Does Preoperative MRI Reduce Positive Margins after Breast-Conserving Surgery?

BACKGROUND: Breast-conserving surgery (BCS) is a mainstay for breast cancer management, and obtaining negative margins is critical. Some have advocated for the use of preoperative magnetic resonance imaging (MRI) in reducing positive margins after BCS. We sought to determine whether preoperative MRI was associated with reduced positive margins. PATIENTS AND METHODS: The SHAVE/SHAVE2 trials were multicenter trials in ten US centers with patients with stage 0-3 breast cancer undergoing BCS. Use of preoperative MRI was at the discretion of the surgeon. We evaluated whether or not preoperative MRI was associated with margin status prior to randomization regarding resection of cavity with shave margins. RESULTS: A total of 631 patients participated. Median age was 64 (range 29-94) years, with a median tumor size of 1.3 cm (range 0.1-9.3 cm). Patient factors included 26.1% of patients (165) had palpable tumors, and 6.5% (41) received neoadjuvant chemotherapy. Tumor factors were notable for invasive lobular histology in 7.0% (44) and extensive intraductal component (EIC) in 32.8% (207). A preoperative MRI was performed in 193 (30.6%) patients. Those who underwent preoperative MRI were less likely to have a positive margin (31.1% versus 38.8%), although this difference was not statistically significant (p = 0.073). On multivariate analysis, controlling for patient and tumor factors, utilization of preoperative MRI was not a significant factor in predicting margin status (p = 0.110). Rather, age (p = 0.032) and tumor size (p = 0.040) were the only factors associated with margin status. CONCLUSION: These data suggest that preoperative MRI is not associated margin status; rather, patient age and tumor size are the associated factors.

Contribution of cost to treatment nonadherence in the US breast cancer survivors: a population-based analysis.

INTRODUCTION: Breast cancer survivors are often prescribed medications for at least 5 years to reduce recurrence risk, yet some forego this treatment due to cost. We sought to elucidate the prevalence of this and the factors contributing to it. METHODS: The National Health Interview Survey (NHIS) is a population-based survey, representative of the civilian non-institutionalized US population, administered annually by the CDC. People diagnosed with breast cancer within the past 5 years surveyed in the 2018 NHIS formed the cohort of interest. RESULTS: Of the 24,858 breast cancer survivors surveyed, representing 244,607,304 in the population, 6.32% stated that they needed a prescription medicine within the past 12 months, but didn't get it filled because they couldn't afford it. Of those who had gotten a prescription within the past 12 months, 5.71, 5.94 and 7.48% had either skipped doses, taken less medication than prescribed, or delayed filling a prescription, respectively, to save money. 11.99% of people had done at least one of these, thereby foregoing treatment. On bivariate analyses, factors associated with foregoing treatment included age, race, education, family income, and insurance status (p < 0.001 for all). On multivariable analysis, age, race, family income, and insurance status were all independent predictors of foregoing treatment (p < 0.001 for all); education status was not significant in the model (p = 0.211). CONCLUSION: Roughly 12% of breast cancer survivors who are prescribed medications within the first 5 years of their diagnosis will forego treatment due to cost. Family income and insurance status are key modifiable drivers of this.

Disparities in Breast Cancer Screening Between Caucasian and Asian American Women.

INTRODUCTION: Asian American women have lower breast cancer incidence and mortality than their non-Hispanic White (NHW) counterparts. We sought to determine whether differences in screening practices could explain, in part, the variation in breast cancer detection rate. METHODS: The 2015 National Health Interview Survey, an annual survey that is representative of the civilian, noninstitutionalized American population, was used to determine whether mammography usage was different between Asian and NHW women. Women ≥40 y of age who identified as either Asian or NHW were included. RESULTS: A total of 7990 women ≥40 y of age (6.12% Asian, 93.88% NHW), representing 53,275,420 women in the population, were included in our cohort of interest; 71.49% of Asian and 74.46% of NHW women reported having had a mammogram within the past 2 y (P = 0.324). Controlling for education, insurance, family income, marital status, and whether they were born in the United States, Asians were less likely to have had a mammogram within the past 2 y than their NHW counterparts (odds ratio = 0.68; 95% confidence interval: 0.46-0.99, P = 0.047). Of patients who had an abnormal mammogram, there was no difference in the biopsy rate (20.35% versus 25.97%, P = 0.4935) nor in the rate of cancer diagnosis among those who had a biopsy (7.70% versus 12.86%, P = 0.211) between Asian and NHW women, respectively. CONCLUSIONS: Our findings suggest that the lower breast cancer incidence among the Asian population may, in part, be explained by a lower screening mammography rate in this population.

