Combined pathologic-genomic algorithm for early-stage breast cancer improves cost-effective use of the 21-gene recurrence score assay

Background

The 21-gene recurrence score (RS) (Oncotype DX®; Genomic Health, Redwood City, CA) partitions hormone receptor positive, node negative breast cancers into three risk groups for recurrence. The Anne Arundel Medical Center (AAMC) model has previously been shown to accurately predict RS risk categories using standard pathology data. A pathologic-genomic (P-G) algorithm then is presented using the AAMC model and reserving the RS assay only for AAMC intermediate-risk patients.

Patients and methods

A survival analysis was done using a prospectively collected institutional database of newly diagnosed invasive breast cancers that underwent RS assay testing from February 2005 to May 2015. Patients were assigned to risk categories based on the AAMC model. Using Kaplan-Meier methods, 5-year distant recurrence rates (DRR) were evaluated within each risk group and compared between AAMC and RS-defined risk groups. Five-year DRR were calculated for the P-G algorithm and compared with DRR for RS risk groups and the AAMC model's risk groups.

Results

A total of 1268 cases were included. Five-year DRR were similar between the AAMC low-risk group (2.7%, n = 322) and the RS < 18 low-risk group (3.4%, n = 703), as well as between the AAMC high-risk group (22.8%, n = 230) and the RS > 30 high-risk group (23.0%, n = 141). Using the P-G algorithm, more patients were categorized as either low or high risk and the distant metastasis rate was 3.3% for the low-risk group (n = 739) and 24.2% for the high-risk group (n = 272). Using the P-G algorithm, 44% (552/1268) of patients would have avoided RS testing.

Conclusions

AAMC model is capable of predicting 5-year recurrences in high- and low-risk groups similar to RS. Further, using the P-G algorithm, reserving RS for AAMC intermediate cases, results in larger low- and high-risk groups with similar prognostic accuracy. Thus, the P-G algorithm reliably identifies a significant portion of patients unlikely to benefit from RS assay and with improved ability to categorize risk.

Abstract P3-09-05: Getting the most out of the 21-gene recurrence score assay: Increasing actionable results with a combined pathologic-genomic model

Introduction: The 21-gene recurrence score (RS) assay categorizes hormone receptor positive, node negative breast cancers (BC) into 3 risk groups for recurrence. We previously showed that the AAMC Model, using only standard pathology data, accurately does the same. This study compares the recurrence rate of the AAMC Model's risk groups to RS-based risk groups. A 2-step approach then is used, in which the AAMC model is applied first, and the RS assay is used only for AAMC intermediate risk cases. AAMC intermediate cases were reclassified by RS into low or high risk groups.

Methods: From a prospective registry of newly diagnosed BC, we selected invasive, hormone receptor positive, HER2 negative, lymph node negative cases from 2005 to 2015 tested with RS assay. Five-year Kaplan-Meier distant recurrence rates were calculated for each risk category.

Results: 1268 cases were included. Five-year recurrence rates were similar between the AAMC Model's low risk group and RS&lt;18 low risk group, as well as between the AAMC Model's high risk group and the RS&gt;30 high risk group. Applying the RS assay to the 715 cases in the AAMC Model's intermediate group resulted in re-classifying 417 (58%) as low risk and 41 (6%) as high risk. Using RS alone, 33% of cases were intermediate risk (n=424), whereas in the 2-step approach 20% were intermediate risk (n=257). For the 2-step approach, the 5-year distant recurrence rate was 3.3% for the low risk group (n=740) and 24.4% for the high risk group (n=271).

Conclusions: Five-year recurrence rates in the AAMC Model's low and high risk groups were similar to those in RS-based risk groups. The 2-step approach, with RS used only for AAMC intermediate cases, resulted in larger low and high risk groups with equivalent prognostic accuracy, compared to use of the RS assay alone. The 2-step approach reliably identifies a large number of patients unlikely to benefit from 21 gene assay and provides substantial cost savings.

Kaplan-Meier Calculated 5-year Distant Recurrences Rates for 4 Models: 1268 Patients Oncotype DXTAILORxAAMC Model2 Step Model with OncotypeDX for AAMC IntermediatesLow RiskRS &lt; 18 (n=703)RS &lt; 11 (n=250)Grade 1 and PR ≥ 1% (n=323)AAMC Low or AAMC intermediate/RS &lt;18 (n=740) 3.4% (95% CI 1.6 – 5.1%, nf=17)4.0% (95% CI 0.8 – 7.2%, nf=8)2.7% (95% CI 0.0 – 5.4%, nf=5)3.3% (95% CI 1.4 – 5.2%, nf=16)Intermediate RiskRS 18 - 30 (n=424)RS 11 - 25 (n=787)Not meeting AAMC definition for low or high risk (n=715)AAMC Intermediate and RS 18-30 (n=257) 15.2% (95% CI 10.3 – 20.1%, nf=38)7.3% (95% CI 4.7 – 9.9%, nf=35)8.4% (95% CI 5.4 – 11.3%, nf=36)12.0% (95% CI 5.8 – 18.1%, nf=15)High RiskRS &gt; 30 (n=141)RS &gt; 25 (n=231)Grade 3 or ER &lt; 20% (n=230)AAMC High or AAMC intermediate/RS &gt; 30 (n=271) 23.0% (95% CI 14.7 – 31.3%, nf=27)22.9% (95% CI 15.9 – 29.9%, nf=39)22.8% (95% CI 16.1 – 29.5%, nf=41)24.4% (95% CI 18.0 – 30.7%, nf=51)RS= Recurrence Score, nf=number of recurrences, CI = confidence interval.

Citation Format: Mylander C, Rosman M, Gage M, Fujii T, Le Du F, Raghavendra A, Sinha A, Espinosa Fernandez JR, James A, Ueno N, Tafra L, Jackson R. Getting the most out of the 21-gene recurrence score assay: Increasing actionable results with a combined pathologic-genomic model [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-09-05.

Abstract P2-05-13: Negative progesterone receptor is associate early breast cancer relapse, even among good prognosis tumors

Background/objective: A minority of estrogen-receptor (ER) positive breast cancers lack progesterone receptor (PR) expression, but little is known of the clinical meaning of PR negativity (PR-). In the present study we sought to clarify the association between PR- and outcomes of ER+, human-epidermal growth factor (HER2)-negative breast cancers using a large, single institution database.

Methods: We retrospectively analyzed consecutive, non-metastatic, unilateral HER2- invasive breast cancers diagnosed between 2000 and 2011. Records were reviewed for age at diagnosis, disease stage, tumor features, and histologically confirmed recurrence. ER+ and PR+ status was defined as ≥1% immunoreactive cells. We used Kaplan-Meier curves to determine the association between PR- and early (≤5 years) and late (&gt;5 years) disease recurrence, defined as locoregional or distant breast cancer relapse &gt;6 months after diagnosis.

Results: We identified 1,933 patients with TN (n=337) or ER+/HER2- (n=1,596) breast cancer. Patients with ER+/PR- (n=107) vs. ER+/PR+ (n=1,489) tumors did not differ in age or disease stage at diagnosis; however, PR- tumors were more frequently high grade (37.9% vs. 17.8%, p&lt;0.001), with higher median Ki67 indices (20.0% vs. 10.0%, p&lt;0.001). Median ER expression was also lower in PR- as compared to PR+ tumors (80.0% vs. 90.0%, p&lt;0.001).

