A Comprehensive Assessment of Radial Scars on Core Needle Biopsy in Patients with or without Breast Cancer: Upgrade Rate and Implications on Management.

BACKGROUND: Radial scars/radial sclerosing lesions (RS) are benign breast lesions identified on core needle biopsy (CNB) which can upgrade to malignancy at excision. There is limited data on RS detection and upgrade rates with more sensitive imaging such as magnetic resonance imaging (MRI) and none during their detection for breast cancer workup and its implication on patient treatment decisions. METHODS: A retrospective institutional study of RS diagnosed on CNB between January 2008 and December 2017 was conducted. Clinicopathologic and radiologic features of RS, patient treatment decisions, upgrade rates and long-term follow-up were examined. RESULTS: We identified 133 patients with RS on CNB, of whom 106 opted for surgery for an upgrade rate to malignancy of 1.9%, 2 patients. Radial scar was diagnosed on mammogram in 60%, MRI in 25% and ultrasound in 15% of patients. In this cohort, 32 patients had their RS detected during breast cancer workup (coexistent group) and they were more likely to have their radial scar detected by MRI (60% vs. 14%, P < .001) and undergo more extensive surgery (94% vs. 75%, P = .02). Among the 27 patients electing observation of their RS, only one (3.7%) developed breast cancer. CONCLUSIONS: Our results show an extremely low upgrade rate to malignancy of RS, regardless if there is coexisting breast cancer elsewhere. Despite this, RS still prompted more extensive surgical excisions. The findings do not support excision of RS even among breast cancer patients when identified at a separate site from their cancer.

Multiorganizational consensus to define guiding principles for perioperative pain management in patients with chronic pain, preoperative opioid tolerance, or substance use disorder.

Significant knowledge gaps exist in the perioperative pain management of patients with a history of chronic pain, substance use disorder, and/or opioid tolerance as highlighted in the US Health and Human Services Pain Management Best Practices Inter-Agency Task Force 2019 report. The report emphasized the challenges of caring for these populations and the need for multidisciplinary care and a comprehensive approach. Such care requires stakeholder alignment across multiple specialties and care settings. With the intention of codifying this alignment into a reliable and efficient processes, a consortium of 15 professional healthcare societies was convened in a year-long modified Delphi consensus process and summit. This process produced seven guiding principles for the perioperative care of patients with chronic pain, substance use disorder, and/or preoperative opioid tolerance. These principles provide a framework and direction for future improvement in the optimization and care of 'complex' patients as they undergo surgical procedures.

Management of Radiographic Lesions of the Breast.

Breast imaging plays an essential role in the diagnosis and management of breast disease. From screening asymptomatic patients to evaluating clinical abnormalities on diagnostic studies, breast imaging provides critical information to the breast surgeon. Available imaging studies include those that have been proved over many years, like mammography, and those that take advantage of increasingly sophisticated technology, like breast MRI. Image-guided biopsy provides a safe means of evaluating indeterminate findings on imaging. Understanding how these tools are best used can help breast surgeons provide the best care for their patients.

Targeted Intraoperative Radiotherapy (TARGIT-IORT) for Early-Stage Invasive Breast Cancer: A Single Institution Experience.

