Response in axillary lymph nodes to neoadjuvant chemotherapy for breast cancers: correlation with breast response, pathologic features, and accuracy of radioactive seed localization.

OBJECTIVES: This study examined the accuracy of radioactive seed localization (RSL) of lymph nodes (LNs) following neoadjuvant chemotherapy (NAC) for invasive breast carcinoma, recorded pathologic features of LNs following NAC, evaluated concordance of response between breast and LNs, and identified clinicopathologic factors associated with higher risk of residual lymph node involvement. METHODS: Clinical records, imaging, and pathology reports and slides were retrospectively reviewed for 174 breast cancer patients who received NAC. Chi-square and Fisher's exact tests were used to compare differences in risk of residual lymph node disease. RESULTS: Retrieval of biopsied pre-therapy positive LN was confirmed in 86/93 (88%) cases overall, and in 75/77 (97%) of cases utilizing RSL. Biopsy clip site was the best pathologic feature to confirm retrieval of a biopsied lymph node. Pre-therapy clinical N stage > 0, positive pre-therapy lymph node biopsy, estrogen and progesterone receptor positivity, Ki67 < 50%, HR + /HER2- tumors, and residual breast disease had higher likelihood of residual lymph node disease after NAC (p < 0.001). CONCLUSIONS: RSL-guided LN excision improves retrieval of previously biopsied LNs following NAC. The pathologist can use histologic features to confirm retrieval of targeted LNs, and tumor characteristics can be used to predict a higher risk of residual LN involvement.

Single-institution outcomes after excision of benign phyllodes tumors: low recurrence risk even with positive margins.

PURPOSE: Benign phyllodes tumors (BPT) are rare breast neoplasms with clinical behavior that poses low recurrence risk. Guidelines regarding appropriate margins recommend surgical excision to negative margins, sometimes requiring re-excision surgery. Contemporary experience suggests that re-excision in the face of positive margins may not be needed. METHODS: This is a retrospective review of a single-institution experience with BPT from 2010 to 2019 with 102 patients. Demographics, outcomes and follow-up were analyzed. RESULTS: The median age was 37 years. 95% had a pre-operative biopsy and only 6% were confirmed BPT before surgery.56% had positive margins and were more likely to be younger and have a pre-operative diagnosis of fibroadenoma. The median follow-up was 33 months. Between the positive and negative margin groups, recurrence rates were not significantly different (p = 0.87). CONCLUSION: Positive margins on excision of BPT poses a low recurrence risk and re-excision surgery is not necessary.

Timely cancer genetic counseling and testing for young women with breast cancer: impact on surgical decision-making for contralateral risk-reducing mastectomy.

PURPOSE: Genetic testing (GT) can identify individuals with pathogenic/likely pathogenic variants (PV/LPVs) in breast cancer (BC) predisposition genes, who may consider contralateral risk-reducing mastectomy (CRRM). We report on CRRM rates in young women newly diagnosed with BC who received GT through a multidisciplinary clinic. METHODS: Clinical data were reviewed for patients seen between November 2014 and June 2019. Patients with non-metastatic, unilateral BC diagnosed at age ≤ 45 and completed GT prior to surgery were included. Associations between surgical intervention and age, BC stage, family history, and GT results were evaluated. RESULTS: Of the 194 patients, 30 (15.5%) had a PV/LPV in a BC predisposition gene (ATM, BRCA1, BRCA2, CHEK2, NBN, NF1), with 66.7% in BRCA1 or BRCA2. Of 164 (84.5%) uninformative results, 132 (68%) were negative and 32 (16.5%) were variants of uncertain significance (VUS). Overall, 67 (34.5%) had CRRM, including 25/30 (83.3%) PV/LPV carriers and 42/164 (25.6%) non-carriers. A positive test result (p < 0.01) and significant family history were associated with CRRM (p = 0.02). For the 164 with uninformative results, multivariate analysis showed that CRRM was not associated with age (p = 0.23), a VUS, (p = 0.08), family history (p = 0.10), or BC stage (p = 0.11). CONCLUSION: In this cohort of young women with BC, the identification of a PV/LPV in a BC predisposition gene and a significant family history were associated with the decision to pursue CRRM. Thus, incorporation of genetic services in the initial evaluation of young patients with a new BC could contribute to the surgical decision-making process.

