A framework for role allocation in education, research and leadership services in Canadian academic divisions of general surgery: a modified Delphi consensus.

BACKGROUND: Moving toward a funding standard similar to that for clinical services for roles essential to the functioning of education, research and leadership services within divisions of general surgery is necessary to strengthen divisional resilience. We aimed to identify roles and underlying tasks in these services central to sustainable functioning of Canadian academic divisions of general surgery. METHODS: Between June 2018 and October 2020, we used a 4-step modified Delphi method (online survey, face-to-face nominal group technique [n = 12], semistructured telephone interview [n = 8] and nominal group technique [n = 12]) to achieve national consensus from an expert panel of all 17 heads of academic divisions of general surgery in Canada on the roles and accompanying tasks essential to education, research and leadership services within an academic division of general surgery. We used 70% agreement to determine consensus. RESULTS: The expert panel agreed that a framework for role allocation in education, research and leadership services was relevant and necessary. Consensus was reached for 7 roles within the educational service, 3 roles within the research service and 5 roles within the leadership service. CONCLUSION: Our framework represents a national consensus that defines role standards for education, research and leadership services in Canadian academic divisions of general surgery. The framework can help divisions build resiliency, and enable sustained and deliberate advances in these services.

A population-based study of treatment patterns, 10-year recurrence and breast cancer-specific mortality in a cohort of elderly patients with breast cancer.

BACKGROUND: We compared disease characteristics, therapies offered and received, and outcomes between older (>75 years) and younger (60-75 years) women with breast cancer (BC) from a regional database in Ontario, Canada. METHODS: BC surgical cases from 12 hospitals were included. Younger (60-75 years) and older (>75 years) groups were compared. Cox proportional hazards regression with competing risk analyses assessed the relationship between predictor variables, 10-year recurrence and BC-specific mortality. RESULTS: Our sample comprised 774 women; 33.5% were older. Older women had larger tumours, were more likely to have positive nodes, had more comorbidities, were more likely to undergo mastectomy, had less nodal surgery, were less likely to receive adjuvant therapies, and experienced more recurrences and BC-specific deaths (p < 0.05). Significant predictors of recurrence were older age, higher grade and disease stage, and omission of nodal surgery. Older age, higher grade, and stage were predictors of BC-specific mortality. CONCLUSION: Older BC patients (>75 years) received less treatment and experienced increased recurrence and BC-specific mortality.

Adoption and outcomes of radioguided seed localization for non-palpable invasive and in-situ breast cancer at three academic tertiary care centers.

INTRODUCTION: Radioguided seed localization (RSL) is an alternative technique to wire-guided localization (WL) for localizing non-palpable breast lesions for breast conserving surgery. The purpose of this study was to assess adoption and outcomes of RSL at 3 academic hospitals in our city. METHODS: Data for consecutive invasive and in-situ breast cancer cases localized with RSL or WL at 3 hospitals between January 2012 and February 2016 were abstracted. Data analysis was conducted using the Student's t-test, ANOVA with Tukey's HSD test for post-hoc multiple comparisons, and chi-squared test. RESULTS: There were 803 consecutive cases. Hospital 1 exclusively used RSL (247 cases), whereas H2 adopted RSL (109 cases), but continued to use WL (347 cases). Hospital 3 exclusively used WL (100 cases). There was no difference between RSL and WL groups in positive margin rate (p = 0.337), re-operation (p = 0.413), or mean specimen volume (p = 0.190). DISCUSSION: There has been variable adoption of RSL in our city. Despite this, relevant surgical outcomes have been similar across groups. The causes of variable adoption of this novel technique merit further investigation.

Breast cancer recurrence following radioguided seed localization and standard wire localization of nonpalpable invasive and in situ breast cancers: 5-Year follow-up from a randomized controlled trial.