Over a median follow-up of 84 months, there were 119 early and 54 late locoregional or distant breast cancer relapses. Negative PR was strongly associated with early relapse, with PR- tumors demonstrating a 2.1-fold higher hazard of relapse in the first 5 years as compared to PR+ tumors (95% CI 1.0-4.2)

Hazards of early (&lt;5 years) breast cancer relapse by hormone status. Shown are univariable Cox proportional hazard ratios and 95% confidence intervals among all tumors, and in subsets defined by %ER, node status, Ki67, and grade. All tumors n=1,933High ER (80-100%) n=1,383TN3.9 (2.6-5.6)*--PR 0%2.1 (1.0-4.2)*1.7 (0.6-4.6)PR 1-100%ReferenceReference Node-negative n=1,299Node-positive n=634TN4.3 (2.5-7.5)*3.6 (2.1-6.0)*PR 0%2.7 (1.0-7.0)*1.6 (0.6-4.5)PR 1-100%ReferenceReference Ki67 &lt;14% n=768Ki67 ≥14% n=997TN**2.4 (1.5-3.8)*PR 0%4.1 (1.2-14.1)*1.6 (0.7-3.8)PR 1-100%ReferenceReference Grade 1/2 n=1,337Grade 3 n=564TN3.4 (1.4-7.9)*1.9 (1.2-3.3)*PR 0%2.0 (0.7-5.7)1.2 (0.4-3.5)PR 1-100%ReferenceReference*p&lt;0.05; **too few subjects/events for analysis.

Negative PR remained significantly associated with a higher hazard of early relapse even in node-negative (HR 2.7, 95%CI 1.0-7.0) and low-proliferating tumors (Ki67&lt;14%, HR 4.1, 95%CI 1.2-14.1). There was no significant association between PR- and late breast cancer relapse (HR 0.7, 95%CI 0.2-2.9).

Conclusions: Compared to ER+/PR+ breast cancers, ER+/PR- breast cancers have a significantly greater risk of early recurrence, similar to triple-negative cancers. These results suggest that negative PR expression is importantly and independently associated with early breast cancer prognosis, and may be an indicator of unique tumor biology.

Citation Format: Winner M, Rosman M, Mylander C, Jackson RS, Pozo ME, Wolff AC, Tafra L, Umbricht CB. Negative progesterone receptor is associate early breast cancer relapse, even among good prognosis tumors [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-13.

Abstract PD7-03: A model using grade and hormone receptor staining defines groups at low vs. high risk for distant metastasis: Comparison to the 21-gene recurrence score

Background: The 21-gene recurrence score (RS) combines breast cancer (BC) expression of multiple genes into a single number which is prognostic for BC recurrence. We previously showed that a model using standard pathology data (AAMC Risk Groups) has substantial overlap with RS Risk Groups. The present study compared the recurrence rate of AAMC Risk Groups to that of RS-based Risk Groups as defined by the TAILORx trial and OncotypeDX (ODX) assay.

Methods: From a prospective registry of BC treated at MD Anderson Cancer Center (2/2005 – 5/2015), we selected cases tested with ODX. Cases were excluded for: other cancer in the past 5 years, T4 stage, node positivity, missing grade, missing ER%, ER&PR&lt;1% or HER2 positivity. Three methods were used to categorize distant metastatic risk: ODX and TAILORx Risk Groups were defined using RS, and AAMC Risk Groups were defined using grade and ER/PR level (Tables). For each method, the proportion of patients experiencing metastasis was calculated within Risk Groups.

Results: 1296 cases were included, with a mean follow-up of 3.5 years (25% had ≥ 4.9 years of follow-up). 82 cases (6.3%, 95% CI 5.1 – 7.8%) experienced distant metastasis, with a mean time-to-metastasis of 2.7 years. The proportion of patients experiencing distant metastasis was similar between the AAMC Low Risk Group (1.5%) and the TAILORx (3.2%) and ODX (2.4%) Low Risk Groups. The AAMC Low Risk Group was less than half the size of the ODX Low Risk Group. Of the 5 recurrences in the AAMC Low Risk Group, 1 was ODX Low Risk and 4 were ODX Intermediate Risk; 2 had 1% PR staining. Of the 17 recurrences in the ODX Low Risk Group, 1 was AAMC Low Risk and 5 (all grade 3) were AAMC High Risk; 3 had PR staining &lt; 10%. The proportion of patients experiencing distant metastasis was similar between the AAMC High Risk Group (17.4%) and the TAILORx (16.4%) and ODX (18.2%) High Risk Groups. The number of patients in the AAMC High Risk Group was greater than the ODX High Risk Group.

Table 1: Distant Metastasis in Low Risk GroupsAAMC Definition (n=329)TAILORx Definition (n=250)OncotypeDX Definition (n=704)Low Risk DefinitionGrade 1 & PR ≥1%RS &lt; 11RS &lt;18% with Distant Metastasis1.5% (95% CI 0.6–3.7%; n=5)3.2% (95% CI 1.5-6.4%, n=8)2.4% (95% CI 1.5-3.9%, n=17)% in Common with AAMC Low Risk Group100% (329/329)31.7% (80/250)33.3% (235/704)

Table 2: Distant Metastasis in High Risk GroupsAAMC Definition (n=235)TAILORx Definition (n=238)OncotypeDX Definition (n=148)High Risk DefinitionGrade 3 or ER &lt;20%RS &gt; 25RS &gt; 30% with Distant Metastasis17.4% (95% CI 12.9-23.0%, n=41)16.4% (95% CI 12.0-21.8%, n=39)18.2% (95% CI 12.6– 25.6%, n=27)% in Common with AAMC High Risk Group100% (235/235)56.7% (135/238)70.3% (104/148)

Conclusions: AAMC Low and High Risk Groups were prognostic of the likelihood of distant metastasis, and performed similarly to TAILORx and ODX Low and High Risk Groups. If RS were omitted for AAMC Low and High Risk cases, 44% [(329+235)/1296] of cases in the present cohort could have been spared ODX testing. The AAMC Risk Groups, using standard pathology data, can reliably identify a large number of patients unlikely to benefit from ODX testing and thus provide substantial cost savings.

Citation Format: Mylander C, Jackson RS, Rosman M, Fujii T, Le Du F, Raghavendra A, Sinha A, Ueno NT, Tafra L. A model using grade and hormone receptor staining defines groups at low vs. high risk for distant metastasis: Comparison to the 21-gene recurrence score [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD7-03.

Abstract P4-06-03: Assays on core biopsies and surgically resected tumors may result in different subtyping of the invasive breast cancer from the same patient

Background Core biopsies (CBs) are often used for biomarker expression assays to determine the treatment regimen. However, a number of other clinically important analyses (e.g. OncoType Dx), are performed on surgically resected tumors (SRTs). A previous study has shown that biomarkers ER, PR, and Ki67 expressed higher in CBs than in SRTs. Here we analyze how this difference impacts the subtyping of ER+ breast tumors.