Purpose/Objective: We present our single-institution experience in the management of invasive breast cancer with targeted intraoperative radiotherapy (TARGIT-IORT), focusing on patient suitability for IORT determined by the American Society for Radiation Oncology (ASTRO) Accelerated Partial Breast Irradiation (APBI) consensus guidelines. Materials/Methods: We identified 237 patients treated for biopsy-proven early-stage invasive breast cancer using low energy x-ray TARGIT-IORT at the time of lumpectomy between September 2013 and April 2020 who were prospectively enrolled in an institutional review board (IRB) approved database. We retrospectively reviewed preoperative and postoperative clinicopathologic factors to determine each patient's ASTRO APBI suitability (suitable, cautionary or unsuitable) according to the 2017 consensus guidelines (CG). Change in suitability group was determined based on final pathology. Kaplan-Meier methods were used to estimate the survival probability and recurrence probability across time. Results: 237 patients were included in this analysis, based on preoperative clinicopathologic characteristics, 191 (80.6%) patients were suitable, 46 (19.4%) were cautionary and none were deemed unsuitable. Suitability classification changed in 95 (40%) patients based on final pathology from lumpectomy. Increasing preoperative lesion size or a body mass index (BMI) ≥ 30 kg/m2 were significant predictors for suitability group change. Forty-one (17.3%) patients received additional adjuvant whole breast radiotherapy after TARGIT-IORT. At a median follow up of 38.2 months (range 0.4 - 74.5), five (2.1%) patients had ipsilateral breast tumor recurrences (IBTR), including two (0.8%) true local recurrences defined as a recurrence in the same quadrant as the initial lumpectomy bed with the same histology as the initial tumor. IBTR occurred in 1/103 (0.09%) patient in the post-op suitable group, 4/98 (4.08%) patients in the post-op cautionary group, and no patients in the post-op unsuitable group. At 3-years, the overall survival rate was 98.4% and the local recurrence free survival rate was 97.1%. Conclusion: There is a low rate of IBTR after TARGIT-IORT when used in appropriately selected patients. Change in suitability classification pre to postoperatively is common, highlighting a need for further investigation to optimize preoperative patient risk stratification in this setting. Patients who become cautionary or unsuitable based on final pathology should be considered for additional adjuvant therapy.

Shaves off the Cavity or Specimen in Lumpectomy for Breast Cancer.

INTRODUCTION: Re-excision for positive margins (margins where tumor is positive) after breast conserving surgery (BCS) is common and burdensome for breast cancer patients. Routine shave margins can reduce positive margins and re-excision rates. Cavity shaving margin (CSM) removes margins from the lumpectomy cavity edges, whereas specimen shave margin (SSM) requires ex vivo removal of margins from the resected specimen. METHODS: We assessed breast cancer patients undergoing BCS who received CSM or SSM procedures from 2017 to 2019. CSM and SSM techniques were compared by analyzing positive rates of primary and final shaved margins, re-excision rates, and tissue volumes removed. RESULTS: Of 116 patients included in this study, 57 underwent CSM and 59 underwent SSM. Primary margins were positive or close in 19 CSM patients and 21 SSM patients (33% versus 36%; P = 0.798). Seventeen CSM patients had a tumor in shaved margin specimens, compared to four patients for SSM (30% versus 7%; P < 0.001); however, final shave margins were similar (5% versus 5%; P = 0.983). Volumes of shave specimens were higher with SSM (40.7 versus 13.4 cm3; P < 0.001), but there was no significant difference in the total volume removed (146.8 versus 134.4 cm3; P = 0.540). For tumors 2 cm or larger, the total volume removed (140 versus 206 cm3; P = 0.432) and rates of final margin positivity (7.5% versus 0%; P = 0.684) were similar for both techniques. CONCLUSIONS: CSM and SSM are effective techniques for achieving low re-excision rates. Our findings suggest that surgeons performing either CSM or SSM may maintain operative preferences and achieve similar results.

A multisociety organizational consensus process to define guiding principles for acute perioperative pain management.

The US Health and Human Services Pain Management Best Practices Inter-Agency Task Force initiated a public-private partnership which led to the publication of its report in 2019. The report emphasized the need for individualized, multimodal, and multidisciplinary approaches to pain management that decrease the over-reliance on opioids, increase access to care, and promote widespread education on pain and substance use disorders. The Task Force specifically called on specialty organizations to work together to develop evidence-based guidelines. In response to this report's recommendations, a consortium of 14 professional healthcare societies committed to a 2-year project to advance pain management for the surgical patient and improve opioid safety. The modified Delphi process included two rounds of electronic voting and culminated in a live virtual event in February 2021, during which seven common guiding principles were established for acute perioperative pain management. These principles should help to inform local action and future development of clinical practice recommendations.

Complication Rates After Intraoperative Radiation Therapy: Do Applicator Size and Distance to Skin Matter?