Omission of Radiation in Conservative Treatment for Breast Cancer: Opportunity for De-escalation of Care.

INTRODUCTION: De-escalation of breast cancer treatment aims to reduce patient and financial toxicity without compromising outcomes. Level I evidence and National Comprehensive Cancer Network guidelines support omission of adjuvant radiation in patients aged >70 y with hormone-sensitive, pT1N0M0 invasive breast cancer treated with endocrine therapy. We evaluated radiation use in patients eligible for guideline concordant omission of radiation. METHODS: Subgroup analysis of patients eligible for radiation omission from two pooled randomized controlled trials, which included stage 0-III breast cancer patients undergoing breast conserving surgery, was performed to evaluate factors associated with radiation use. RESULTS: Of 631 patients, 47 (7.4%) met radiation omission criteria and were treated by 14 surgeons at eight institutions. The mean age was 75.3 (standard deviation + 4.4) y. Majority of patients identified as White (n = 46; 97.9%) and non-Hispanic (n = 44; 93.6%). The mean tumor size was 1.0 cm; 37 patients (88.1%) had ductal, 4 patients (9.5%) had lobular, and 17 patients (40.5%) had low-grade disease. Among patients eligible for radiation omission, 34 (72.3%) patients received adjuvant radiation. Those who received radiation were significantly younger than those who did not (74 y, interquartile range = 4 y, versus 78 y, interquartile range = 11 y, P = 0.03). There was no difference in radiation use based on size (P = 0.4), histology (P = 0.5), grade (P = 0.7), race (P = 1), ethnicity (P = 0.6), institution (P = 0.1), gender of the surgeon (P = 0.7), or surgeon (P = 0.1). CONCLUSIONS: Fewer than 10% of patients undergoing breast conservation met criteria for radiation omission. Nearly three-quarters received radiation therapy with younger age being a driver of radiation use, suggesting ample opportunity for de-escalation, particularly among younger eligible patients.

HPV vaccination and factors influencing vaccine uptake among people of Indian ancestry living in the United States.

Approximately one-quarter of annual global cervical cancer deaths occur in India, possibly due to cultural norms promoting vaccine hesitancy. We sought to determine whether people of Indian ancestry (POIA) in the USA exhibit disproportionately lower human papilloma virus (HPV) vaccination rates than the rest of the US population. We utilised the 2018 National Health Interview Survey to compare HPV vaccine initiation and completion rates between POIA and the general US population and determined factors correlating with HPV vaccine uptake among POIA. Compared to other racial groups, POIA had a significantly lower rate of HPV vaccination (8.18% vs. 12.16%, 14.70%, 16.07% and 12.41%, in White, Black, Other Asian and those of other/mixed ancestry, respectively, P = 0.003), but no statistically significant difference in vaccine series completion among those who received at least one injection (3.17% vs. 4.27%, 3.51%, 4.31% and 5.04%, P = 0.465). Among POIA, younger individuals (vs. older), single individuals (vs. married), those with high English proficiency (vs. low English proficiency), those with health insurance and those born in the USA (vs. those born outside the USA) were more likely to obtain HPV vaccination (P = 0.018, P = 0.006, P = 0.029, P = 0.020 and P = 0.019, respectively). Public health measures promoting HPV vaccination among POIA immigrants may substantially improve vaccination rates among this population.

Exploring the impact of exercise and mind-body prehabilitation interventions on physical and psychological outcomes in women undergoing breast cancer surgery.

