options across different countries. OPAT, a cost-effective alternative to inpatient care for patients requiring IV antimicrobial therapy, has demonstrated multiple benefits such as patient satisfaction, economic cost savings, and reduced hospital-acquired infections. Despite these advantages, there is considerable international variation in OPAT use and implementation. By examining the OPAT structures of multiple countries, we aim to identify areas of variation and explore opportunities for expansion and improvement of OPAT services., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy.)

The production of anthropomorphic phantoms generated from tissue-equivalent materials is challenging but offers an excellent copy of the typical environment encountered in typical patients. High-quality dosimetry measurements and the correlation of the measured dose with the biological effects elicited by it are a prerequisite in preparation of clinical trials with novel radiotherapy approaches. We designed and produced a partial upper arm phantom from tissue-equivalent materials for use in experimental high-dose-rate radiotherapy. The phantom was compared to original patient data using density values and Hounsfield units obtained from CT scans. Dose simulations were conducted for broad-beam irradiation and microbeam radiotherapy (MRT) and compared to values measured in a synchrotron radiation experiment. Finally, we validated the phantom in a pilot experiment with human primary melanoma cells.

Rib fractures represent a substantial health burden. Chest injuries contribute to 25% of deaths after trauma and survivors can experience long-standing consequences, such as reduced functional capabilities and loss of employment. Over recent years, there has been an increase in the awareness of the importance of early identification, aggressive pain management and adequate safety netting for patients with chest injuries. Substandard management leads to increased rates of morbidity and mortality. The development of protocols in the emergency department (ED) for management of patients with chest wall injuries has demonstrated reduction of complication rates.Our aim was to develop an evidence-based, multidisciplinary chest injury pathway for the management of patients presenting with rib injury to our ED.Prior to implementation of the pathway in our department, only 39% of patients were documented as having received analgesia and only 7% of discharged patients had documented written verbal advice. There was no standardised method to perform regional anaesthetic blocks. Using quality improvement methods, we standardised imaging modality, risk stratification with a scoring system, analgesia with emphasis on regional anaesthesia blocks and disposition with information leaflets for those discharged.Implementation of the pathway increased rates of documented analgesia received from 39% to 70%. The number of regional anaesthetic blocks performed went from 0% to 60% and the number of patients receiving discharge advice went from 7% to 70%. Compliance of doctors and nurses with the pathway was 63%.Our previous audits showed substandard management of patients with chest injuries in our department. Through this quality improvement project, we were able to improve the quality of care provided to patients attending with rib fractures by increasing rate of analgesia received, regional blocks performed and discharge advice given., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: Conflict of interest The authors declare that there is no conflict of interests.

Background: Ambulatory management of isolated acute deep venous thrombosis (DVT) is the recommended standard of care in selected populations. However, in practice a significant number of patients continue to be managed as in-patients., Objectives: In this study we aimed to evaluate acute DVT treatment pathways in our emergency department (ED) in practice and to identify barriers to outpatient management., Methods: This study was a cross-sectional analysis of prospectively collected data pertaining to consecutive patients presenting to the ED of a large, city center, academic teaching hospital over a 46 week period who were diagnosed with DVT., Results: Implementation of an outpatient care pathway led to the majority of patients presenting with DVT in our institution being treated without hospital admission. Forty percent (31/78) of patients with DVT were treated with a direct oral anticoagulant (DOAC) as an outpatient in line with international best practice guidelines., Conclusion: The study provides a clear picture of the clinical profile and management of patients in clinical practice. Due to the lack of resources and supported infrastructure it is difficult to effectively implement outpatient venous thromboembolism (VTE) management to its full potential. Directing resources towards strategies which facilitate outpatient DVT treatment among vulnerable patient groups could represent a means of reducing hospital admissions for DVT in urban centers. Our study highlights the success and clinical limitations of the outpatient treatment model, which should become standard as part of wider VTE care., Competing Interests: Competing interestsThis study was partially supported by an unrestricted grant from Bayer pharmaceuticals.