BACKGROUND: Intraoperative radiation therapy (IORT) has gained popularity for early stage breast cancer treatment. Few studies have examined the relationship between complications and both demographic and technical factors. The objective of the current study was to determine if applicator size or distances to the skin were significant risk factors for complications. METHODS: Data was prospectively collected on patients who underwent lumpectomy followed by IORT from November 1, 2013 to August 31, 2018. Exclusion criteria included any prior radiation exposure or personal history of breast cancer. Comorbid conditions such as body mass index, diabetes, and smoking as well as technical specifications such as applicator size and distances to the skin were included for investigation. Student's t-test, Fisher's exact test, and odds ratios were utilized for statistical analysis. RESULTS: The study was comprised of 219 patients. None developed Clavien-Dindo grade 2 or above complications. Of 21.0% (n = 46) had minor complications. The most common complication was a palpable breast seroma (n = 37). Diabetes was the only comorbid condition with increased risk for complications (OR 3.2; 95% CI1.3-7.5; P = 0.008). The applicator sizes and average skin distances were similar between groups. Surprisingly, the closest skin distance was not a significant risk factor for post-operative complications (1.4 +/- 1.6 versus 1.4 +/- 1.9 cm; P = 1.0). CONCLUSION: Neither applicator size nor the closest skin distance were associated with increased complications. Traditionally described risk factors such as BMI and smoking were not predictive. This data provides support for potentially expanding the utilization for IORT without increasing complications.

Outcome Disparities Among Men and Women With COVID-19: An Analysis of the New York City Population Cohort.

BACKGROUND: Growing evidence suggests a possible sex disparity in COVID-19 disease related outcomes. OBJECTIVE: To explore the sex disparity in COVID-19 cases and outcomes using New York City (NYC) population level data. SETTING: NYC surveillance data from February 29 to June 12, 2020. PARTICIPANTS: Individuals tested for COVID-19 in metropolitan NYC.Outcome Measurements and Statistical Analysis: Outcomes of interest included rates of COVID-19 case positivity, hospitalization and death. Relative risks and case fatality rates were computed for all outcomes based on sex and were stratified by age groups. RESULTS AND LIMITATIONS: 911,310 individuals were included, of whom 434,273 (47.65%) were male and 477,037 (52.35%) were female. Men represented the majority of positive cases (n=106,275, 51.36%), a majority of hospitalizations (n=29,847, 56.44%), and a majority of deaths (n=13,054, 59.23%). Following population level adjustments for age and sex, testing rates of men and women were equivalent. The majority of positive cases and hospitalizations occurred in men for all age groups except age >75 years, and death was more likely in men of all age groups. Men were at a statistically significant greater relative risk of case positivity, hospitalization, and death across all age groups except those <18 years of age. The most significant difference for case positivity was observed in the 65–74 age group (RR 1.22, 95%CI 1.19–1.24), for hospitalization in the 45–65 age group (RR 1.85, 95% 1.80–1.90), and for death in the 18–44 age group (RR 3.30, 95% CI 2.82–3.87). Case fatality rates were greater for men in all age-matched comparisons to women. Limitations include the use of an evolving surveillance data set and absence of further demographic characteristics such as ethnographic data. CONCLUSION: Men have higher rates of COVID-19 positivity, hospitalization, and death despite greater testing of women; this trend remains after stratification by age. J Drugs Dermatol. 2020;19(10):960-967. doi:10.36849/JDD.2020.5590.

Pain Management in Breast Surgery: Recommendations of a Multidisciplinary Expert Panel-The American Society of Breast Surgeons.