Methods Female patients enrolled in the Clinical Breast Care Project (CBCP) from a civilian site were selected for this study, where expression of ER, PR, HER2, and Ki67 were assayed by IHC in a reference lab on CBs; the same 4 assays were performed on SRTs by a CBCP central lab. Both labs are CLIA-certified. Patients treated with neoadjuvant chemotherapy and those with multiple tumors were excluded. 167 cases were identified for this study to compare assays performed on CBs and SRTs from the same patients. ER and PR were positive if &gt;1% nuclear staining, HER2 was negative if IHC = 0 or 1+, positive if IHC = 3+, and for IHC = 2+ FISH was used for the final call. Ki67 was positive if &gt; = 15% nuclear staining. LA was ER+/HER2-/Ki67-, LB1 was ER+/HER2-/Ki67+, and LB2 was ER+/HER2+. For histologic grades, only readings from the central lab on SRTs were used. Statistical analyses were performed using SAS.

Results This analysis confirmed that Ki67, ER, and PR showed higher percent nuclear staining in CBs than in SRTs from the same patients. The difference for Ki67 was more striking and unidirectional. ER and PR cases clustered at the upper percent levels. Histograms with a bin-width of 15% show a peak at 15% for Ki67 difference between CBs and SRTs, whereas the peaks for ER and PR differences were at 0%. McNemar's (or Exact McNemar’s) test showed significant differences between the binary status calls for Ki67 (p = 3.2E-15) and ER (p = 0.012), but not for PR (p = 0.65). Assays on CBs and SRTs resulted in different subtype calls for the cases (Table 1). Grade distributions were different between LA and LB (p&lt;0.001 for both CB- and SRT-based subtypes, Chi-Square or Fisher's Exact test), but not so between LB1 and LB2 (p = 0.23 for CB, 0.31 for SRT). However, SRT-based LB1 cases concentrate more on higher grades compared to CB-based cases (p = 0.048).

Table 1. ER+ subtypes based on IHC assays (from CBs and SRTs) and corresponding grades (from SRTs) CBSRTSubtypeG1G2G3G1G2G3LA2126034518LB11435342820LB2036032

Discussion On IHC assays, Ki67 expression is strikingly higher in CBs than in SRTs, and ER expression is also higher in CBs than in SRTs. This directly resulted in more LB than LA subtypes based on CBs. SRT-based LB1 cases concentrate more on higher grades compared to CB-based cases, which is more consistent with the observation that LB subtypes have worse outcomes. A limitation of this study is that technical differences between the labs may contribute to the observed differences between CBs and SRTs. Further studies need to be performed to determine whether SRT should also be assayed in addition to CB for treatment regimen decision-making.

The views expressed in this abstract are those of the authors and do not reflect the official policy of the Department of Defense, or US Government.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-06-03.

Abstract OT2-1-04: Intraoperative assessment of tumor margins with a new optical imaging technology: A multi-center, randomized, blinded clinical trial

Background: Partial mastectomy is the most commonly performed procedure for invasive breast cancer and is associated with a reexcision rate commonly ranging from 20% to 40% in the literature. This high rate of reexcision is associated with significant additional cost (estimated over $4,000 per reexcision) and lower quality outcomes.

Optical coherence tomography (OCT) is a high-resolution imaging technology that images tissue structure with micron-scale resolution – on the same scale as histopathology. It is similar to ultrasound except it uses near infra-red light waves instead of sound waves to create detailed images several millimeters deep into tissue. Although widely used in ophthalmology with growing use in cardiovascular imaging, high-resolution OCT imaging has a narrow depth of focus and requires instrumentation that is not well suited for intraoperative use. Drawing from OCT technology, interferometric synthetic aperture microscopy (ISAM) is a computational imaging technique that creates high-resolution, always in-focus images in software with basic optical instrumentation. A high-resolution ISAM probe and imaging system has been developed for intraoperative imaging of tissue structure and has the potential to broadly impact intraoperative assessment of tumor margins. Intraoperative ISAM imaging of the excised breast cancer specimen margins and in vivo imaging within the surgical cavity may reduce the high rate of reexcision associated with partial mastectomy.

Trial Design: The trial design is a prospective, multi-center, randomized, double arm study comparing the reexcision rate of standard of care partial mastectomy versus the reexcision rate of standard of care partial mastectomy plus intraoperative ISAM imaging.

Inclusion Criteria: Women histologically diagnosed with invasive carcinoma of the breast (invasive ductal or lobular)Undergoing partial mastectomy (lumpectomy) procedureAge 18 years or more

Exclusion Criteria Multicentric diseaseBilateral diseaseNeoadjuvant systemic therapyAll T4 tumorsPrevious radiation in the operated breastPrior surgical procedure in the same quadrantImplants in the operated breastPregnancyLactationParticipating in any other investigational study which can influence collection of valid data

Primary Endpoints Measure of surgical reexcision rateRate of tumor at final surgical marginsSecondary EndpointsVolume of tissue excisedClinical and economic measures of addressing asymmetry

Statistical Methods: The trial is designed to show superiority of the ISAM imaging arm to the standard of care. Statistical design is two group, continuity corrected chi-squared test of equal proportions with 90% power and alpha=0.05. The trial design assumes a baseline reoperation rate in the standard of care arm of 24% with at least a 50% reduction in the ISAM imaging arm.

Present Accrual and Target Accrual

Not yet recruiting. Target accrual is 230 patients in the partial mastectomy + imaging arm and 230 patients in the standard of care partial mastectomy arm.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT2-1-04.

P3-12-02: Intra-Operative Margin Assessment of Diffuse Disease with MarginProbe” as an Adjunct to Standard of Care, Results from a Randomized Prospective Multi Center Study

Background

The ability to obtain negative margins with a single surgical procedure remains a challenge, particularly in patients with diffuse disease such as DCIS and lobular pathology. A novel device (MarginProbe, Dune Medical Devices, Inc.) is intended to provide surgeons with real time, intraoperative detection of cancerous tissues at the margins of excised specimens. A study was performed to determine if there was a device-associated improvement in complete surgical resection (CSR) and therefore a decrease in the rate of patients requiring re-excision with these disease types. The current analysis stratified the data based on tumor type with a special focus on DCIS patients, patient with a DCIS component, and lobular patients.

Methods: All 596 patients underwent breast conservation, with image-guided localization, and were randomized in a prospective, international, multicenter (n=21) study. Randomization occurred in the operating room, following standard lumpectomy procedure, including palpation followed by additional cavity resections as indicated. In the device arm, MarginProbe was used on each specimen margin and device positive readings required additional resections of the cavity. Pathologists were blinded to study arm. Re-excision criteria were not dictated by the protocol.

A primary endpoint of this study was CSR, defined as the correct intraoperative identification and resection (if not skin or fascia) of all positive margins on the main lumpectomy specimen. Positive lumpectomy specimens were defined as those having at least one margin having cancer ≤1mm from the surface. Successful CSR results in reduced positive margin rate after lumpectomy.