BACKGROUND: This study compared 5-year breast cancer (BC) recurrence rates in patients randomized to radioguided seed localization (RSL) or wire localization (WL) for non-palpable BC undergoing breast conserving surgery. METHODS: Chart review of follow-up visits and surveillance imaging was conducted. Data collected included patient and tumour factors, adjuvant therapies and BC recurrence (local recurrence (LR), regional recurrence (RR), and distant metastasis (DM)). Univariate analysis was used. RESULTS: Follow-up data were available for 298 patients (98%) and median follow-up time was 65 months. There were 11 (4%) cases of BC recurrence and median time to recurrence was 26 months. LR occurred in 8 patients (6 WL and 2 RSL; p = 0.28). Positive margins at first surgery (p = 0.024) and final surgery (p = 0.004) predicted for BC recurrence. CONCLUSIONS: There was no detectable difference in BC recurrence between WL and RSL groups and positive margins at initial or final surgery both predicted for BC recurrence.

Predictors of 5-year local, regional, and distant recurrent events in a population-based cohort of breast cancer patients.

BACKGROUND: The study purpose was to identify tumor and surgeon predictors of local recurrence (LR), regional recurrence (RR), and distant metastasis (DM) after breast cancer (BC) surgery in a population-based cohort. METHODS: Consecutive BC surgical cases from 12 hospitals in South Central Ontario between May 2006 and October 2006 were included. Data collected on chart review included patient and tumor factors, surgery type, adjuvant treatment, surgeon specialty, surgeon case volume, and practice type. Univariate and multivariable survival analyses were performed. RESULTS: Median follow-up was 5.5 years for 402 patients (97% of sample). LR, RR, and DM occurred in 18 (4.5%), 10 (2.5%), and 47 (12%) patients, respectively. Significant predictors of BC recurrence (LR or RR or DM) were tumor size and grade, nodal status, and lymphovascular invasion on multivariable analysis. CONCLUSION: Tumor factors such as size, grade, lymphovascular invasion, and nodal status predicted BC recurrence, while practice type, surgeon specialty, and case volume did not.

Effects of a regional guideline for completion axillary lymph node dissection in women with breast cancer to reduce variation in surgical practice: A qualitative study of physicians' views.

BACKGROUND: Recently the impact of completion axillary lymph node dissection (cALND) after positive sentinel lymph node biopsy on significant outcomes has been questioned, leading to variation in surgical practice. To address this variation, a multidisciplinary working group created a regional guideline for cALND. We explored the views and experiences of surgeons, medical oncologists (MOs), radiation oncologists (ROs) in a qualitative study that examined guideline implementation in practice. METHODS: The Pathman framework (awareness, agreement, adoption and adherence) informed the interview guide design and analysis. Semi-structured interviews were conducted with MOs, ROs and surgeons and transcribed. Transcripts were coded independently by 2 members of the study team and analyzed. Disagreements were resolved through consensus. RESULTS: Twenty-eight physicians (5 MO; 6RO; 17S) of 41 (68% of those approached) were interviewed. Ten of 11 (91%) hospital sites (54% community; 46% academic) and all 4 cancer clinics within the region were represented. Twenty-seven physicians (96%) were aware of the guideline, with all physicians reporting agreement and general adherence to the guideline. Most physicians indicated nodal factors, age and patient preference were key components of cALND decision-making. Physicians from all disciplines perceived that the guideline helped reduce variation in practice across the region. There were concerns that the guideline could be applied rigidly and not permit individual decision-making. CONCLUSIONS: Physicians identified breast cancer as an increasingly complex and multidisciplinary issue. Facilitators to guideline implementation included perceived flexibility and buy-in from all disciplines, while individual patient factors and controversial supporting evidence may hinder its implementation.

Association between mesothelin expression and survival outcomes in patients with triple-negative breast cancer: a protocol for a systematic review.