Objectives: To determine the incidence of venous thromboembolism (VTE) and the incidence of hospital-acquired VTE (HA-VTE) arising within the population served by the Ireland East Hospital Group (IEHG)., Design: /home/user/Documents/Sathish Kumar G/RFO/June/21-06-2019/bmjopen&#95;iss&#95;9&#95;7&#95;20190621&#95;1/ A retrospective observational study was conducted using hospital discharge data obtained from the hospital inpatient enquiry data reporting system. In this system, VTE events recorded as 'primary diagnosis' represented the reason for initial hospital admission, whereas VTE recorded as a 'secondary diagnosis' occurred following admission and were therefore used as an approximation of HA-VTE. These data were used to estimate the overall incidence of VTE and the proportion of these events which were hospital-acquired., Setting: The IEHG is the largest hospital group in the Irish healthcare system and serves a population of over 1 million individuals., Participants: Data were generated from records pertaining to the 2727 patient admission episodes where a diagnosis of VTE was made during the 22-month study period., Results: During the study period, 2727 VTE events were recorded within the IEHG (which serves a population of 1 036 279) corresponding to an incidence of 1.44 (95% CI 1.36 to 1.51) per 1000 per annum. 1273 (47%) of VTE events were recorded as secondary VTE. The incidence of VTE was highest among individuals over 85 years of age (16.03 per 1000;95% CI 12.81 to 19.26) and was more common following emergency hospital admission., Conclusion: These data suggest that HA-VTE accounts for at least 47% of all VTE events arising within a hospital group serving a population of over 1 million individuals within the Ireland. Given that HA-VTE is a well-recognised source of (potentially preventable) hospital deaths, these findings provide a compelling argument for prioritising strategies directed at reducing the risk of VTE among hospital patients served by the IEHG and within the Ireland as a whole., Competing Interests: Competing interests: FNA has received research funding from Leo Pharma and Bayer however these awards are not relevant to the current study., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Globally, malignant melanoma shows a steady increase in the incidence among cancer diseases. Malignant melanoma represents a cancer type where currently no biomarker or diagnostics is available to identify disease stage, progression of disease or personalized medicine treatment. The aim of this study was to assess the tissue expression of alpha-synuclein, a protein implicated in several disease processes, in metastatic tissues from malignant melanoma patients. A targeted Selected Reaction Monitoring (SRM) assay was developed and utilized together with stable isotope labeling for the relative quantification of two target peptides of alpha-synuclein. Analysis of alpha-synuclein protein was then performed in ten metastatic tissue samples from the Lund Melanoma Biobank. The calibration curve using peak area ratio (heavy/light) versus concentration ratios showed linear regression over three orders of magnitude, for both of the selected target peptide sequences. In support of the measurements of specific protein expression levels, we also observed significant correlation between the protein and mRNA levels of alpha-synuclein in these tissues. Investigating levels of tissue alpha-synuclein may add novel aspect to biomarker development in melanoma, help to understand disease mechanisms and ultimately contribute to discriminate melanoma patients with different prognosis.

Background: The objectives and goals of the Southern Swedish Malignant Melanoma (SSMM) are to develop, build and utilize cutting edge biobanks and OMICS platforms to better understand disease pathology and drug mechanisms. The SSMM research team is a truly cross-functional group with members from oncology, surgery, bioinformatics, proteomics, and genomics initiatives. Within the research team there are members who daily diagnose patients with suspect melanomas, do follow-ups on malignant melanoma patients and remove primary or metastatic lesions by surgery. This inter-disciplinary clinical patient care ensures a competence build as well as a best practice procedure where the patient benefits., Methods: Clinical materials from patients before, during and after treatments with clinical end points are being collected. Tissue samples as well as bio-fluid samples such as blood fractions, plasma, serum and whole blood will be archived in 384-high density sample tube formats. Standardized approaches for patient selections, patient sampling, sample-processing and analysis platforms with dedicated protein assays and genomics platforms that will hold value for the research community are used. The patient biobank archives are fully automated with novel ultralow temperature biobank storage units and used as clinical resources., Results: An IT-infrastructure using a laboratory information management system (LIMS) has been established, that is the key interface for the research teams in order to share and explore data generated within the project. The cross-site data repository in Lund forms the basis for sample processing, together with biological samples in southern Sweden, including blood fractions and tumor tissues. Clinical registries are associated with the biobank materials, including pathology reports on disease diagnosis on the malignant melanoma (MM) patients., Conclusions: We provide data on the developments of protein profiling and targeted protein assays on isolated melanoma tumors, as well as reference blood standards that is used by the team members in the respective laboratories. These pilot data show biobank access and feasibility of performing quantitative proteomics in MM biobank repositories collected in southern Sweden. The scientific outcomes further strengthen the build of healthcare benefit in the complex challenges of malignant melanoma pathophysiology that is addressed by the novel personalized medicines entering the market.

Background: Signal transduction pathways convey information from the outside of the cell to transcription factors, which in turn regulate gene expression. Our objective is to analyze tumor gene expression data from microarrays in the context of such pathways., Results: We use pathways compiled from the TRANSPATH/TRANSFAC databases and the literature, and three publicly available cancer microarray data sets. Variation in pathway activity, across the samples, is gauged by the degree of correlation between downstream targets of a pathway. Two correlation scores are applied; one considers all pairs of downstream targets, and the other considers only pairs without common transcription factors. Several pathways are found to be differentially active in the data sets using these scores. Moreover, we devise a score for pathway activity in individual samples, based on the average expression value of the downstream targets. Statistical significance is assigned to the scores using permutation of genes as null model. Hence, for individual samples, the status of a pathway is given as a sign, + or -, and a p-value. This approach defines a projection of high-dimensional gene expression data onto low-dimensional pathway activity scores. For each dataset and many pathways we find a much larger number of significant samples than expected by chance. Finally, we find that several sample-wise pathway activities are significantly associated with clinical classifications of the samples., Conclusion: This study shows that it is feasible to infer signal transduction pathway activity, in individual samples, from gene expression data. Furthermore, these pathway activities are biologically relevant in the three cancer data sets.