Results: Results are presented in Table 1. The improvement in CSR was significant for all diagnosis types. The decrease in candidates for re-excision due to failed CSR was significant for all DCIS and mixed tumor types.

Use of a novel device to reduce positive margins for ductal carcinoma in situ

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Background: The ability to obtain negative margins with a single surgical procedure remains a challenge, particularly in patients with ductal carcinoma in situ (DCIS). A novel device (MarginProbe, Dune Medical Devices, Inc.) is intended to provide surgeons with real-time, intraoperative detection of cancerous tissues at the margins of excised specimens. A study was performed to determine if there was a device-associated improvement in complete surgical resection (CSR) and therefore a decreased re-excision rate in patients with a DCIS component.

Methods: 596 patients who were undergoing breast conservation using needle localization were randomized in a prospective, international, multicenter (n=21) study. Randomization occurred in the operating room, following standard of care lumpectomy, including palpation followed by indicated additional cavity resections. Device positive readings required additional resections of the cavity. Pathologists were blinded to study arm. A primary endpoint of this study was CSR, defined as the correct intraoperative identification and resection (if not skin or fascia) of all positive margins on the main lumpectomy specimen. Positive lumpectomy specimens were those having at least one margin having cancer ≤1mm from the surface. Successful CSR results in reduced positive margin rate after lumpectomy.

Results: The improvement in CSR was significant for each diagnosis (p<0.0001). The decrease in candidates for reexcision due to failed CSR was significant for all pathology involving DCIS (p<0.0001). Overall results are presented in the table.

Conclusions: Device use delivered significant improvement in CSR and therefore a significant decrease in reexcision rates for patients with DCIS. Further studies need to be conducted evaluating the use of the device on additional margins that the surgeon may resect or in the actual cavity.

[Table: see text]

Abstract P4-06-09: Genetic Signature Discriminating Metastatic from Non-Metastatic Small Tumors

Background: The widespread use of mammographic screening resulted in increased diagnosis of small (&lt;2 cm; T1) tumors. Small tumors are associated with better prognosis, including a lower likelihood of developing metastasis, than larger tumors. Although this lower propensity to metastasize suggests that less aggressive treatments may be warranted in patients with T1 tumors, a subset of patients with small tumors (10-20%) will be diagnosed with lymph node metastasis.

Methods: Frozen breast specimens were collected from women with T1 tumors and either negative (n=29) or positive (n=15) lymph node status. RNA was isolated from pure tumor cell populations after laser microdissection. Gene expression data was generated using HG U133A 2.0 arrays (Affymetrix). Differential expression was determined using Mann-Whitney testing using a P-value &lt; 0.001 to define significance. Results for ESR1 were validated by immunohistochemistry.

Results: Tumor characteristics did not differ significantly between groups in terms of age at diagnosis, grade, HER2 or PR status; however, tumors from patients with positive lymph nodes (47%) were significantly (P&lt;0.05) more frequently ER negative compared to node negative (14%) patients. Gene expression analysis revealed 17 genes that were differentially expressed between node negative and node positive tumors: 6 with higher expression in node positive, including AURKA, and 11 with higher expression in node negative patients, including ESR1 and EPHX2. Of note, ESR1 was expressed at &gt;4X higher levels in tumors without metastasis, in agreement with IHC findings.

Conclusions: Small metastatic tumors differ in gene expression from those without metastasis. EPHX2 has been implicated as a metastasis suppressor while AURKA has been implicated as a metastasis promoter. These results suggest that small tumors have different propensities to metastasize and the genetic signature may serve as a new molecular tool to discriminate metastatic and non-metastatic small tumors, allowing appropriate treatment and risk assessment to be performed.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-06-09.

Abstract P6-04-10: Genetic Discrimination of Aggressive from Indolent DCIS

Background: Treatment options for DCIS vary from surgical excision with or without radiation and/or chemopreventive therapy, or mastectomy. Intuitively, more aggressive treatment options should lead to improved survival rates, however, studies have shown no difference in breast cancer mortality between women treated with wide excision only versus those with excision plus radiation and treatments can be costly, lengthy and associated with side effects. To avoid over-treating women with indolent disease, while intensively treating women with aggressive disease, new molecular tools must be developed to supplement pathological information to classify DCIS lesions and predict clinical outcome.

Methods: Formalin-fixed paraffin-embedded (FFPE) pure DCIS biopsy specimens were collected from the pathology archives of the Anne Arundel Medical Center. Samples included those with poor prognosis characterized by either recurrence of DCIS or progression to invasive cancer (n=7) and those good prognosis, having ≥5-year disease-free survival (n=10). RNA was isolated after laser-microdissection of pure tumor cells and hybridized to Breast Cancer DSA™ microarrays (Almac Diagnostics). S-way ANOVA was used to account for batch effects and then Support Vector Machine (SVM) was used to identify candidate genes effective at discriminating good from poor prognosis DCIS. Pathway analysis was performed using MetaCore (GeneGeo).

Results: 328 genes were found to be differentially expressed between good and poor prognosis specimens (P&lt;0.01). Preliminary analysis with SVM found that a 70-gene candidate signature from these 328 genes wasoptimal under the tested conditions for discriminating favorable from poor prognosis DCIS. This candidate signature included genes such as MEF2C, PTK2 and ZBTB2. Pathway analysis revealed that genes involved in cytoskeleton modeling, apoptosis and survival, DNA damage repair and cell adhesion are expressed at lower levels in poor prognosis DCIS while those involved in cell cycle, immune response and cell proliferation are expressed at higher levels.

Conclusions: While studies have attempted to identify molecular profiles associated with aggressive DCIS by comparing DCIS co-occurring with invasive disease to pure DCIS, to our knowledge, this is the first study that identified a candidate molecular signature of prognosis in pure DCIS. Although many of the 70 genes found to differ between favorable and poor prognosis DCIS have not been previously associated with breast cancer or have unknown function, MEF2C and PTK2 have been implicated in invasion and migration, while ZBTB2 is a master regulator of p53 and stimulates cellular proliferation. These data demonstrate aggressive DCIS do differ from indolent DCIS at the genetic level and that these differences may be useful in developing molecular tools to classify DCIS lesions and guide appropriate treatment.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-04-10.

The risk of breast cancer recurrence in the sentinel lymph node era

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Background: Sentinel lymph node biopsy (SLNB), the preferred method of axillary staging in early breast cancer, is more sensitive and accurate compared to axillary node dissection. However, this data has not been incorporated into current prognostic models estimating the risk of breast cancer recurrence. We hypothesize that prognostic models based on data in the pre-SLN era underestimate survival and exaggerate benefits resulting from adjuvant therapy. In order to evaluate this hypothesis, we examined the disease free survival (DFS) and overall survival (OS) in an IRB approved, prospective, multicenter study of SLNB. Methods: From 1996–2005, 564 patients who had invasive disease in whom a SLN was found were examined from two experienced sites . Data was analyzed with regards to SLN status, tumor size, grade, lymphovascular invasion (LVI), age, estrogen receptor (ER) status and use of chemotherapy with respect to DFS and OS. Results: Median age was 57 years, tumor size was 1.5 (range 0.08–10.5) cm and follow-up was 46.2 (range 1–104.5) months. The SLN was positive in 31.2% of patients. The Kaplan-Meier (K-M) 5 year estimate of OS was 94.5(±1)% and DFS 88(±2)%. Tumor grade and size, LVI, ER- and +SLN significantly correlated with poorer DFS and OS by univariate analysis. By multivariate analysis, however, SLN status was the only statistically significant predictor for DFS (p = 0.004; HR = 3.4; CI = 1.5 - 8.0) and OS (p = 0.0051; HR = 7.3; CI = 1.8–29.4). SLN negative patients showed K-M 5 year DFS and OS estimates of 94(±)% and 97.4(±1)% respectively. There was no significant difference in DFS for SLN- patients treated with or without chemotherapy (p = 0.3). Conclusions: SLN status was the only significant predictor of DFS and OS. In node negative patients, we observed a higher DFS and OS than current statistical models based on historical data would have predicted. In this new era of SLNB, the magnitude of benefit from adjuvant therapy in sentinel node negative patients should be re-evaluated.