PURPOSE: To compare the impact of exercise and mind-body prehabilitation interventions on changes in quality of life and cancer treatment-related symptoms in women with newly diagnosed breast cancer. METHODS: The following describes a secondary analysis of a randomized window of opportunity trial (The Pre-Operative Health and Body Study). Forty-nine women were randomized to participate in either an exercise prehabilitation intervention or a mind-body prehabilitation intervention from the time of enrollment to surgery. Participants (N = 47) completed measures of quality of life, anxiety, depression, and stress at the time of enrollment (T1), post-intervention/surgery (T2), and one-month post-surgery (T3). Changes in outcome measures between groups were compared over time using longitudinal models. RESULTS: Mind-body group participants experienced significant improvements in cognitive functioning in comparison to exercise group participants between T1 and T3 (difference in average change: -9.61, p = 0.04, d = 0.31), otherwise, there were no significant differences between groups. Within group comparisons demonstrated that both groups experienced improvements in anxiety (exercise: average change = -1.18, p = 0.03, d = 0.34; mind-body: average change = -1.69, p = 0.006, d = 0.43) and stress (exercise: average change = -2.33, p = 0.04, d = 0.30; mind-body: average change = -2.59, p = 0.05, d = 0.29), while mind-body group participants experienced improvements in insomnia (average change = -10.03, p = 0.04, d = 0.30) and cognitive functioning (average change = 13.16, p = 0.0003, d = 0.67). CONCLUSIONS: Both prehabilitation interventions impacted cancer treatment-related symptoms. Further work in larger groups of patients is needed to evaluate the efficacy of prehabilitation interventions on quality of life in women with breast cancer. Pre-operative exercise and mind-body interventions may impact physical and/or psychological effects of cancer diagnosis and treatment in women with breast cancer. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01516190. Registered January 24, 2012.

Resection of Cavity Shave Margins in Stage 0-III Breast Cancer Patients Undergoing Breast Conserving Surgery: A Prospective Multicenter Randomized Controlled Trial.

OBJECTIVE: Single-center studies have demonstrated that resection of cavity shave margins (CSM) halves the rate of positive margins and re-excision in breast cancer patients undergoing partial mastectomy (PM). We sought to determine if these findings were externally generalizable across practice settings. METHODS: In this multicenter randomized controlled trial occurring in 9 centers across the United States, stage 0-III breast cancer patients undergoing PM were randomly assigned to either have resection of CSM ("shave" group) or not ("no shave" group). Randomization occurred intraoperatively, after the surgeon had completed their standard PM. Primary outcome measures were positive margin and re-excision rates. RESULTS: Between July 28, 2016 and April 13, 2018, 400 patients were enrolled in this trial. Four patients (2 in each arm) did not meet inclusion criteria after randomization, leaving 396 patients for analysis: 196 in the "shave" group and 200 to the "no shave" group. Median patient age was 65 years (range; 29-94). Groups were well matched at baseline for demographic and clinicopathologic factors. Prior to randomization, positive margin rates were similar in the "shave" and "no shave" groups (76/196 (38.8%) vs. 72/200 (36.0%), respectively, P = 0.604). After randomization, those in the "shave" group were significantly less likely than those in the "no shave" group to have positive margins (19/196 (9.7%) vs. 72/200 (36.0%), P < 0.001), and to require re-excision or mastectomy for margin clearance (17/196 (8.7%) vs. 47/200 (23.5%), P < 0.001). CONCLUSION: Resection of CSM significantly reduces positive margin and re-excision rates in patients undergoing PM.

Debate: Postmastectomy Radiation Therapy in T1/2N1 Disease.

Although postmastectomy radiation therapy is known to reduce local recurrence in patients with T1/2N1 breast cancer, some have postulated that not all patients require this treatment. In this era of genomic analyses and personalized therapy, clinicians have debated whether the toxicity of post-mastectomy radiation therapy (PMRT) can be avoided for some subsets of patients. However, the data in this regard remain controversial, particularly as surgeons de-escalate the surgical management of the axilla. Several ongoing clinical trials may provide a glimpse into optimal management in this scenario. However, the "right" answer to this debate currently remains unclear.

Assessing Interobserver Variability of Cosmetic Outcome Assessment in Breast Cancer Patients Undergoing Breast-Conservation Surgery.