BACKGROUND: Mesothelin is a membrane-bound glycoprotein. Although the biologic function of mesothelin is not very clear, researchers have found that it plays a role in the survival, proliferation, and migration of tumor cells. Identified as a tumor-associated biomarker, mesothelin is more often overexpressed in triple-negative breast cancer (TNBC) than in common luminal breast tumor subtype or normal tissues. The objective of this review is to determine the association between the expression of mesothelin and overall survival in patients with TNBC. METHODS/DESIGN: We will search the following electronic databases: MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, and Web of Science with no time or language restriction. Prospective or retrospective longitudinal studies that investigate mesothelin expression in TNBC or the prognosis of TNBC with mesothelin baseline measurement will be selected. Two reviewers will independently assess every abstract or full text for inclusion. Data on clinical outcomes, as well as on study design, research setting, study population, demographic characteristics of the participants, and methodological quality, will be extracted using a structured codebook developed by the authors. A pooled measure of associations will be assessed through meta-analyses if appropriate. Heterogeneity across the included studies will be evaluated using the I (2) statistics. Findings will be reported according to the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The quality of evidence and risk of bias of the studies will be evaluated. DISCUSSION: The aim of this systematic review is to synthesize the evidence regarding the association between the expression of mesothelin and the survival outcomes of patients with TNBC. A better understanding of the expression frequency and prognostic value of mesothelin in TNBC will be essential to identifying a novel therapeutic target. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42016036212.

A Population-Based Study of the Effects of a Regional Guideline for Completion Axillary Lymph Node Dissection on Axillary Surgery in Patients with Breast Cancer.

INTRODUCTION: Evidence from the American College of Surgeons Oncology Group (ACOSOG) Z0011 trial suggests completion axillary lymph node dissection (cALND) after positive sentinel lymph node biopsy (+SLNB) does not improve outcomes in select patients, leading to practice variation. A multidisciplinary group of surgeons, oncologists, and pathologists developed a regional guideline for cALND which was disseminated in August 2012. We assessed the impact of Z0011 and the regional guideline on cALND rates. METHODS: Consecutive invasive breast cancer cases undergoing SLNB were reviewed at 12 hospitals. Patient, tumor, and process measures were collected for three time periods: TP1, before publication of Z0011 (May 2009-August 2010); TP2, after publication of Z0011 (March 2011-June 2012); and TP3, after guideline dissemination (January 2013-April 2014). Cases were categorized by whether they met the guideline criteria for cALND (i.e. ≤50 years, mastectomy, T3 tumor, three or more positive sentinel lymph nodes [SLNs]) or not (e.g. age > 50 years, breast-conserving surgery, T1/T2 tumor, and one to two positive SLNs). RESULTS: The SLNB rate increased from 56 % (n = 620), to 70 % (n = 774), to 78 % (n = 844) in TP1, TP2, and TP3, respectively. Among cases not recommended for cALND using the guideline criteria, cALND rates decreased significantly over time (TP1, 71 %; TP2, 43 %; TP3, 17 %) [p < 0.001]. The cALND rate also decreased over time among cases recommended to have cALND using the guideline criteria (TP1, 92 %; TP2, 69 %; TP3, 58 %) [p < 0.001]. Based on multivariable analysis, age and nodal factors appeared to be significant factors for cALND decision making. CONCLUSION: Publication of ACOSOG Z0011 and regional guideline dissemination were associated with a marked decrease in cALND after +SLNB, even among several cases in which the guideline recommended cALND.

A Retrospective Study Evaluating the Impact of Preoperative Breast MRI on Surgical Decision-Making in Young Patients (≤50 Years) with Invasive Breast Cancer.