Opioid overdose accounted for more than 47,000 deaths in the United States in 2018. The risk of new persistent opioid use following breast cancer surgery is significant, with up to 10% of patients continuing to fill opioid prescriptions one year after surgery. Over prescription of opioids is far too common. A recent study suggested that up to 80% of patients receiving a prescription for opioids post-operatively do not need them (either do not fill the prescription or do not use the medication). In order to address this important issue, The American Society of Breast Surgeons empaneled an inter-disciplinary committee to develop a consensus statement on pain control for patients undergoing breast surgery. Representatives were nominated by the American College of Surgeons, the Society of Surgical Oncology, The American Society of Plastic Surgeons, and The American Society of Anesthesiologists. A broad literature review followed by a more focused review was performed by the inter-disciplinary panel which was comprised of 14 experts in the fields of breast surgery, anesthesiology, plastic surgery, rehabilitation medicine, and addiction medicine. Through a process of multiple revisions, a consensus was developed, resulting in the outline for decreased opioid use in patients undergoing breast surgery presented in this manuscript. The final document was reviewed and approved by the Board of Directors of the American Society of Breast Surgeons.

Akt Inhibition Is Associated With Favorable Immune Profile Changes Within the Tumor Microenvironment of Hormone Receptor Positive, HER2 Negative Breast Cancer.

Background: The PI3K/Akt/mTOR pathway in part impacts tumorigenesis through modulation of host immune activity. To assess the effects of Akt inhibition on the tumor micro-environment (TME), we analyzed tumor tissue from patients with operable hormone receptor positive, HER2 negative breast cancer (BC) treated on a presurgical trial with the Akt inhibitor MK-2206. Methods: Quantitative multiplex immunofluorescence (qmIF) was performed using CD3, CD8, CD4, FOXP3, CD68, and pancytokeratin on biopsy and surgical specimens of MK-2206 and untreated, control patients. nanoString was performed on surgical specimens to assess mRNA expression from MK-2206-treated vs. control patients. Results: Increased CD3+CD8+ density was observed in post vs. pre-treatment tissue in the MK-2206-treated vs. control patients (87 vs. 0.2%, p < 0.05). MK-2206 was associated with greater expression of interferon signaling genes (e.g., IFI6, p < 0.05) and lower expression of myeloid genes (CD163, p < 0.05) on differential expression and gene set enrichment analyses. Greater expression of pro-apoptotic genes (e.g., BAD) were associated with MK-2206 treatment (p < 0.05). Conclusion: Akt inhibition in operable BC was associated with a favorable immune profile in the TME, including increased CD3+CD8+ density and greater expression of interferon genes. Additional studies are warranted, as this may provide rationale for combining Akt inhibition with immunotherapy.

The Effect of Surgical Trainee Education on Opioid Prescribing: An International Evaluation.

INTRODUCTION: Up to 6% of opioid naive patients who undergo surgery become chronic opioid users. The aim of this study was to determine if formal opioid prescribing education of general surgery residents is associated with decreased opioid prescribing postoperatively. METHODS: We surveyed surgery residents at 3 general surgery programs in the United States and 1 in Israel. Residents were divided into 2 groups based on whether or not they received formal opioid prescribing education. RESULTS: Of those surveyed, 107 (50%) responded. 45% of residents had formal opioid prescribing education, which included instructional videos, current literature, and hospital guidelines. For the 4 operations analyzed, residents who received no formal teaching prescribed a higher number of opioids (lumpectomy p = 0.001, open inguinal hernia repair p = 0.004, laparoscopic appendectomy p = 0.007, thyroidectomy p = 0.002). The largest difference in opioid prescribing was seen in "high prescribers," defined as residents prescribing 15 or more opioid pills. For thyroidectomy, 24.4% of residents without formal education prescribed 20 or more oxycodone 5mg pills compared to 0% of residents with formal education. The Israeli cohort was less likely to receive a pain focused education and was also less likely to prescribe opioids to their patients for all 4 procedures evaluated. CONCLUSIONS: Although a minority of general surgery residents are receiving an opioid prescribing education, a formal educational program was associated with significantly decreased opioid prescribing. There is a need for a generalizable educational opioid program for surgery residents.

Presenting for Duty: Lessons From A Specialty Surgery Division at the Pandemic Epicenter.