BACKGROUND: Inter-rater reliability between breast surgical oncologists and reconstructive surgeons using cosmesis scales, and the correlation between their observations and patients' own subjective assessments, is poorly understood. METHODS: Patients undergoing BCS in a prospective trial rated their cosmetic outcome on a Likert scale (poor/fair/good/excellent) at the postoperative and 1-year time points; photographs were also taken. Three breast surgical oncologists (not involved in these cases) and two reconstructive surgeons were asked to independently rate cosmesis using the Harvard/NSABP/RTOG scale. RESULTS: Overall, 55 and 17 patients had photographs and Likert self-evaluations at the postoperative and 1-year time points, respectively. There was poor agreement between surgeon and patient ratings postoperatively [kappas - 0.042 (p = 0.659), 0.069 (p = 0.226), and 0.076 (p = 0.090) for the breast surgical oncologists; and 0.018 (p = 0.689) and 0.112 (p = 0.145) for the reconstructive surgeons], and poor interobserver agreement between surgeons of the same specialty (kappa - 0.087, 95% confidence interval [CI] - 0.091 to - 0.082, p = 0.223 for breast surgical oncologists; and kappa - 0.150, 95% CI - 0.157 to - 0.144, p = 0.150, for reconstructive surgeons). At 1 year, the interobserver agreement between breast surgical oncologists was better (kappa 0.507, 95% CI 0.501-0.512, p < 0.001); however, there was still poor correlation between the reconstructive surgeons (kappa - 0.040, 95% CI - 0.049 to - 0.031, p = 0.772). Agreement between surgeon and patient ratings remained poor at this time point [kappas - 0.115 (p = 0.477), 0.177 (p = 0.245), and 0.101 (p = 0.475) for breast surgical oncologists; and 0.335 (p = 0.037) and -0.118 (p = 0.221) for reconstructive surgeons]. CONCLUSION: Despite gradation scales for measuring cosmesis after BCS, high levels of agreement between surgeons is lacking and these do not always reflect patients' subjective assessments.

A Randomized, Controlled Trial of Cavity Shave Margins in Breast Cancer.

BACKGROUND: Routine resection of cavity shave margins (additional tissue circumferentially around the cavity left by partial mastectomy) may reduce the rates of positive margins (margins positive for tumor) and reexcision among patients undergoing partial mastectomy for breast cancer. METHODS: In this randomized, controlled trial, we assigned, in a 1:1 ratio, 235 patients with breast cancer of stage 0 to III who were undergoing partial mastectomy, with or without resection of selective margins, to have further cavity shave margins resected (shave group) or not to have further cavity shave margins resected (no-shave group). Randomization occurred intraoperatively after surgeons had completed standard partial mastectomy. Positive margins were defined as tumor touching the edge of the specimen that was removed in the case of invasive cancer and tumor that was within 1 mm of the edge of the specimen removed in the case of ductal carcinoma in situ. The rate of positive margins was the primary outcome measure; secondary outcome measures included cosmesis and the volume of tissue resected. RESULTS: The median age of the patients was 61 years (range, 33 to 94). On final pathological testing, 54 patients (23%) had invasive cancer, 45 (19%) had ductal carcinoma in situ, and 125 (53%) had both; 11 patients had no further disease. The median size of the tumor in the greatest diameter was 1.1 cm (range, 0 to 6.5) in patients with invasive carcinoma and 1.0 cm (range, 0 to 9.3) in patients with ductal carcinoma in situ. Groups were well matched at baseline with respect to demographic and clinicopathological characteristics. The rate of positive margins after partial mastectomy (before randomization) was similar in the shave group and the no-shave group (36% and 34%, respectively; P=0.69). After randomization, patients in the shave group had a significantly lower rate of positive margins than did those in the no-shave group (19% vs. 34%, P=0.01), as well as a lower rate of second surgery for margin clearance (10% vs. 21%, P=0.02). There was no significant difference in complications between the two groups. CONCLUSIONS: Cavity shaving halved the rates of positive margins and reexcision among patients with partial mastectomy. (Funded by the Yale Cancer Center; ClinicalTrials.gov number, NCT01452399.).

Quality of Life and Body Image as a Function of Time from Mastectomy.

BACKGROUND: We sought to determine the impact of time after surgery on quality of life (QoL) and body image in breast cancer patients undergoing mastectomy. METHODS: Female patients with unilateral breast cancer who had undergone mastectomy were surveyed regarding their body image (Body Image After Breast Cancer Questionnaire; BIBCQ) and QoL (FACT-B). Data were analyzed using nonparametric statistics (SPSS version 24). RESULTS: Ninety-four of the 109 patients approached completed both surveys (86.2% response rate). Median patient age at the time of surgery was 49.5 (range 29-82); the survey was administered at a median of 14.2 months postoperatively (range 0.3-192.1 months). Seventy-four patients (78.7%) had reconstruction, and 52 patients (55.3%) chose to undergo contralateral prophylactic mastectomy. Patients who reported an above average overall body image perception on the BIBCQ tended to be further out from their surgery than those who reported a below average perception (median 20.9 vs. 8.1 months, respectively, p = 0.009). Patients who reported above average QoL also tended to be further out from their surgery compared with those with below average overall QoL (median 21.8 vs. 6.4 months, respectively, p = 0.004). Receipt of reconstruction, contralateral prophylactic mastectomy, disease stage, patient race, education, insurance type, income, marital status, employment status, and age at surgery did not significantly affect body image nor QoL in this cohort. CONCLUSIONS: Better body image perception and higher QoL were associated with being further out from surgery. These findings suggest that body image and QoL may improve with time, as patients acclimatize to their "new normal."