No significant financial relationships to disclose.

Sentinel node biopsy for breast cancer

Sentinel node biopsy is more frequently being used as a replacement for axillary node dissection as single and multicenter trials confirm its ability to predict the presence of disease in the remaining lymph nodes. There have been a variety of techniques used with varying success and data supporting each of these techniques is presented. In addition, a number of factors have been found to influence the identification and false negative rates, and these are discussed as well. There remain many areas of controversy surrounding this new surgical technique, including: the appropriate method of pathological analysis of the sentinel node, use of lymphoscintigraphy, usefulness of internal mammary sentinel node biopsy, and use of sentinel node biopsy for ductal carcinoma in situ. The Literature is reviewed on these controversial areas.

Preoperative chemotherapy and sentinel lymphadenectomy for breast cancer

BACKGROUND

Sentinel lymphadenectomy (SL) for breast cancer is becoming the standard of care for selected patients treated by experienced surgeons. One of the few contraindications for performing SL alone is prior chemotherapy (PC). There are, however, no data to support that PC interferes with the ability of the sentinel node to predict the presence of disease in the remaining axillary lymph nodes. The goal of this study was to determine the effect of PC on patients undergoing SL for breast cancer.

METHODS

A multicenter trial was organized in 1997 to evaluate the diagnostic accuracy of SL in patients with breast cancer. Investigators were recruited after attending a course on the technique of SL. Technetium-99 and isosulfan blue were injected into the peritumor region and a gamma probe was used to aid identification of the sentinel nodes. The only exclusion criteria for entrance into the trial were palpable or suspicious axillary lymph nodes. A total of 968 patients were enrolled in the trial. Twenty-nine patients were treated with PC and compared with 939 patients not receiving PC.

RESULTS

The overall, sentinel node identification rate for the PC patients was 93% (27 of 29) compared with 88% (822 of 939) for patients not treated with PC. There were no false negatives in those patients receiving PC compared with a 13% (25 of 193) false negative rate in those patients not receiving PC. The mean tumor size was 1.4 cm for the PC group and 0.6 cm for the remaining patients (P <0.005). The mean number of sentinel nodes found was 2.0 for the non-PC group and 2.5 for the PC group (not significant). As expected, a higher proportion of patients had positive axillary nodes in the PC group (52%, 15 of 29) compared with the remaining patients (21%, 200 of 939).

CONCLUSION

In this small group of patients, PC did not adversely impact the false negative or identification rate. Most patients receiving chemotherapy have larger tumors and a higher chance of harboring metastatic disease but a significant group of these patients (48%) without metastases can potentially be spared an axillary node dissection.

The learning curve and sentinel node biopsy

BACKGROUND

The ability of sentinel node biopsy (SNB) to replace axillary node dissection for accurate breast cancer staging is absolutely dependent on the consistent and accurate determination and removal of the "true" sentinel node. There are a wide variety of variables that affect the ability of the physician to achieve this goal. One important and potentially controllable variable is physician training and competence to employ the available techniques successfully. There is a large diversity of opinion regarding the minimum number of cases required under supervision prior to independent utilization of the technique but there are data to support at least 20 cases done in conjunction with axillary dissection or under direct supervision.

METHODS

Data from single institution and multicenter trials are reviewed and the learning curves are described. An overview of surgical education methods, testing, and credentialing is also addressed.

RESULTS

A review of single institution series show that the false negative rate and identification rates vary considerably. In all cases where authors published a second series success rate improved compared with their initial series. Of the four multicenter trials only two can provide reliable learning curves and these have shown a decrease in the false negative rate to < or = 5% after 20 to 30 procedures are performed.

CONCLUSIONS

There are data to show that there is a definite learning curve for SNB that cannot be ignored. It is possible that other factors, (ie, a skin injection with technetium-99, Sappeys plexus injection, and mentoring) could decrease this learning curve but until compelling evidence to suggest otherwise is available, surgeons should obtain a minimum experience of 20 cases.

Comparison of intradermal and subcutaneous injections in lymphatic mapping

BACKGROUND

Sentinel node biopsy (SNB) for melanoma, with its intradermal (ID) injection, has a higher success rate than SNB for breast cancer, which is typically performed with a subcutaneous (SC) or peritumor injection. It is hypothesized that this is in part due to a slower transit time of lymphatic mapping agents through the parenchymal lymphatics of the breast. No study has investigated differences in transit time between different tissues to account for this clinical observation. The goal of the study was to compare transit time between ID and SC injections with common agents used in lymphatic mapping.

METHODS

Four injection sites on five domestic pigs were used. Sites were bilateral and included cervical, forelimb, hindlimb, and flank areas. Agents included technetium sulfur colloid (Tc99, filtered and unfiltered), isosulfan blue (IB) dye, and fluorescein (FL) dye. At each site both ID and SC injections were made and the transit time to reach the sentinel node was recorded. The transit time differences were calculated per centimeter distance from the draining lymph node basin.

RESULTS

Sentinel nodes were identified draining all sites and found to be hot, blue, or fluorescent (using a Wood's lamp for identification). The cervical and forelimb injection sites drained to the same cervical lymph node basin and both SC and ID injection sites drained to the same sentinel node. Similarly, the hindlimb and flank injection sites both drained to inguinal lymph node basins. The slowest transit time occurred with Tc99 injected SC and the fastest occurred with Tc99 injected ID, whereas both FL dye and IB traveled rapidly to the sentinel node whether injected SC or ID. Large differences were found using unfiltered Tc99 depending on its injection ID (2.7 s/cm +/- 0.5) vs SC (249 s/cm +/- 14.7, P = 0.008).

CONCLUSIONS

Tc99 ID injections were significantly faster than SC injection. The slowest and fastest SC injection agents were unfiltered Tc99 and IB, respectively. Dermal injections provide faster transit of lymphatic agents and may improve the identification rate when applied to patients with breast cancer.

Multicenter trial of sentinel node biopsy for breast cancer using both technetium sulfur colloid and isosulfan blue dye

OBJECTIVE

To determine the factors associated with false-negative results on sentinel node biopsy and sentinel node localization (identification rate) in patients with breast cancer enrolled in a multicenter trial using a combination technique of isosulfan blue with technetium sulfur colloid (Tc99).