MINI-ABSTRACT: The coronavirus disease 2019 (COVID-19) pandemic has had catastrophic repercussions across the world and here in the United States. The healthcare system in New York City, the epicenter, has faced significant disruptions due to the sheer volume of cases and critical care needs of severely ill patients. For surgical specialty services, the postponement of all elective surgeries, redeployment of faculty and staff, and cancellation of outpatient clinics became a rapid reality. These circumstances required a nimble restructuring of services and communications to facilitate continued support of academic and clinical missions. Throughout the course of the pandemic, significant adjustments were made in regards to duties, patient services, and communication. The frameworks and techniques utilized are described along with the relevant outcomes. Immediate restructuring of tumor boards, a focused multidisciplinary approach to management that incorporated the barriers presented by the pandemic, optimization of telehealth services, inclusive communication, and a service-oriented approach to redeployment were critical to sustaining the Division of Breast, Melanoma, and Soft Tissue surgery.

Human Tumor-Associated Macrophage and Monocyte Transcriptional Landscapes Reveal Cancer-Specific Reprogramming, Biomarkers, and Therapeutic Targets.

The roles of tumor-associated macrophages (TAMs) and circulating monocytes in human cancer are poorly understood. Here, we show that monocyte subpopulation distribution and transcriptomes are significantly altered by the presence of endometrial and breast cancer. Furthermore, TAMs from endometrial and breast cancers are transcriptionally distinct from monocytes and their respective tissue-resident macrophages. We identified a breast TAM signature that is highly enriched in aggressive breast cancer subtypes and associated with shorter disease-specific survival. We also identified an auto-regulatory loop between TAMs and cancer cells driven by tumor necrosis factor alpha involving SIGLEC1 and CCL8, which is self-reinforcing through the production of CSF1. Together these data provide direct evidence that monocyte and macrophage transcriptional landscapes are perturbed by cancer, reflecting patient outcomes.

Isolation of Mouse and Human Tumor-Associated Macrophages.

The tumor microenvironment is a complex network of cells that support tumor progression and malignancy. It has been demonstrated that tumor cells can educate the immune system to promote a tumor-friendly environment. Among all these immune cells, tumor-associated macrophages (TAMs) are well represented and their presence in mouse models has been shown to promote tumor progression and metastasis. These effects are through the stimulation of angiogenesis, enhancement of tumor cell invasion and intravasation, immunosuppression, and at the metastatic site tumor cell extravasation and growth. However, the precise mechanisms are not fully understood. Furthermore there is limited information on TAMs derived from human cancers. For this reason it is important to be able to extract TAMs from tumors in order to compare their phenotypes, functions, and transcriptomes with normal resident tissue macrophages. Isolation of these cells is challenging due to the lack of markers and standardized protocols. Here we show an optimized protocol for the efficient isolation and extraction of resident macrophages and TAMs from human and mouse tissues by using multicolor flow cytometry. These protocols allow for the extraction of thousands of macrophages in less than 5 h from tissues as small as half a gram. The isolated macrophages can then be used for both "omics" and in vitro studies.

A phase I-II study of the histone deacetylase inhibitor vorinostat plus sequential weekly paclitaxel and doxorubicin-cyclophosphamide in locally advanced breast cancer.

Histone deacetylases (HDACs) are a family of enzymes that regulate chromatin remodeling and gene transcription. Vorinostat is a panHDAC inhibitor that sensitizes breast cancer cells to taxanes and trastuzumab by suppressing HDAC6 and Hsp90 client proteins. Fifty-five patients with clinical stage IIA-IIIC breast cancer received 12 weekly doses of paclitaxel (80 mg/m(2)) plus vorinostat (200-300 mg PO BID) on days 1-3 of each paclitaxel dose plus trastuzumab (for Her2/neu positive disease only), followed by doxorubicin/cyclophosphamide (60/600 mg/m(2) every 2 weeks plus pegfilgrastim). The primary study endpoint was pathologic complete response (pCR). pCR occurred in 13 of 24 evaluable patients with Her2-positive disease (54, 95 % confidence intervals [CI] 35-72 %), which met the prespecified study endpoint. pCR occurred in 4 of 15 patients with triple negative disease (27, 95 % CI 11-52 %) and none of 12 patients with ER-positive, Her2/neu negative disease (0, 95 % CI 0-24 %), which did not meet the prespecified endpoint. ER-positive tumors exhibited lower Ki67 and higher Hsp70 expression, and HDAC6, Hsp70, p21, and p27 expression were not predictive of response. Vorinostat increased acetylation of Hsp90 and alpha tubulin, and reduced expression of Hsp90 client proteins and HDAC6 in the primary tumor. Combination of vorinostat with weekly paclitaxel plus trastuzumab followed by doxorubicin-cyclophosphamide is associated with a high pCR rate in locally advanced Her2/neu positive breast cancer. Consistent with cell line and xenograft data, vorinostat increased acetylation of Hsp90 and alpha tubulin, and decreased Hsp90 client protein and HDAC6 expression in human breast cancers in vivo.