INTRODUCTION: Breast magnetic resonance imaging (MRI) is considered a more sensitive diagnostic test for detecting invasive breast cancer than mammography or breast ultrasound. Breast MRI may be particularly useful in younger premenopausal women with higher density breast tissue for differentiating between dense fibroglandular breast tissue and breast malignancies. The main objective of this study was to determine the impact of preoperative breast MRI on surgical decision-making in young women with breast cancer. METHODS: A retrospective review of patients with newly diagnosed invasive breast cancer and age of ≤50 years was performed. All patients underwent physical examination, preoperative mammogram, breast ultrasound, and bilateral breast MRI. Two breast cancer surgeons reviewed the preoperative mammogram report, breast ultrasound report, and physical examination summary and were asked if they would recommend a lumpectomy, a quandrantectomy, or a mastectomy. A few weeks later, the two surgeons were shown the same information with the breast MRI report and were asked what type of surgery they would now recommend. In each case, MRI was classified by two adjudicators as having affected the surgical outcome in a positive, negative, or neutral fashion. A positive impact was defined as the situation where breast MRI detected additional disease that was not found on physical examination, mammogram, or breast ultrasound and led to an appropriate change in surgical management. A negative impact was defined as the situation where breast MRI led the surgeon to recommend more extensive surgery, with less extensive disease actually found at pathology. No impact was defined as the situation where MRI findings did not alter surgical recommendations or outcomes. RESULTS: Of 37 patients whose charts were reviewed, five patients were deemed to be ineligible due to having received neoadjuvant chemotherapy, having previous breast implants, or having had their tumor fully excised during biopsy. In total, 32 patients met the inclusion criteria of this study and were appropriate for analysis. The median age of our study patient population was 42 years. The pathologic diagnosis was invasive ductal carcinoma in 91% (29/32) of patients and invasive lobular carcinoma in 9% (3/32) of patients. For surgeon A, clinical management was altered in 21/32 (66%) patients, and for surgeon B, management was altered in 13/32 (41%) patients. The most common change in surgical decision-making after breast MRI was from breast-conserving surgery to a mastectomy. Mastectomy rates were similar between both surgeons after breast MRI. After reviewing the pathology results and comparing them with the breast MRI results, it was determined that breast MRI led to a positive outcome in 13/32 (41%) patients. Breast MRI led to no change in surgical management in 15/32 (47%) patients and resulted in a negative change in surgical management in 4/32 (13%) patients. Bilateral breast MRI detected a contralateral breast cancer in 2/32 (6%) patients. CONCLUSIONS: Preoperative breast MRI alters surgical management in a significant proportion of younger women diagnosed with breast cancer. Prospective studies are needed to confirm these findings and to help determine if this change in surgical decision-making will result in improved local control.

A cosmesis outcome substudy in a prospective, randomized trial comparing radioguided seed localization with standard wire localization for nonpalpable, invasive, and in situ breast carcinomas.

BACKGROUND: The primary study objective was to compare the cosmetic result of radioguided seed localization (RSL) with wire localization (WL). METHODS: A subgroup of patients enrolled in a multicentered, randomized trial comparing WL with RSL participated. Frontal photographs were taken 1 and 3 years postsurgery. The European Organization for Research and Treatment of Cancer Cosmetic Rating System was used to evaluate cosmesis outcomes by the patient and a panel of 5 raters. RESULTS: The study enrolled 73 patients (WL, n = 38; RSL, n = 35). Most patients rated their overall cosmesis as "excellent" or "good" (76% WL, 80% RSL). Patient and panel ratings on all cosmetic outcomes were similar between groups. Multivariable regression for overall cosmesis found larger specimen volume and reoperation to be predictors of worse ratings. CONCLUSIONS: All cosmetic outcomes assessed were similar after WL and RSL. The comparable outcomes may reflect similar reoperation rates and volumes of excision between groups.

Survey of American and Canadian general surgeons' perceptions of margin status and practice patterns for breast conserving surgery.