Cutting Instruments to Cut Costs: A Simple Initiative with Breast Surgical Operating Room Trays that Resulted in Substantial Savings.

BACKGROUND: A substantial expense in surgical care is incurred in the operating room (OR). We evaluated the financial impact of a systematic reduction in instrument tray contents on charges for breast surgery procedures. METHODS: A catalog of OR trays historically used for breast procedures (excisional biopsy, segmental and total mastectomy with or without axillary staging) was reviewed by four dedicated breast surgeons and downsized to a single tray accommodating all surgeon preferences. A matched-case comparison was performed pre- and post-downsizing. Cost analysis for salary and benefits (S&B) and unit supply cost (USC) pre- and post-downsizing were carried out. Instrument number, OR tray weights, set-up, and breakdown times were also compared. RESULTS: Post-downsizing, OR tray counts were reduced from 132 to 67 instruments (49%) and tray weight decreased from 30 to 20 pounds (33%). Scrub technician set-up and breakdown times were shorter by 22% and 25%, respectively. Comparing 449 matched cases (239 pre- and 210 post-downsizing), S&B and USC post-downsizing were decreased collectively for all procedures (p < 0.0001). With an average variance of S&B and USC (pre- to post-intervention) of $354, and an annualized case load of 813 operations, this could translate into S&B and USC savings of $287,802 per year. CONCLUSION: Simply downsizing OR breast trays resulted in decreased combined S&B and USC per procedure, leading to a substantial cost savings for the healthcare system. This measure aligns with a value and quality-based approach to patient care and could be easily replicated across institutions and specialties.

Association of Tumor Molecular Subtype and Stage with Breast and Axillary Pathologic Complete Response After Neoadjuvant Chemotherapy for Breast Cancer.

BACKGROUND: Axillary pathologic complete response (pCR) confers higher overall and recurrence-free survival than residual axillary disease. Although breast pCR (ypT0) is associated with a pathologically negative axilla (ypN0) in human epidermal growth factor receptor 2-positive (HER2+) and triple-negative breast cancer (TNBC), how clinical T (cT) and N (cN) staging are associated with ypN0 in other tumor subtypes is incompletely understood. METHODS: A single-institution cancer registry was retrospectively reviewed for patients receiving neoadjuvant chemotherapy (NAC) followed by surgery from 2010 to 2018. Fisher's exact tests compared proportion of breast and axillary pCR by tumor subtype (hormone receptor [HR]-positive /HER2-,HR+/HER2+,HR-/HER2+,HR-/HER2-). Logistic regression determined factors associated with ypN0. Sensitivity analyses determined how cN status affected ypN status by tumor subtype. RESULTS: The study enrolled 1348 patients. The median age was 54 years (interquartile range [IQR], 44-63 years), and 55% of the patients (n = 736) were postmenopausal. The tumor subtypes were HR+/HER2- (12%, n = 155), HR+/HER2+ (48%, n = 653), HR-/HER2+ (25%, n = 343), and TNBC (15%, n = 197). In the study, cT included T0 (1%, n = 18), T1 (20%, n = 272), T2 (53%, n = 713), T3 (17%, n = 230), and T4 (9%, n = 111), and cN included cN0 (51%, n = 687), cN1 (41%, n = 549), cN2 (5%, n = 61), and cN3 (3%, n = 43). Breast pCR and ypN0 occurred most in the HER2+ and TNBC subtypes. A negative association was found between ypN0 and age at diagnosis (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.97-0.99; p < 0.001), cT4 stage (OR, 0.29; 95% CI, 0.09-0.91; p = 0.034), and HR+ subtypes (HR+/HER2-: OR, 0.54; 95% CI, 0.31-0.94; p = 0.028; HR+/HER2+: OR, 0.60; 95% CI, 0.39-0.93; p = 0.024). The HR-/HER2+ subtype was associated with ypN0 (OR, 1.70; 95% CI, 1.05-2.73; p = 0.030), and cN2/cN3 was negatively associated with ypN0 in HR+/HER2+ disease (OR, 0.26; 95% CI, 0.11-0.61; p = 0.002), HR-/HER2+ disease (OR, 0.42; 95% CI, 0.22-0.77; p = 0.005), and TNBC (OR, 0.11; 95% CI, 0.03-0.40; p = 0.001). CONCLUSION: Tumor subtype, clinical stage, and age at diagnosis may be important in consideration of de-escalation of axillary staging.