SUMMARY BACKGROUND DATA

Sentinel node biopsy is a diagnostic test used to detect breast cancer metastases. To test the reliability of this method, a complete lymph node dissection must be performed to determine the false-negative rate. Single-institution series have reported excellent results, although one multicenter trial reported a false-negative rate as high as 29% using radioisotope alone. A multicenter trial was initiated to test combined use of Tc99 and isosulfan blue.

METHODS

Investigators (both private-practice and academic surgeons) were recruited after attending a course on the technique of sentinel node biopsy. No investigator participated in a learning trial before entering patients. Tc99 and isosulfan blue were injected into the peritumoral region.

RESULTS

Five hundred twenty-nine patients underwent 535 sentinel node biopsy procedures for an overall identification rate in finding a sentinel node of 87% and a false-negative rate of 13%. The identification rate increased and the false-negative rate decreased to 90% and 4.3%, respectively, after investigators had performed more than 30 cases. Univariate analysis of tumor showed the poorest success rate with older patients and inexperienced surgeons. Multivariate analysis identified both age and experience as independent predictors of failure. However, with older patients, inexperienced surgeons, and patients with five or more metastatic axillary nodes, the false-negative rate was consistently greater.

CONCLUSIONS

This multicenter trial, from both private practice and academic institutions, is an excellent indicator of the general utility of sentinel node biopsy. It establishes the factors that play an important role (patient age, surgical experience, tumor location) and those that are irrelevant (prior surgery, tumor size, Tc99 timing). This widens the applicability of the technique and identifies factors that require further investigation.

State-of-the-art lymph node staging for breast cancer in the year 2000

Axillary staging for breast cancer is vitally important for determining appropriate adjuvant hormone and chemotherapy. In the absence of distant metastases, axillary lymph node status remains the most accurate predictor of clinical outcome. Sentinel lymph node biopsy is a minimally invasive approach with enhanced accuracy and less morbidity than conventional axillary dissection. The stage is now set for the sentinel lymphadenectomy staging to move from state-of-the-art care to the standard care in coming years.

Credentialing issues with sentinel lymph node staging for breast cancer

Sentinel lymphadenectomy (SL) is a minimally invasive approach for staging patients with breast cancer. SL, when performed in lieu of axillary dissection, is associated with less morbidity and is potentially more cost effective and more accurate than the historical axillary dissection in the detection of regional nodal metastases. The credentialing and privileging of SL, as with any surgical procedure, is by the policies of the local hospital or institution. The suggested credentialing criteria for local hospitals has been an area of controversy. Herein the authors outline the credentialing controversy and suggest criteria for the implementation of sentinel lymph node staging for breast cancer.

The details of successful sentinel lymph node staging for breast cancer

Sentinel lymphadenectomy is an effective and accurate tool for staging breast cancer. In recent years the details of a successful program have become better defined. The authors outline practical considerations for the performance of successful sentinel lymph node staging from a multidisciplinary perspective.

Fine-needle aspiration cytology of metastatic squamous-cell carcinoma arising in a pilonidal sinus, with literature review

Fewer than 50 cases of carcinoma arising in a pilonidal sinus have been reported, with only 5 patients having documented inguinal lymph node metastases. This is the first report of the fine-needle aspiration (FNA) diagnosis of this uncommon clinical situation of squamous-cell carcinoma arising in a pilonidal sinus, metastatic to an inguinal lymph node. We report on a 59-yr-old male with squamous-cell carcinoma arising in a pilonidal sinus who presented with inguinal adenopathy. FNA biopsy of a lymph node was performed, resulting in a diagnosis of metastatic squamous-cell carcinoma. FNA biopsy is useful in the evaluation of patients with inguinal adenopathy and a history of malignancy arising in a pilonidal sinus. The possibility of this rare complication should also be considered when metastatic squamous-cell carcinoma to an inguinal lymph node is diagnosed by FNA cytology in patients having an unknown primary except for a change in a long-standing pilonidal cyst.

Filtered versus unfiltered technetium sulfur colloid in lymphatic mapping: a significant variable in a pig model

BACKGROUND

Lymphatic mapping with sentinel node biopsy is becoming a standard diagnostic test for melanoma and is being extensively investigated for use with other soft tissue tumors. Both filtered and unfiltered technetium sulfur colloid (Tc 99) have been used for preoperative lymphoscintigraphy, as well as intraoperative lymphatic mapping, and it is not clear if one is preferable over the other. The purpose of this study was to compare these two preparations to determine whether the form of Tc 99 used affects the results of lymphatic mapping.

METHODS

Mock skin sites were placed on each extremity of 12 domestic pigs totaling 48 skin sites. Twenty-four of the lesions were injected with unfiltered Tc 99; the remaining 24 were injected with Tc 99 passed over a 0.2-microm filter. Both preparations of Tc 99 were mixed with 1 mL of isosulfan blue before injection. Sentinel node dissection was performed using a gamma probe, with counts recorded over a 10-second period and timed to begin 5 minutes after injection.

RESULTS

Sentinel nodes were identified in all 48 lymph node basins draining the mock sites and characterized as hot (10x background), blue, or both. Significantly more sentinel nodes were found in the filtered (105 total, X = 4.4/basin), than in the unfiltered group (total 53, X = 2.2/basin, P <.0001). The filtered group had both a higher number of nodes that were hot (35 vs. 6) and more nodes that were hot and blue (69 vs. 43). In addition, hot secondary level lymph nodes (iliac and deep cervical) were found in 11 of 24 of the basins (46%) in the filtered group compared to 1 of 24 (4%) in the unfiltered group (P <.003). There was no significant difference in injection site or residual basin counts between the two groups, but in vivo counts over the sentinel node sites were significantly lower in the unfiltered group (X = 2670+/-1829 vs. X = 6027+/-4333; P = .003).

CONCLUSION

Use of filtered Tc 99 results in more sentinel nodes (both hot/blue and hot non-blue) and a higher proportion of secondary lymph nodes. These findings indicate that the Tc 99 preparation used is a significant variable in the results of lymphatic mapping. It is critical that future clinical studies document which preparation of Tc 99 was used. Only large clinical trials will be able to determine whether the additional nodes found with filtered Tc 99 increase the sensitivity of the technique or merely increase the number of nodes that must be removed unnecessarily.

Identification of superior markers for polymerase chain reaction detection of breast cancer metastases in sentinel lymph nodes

Sentinel lymph node biopsy (SLNB) is being evaluated in breast cancer patients to improve detection of metastases and to guide therapy with minimal morbidity. The use of reverse transcription-PCR analysis to increase detection of tumor cells in SLN of breast cancer patients is hampered by the lack of specific markers. In this study, seven markers were evaluated by reverse transcription-PCR for expression in human breast adenocarcinoma lines (BrCa) and in normal nodes from non-cancer patients. Two markers yielded exceptional results; mammaglobin and carcinoembryonic antigen transcripts were detected in 100 and 71% BrCa, respectively, and were absent from all normal lymph nodes. These markers will be used as components of a multimarker panel to evaluate sentinel nodes in an on-going, multicenter clinical trial.