Although breast conservation surgery (BCS) is commonly performed, several aspects of the procedure remain controversial. We undertook a cross-sectional survey to compare Canadian (CDN) and American (AM) general surgeons' reported BCS practice patterns to better understand the cross-border differences in early-stage breast cancer surgery care. A modified Dillman Method survey was mailed to 1,447 AM and 1,443 CDN surgeons. Factors evaluated included preoperative assessment, margin definition, surgical techniques, and re-excision practices. The response rate was 26% and 51% for AM and CDN surgeons, respectively. There was variation in use of preoperative core biopsies. American surgeons required wider margins for invasive cancer and ductal carcinoma in situ, and more often recommend re-excision for invasive cancer with 1 and 2 mm margins (p < 0.05). There was also variability in surgical techniques used for intraoperative margin assessment. Wide variation in BCS practice was observed, with some of this variability related to surgeon country.

An evaluation of intraoperative digital specimen mammography versus conventional specimen radiography for the excision of nonpalpable breast lesions.

BACKGROUND: This study examined the impact of intraoperative digital specimen mammography (IDSM) compared with conventional specimen radiography (CSR) for nonpalpable breast lesions in patients undergoing breast-conserving surgery (BCS). METHODS: In this retrospective cohort study, 201 consecutive image-detected nonpalpable breast lesions underwent BCS after preoperative localization and specimen radiography. Data on patient, tumor, and surgical factors were collected. RESULTS: CSR was performed in 105 patients and IDSM was used in 96 patients. Patient and tumor factors were similar in both groups. Using univariate analysis, CSR resulted in more positive margins (19% vs 6.2%; P = .012). Rates of cavity margin resection, reoperation, and operative times were similar for CSR and IDSM. Independent predictors of positive margins on multivariable analysis were use of CSR, microcalcifications on mammography, the need for bracketing for localization, and no cavity margin excision (all P < .05). CONCLUSIONS: In this study, the use of IDSM resulted in fewer positive margins after BCS, although operative times were similar.

Practice patterns and perceptions of margin status for breast conserving surgery for breast carcinoma: National Survey of Canadian General Surgeons.

BACKGROUND: We surveyed Canadian General Surgeons to examine decision-making in early stage breast cancer. METHODS: A modified Dillman Method was used for this mail survey of 1443 surgeons. Practice patterns and factors that influence management choices for: preoperative assessment, definition of margin status, surgical techniques and recommendations for re-excision were assessed. RESULTS: The response rate was 51% with 41% treating breast cancer. Most (80%) were community surgeons, with equal distribution of low/medium/high volume and years of practice categories. Approximately 25% of surgeons "sometimes or frequently" performed diagnostic excisional biopsies while 90% report "frequently" or "always" performing preoperative core biopsies. There was marked variation in defining negative and close margins, in the use of intra-operative margin assessment techniques and recommendations for re-excision. CONCLUSIONS: Responses revealed significant variation in attitudes and practices. These findings likely reflect an absence of consensus in the literature and potential gaps between best evidence and practice.

A prospective study of tumor and technical factors associated with positive margins in breast-conservation therapy for nonpalpable malignancy.

BACKGROUND: The purpose of this study was to identify factors that predict an increased risk of a positive surgical margin after breast-conserving therapy for nonpalpable carcinoma of the breast. METHODS: In this prospective study, 305 patients with nonpalpable invasive breast cancer or ductal carcinoma in situ were identified and underwent localization lumpectomy. Patient, technical, and tumor factors with a potential to predict margin status were documented. RESULTS: A 20% positive margin rate was observed. Univariate analysis of patient, tumor, and technical factors revealed that localizations performed under stereotactic guidance (P < .001), presence of in situ disease, high tumor grade, larger tumor size, multifocal disease, and presence of mammographic microcalcifications (P < .02) were predictive of positive margins. With the exception of tumor grade and mammographic microcalcifications, multivariable analysis identified the same factors. CONCLUSIONS: This study identified several factors associated with positive margins that should be considered when planning breast-conserving therapy for nonpalpable tumors.