Post-operative Nausea and Analgesia Following Total Mastectomy is Improved After Implementation of an Enhanced Recovery Protocol.

BACKGROUND: Enhanced Recovery Protocols (ERPs) provide a multimodal approach to perioperative care, with the aims of improving patient outcomes while decreasing perioperative antiemetic and narcotic requirements. With high rates of post-operative nausea or vomiting (PONV) following total mastectomy (TM), we hypothesized that our institutional designed ERP would reduce PONV while improving pain control and decrease opioid use. METHODS: An ERP was implemented at a single institution for patients undergoing TM with or without implant-based reconstruction. Patients from the first two months of implementation (ERP group, N = 72) were compared with a retrospective usual-care cohort from a three-month period before implementation (UC group, N = 83). Outcomes included PONV incidence, measured with antiemetic use; patient-reported pain scores; perioperative opioid consumption, measured by oral morphine equivalents (OME); and length of stay (LOS). RESULTS: The characteristics of the two groups were similar. PONV incidence and perioperative opioid consumption were lower in the ERP than the UC group (21% vs. 40%, p 0.011 and mean 44.1 OME vs. 104.3 OME, p < 0.001), respectively. These differences in opioid consumption were observed in the operating room and post-anesthesia care unit (PACU); opioid consumption on the floor was similar between the two groups. Patient-reported pain scores were lower in the ERP than the UC group (mean highest pain score 6.4 vs. 7.4, p 0.003). PACU and hospital LOS were similar between the two groups. CONCLUSION: ERP implementation was successful in decreasing PONV following TM with and without reconstruction, while simultaneously decreasing overall opioid consumption without compromising patient comfort.

Metaplastic breast carcinoma: a clinical-pathologic study of 97 cases with subset analysis of response to neoadjuvant chemotherapy.

Metaplastic breast carcinoma is a rare heterogeneous category of breast cancer, often associated with a poor prognosis. Clinical-pathologic studies with respect to varied morphologic subtypes are lacking. There is also a dearth of studies assessing the response of metaplastic breast carcinoma to neoadjuvant chemotherapy. Cases of metaplastic breast carcinoma diagnosed between 2007 and 2017 were identified. Various clinical-pathologic variables were tested for association with survival. Patients who underwent neoadjuvant chemotherapy were assessed for pathologic response. Median age at diagnosis with metaplastic breast carcinoma was 64 years. With a median follow-up of 39 months, 26 patients (27%) recurred (24 distant and 2 loco-regional). The overall survival rate of the cohort was 66% (64/97). A number of variables were associated with survival in univariable analysis; however, in multivariable analysis, only lymph node status and tumor size (pT3 vs. pT1/2) were significantly associated with all survival endpoints: recurrence-free survival, distant recurrence-free survival, overall survival and breast cancer-specific survival. Twenty-nine of 97 (30%) patients with metaplastic breast carcinoma received neoadjuvant chemotherapy. Five (17%) patients achieved pathologic complete response. Matrix-producing morphology was associated with higher probability of achieving pathologic complete response (p = 0.027). Similar to other breast cancer subtypes, tumor size and lymph node status are prognostic in metaplastic carcinomas. The pathologic complete response rate of metaplastic breast carcinoma in our cohort was 17%, higher than previously reported. Although the matrix-producing subtype was associated with pathologic complete response, there was no survival difference with respect to tumor subtypes.

Randomized Trial Comparing Resection of Primary Tumor with No Surgery in Stage IV Breast Cancer at Presentation: Protocol MF07-01.