Nonpalpable versus palpable invasive breast tumors treated with breast-conserving surgical management

Most mammographically detected breast cancers are small, nonpalpable malignancies that should be amenable to cure by definitive breast-conserving therapy (BCT) consisting of tumor excision and postoperative radiation. We examined this hypothesis by retrospectively comparing the incidence of local recurrence and the rate of survival in breast cancer patients undergoing BCT for nonpalpable versus palpable lesions. Between 1982 and 1991, 345 patients at the John Wayne Cancer Institute, a large referral center for breast diseases, underwent BCT for invasive ductal and/or invasive lobular breast carcinomas: 120 (35%) had nonpalpable lesions detected by mammography (MG group), and 225 (65%) had palpable lesions detected by physical exam (PE group). The clinical and pathologic tumor status and the clinical outcome were recorded in each case. Median tumor size was significantly larger in PE than MG patients (2 cm versus 1 cm, P < 0.001). Only 29 percent of MG patients were premenopausal, compared with 51 percent of PE patients (P < 0.05). Axillary node involvement was more frequent in PE than MG patients (46% versus 19%, P < 0.01). Over a median follow-up of 58 months, local recurrence rates were 8 per cent for both MG and PE patients. In both groups, the incidence of local recurrence increased significantly when tumor was found in the margins of the resected breast specimen. In the MG group, the risk of local recurrence was significantly higher in premenopausal patients (P < 0.05). Survival was similar in both groups. The rate of local recurrence after BCT is the same for nonpalpable and palpable breast tumors. However, nonpalpable lesions have a lower rate of regional node metastases, which may improve survival. Both local recurrence and metastases seem to be related to tumor size. Tumor-free operative margins are the best predictor of local control.

Resection and adjuvant immunotherapy for melanoma metastatic to the lung and thorax

Although melanoma that metastasizes to distant sites is generally associated with a median survival of only 6 to 8 months, certain metastatic sites including the lung may carry a better prognosis than others. Surgical therapy for pulmonary metastases remains controversial because of the variable survival rates reported for previous small series. To determine the prognosis and optimal management of patients with melanoma with pulmonary metastases, we reviewed our 22-year melanoma database of over 6100 patients. Of 984 patients with metastatic melanoma involving the lung or thorax, 106 underwent resection by posterior lateral thoracotomy or median sternotomy. There were no operative deaths, and the median follow-up period for surgical patients was 55 months. The remaining 878 patients were treated without operation with immunotherapy, chemotherapy, radiation therapy, or a combination. In both treatment groups the male/female ratio was approximately 2:1. The primary lesion's Clark level of invasion and Breslow thickness and the patient's age at diagnosis of metastatic disease were not significantly different between the two groups. The 1-year, 3-year, and 5-year survival rates for surgical patients were 77%, 37%, and 27%, respectively, compared with 32%, 7%, and 3% for nonsurgical patients; these differences were highly significant (p = 0.0001). The highest 5-year survival rate (39%) occurred in those patients with a single metastatic lesion. Sixty-three percent of the surgical patients received some form of immunotherapy, compared with 34% of the nonsurgical patients. Multivariate analysis showed that resection and immunotherapy with a melanoma cell vaccine were both independent predictors of survival (p < 0.0001). These results indicate that the prognosis associated with metastatic melanoma may be less dismal than previously thought when distant metastases involve thoracic sites. We believe that surgical resection is the treatment of choice for patients with melanoma with pulmonary metastases; when combined with immunotherapy, this regimen offers the best chance for long-term survival.

Intraportal delivery of immunosuppression to intrahepatic islet allograft recipients

Local delivery of immunosuppressive agents may dampen local alloreactive events with avoidance of systemic toxicity. We investigated the innovative strategy of intraportal (IPO) delivery of three immunosuppressive agents in streptozotocin diabetic rat recipients of islet allografts (Lewis to Wistar-Furth) transplanted intrahepatically. IPO budesonide (BUD, 240 or 360 micrograms/kg per day), a potent steroid, and cyclosporin (CyA, 2 or 4 mg/kg per day) did not prolong graft mean survival time [MST +/- standard deviation (SD)] as compared to nonimmunosuppressed recipients. Fourteen days of IPO FK 506 (0.16 mg/kg per day) significantly increased MST as compared with untreated controls (49 +/- 29 vs 7 +/- 1 days, P < 0.01) and was more effective than intravenous (IV) FK 506 (17 +/- 7 days, P < 0.01). When FK 506 was given for 28 days, the benefit of IPO over IV delivery was reaffirmed (MST 81 +/- 32 vs 34 +/- 4 days, P < 0.01). The potential for toxicity was lessened by lower mean systemic levels in the IPO group as compared to the IV group (1.3 +/- 0.6 vs 3.5 +/- 0.9 ng/mg, P < 0.02). The strategy of continuous IPO FK 506 was effective in the prevention of rejection of intrahepatic islet allografts.

Margin status and local recurrence after breast-conserving surgery

OBJECTIVE

To examine the effect of microscopic tumor at the margins on local recurrence after breast-conserving surgery for invasive carcinoma.

DESIGN

Retrospective review of patients treated with surgical resection followed by radiation therapy.

SETTING

A university-based radiation department and a community-based cancer referral center.

PATIENTS

A consecutive series of 272 women treated between 1982 and 1990.

MAIN OUTCOME MEASURE

Local recurrence according to the histopathologic status of excised margins and the total dose of radiation.

RESULTS

During a mean follow-up period of 48 months, the overall rate of local recurrence was 6.3%. Local recurrence was more frequent (P = .0001) in patients with histologically positive margins (18.2%) than in those with unknown margins (7.1%) or negative margins (3.7%). In the 44 patients with positive margins, the local recurrence rate was 8.3% after radiation doses of 66 Gy or more compared with 21.9% following lower doses.

CONCLUSIONS

Microscopic involvement of resection margins increases the risk of local recurrence following breast-conserving surgery for invasive carcinoma. Therefore, every effort should be made to achieve negative margins intraoperatively.

Planned segmentectomy. A necessity for breast carcinoma

OBJECTIVE AND DESIGN

Some surgeons consider excisional biopsy with gross negative margins to be adequate surgical therapy for breast carcinomas, if followed by axillary dissection and radiation. To test our hypothesis that breast carcinoma necessitates planned operation, we reviewed the incidence of residual cancer tissue (RCT) and the significance of positive margins following excisional breast biopsy and segmentectomy. SETTING, PATIENTS, AND INTERVENTION/OUTCOME MEASURES: Using the clinical database of our multidisciplinary cancer center, we examined the tumor status of segmentectomy specimens from 375 patients treated for breast carcinoma during the past 10 years. All patients underwent excisional biopsy of the tumor mass before definitive treatment with segmentectomy and axillary dissection. Median follow-up was 32 months.

RESULTS

The 284 patients (76%) whose segmentectomy specimens contained residual tumor (RCT-positive patients) had a larger median tumor diameter than RCT-negative patients (2 vs 1 cm, P < .01). Patients with tumor-positive axillary lymph nodes were more likely to be RCT positive (P < .001). Tumors of RCT-positive patients were more frequently identified by physical examination, whereas those of RCT-negative patients were more frequently identified by mammography (P < .001). Overall recurrence rate was 7% (26/384). Recurrence-free survival rates were statistically related to tumor status of the segmentectomy margins (P < .025) but not to RCT in the segmentectomy specimen.