A multicentered, randomized, controlled trial comparing radioguided seed localization to standard wire localization for nonpalpable, invasive and in situ breast carcinomas.

BACKGROUND: Studies suggest radioguided seed localization (RSL) yields fewer positive margins than wire-guided localization (WL). The goal of this study is to determine whether RSL is superior to WL. METHODS: Women with confirmed invasive or ductal carcinoma in situ (DCIS) undergoing localization and breast conserving surgery were enrolled. Outcomes measured include positive margin and reoperation rates, specimen weight, operative and localization times, and surgeon and radiologist ranking of procedural difficulty. RESULTS: Randomization was centralized, concealed, and stratified by surgeon with 153 patients in the WL group and 152 in RSL group. Localizations were performed using either ultrasound (70%) or mammographic guidance (30%). Pathology was either DCIS (18%) or invasive carcinoma (82%). Procedures were performed at 3 sites, by 7 surgeons. Only difference found for patient and tumor characteristics was more multifocal disease in RSL group. Using intention-to-treat analysis, there were no differences in positive margins rates for RSL (10.5%) and WL (11.8%), (P=.99) or for positive or close margins (<1 mm) (RSL 19% and WL 22%; P=.61). Mean operative time (minutes) was shorter for RSL (RSL 19.4 vs WL 22.2; P<.001). Specimen volume, weight, reoperation and localization times were similar. Surgeons ranked the seed technique as easier (P=.008), while radiologists ranked them similarly. Patient's pain rankings during wire localization were higher (P=.038). CONCLUSIONS: In contrast to other trials positive margin and reoperation rates were similar for RSL and WL. However, for RSL operative times were shorter, and the technique was preferred by surgeons, making it an acceptable method for localization.

Technical factors, surgeon case volume and positive margin rates after breast conservation surgery for early-stage breast cancer.

BACKGROUND: For patients with breast cancer, a negative surgical margin at first breast-conserving surgery (BCS) minimizes the need for reoperation and likely reduces postoperative anxiety. We assessed technical factors, surgeon and hospital case volume and margin status after BCS in early-stage breast cancer. METHODS: We performed a retrospective cohort study using a regional cancer centre database of patients who underwent BCS for breast cancer from 2000 to 2002. We considered the influence of patient, tumour and technical factors (e.g., size of specimen and preoperative diagnosis of cancer available) and surgeon and hospital case volume on margin status at first and final operation. We performed univariate and multivariate regression analyses. RESULTS: We reviewed 489 cases. There were no differences in patient or tumour characteristics among the low-, medium- and high-volume surgeon groups. High-volume surgeons were significantly more likely than other surgeons to operate with a confirmed preoperative diagnosis and to resect a larger volume of tissue. In our univariate analysis and at first operation, the rates of positive margins were 16.4%, 32.9% and 29.1% for high-, medium- and low-volume surgeons, respectively (p = 0.002). In the multivariate analysis, tumour factors (palpability, size, histology), presence of a confirmed preoperative diagnosis and size of resection specimen significantly predicted negative margins. However, when we controlled for these and other factors, high surgeon volume was not a predictor of negative margins at first surgery (odds ratio 1.8, 95% confidence interval 0.9-3.8, p = 0.09). Increased hospital volume was not associated with a lower rate of positive margins at first surgery. CONCLUSION: Various tumour and technical factors were associated with negative margins at first BCS, whereas surgeon and hospital volume status were not. Technical steps that are under the control of the operating surgeon are likely effective targets for quality initiatives in breast cancer surgery.

The relationship between surgical factors and margin status after breast-conservation surgery for early stage breast cancer.