BACKGROUND: The MF07-01 trial is a multicenter, phase III, randomized, controlled study comparing locoregional treatment (LRT) followed by systemic therapy (ST) with ST alone for treatment-naïve stage IV breast cancer (BC) patients. METHODS: At initial diagnosis, patients were randomized 1:1 to either the LRT or ST group. All the patients were given ST either immediately after randomization or after surgical resection of the intact primary tumor. RESULTS: The trial enrolled 274 patients: 138 in the LRT group and 136 in the ST group. Hazard of death was 34% lower in the LRT group than in the ST group (hazard ratio [HR], 0.66; 95% confidence interval [CI], 0.49-0.88; p = 0.005). Unplanned subgroup analyses showed that the risk of death was statistically lower in the LRT group than in the ST group with respect to estrogen receptor (ER)/progesterone receptor (PR)(+) (HR 0.64; 95% CI 0.46-0.91; p = 0.01), human epidermal growth factor 2 (HER2)/neu(-) (HR 0.64; 95% CI 0.45-0.91; p = 0.01), patients younger than 55 years (HR 0.57; 95% CI 0.38-0.86; p = 0.007), and patients with solitary bone-only metastases (HR 0.47; 95% CI 0.23-0.98; p = 0.04). CONCLUSION: In the current trial, improvement in 36-month survival was not observed with upfront surgery for stage IV breast cancer patients. However, a longer follow-up study (median, 40 months) showed statistically significant improvement in median survival. When locoregional treatment in de novo stage IV BC is discussed with the patient as an option, practitioners must consider age, performance status, comorbidities, tumor type, and metastatic disease burden.

Magee Equation 3 predicts pathologic response to neoadjuvant systemic chemotherapy in estrogen receptor positive, HER2 negative/equivocal breast tumors.

Magee Equations were derived as an inexpensive, rapid alternative to Oncotype DX. The Magee Equation 3 utilizes immunohistochemical and FISH data for estrogen receptor (ER), progesterone receptor (PR), HER2 and Ki-67 for its calculation (24.30812+ERIHC × (-0.02177)+PRIHC × (-0.02884)+(0 for HER2 negative, 1.46495 for equivocal, 12.75525 for HER2 positive)+Ki-67 × 0.18649). We hypothesize that Magee Equation 3 scores from pre-therapy core biopsy can predict response to neoadjuvant systemic chemotherapy. A prospectively-maintained database of patients who received neoadjuvant systemic therapy from 2010 to 2014 at a single institution was retrospectively reviewed. Pathologic complete response was defined as absence of invasive tumor in the breast and regional lymph nodes. Of the 614 cases, tumors with missing immunohistochemical results and those that were ER negative or HER2 positive were excluded. This resulted in 237 ER positive, HER2 negative/equivocal tumors that formed the basis of this study. Magee Equation 3 scores were divided into 3 categories similar to Oncotype DX, ie, 0 to <18 (low), 18 to <31 (intermediate), and 31 or higher (high) scores. The pathologic complete response rate for low, intermediate and high Magee Equation 3 scores was 0%, 4%, and 36%, respectively. Patients with high Magee Equation 3 scores were 13 times more likely to achieve pathologic complete response compared to those with Magee Equation 3 scores less than 31 (95% CI 5.09-32.87, P<0.0001). For patients that did not achieve pathologic complete response, high Magee Equation 3 correlated with higher recurrence rate, with the majority occurring in patients with positive lymph nodes in the resection specimen. Magee Equation 3 score ≥31 predicts pathologic complete response in the neoadjuvant setting and for tumor recurrence, when pathologic complete response is not achieved. These results show the utility of Magee Equation 3 in predicting patients who will benefit from chemotherapy but warrant prospective multi-institutional validation.

Axillary Staging After Neoadjuvant Chemotherapy for Breast Cancer: A Pilot Study Combining Sentinel Lymph Node Biopsy with Radioactive Seed Localization of Pre-treatment Positive Axillary Lymph Nodes.

BACKGROUND: Neoadjuvant chemotherapy (NAC) downstages axillary disease in 55 % of node-positive (N1) breast cancer. The feasibility and accuracy of sentinel lymph node biopsy (SLNB) after NAC for percutaneous biopsy-proven N1 patients who are clinically node negative (cN0) by physical examination after NAC is under investigation. ACOSOG Z1071 reported a false-negative rate of <10 % if ≥3 nodes are removed with dual tracer, including excision of the biopsy-proven positive lymph node (BxLN). We report our experience using radioactive seed localization (RSL) to retrieve the BxLN with SLNB (RSL/SLNB) for cN0 patients after NAC. METHODS: We performed a retrospective review of a single-institution, prospectively maintained registry for the years 2013 to 2014. Patients with BxLN who received NAC and had RSL/SLNB were identified. All BxLNs were marked with a radiopaque clip before NAC to facilitate RSL. RESULTS: Thirty patients with BxLN before NAC were cN0 after NAC and underwent RSL/SLNB. Median age was 55 years. Disease stage was IIA-IIIB. Twenty-nine of 30 had ductal cancer (12 triple negative and 16 HER-2 positive). One to 11 nodes were retrieved. Twenty-nine of 30 BxLN were successfully localized with RSL. Note was made of the BxLN-containing isotope and/or dye in 22 of 30. Nineteen patients had no residual axillary disease; 11 had persistent disease. All who remained node positive had disease in the BxLN. CONCLUSIONS: RSL/SLNB is a promising approach for axillary staging after NAC in patients whose disease becomes cN0. The status of the BxLN after NAC predicted nodal status, suggesting that localization of the BxLN may be more accurate than SLNB alone for staging the axilla in the cN0 patient after NAC.