Background: Ranked gene lists from microarray experiments are usually analysed by assigning significance to predefined gene categories, e.g., based on functional annotations. Tools performing such analyses are often restricted to a category score based on a cutoff in the ranked list and a significance calculation based on random gene permutations as null hypothesis., Results: We analysed three publicly available data sets, in each of which samples were divided in two classes and genes ranked according to their correlation to class labels. We developed a program, Catmap (available for download at http://bioinfo.thep.lu.se/Catmap), to compare different scores and null hypotheses in gene category analysis, using Gene Ontology annotations for category definition. When a cutoff-based score was used, results depended strongly on the choice of cutoff, introducing an arbitrariness in the analysis. Comparing results using random gene permutations and random sample permutations, respectively, we found that the assigned significance of a category depended strongly on the choice of null hypothesis. Compared to sample label permutations, gene permutations gave much smaller p-values for large categories with many coexpressed genes., Conclusions: In gene category analyses of ranked gene lists, a cutoff independent score is preferable. The choice of null hypothesis is very important; random gene permutations does not work well as an approximation to sample label permutations.

Background: The availability of high throughput methods for measurement of mRNA concentrations makes the reliability of conclusions drawn from the data and global quality control of samples and hybridization important issues. We address these issues by an information theoretic approach, applied to discretized expression values in replicated gene expression data., Results: Our approach yields a quantitative measure of two important parameter classes: First, the probability P(sigma|S) that a gene is in the biological state sigma in a certain variety, given its observed expression S in the samples of that variety. Second, sample specific error probabilities which serve as consistency indicators of the measured samples of each variety. The method and its limitations are tested on gene expression data for developing murine B-cells and a t-test is used as reference. On a set of known genes it performs better than the t-test despite the crude discretization into only two expression levels. The consistency indicators, i.e. the error probabilities, correlate well with variations in the biological material and thus prove efficient., Conclusions: The proposed method is effective in determining differential gene expression and sample reliability in replicated microarray data. Already at two discrete expression levels in each sample, it gives a good explanation of the data and is comparable to standard techniques.

The development of a mature B lymphocyte from a bone marrow stem cell is a highly ordered process involving stages with defined features and gene expression patterns. To obtain a deeper understanding of the molecular genetics of this process, we have performed RNA expression analysis of a set of mouse B lineage cell lines representing defined stages of B cell development using Affymetrix microarrays. The cells were grouped based on their previously defined phenotypic features, and a gene expression pattern for each group of cell lines was established. The data indicated that the cell lines representing a defined stage generally presented a high similarity in overall expression profiles. Numerous genes could be identified as expressed with a restricted pattern using dCHIP-based, quantitative comparisons or presence/absence-based, probabilistic state analysis. These experiments provide a model for gene expression during B cell development, and the correctly identified expression patterns of a number of control genes suggest that a series of cell lines can be useful tools in the elucidation of the molecular genetics of a complex differentiation process.

A number of studies have implicated a role for the cell surface glycoprotein CD44 in several biologic events, such as lymphopoiesis, homing, lymphocyte activation, and apoptosis. We have earlier reported that signaling via CD44 on naive B cells in addition to B-cell receptor (BCR) and CD40 engagement generated a germinal center-like phenotype. To further characterize the global role of CD44 in B differentiation, we examined the expression profile of human B cells cultured in vitro in the presence or absence of CD44 ligation, together with anti-immunoglobulin (anti-Ig) and anti-CD40 antibodies. The data sets derived from DNA microarrays were analyzed using a novel statistical analysis scheme created to retrieve the most likely expression pattern of CD44 ligation. Our results show that genes such as interleukin-6 (IL-6), IL-1alpha, and beta(2)-adrenergic receptor (beta(2)-AR) were specifically up-regulated by CD44 ligation, suggesting a novel role for CD44 in immunoregulation and inflammation.