Breast cancer histopathology is predictive of low-risk Oncotype Dx recurrence score.

BACKGROUND: Oncotype Dx is a genetic test that has been incorporated into the 2017 AJCC breast cancer staging system for ER positive, HER2-negative, lymph node-negative patients to predict the risk of recurrence. Recent data suggest that immunohistochemistry (ER, PR, HER2, and Ki-67) and histologic subtype may identify patients that will not benefit from Oncotype Dx testing. METHODS: A total of 371 patients underwent Oncotype Dx testing at our institution from 2012 to 2016. Oncotype recurrence score was categorized as low- (ORS = 0-10), intermediate- (11-25), or high risk (26-100). Invasive carcinomas were categorized based on histologic subtype as "favorable" (mucinous, tubular, cribriform, tubulolobular, and lobular) and "unfavorable" (ductal, mixed ductal and lobular, and micropapillary carcinoma). All cases were estrogen receptor positive and HER2-negative. Clinical and histologic predictors of low-risk ORS were assessed in univariate and multivariate logistic regression. RESULTS: A total of 371 patients were categorized by ORS as low risk (n = 85, 22.9%), intermediate risk (n = 244, 65.8%), and high risk (n = 42, 11.3%). The histologic subtypes with the highest percentage of high-risk ORS were invasive micropapillary (n = 4/17, 23.5%), pleomorphic lobular (n = 2/10, 20%), and ductal carcinoma (n = 28/235, 11.9%). Low-grade invasive carcinomas with favorable histology rarely had a high-risk ORS (n = 1/97, 1%). In a simple multivariable model, favorable histologic subtype (OR = 2.39, 95% CI: 1.10 to 5.15, P = 0.026), and histologic grade (OR = 1.76, 95% CI: 1.07 to 2.90, P = 0.025) were the only significant predictors of an ORS less than 11 in estrogen receptor positive, HER2-negative, and lymph node-negative patients. CONCLUSION: We question the utility of performing Oncotype Dx in subtypes of invasive carcinoma that are associated with excellent prognosis. We propose that immunohistochemistry for ER, PR, and HER2 is sufficient for patients with low-grade invasive carcinomas and can be used as a surrogate for Oncotype Dx.

Economic Impact of Routine Cavity Margins Versus Standard Partial Mastectomy in Breast Cancer Patients: Results of a Randomized Controlled Trial.

OBJECTIVE: The aim of the study was to compare costs associated with excision of routine cavity shave margins (CSM) versus standard partial mastectomy (PM) in patients with breast cancer. BACKGROUND: Excision of CSM reduces re-excision rates by more than 50%. The economic implications of this is, however, unclear. METHODS: Between October 21, 2011 and November 25, 2013, 235 women undergoing PM for Stage 0-III breast cancer were randomized to undergo either standard PM ("no shave", n = 116) or have additional CSM taken ("shave", n = 119). Costs from both a payer and a hospital perspective were measured for index surgery and breast cancer surgery-related care through subsequent 90 days. RESULTS: The 2 groups were well-matched in terms of baseline characteristics. Those in the "shave" group had a longer operative time at the initial surgery (median 76 vs 66 min, P < 0.01), but a lower re-excision rate for positive margins (13/119 = 10.9% vs 32/116 = 27.6%, P < 0.01). Actual direct hospital costs associated with operating room time ($1315 vs. $1137, P = 0.03) and pathology costs ($1195 vs $795, P < 0.01) were greater for the initial surgery in patients in the "shave" group. Taking into account the index surgery and the subsequent 90 days, there was no significant difference in cost from either the payer ($10,476 vs $11,219, P = 0.40) or hospital perspective ($5090 vs $5116, P = 0.37) between the "shave" and "no shave" groups. CONCLUSIONS: Overall costs were not significantly different between the "shave" and "no shave" groups due to significantly fewer reoperative surgeries in the former.