Myeloid WNT7b mediates the angiogenic switch and metastasis in breast cancer.

Oncogenic targets acting in both tumor cells and tumor stromal cells may offer special therapeutic appeal. Interrogation of the Oncomine database revealed that 52 of 53 human breast carcinomas showed substantial upregulation of WNT family ligand WNT7B. Immunolabeling of human mammary carcinoma showed that WNT7B immunoreactivity was associated with both tumor cells and with tumor-associated macrophages. In the MMTV-PymT mouse model of mammary carcinoma, we found tumor progression relied upon WNT7B produced by myeloid cells in the microenvironment. Wnt7b deletion in myeloid cells reduced the mass and volume of tumors due to a failure in the angiogenic switch. In the tumor overall, there was no change in expression of Wnt/ß-catenin pathway target genes, but in vascular endothelial cells (VEC), expression of these genes was reduced, suggesting that VECs respond to Wnt/ß-catenin signaling. Mechanistic investigations revealed that failure of the angiogenic switch could be attributed to reduced Vegfa mRNA and protein expression in VECs, a source of VEGFA mRNA in the tumor that was limiting in the absence of myeloid WNT7B. We also noted a dramatic reduction in lung metastasis associated with decreased macrophage-mediated tumor cell invasion. Together, these results illustrated the critical role of myeloid WNT7B in tumor progression, acting at the levels of angiogenesis, invasion, and metastasis. We suggest that therapeutic suppression of WNT7B signaling might be advantageous due to targeting multiple aspects of tumor progression.

Evaluation of serum Amphiregulin levels in breast cancer patients and cancer-free controls.

BACKGROUND: Expression of the Epidermal Growth Factor Receptor ligand, Amphiregulin, has been associated with estrogen receptor positive breast cancer. As Amphiregulin is proteolytically released from the surface of breast cancer cells, we investigated the levels of Amphiregulin in the serum of breast cancer patients and cancer-free women to evaluate its potential utility as a breast cancer biomarker. FINDINGS: Serum Amphiregulin levels were quantified by ELISA from 125 cancer-free women and 114 breast cancer patients. No significant association between serum Amphiregulin levels and breast cancer status was detected at two cut-points evaluated. CONCLUSIONS: Measurement of serum Amphiregulin levels lacks the necessary sensitivity and specificity for breast cancer screening in the general population.

A renewable tissue resource of phenotypically stable, biologically and ethnically diverse, patient-derived human breast cancer xenograft models.