BACKGROUND: The study's aim was to identify technical factors that are predictive of negative margins after breast-conserving surgery (BCS). METHODS: This was a retrospective, cohort study of patients who underwent BCS for early-stage cancer from 2000 to 2002. Pathological and specific surgical factors were compared with margin status. Univariate and multivariate regression analyses were performed. RESULTS: Four hundred eighty-nine cases were reviewed. The positive margin rate after the initial surgery was 26%. In univariate analysis, lobular histology, size, grade, multifocality, and the presence of EIC and LVI were associated with positive margins (P < .05). The absence of cavity margin dissection and specimen orientation labeling, the absence of a confirmed diagnosis, and smaller volumes of excision were also associated with positive margins (P < .05). In multivariate analysis, confirmed diagnosis, small tumor size, ductal histology, absence of LVI and multifocality, palpability, cavity margin dissection, and larger volumes of excision were predictors of negative margins. CONCLUSIONS: This study shows that specific surgical factors are predictive of margin status. Both tumor and technical factors should be considered when planning BCS.

The feasibility and responsiveness of the health utilities index in patients with early-stage breast cancer: a prospective longitudinal study.

BACKGROUND: The health utilities index (HUI3) is a health measurement instrument based on individuals' preferences for different health states. Breast cancer (BC) is common, with a high proportion of long-term survivors, making evaluation of treatment effects important. Feasibility and responsiveness of HUI3 was compared to the short-form 36 (SF-36) in patients with BC. METHODS: HUI3 and SF-36 were administered eight times: at initial surgical consultation, 1 week before surgery; 1 week, 3, 6, 12, 18, and 24 months after surgery. Effect size, analysis of variance, and Pearson product moment correlations were calculated. BC data were compared to normative values. RESULTS: Eighty-five patients were enrolled. Ninety-one percent of planned assessments were completed. HUI3 showed significant responsiveness (P < 0.01) after surgery and during recovery. HUI3 scores correlated with SF-36 scores. Comparison to normative data demonstrated the significant detrimental effect of BC diagnosis. Results showed long-term effects of treatment on physical health and positive effects on mental/emotional health in BC survivors. CONCLUSION(S): HUI3 was found to be feasible and responsive in our cohort of BC patients. Changes in HUI3 values over time, and compared to normative data, paralleled SF-36 scores. HUI3 is a valuable tool in health-related quality of life and cost-utility studies in patients with BC.

A prospective evaluation of positron emission tomography scanning, sentinel lymph node biopsy, and standard axillary dissection for axillary staging in patients with early stage breast cancer.

BACKGROUND: Positron emission tomography (PET) is a noninvasive imaging modality that can detect malignant lymph nodes. This study determined the sensitivity, specificity, predictive values, and likelihood ratios of PET scanning compared with standard axillary lymph node dissection (ALND) and sentinel lymph node biopsy (SLNB) in staging the axilla in women with early stage breast cancer. METHODS: Women with clinical stage I or II breast cancer had whole body PET scanning before ALND and SLNB, in a prospective, blinded protocol. ALND were evaluated by standard hematoxylin and eosin (H&E) staining techniques, while sentinel nodes were also examined for micrometastatic disease. RESULTS: A total of 98 patients were recruited. PET compared with ALND demonstrated sensitivity of 0.40 (95% CI, 0.16, 0.68), specificity 0.97 (CI, 0.90, 0.99), positive likelihood ratio 14.4 (CI, 3.21, 64.5), positive predictive value 0.75 (CI, 0.35, 0.97), and false-negative rate of 0.60 (CI, 0.32, 0.84). Test properties were similar for PET compared with sentinel nodes positive by H&E staining. A few false-positive scans (0.028, CI, 0.003, 0.097) were seen. Multiple logistic regression analysis found that PET accuracy was better in patients with high grade and larger tumors. Increased size and number of positive nodes were also associated with a positive PET scan. CONCLUSIONS: The sensitivity of PET compared with ALND and SLNB was low, whereas PET scanning had high specificity and positive predictive values. The study suggests that PET scanning cannot replace histologic staging in early stage breast cancer. The low rate of false-positive findings suggests that PET can identify women who can forego SLNB and require full axillary dissection.