Association of LN Evaluation with Survival in Women Aged 70 Years or Older With Clinically Node-Negative Hormone Receptor Positive Breast Cancer.

BACKGROUND: Some suggest that lymph node (LN) evaluation not be performed routinely in women aged ≥70 years with clinically (c) LN-negative (-), hormone receptor (HR)-positive (+) breast cancer. We sought to determine the association of omission of LN evaluation on survival. METHODS: Patients who met the above criteria and were diagnosed from 2004 to 2012 were identified in the NCDB and SEER databases. Overall survival (OS) and breast cancer-specific survival (BCSS) were determined. RESULTS: Using the NCDB, we identified 157,584 cLN- HR+ patients aged ≥70 years in whom survival and LN evaluation data were available. A total of 126,638 patients (80.2%) had regional LN surgery. With a median follow-up of 41.6 months, there was a significant difference in OS between those who had LN evaluation and those who did not (median OS: 100.5 vs. 70.9 months, respectively, p < 0.001). After adjusting for patient age, race, insurance, income, comorbidities, tumor characteristics and treatment, patients who had undergone LN evaluation still had a lower hazard rate for death than those who had not (hazard ratio = 0.633; 95% confidence interval [CI] 0.613-0.654, p < 0.001). We then did a parallel analysis using SEER data that showed LN evaluation was associated with a lower hazard rate for both BCSS (hazard ratio = 0.452; 95% CI 0.427-0.479, p < 0.001) and non-BCSS (hazard ratio = 0.465; 95% CI 0.447-0.482, p < 0.001). CONCLUSIONS: Roughly 20% of patients older than aged 70 years with cLN-, HR+ breast cancer did not have LN evaluation. Those who did had better OS controlling for sociodemographic, pathologic, and treatment variables; however, this may be due to patient selection.

Society of Surgical Oncology Breast Disease Working Group Statement on Prophylactic (Risk-Reducing) Mastectomy.

Over the past several years, there has been an increasing rate of bilateral prophylactic mastectomy (BPM) and contralateral prophylactic mastectomy (CPM) surgeries. Since publication of the 2007 SSO position statement on the use of risk-reducing mastectomy, there have been significant advances in the understanding of breast cancer biology and treatment. The purpose of this manuscript is to review the current literature as a resource to facilitate a shared and informed decision-making process regarding the use of risk-reducing mastectomy.

Quantitative assessment of the spatial heterogeneity of tumor-infiltrating lymphocytes in breast cancer.

BACKGROUND: Tumor-infiltrating lymphocyte (TIL) count in breast cancer carries prognostic information and represents a potential predictive marker for emerging immunotherapies. However, the distribution of the lymphocyte subpopulations is not well defined. The goals of this study were to examine intratumor heterogeneity in TIL subpopulation counts in different fields of view (FOV) within each section, in different sections from the same biopsy, and between biopsies from different regions of the same cancer using quantitative immunofluorescence (QIF). METHODS: We used multiplexed QIF to quantify cytokeratin-positive epithelial cells, and CD3-positive, CD8-positive and CD20-positive lymphocytes in tissue sections from multiple biopsies obtained from different areas of 31 surgically resected primary breast carcinomas (93 samples total). Log2-transformed QIF scores or concordance and variance component analyses with linear mixed-effects models were used. Cohen's kappa index [k] of high versus low scores, defined as above and below the median, was used to measure sample similarity between areas. RESULTS: We found a strong positive correlation between CD3 and CD8 levels across all patients (Pearson correlation coefficient [CC] = 0.827). CD3 and CD8 showed a weaker but significant association with CD20 (CC = 0.446 and 0.363, respectively). For each marker, the variation between different FOVs in the same section was higher than the variation between sections or between biopsies of the same cancer. The intraclass correlation coefficients (ICC) were 0.411 for CD3, 0.324 for CD8, and 0.252 for CD20. In component analysis, 66-69 % of the variance was attributable to differences between FOVs in the same section and 30-33 % was due to differences between biopsies from different areas of the same cancer. Section to section differences were negligible. Concordance for low versus high marker status assignment in single biopsies compared to all three biopsies combined yielded k = 0.705 for CD3, k = 0.655 for CD8, and k = 0.603 for CD20. CONCLUSIONS: T and B lymphocytes show more heterogeneity across the dimensions of a single section than between different sections or regions of a given breast tumor. This observation suggests that the average lymphocyte score from a single biopsy of a tumor is reasonably representative of the whole cancer.