CONCLUSION

Diagnostic breast biopsy is not a substitute for planned excision to remove all malignant tissue. Anything less than a preconceived surgical procedure may leave a significant amount of malignant tissue.

Effects of cotransplanted fetal liver on fetal pancreas isografts

Ricordi et al. described a hepatotrophic effect mediated by pancreatic islets on cotransplanted hepatocytes. We found a reciprocal salutary effect of fetal liver (FL) on fetal pancreas (FP) in the intramural small bowel (ISB) site. To further investigate this intriguing finding, composite FP/FL isografts were transplanted to the conventional renal subcapsular (RSC) site and the accessible but historically inhospitable intramuscular site in streptozotocin-diabetic Lewis rats. A comparison of recipients of FP/FL and FP alone found the proportion rendered normoglycemic was site dependent. All recipients of either composite FP/FL grafts or FP alone transplanted in the ISB site became normoglycemic. The proportion of normoglycemic recipients was lower in the RSC site (71% FP and 40% FP/FL) and the i.m. site (14% FP and 67% FP/FL). Importantly, regardless of site, normoglycemia was established with an accelerated time course in recipients of FP/FL versus FP alone (24 +/- 8 vs. 67 +/- 43 days; P = 0.001). Normal (or more rapid) glucose clearance after challenge was achieved in all normoglycemic recipients except those transplanted in the RSC site. On histological examination of excised FP/FL grafts, hepatocytes were present in association with islets. Cyclosporine-induced islet toxicity could not be overcome in 6 recipients of FP alone, but 6 of 8 recipients of FP/FL became normoglycemic (P less than 0.01). To assess the effect of FP on hepatocytes, allografts (Wistar donors) of FP or FP/FL were cotransplanted in the ISB of enzyme-deficient jaundiced Gunn rats. Immunosuppression consisted of rapamycin (0.8 mg/kg/day) infused intravenously for 4 weeks. In the FP/FL group (n = 4), the mean serum bilirubin level decreased from 8.6 to 4.9 mg/dl at 6 weeks after transplantation. This was a significant difference as compared with the increased mean serum bilirubin from 6.9 to 7.8 mg/dl (P less than 0.05; paired Student's t test) in recipients of FL alone (n = 4). In conclusion, we found a mutual paracrine effect on islets and hepatocytes transplanted as a composite FP/FL graft. FL hastened the establishment of normoglycemia following transplantation of FP in diabetic rats, and FP enhanced FL transplant function in Gunn rats.

Studies of composite grafts of fetal pancreas (FP) and fetal liver (FL) in the streptozotocin-induced diabetic rat

A hepatotrophic effect of pancreatic islets on co-transplanted hepatocytes has been described recently by Ricordi et al. We investigated a possible reciprocal effect of co-transplanted fetal liver (FL) on fetal pancreas (FP) isografted into streptozotocin diabetic rats. FL was co-transplanted with FP in three sites: the new intramural small bowel (ISB) site, the conventional renal subcapsular (RSC) site, and the historically inhospitable intramuscular (IM) site. Overall, as compared to grafts of FP alone, composite FP/FL grafts consistently provided earlier restoration of normoglycemia in streptozotocin diabetic recipients (24 +/- 8 vs. 67 +/- 43 days P = 0.001). The proportion of recipients rendered normoglycemic and the clearance of glucose was site-dependent. For FP and FP/FL recipients respectively, the ISB site resulted in 100% normoglycemia in both groups (19/19 and 6/6), the RSC site resulted in 71% (5/7) and 40% (2/5) and the IM site resulted in 14% (1/7) and 67% (6/9). In normoglycemic recipients, glucose clearance was normal or supraphysiologic except for the RSC site. Composite isografts brought about normoglycemia in 75% (6/8) of recipients treated with beta-cell toxic doses of cyclosporine that prevented reversal of diabetes in recipients of FP alone. Co-transplantation of FL benefits FP through paracrine mechanisms mediated by unknown factor(s). Thus, as compared to grafts of FP alone, composite FP/FL grafts established normoglycemia more rapidly, mitigated cyclosporine toxicity and corrected diabetes when transplanted in the small bowel site. There are several mediators that may be responsible for these paracrine effects between the liver cells and the pancreas. IGF-1 elaborated by FL is the most likely trophic factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Beneficial effects of fetal liver tissue on fetal pancreatic transplantation

Recently, composite grafts of hepatocytes and islets have been shown to improve the survival of hepatocytes. The possibility of a reciprocal effect of hepatocytes on islet function was investigated. Diabetic Lewis rats were isografted with (1) fetal pancreas and fetal liver (FP/FL), (2) fetal pancreas alone (FP), and (3) fetal pancreas and fetal spleen (FP/FS). Grafts were transplanted to the small bowel subserosa. All (6/6) FP/FL recipients were cured (glucose less than 250 mg/dl for greater than 30 days), whereas only 72% (13/18) of FP alone and 60% (3/5) of FP/FS recipients were cured. The amount of time to normoglycemia for FP/FS recipients was less (26 +/- 15 days) compared with FP (50 +/- 29 days) or FP/FS recipients (71 +/- 40 days). Mean glucose levels at 6 weeks were 166 +/- 78 mg/dl, 237 +/- 97 mg/dl, and 355 +/- 81 mg/dl in cured FP/FL, FP, and FP/FS recipients, respectively. Glucose tolerance test results were not significantly different from those of nondiabetic control rats. In contrast to FP alone, FP/FL recipients had well-granulated hyperplastic islets and hepatocytes on histologic examination. When new isograft recipients were treated with cyclosporine, all FP recipients remained hyperglycemic; however, 75% (6/8) of FP/FL recipients were cured. In conclusion, FL in a composite graft with FP resulted in better engraftment, earlier isograft function, and protection from cyclosporine islet toxicity.

Topographical variations in the morphology and biochemistry of adult canine tibial plateau articular cartilage

Topographically, there are both morphological and biochemical differences in the articular cartilage of the tibial plateau of normal adult dogs when the cartilage covered by the meniscus is compared with that more centrally placed and not covered by meniscus. Histologically, differences are present in the surface morphology, in intra- and extracellular lipid content, and in the morphology of the mineralization front. Electron microscopy shows, in the covered cartilage, variability in collagen fiber size, with evenly spaced fibers apparently randomly distributed and an orderly relationship between the proteoglycans and collagen, whereas in the uncovered area, the collagen is aggregated into bundles and appears to be dissociated in large part from the proteoglycans. The most striking feature in the biochemistry of the two regions is an increased water content in the uncovered cartilage, as compared with the covered. In addition, there is an increased amount of proteoglycans that can be extracted in the uncovered cartilage. The heterogeneity of the cartilage on the tibial plateau should be taken into account when considering both the histologic and biochemical variations found in osteoarthritic cartilage; and when reflecting on the pathogenesis of osteoarthritis.