Breast cancer research is hampered by difficulties in obtaining and studying primary human breast tissue, and by the lack of in vivo preclinical models that reflect patient tumor biology accurately. To overcome these limitations, we propagated a cohort of human breast tumors grown in the epithelium-free mammary fat pad of severe combined immunodeficient (SCID)/Beige and nonobese diabetic (NOD)/SCID/IL-2γ-receptor null (NSG) mice under a series of transplant conditions. Both models yielded stably transplantable xenografts at comparably high rates (∼21% and ∼19%, respectively). Of the conditions tested, xenograft take rate was highest in the presence of a low-dose estradiol pellet. Overall, 32 stably transplantable xenograft lines were established, representing 25 unique patients. Most tumors yielding xenografts were "triple-negative" [estrogen receptor (ER)-progesterone receptor (PR)-HER2+; n = 19]. However, we established lines from 3 ER-PR-HER2+ tumors, one ER+PR-HER2-, one ER+PR+HER2-, and one "triple-positive" (ER+PR+HER2+) tumor. Serially passaged xenografts show biologic consistency with the tumor of origin, are phenotypically stable across multiple transplant generations at the histologic, transcriptomic, proteomic, and genomic levels, and show comparable treatment responses as those observed clinically. Xenografts representing 12 patients, including 2 ER+ lines, showed metastasis to the mouse lung. These models thus serve as a renewable, quality-controlled tissue resource for preclinical studies investigating treatment response and metastasis.

Reduced dose and intermittent treatment with lapatinib and trastuzumab for potent blockade of the HER pathway in HER2/neu-overexpressing breast tumor xenografts.

PURPOSE: We have shown that incomplete blockade of the human epidermal growth factor (HER) pathway is a mechanism of resistance to treatment with trastuzumab (T) in HER2-overexpressing tumor xenografts. We now investigate whether the addition of lapatinib (L), a dual HER1/2 kinase inhibitor, to T results in more potent inhibition of the pathway and therefore inhibition of tumor growth, and whether reduced dose and intermittent treatment with the combination is equally effective. EXPERIMENTAL DESIGN: Nude mice bearing HER2-overexpressing MCF7/HER2-18 or BT-474 xenograft tumors were treated with L and T, alone or in various combinations with other HER inhibitors. L + T for short duration (14 and 42 days), intermittent administration (14 days on/off), and reduced dosing (half dose) was also investigated. Inhibition of tumor growth, downstream signaling, proliferation, and induction of apoptosis were assessed. All statistical tests were two-sided. RESULTS: L + T was the most effective regimen in both MCF7/HER2-18 and BT-474 xenografts with complete regression (CR) of tumor observed in all mice. Intermittent and reduced dose treatment (½ dose) resulted in high rates of CR and low rates of tumor recurrence that were comparable to full dose continuous treatment. L + T resulted in significantly reduced downstream signaling and proliferation, and increased apoptosis. CONCLUSIONS: L + T is a potent and effective combination even when given in reduced dose or intermittent schedule potentially resulting in lower toxicity and reduced cost if translated to patients. These findings warrant timely clinical testing.

Morbidity of sentinel node biopsy in breast cancer: the relationship between the number of excised lymph nodes and lymphedema.

BACKGROUND: Despite the reduced morbidity associated with sentinel lymph node biopsy (SLNB), lymphedema remains a clinically relevant complication. We hypothesized that a higher number of lymph nodes (LNs) removed during SLNB is associated with a higher risk of lymphedema. METHODS: Six hundred patients with clinically node-negative breast cancer who underwent SLNB were prospectively studied. Circumferential bilateral upper extremity measurements were performed preoperatively and at 3-8 years after surgery. Association of lymphedema with total number of LNs excised and other clinicopathologic variables was analyzed by the Spearman rank correlation coefficient, Fisher's exact test, Wilcoxon rank sum test, and logistic regression. RESULTS: At a median follow-up of 5 years, 5% of patients had developed lymphedema. Factors associated with lymphedema included weight and body mass index. There was no association between the number of LNs removed and the change in upper extremity measurements or in the incidence of lymphedema. Among patients with lymphedema (n = 31) compared to those without, the mean (3.9 vs. 4.2), median (4 vs. 3), and range (1-9 vs. 1-17) of number of LNs removed were similar (P = 0.93). Among the 33 women with ≥ 10 LNs removed, none developed lymphedema. CONCLUSIONS: In this population of 600 women who underwent SLNB, there is no correlation between number of LNs removed and change in upper extremity circumference or incidence of lymphedema. These data suggest that other factors, such as the global disruption of the lymphatic channels during axillary lymph node dissection, play a larger role in development of lymphedema than does the number of LNs removed.