Predictive value of axillary nodal imaging by magnetic resonance imaging based on breast cancer subtype after neoadjuvant chemotherapy.

BACKGROUND: Magnetic resonance imaging (MRI) is commonly used to determine residual breast disease after neoadjuvant chemotherapy (NCT) for cancer. Few studies have assessed its role in predicting nodal response, by cancer subtype. METHODS: A retrospective review was completed using our institutional cancer registry. Patients who started NCT from 2005 to 2010 with clinically node positive disease were evaluated. Those who underwent post-NCT breast MRI were selected. Radiologic response was determined by an independent review. Nodal involvement was confirmed pathologically after surgery. RESULTS: A total of 135 patients underwent post-NCT breast MRI. The positive and negative predictive values of MRI are 93% and 26%, respectively. A subset analysis by cancer phenotype demonstrates triple negative cancers have the highest sensitivity (68%) and luminal cancers have the highest positive predictive value (100%). CONCLUSIONS: This study demonstrates that MRI post-NCT, even by cancer subtype, cannot reliably predict residual nodal disease because of high false-negative rates (low negative-predictive value).

Breast cancer-related lymphedema after axillary lymph node dissection: does early postoperative prediction model work?

PURPOSE: Early detection and timely intervention demonstrate the greatest promise of reducing the incidence of late-stage lymphedema in breast cancer patients undergoing axillary lymph node dissection (ALND). A nomogram was developed for predicting the risk of lymphedema (LE) in patients with ALND. This study's aim was to test the early postoperative prediction model for the diagnosis of clinical and subclinical LE after ALND. METHODS: Patients requiring ALND were identified preoperatively through our LE program database. Measurements using metered tape with bioimpedance spectroscopy (L-Dex U400) were obtained preoperatively (n = 180) and at 3-6-month intervals postoperatively. The 5-year probability of LE after ALND was calculated using the Cleveland Clinic Risk Calculator. The discrimination of the nomogram was assessed by calculating the area under (AUC) the receiver operating characteristic curve. RESULTS: LE was present in 36.1% (n = 65) of 180 patients with ALND. Of these 65 patients, 22 (12.2%) had clinical LE and 43 (23.9%) had subclinical LE. Statistical analyses showed significant differences in BMI and receipt of radiotherapy between patients with and without LE (p = 0.03 and p = 0.01, respectively). AUC was 0.601, 0.614, and 0.600 for the nomogram using any LE, clinical LE, and subclinical LE patients, respectively. CONCLUSIONS: The recently created prediction model for the diagnosis of LE in ALND is not accurate in predicting who will develop clinical or subclinical LE. Periodic monitoring of women with ALND is the most effective method to aid in reducing clinical LE incidence through early detection and timely intervention of LE.

Developing in vitro models of human ductal carcinoma in situ from primary tissue explants.

Because there are currently no reliable predictors for progression of ductal carcinoma in situ (DCIS) to invasive disease, nearly all patients receive comprehensive therapy, leading to over-treatment in many cases. Few in vitro models for studying DCIS progression have been developed. We report here the successful culture and expansion of primary DCIS from surgical specimens using a conditional reprogramming protocol. Patients with percutaneous core-needle biopsy demonstrating DCIS were enrolled in a tissue banking protocol after informed consent was received. Fresh tissue was taken from lumpectomy or mastectomy specimens, mechanically and enzymatically dissociated, cultured in medium conditioned by irradiated mouse fibroblasts and supplemented with rho-associated protein kinase (ROCK) inhibitor, and characterized by immunocytochemistry. Out of 33 DCIS cases, 58% (19) were expanded for up to 2 months in culture, and 42% (14) were frozen immediately after mechanical dissociation for future growth. The cultures are almost exclusively composed of cytokeratin 8- and EpCAM-positive luminal and cytokeratin 14-, cytokeratin 5-, and p63-positive basal mammary epithelial cells, suggesting maintenance of heterogeneity in vitro. Furthermore, as assessed by luminal and basal marker expression, these cells retain their cellular identities both in the "conditionally reprogrammed" proliferative state and after conditioned media and ROCK inhibitor withdrawal. When grown to 100 % confluency, the cultures organize into luminal and basal layers as well as luminal compartments surrounded by basal cells. Primary cultures of DCIS derived directly from patient tissues can be generated and may serve as in vitro models for the study of DCIS.