Previous studies have suggested that the early-B-cell-specific mb-1(Igalpha) promoter is regulated by EBF and Pax-5. Here, we used in vivo footprinting assays to detect occupation of binding sites in endogenous mb-1 promoters at various stages of B-cell differentiation. In addition to EBF and Pax-5 binding sites, we detected occupancy of a consensus binding site for E2A proteins (E box) in pre-B cells. EBF and E box sites are crucial for promoter function in transfected pre-B cells, and EBF and E2A proteins synergistically activated the promoter in transfected HeLa cells. Other data suggest that EBF and E box sites are less important for promoter function at later stages of differentiation, whereas binding sites for Pax-5 (and its Ets ternary complex partners) are required for promoter function in all mb-1-expressing cells. Using DNA microarrays, we found that expression of endogenous mb-1 transcripts correlates most closely with EBF expression and negatively with Id1, an inhibitor of E2A protein function, further linking regulation of the mb-1 gene with EBF and E2A. Together, our studies demonstrate the complexity of factors regulating tissue-specific transcription and support the concept that EBF, E2A, and Pax-5 cooperate to activate target genes in early B-cell development.

Purpose: The tumor suppressor gene Smad4/DPC4, a key transcription factorin transforming growth factor beta (TGF-beta) signaling cascades,is inactivated in 50% of pancreatic adenocarcinomas. We seek to determine the role of Smad4/DPC4 in the suppression of tumor cell growth and in the regulation of TGF-beta-mediated expression of cell-cycle regulatory genes p15(ink4b) and p21(waf1)., Experimental Design: Smad4/DPC4 is overexpressed by adenoviral infection in CFPac-1 pancreatic cancer cells, in which the Smad4/DPC4 is homozygously deleted, and in Capan-1 pancreatic cancer cells, in which Smad4/DPC4 is not expressed. Expression of the TGF-beta downstream target gene p21(waf1), regulation of the p15(ink4b) promoter, anchorage-independent growth, and tumorigenesis were examined., Results: We demonstrate that expression of Smad4/DPC4 in Capan-1 cells reduced anchorage-independent growth by more than 50%, and inhibited xenograft tumor growth. However, overexpression of Smad4/DPC4 did not inhibit CFPac-1 cell growth. Interestingly, Smad4/DPC4 induced expression of p15(ink4b), p21(waf1), and TGF-beta-responsive reporter gene in Capan-1 but not in CFPac-1 cells. Furthermore, we found a previously unidentified Smad4 binding element (SBE) located in the region between -356 and -329 bp of the p15(ink4b) promoter. The p15(ink4b) promoter reporter gene assays revealed that Smad4-dependent transcriptional activation is mediated by this SBE, which indicates that p15(ink4b) is one of the downstream target genes regulated by Smad/DPC4., Conclusion: These results explain the role of Smad4/DPC4 in TGF-beta-mediated inhibition of cell proliferation in vitro and in vivo. Moreover, these results suggest that Smad4/DPC4-mediated tumor suppression and induction of TGF-beta-regulated cell-cycle-inhibitory genes may depend on additional factors that are absent in CFPac-1 cells.

Objective: To determine the incidence and prognostic significance of documented eradication of breast cancer axillary lymph node (ALN) metastases after neoadjuvant chemotherapy., Summary Background Data: Neoadjuvant chemotherapy is the standard of care for patients with locally advanced breast cancer and is being evaluated in patients with earlier-stage operable disease., Methods: One hundred ninety-one patients with locally advanced breast cancer and cytologically documented ALN metastases were treated in two prospective trials of doxorubicin-based neoadjuvant chemotherapy. Patients had breast surgery with level I and II axillary dissection followed by additional chemotherapy and radiation treatment. Nodal sections from 43 patients who were originally identified as having negative ALNs at surgery were reevaluated and histologically confirmed to be without metastases. An additional 1112 sections from these lymph node blocks were obtained; half were stained with an anticytokeratin antibody cocktail and analyzed. Survival was calculated using the Kaplan-Meier method., Results: Of 191 patients with positive ALNs at diagnosis, 23% (43 patients) were converted to a negative axillary nodal status on histologic examination (median number of nodes removed = 16). Of the 43 patients with complete axillary conversion, 26% (n = 11) had N1 disease and 74% (n = 32) had N2 disease. On univariate analysis, patients with complete versus incomplete histologic axillary conversion were more likely to have initial estrogen-receptor-negative tumors, smaller primary tumors, and a complete pathologic response in the primary tumor. The 5-year disease-free survival rates were 87% in patients with preoperative eradication of axillary metastases and 51% for patients with residual nodal disease after neoadjuvant chemotherapy. Of the 39 patients with complete histologic conversion for whom nodal blocks were available, occult nodal metastases were found in additional nodal sections in 4 patients (10%). At a median follow-up of 61 months, the 5-year disease-free survival rates were 87% in patients without occult nodal metastases and 75% in patients with occult nodal metastases., Conclusions: Neoadjuvant chemotherapy can completely clear the axilla of microscopic disease before surgery, and occult metastases are found in only 10% of patients with a histologically negative axilla. The results of this study have implications for the potential use of sentinel lymph node biopsy as an alternative to axillary dissection in patients treated with neoadjuvant chemotherapy.