Factors affecting cosmesis after breast conserving surgery without oncoplastic techniques in an experienced comprehensive breast center.

We aimed to study the factors affecting cosmetic outcome (CO) in breast conserving surgery (BCS) without oncoplastic techniques in our center with a BCS rate higher than 60% in more than 1000 breast cancer surgeries a year. In this study 284 patients who underwent BCS without oncoplastic techniques were included. Surgeries were performed by two experienced breast surgeons with more than 25 years of experience. These patients were followed in our established Wellness Clinic postoperatively. The CO is evaluated according to the "Harvard Breast Cosmesis Grading Scale" by a breast surgeon who did not participate in the patient's surgery. The correlation among patient factors (age, breast volume, menopausal status), tumor factors (size, location, distance to areola) and treatment factors (excision volume, breast skin excision, axillary surgery, adjuvant therapy) and CO were evaluated. The mean age was 57.6 [33-98] years in the successful CO group and 58.1 [34-85] years in the unsuccessful CO group (p > 0.05). The mean follow-up time was 37.9 [24-84] months. The CO was successful in 88.7% (n:252) of the patients. Tumor size, retroareolar location of the tumor, adjuvant chemotherapy administration and whole breast radiation therapy (WBRT) were correlated with a poorer CO (p < 0.05). We were able to attain a successful CO in approximately 90% of our patients. Adding oncoplastic techniques to the surgical management of larger tumors and retroareolar tumors, may increase the percentage of good CO. In selected patients choosing balloon brachytherapy instead of WBRT, may also have positive effects on CO.

Localizing high-risk lesions for excisional breast biopsy: a comparison between radioactive seed localization and wire localization.

BACKGROUND: Improved resolution and utilization of screening breast imaging has increased identification of nonpalpable high-risk lesions (HRL) and subsequent excisional breast biopsies (EBBs). Wire localization (WL), used most commonly for EBBs, may have shortcomings, including wire displacement, patient discomfort, limitations with incision planning and scheduling logistics. Radioactive seed localization (RSL) may overcome these drawbacks. The purpose of this study was to compare WL and RSL for EBBs for HRLs. METHODS: All single-site EBBs for HRL performed by four breast surgeons were retrospectively reviewed over two consecutive 1-year periods. Patients with cancer on percutaneous core biopsy (CB) were excluded. Clinicopathologic information, operative time, targeted lesion retrieval rate, and upstage rate were collected. RESULTS: A total of 324 EBBs for HRL were performed: 196 using WL and 128 using RSL. CB pathology was atypical hyperplasia in 56 % of WLs and 62 % of RSLs. The remaining pathologies were radial scar, papilloma, atypical papilloma or lobular carcinoma in situ. Mean age was 54 years. OR time was 27 ± 8 min for WL and 27 ± 7 min for RSL (p = 0.9). Upstage rate was 6 and 5 % for WLs and RSLs, respectively (p = 0.5). Targeted lesions were retrieved in 98 % of WL and 99 % of RSL (p = 0.5). SV was 37.2 ± 32.8 cm(3) and 25.7 ± 22.3 cm(3) for WL and RSL, respectively (p = 0.001). CONCLUSIONS: RSL is comparable to WL for EBB of HRLs with similar OR times and upstage rates. SV is significantly decreased with RSL and may translate into improved cosmetic outcomes without sacrificing the diagnostic accuracy of the EBB.

Discovery of new antimalarial chemotypes through chemical methodology and library development.

In an effort to expand the stereochemical and structural complexity of chemical libraries used in drug discovery, the Center for Chemical Methodology and Library Development at Boston University has established an infrastructure to translate methodologies accessing diverse chemotypes into arrayed libraries for biological evaluation. In a collaborative effort, the NIH Chemical Genomics Center determined IC(50)'s for Plasmodium falciparum viability for each of 2,070 members of the CMLD-BU compound collection using quantitative high-throughput screening across five parasite lines of distinct geographic origin. Three compound classes displaying either differential or comprehensive antimalarial activity across the lines were identified, and the nascent structure activity relationships (SAR) from this experiment used to initiate optimization of these chemotypes for further development.

Evaluation of VIDAS UP Listeria assay (LPT) for the detection of Listeria in a variety of foods and environmental surfaces: First Action 2013.10.

The VIDAS UP Listeria (LPT) is an automated rapid screening enzyme phage-ligand based assay for the detection of Listeria species in human food products and environmental samples. The VIDAS LPT method was compared in a multi-laboratory collaborative study to AOAC Official Method 993.12 Listeria monocytogenes in Milk and Dairy Products reference method following current AOAC guidelines. A total of 14 laboratories participated, representing government and industry, throughout the United States. One matrix, queso fresco (soft Mexican cheese), was analyzed using two different test portion sizes, 25 and 125 g. Samples representing each test portion size were artificially contaminated with Listeria species at three levels, an uninoculated control level [0 colony-forming units (CFU)/test portion], a low-inoculum level (0.2-2 CFU/test portion), and a high-inoculum level (2-5 CFU/test portion). For this evaluation, 1800 unpaired replicate test portions were analyzed by either the VIDAS LPT or AOAC 993.12. Each inoculation level was analyzed using the Probability of Detection (POD) statistical model. For the low-level inoculated test portions, difference in collaborator POD (dLPOD) values of 0.01, (-0.10, 0.13), with 95% confidence intervals, were obtained for both 25 and 125 g test portions. The range of the confidence intervals for dLPOD values for both the 25 and 125 g test portions contains the point 0.0 indicating no statistically significant difference in the number of positive samples detected between the VIDAS LPT and the AOAC methods. In addition to Oxford agar, VIDAS LPT test portions were confirmed using Agar Listeria Ottavani and Agosti (ALOA), a proprietary chromogenic agar for the identification and differentiation of L. monocytogenes and Listeria species. No differences were observed between the two selective agars. The VIDAS LPT method, with the optional ALOA agar confirmation method, was adopted as Official First Action status for the detection of Listeria species in a variety of foods and environmental samples.

Evaluation of VIDAS Listeria monocytogenes Xpress (LMX) for the detection of Listeria monocytogenes in a variety of foods: First Action 2013.11.

The VIDAS Listeria monocytogenes Xpress (LMX) is an automated rapid screening enzyme immunoassay for the detection of Listeria monocytogenes in food products. The VIDAS LMX method was compared in a multi-laboratory collaborative study to AOAC Official Method 993.12 Listeria monocytogenes in Milk and Dairy Products reference method following current AOAC guidelines. A total of 14 laboratories participated, representing government and industry, throughout the United States. One matrix, queso fresco (soft Mexican cheese), was analyzed using two different test portion sizes, 25 and 125 g. Samples representing each portion size were artificially contaminated with L. monocytogenes at three levels: an uninoculated control level [0 colony forming units (CFU)/test portion], a low inoculum level (0.2-2 CFU/test portion), and a high inoculum level (2-5 CFU/test portion). For this evaluation, 1800 unpaired replicate test portions were analyzed by either the VIDAS LMX or AOAC 993.12. Each level was analyzed using the Probability of Detection (POD) statistical model. For the low-level inoculated test portions, difference in collaborator POD (dLPOD) values of 0.04, (-0.08, 0.15) and 0.01, (-0.10, 0.13), with 95% confidence intervals, were obtained, respectively, for 25 and 125 g test portions. The range of the confidence intervals for dLPOD values for both the 25 and 125 g test portions contain the point 0.0 indicating no statistically significant difference in the number of positive samples detected between the VIDAS LMX and the AOAC method. In addition to Oxford Agar (OXA), VIDAS LMX test portions were confirmed using Agar Listeria Ottavani and Agosti (ALOA), a proprietary chromogenic agar for the identification and differentiation of L. monocytogenes and Listeria species. No differences were observed between the two selective agars. The VIDAS LMX method, with the optional ALOA agar confirmation method, was adopted as Official First Action status for the detection of L. monocytogenes in a variety of foods.