High-risk Ductal Carcinoma In Situ Research Articles

Trends in breast biopsy pathology diagnoses among women undergoing mammography in the United States: a report from the Breast Cancer Surveillance Consortium.

Current data on the pathologic diagnoses of breast biopsy after mammography can inform patients, clinicians, and researchers about important population trends. Breast Cancer Surveillance Consortium data on 4,020,140 mammograms between 1996 and 2008 were linked to 76,567 pathology specimens. Trends in diagnoses in biopsies by time and risk factors (patient age, breast density, and family history of breast cancer) were examined for screening and diagnostic mammography (performed for a breast symptom or short-interval follow-up). Of the total mammograms, 88.5% were screening and 11.5% diagnostic; 1.2% of screening and 6.8% of diagnostic mammograms were followed by biopsies. The frequency of biopsies over time was stable after screening mammograms, but increased after diagnostic mammograms. For biopsies obtained after screening, frequencies of invasive carcinoma increased over time for women ages 40-49 and 60-69, Ductal carcinoma in situ (DCIS) increased for those ages 40-69, whereas benign diagnoses decreased for all ages. No trends in pathology diagnoses were found following diagnostic mammograms. Dense breast tissue was associated with high-risk lesions and DCIS relative to nondense breast tissue. Family history of breast cancer was associated with DCIS and invasive cancer. Although the frequency of breast biopsy after screening mammography has not changed over time, the percentages of biopsies with DCIS and invasive cancer diagnoses have increased. Among biopsies following mammography, women with dense breasts or family history of breast cancer were more likely to have high-risk lesions or invasive cancer. These findings are relevant to breast cancer screening and diagnostic practices.

Chromosomal copy number alterations (CNAs) for risk assessment of ductal carcinoma in situ (DCIS).

565 Background: Population-wide screening mammography has contributed to a significant increase in the diagnosis of DCIS, raising questions about over-diagnosis and over-treatment. We aimed to determine whether adding genomic variables to standard clinico-pathologic factors may identify low-risk versus high-risk DCIS, with an ultimate goal of tailoring therapy. Methods: Patient-level clinical and pathologic data were extracted from the electronic medical records of Stanford Cancer Institute and linked to demographic data from the population-based California Cancer Registry; results were integrated with data from tissue microarrays of biopsies revealing DCIS only versus concurrent invasive breast cancer (IBC) with DCIS. We used fluorescence in situ hybridization to investigate the predictive values of CNAs of 1q, 8q24 and 11q13 (reported by The Cancer Genome Atlas to be among the most frequent CNAs in IBC) in the DCIS component of the biopsies. Multivariable logistic regression analysis was performed to de...

Lapatinib inhibits stem/progenitor proliferation in preclinical in vitro models of ductal carcinoma in situ (DCIS)

Breast-conserving surgery for ductal carcinoma in situ (DCIS) is often combined with irradiation, reducing recurrence rates to 20% within 10 years; however, there is no change in overall survival. Evidence in the invasive breast indicates that breast cancer stem cells (CSCs) are radiotherapy-resistant and are capable of re-initiating a tumor recurrence; hence, targeting CSCs in high risk DCIS patient may improve survival. HER2 is overexpressed in 20% of DCIS and is known to be highly active in breast CSCs; we therefore investigated the effect of Lapatinib on DCIS CSC activity using 2 in vitro culture systems. Two DCIS cell lines DCIS.com (HER2 normal) and SUM225 (HER2 overexpressed) as well as DCIS cells from patient samples (n = 18) were cultured as mammospheres to assess CSC activity and in differentiated 3D-matrigel culture to determine effects within the non-CSCs. Mammosphere formation was reduced regardless of HER2 status, although this was more marked within the HER2-positive samples. When grown as differentiated DCIS acini in 3D-matrigel culture, Lapatinib only reduced acini size in the HER2-positive samples via decreased proliferation. Further investigation revealed lapatinib did not reduce self-renewal activity in the CSC population, but their proliferation was decreased regardless of HER2 status. In conclusion we show Lapatinib can reduce DCIS CSC activity, suggesting that the use of Lapatinib in high-risk DCIS patients has the potential to reduce recurrence and the progression of DCIS to invasive disease.

Preliminary Results From a Multicenter Prospective Study (JROSG 05-5) on Postoperative Radiation Therapy for Patients With High-Risk Ductal Carcinoma In Situ (DCIS) With Involved Margins or Margin Widths Not More Than 1 mm

In a study of patients with high-risk DCIS for whom margin widths were less than 1 mm after breast conservation surgery followed by postoperative radiation therapy (RT), Silverstein et al. reported an 8-year ipsilateral breast recurrence probability of 30%, with approximately 80% of recurrence developing within 3 years. This retrospective study included the various RT schedules. Only a few prospective studies have evaluated the role of postoperative RT for only high-risk DCIS. The present prospective study aimed to evaluate the effectiveness of postoperative RT which included whole breast irradiation followed by boost irradiation in patients with high-risk DCIS.

A Multigene Expression Assay to Predict Local Recurrence Risk for Ductal Carcinoma In Situ

A Multigene Expression Assay to Predict Local Recurrence Risk for Ductal Carcinoma In Situ

In Vivo Assessment of Ductal Carcinoma in Situ Grade: A Model Incorporating Dynamic Contrast-enhanced and Diffusion-weighted Breast MR Imaging Parameters

To develop a model incorporating dynamic contrast material-enhanced (DCE) and diffusion-weighted (DW) magnetic resonance (MR) imaging features to differentiate high-nuclear-grade (HNG) from non-HNG ductal carcinoma in situ (DCIS) in vivo. This HIPAA-compliant study was approved by the institutional review board and requirement for informed consent was waived. A total of 55 pure DCIS lesions (19 HNG, 36 non-HNG) in 52 women who underwent breast MR imaging at 1.5 T with both DCE and DW imaging (b = 0 and 600 sec/mm(2)) were retrospectively reviewed. The following lesion characteristics were recorded or measured: DCE morphology, DCE maximum lesion size, peak initial enhancement at 90 seconds, worst-curve delayed enhancement kinetics, apparent diffusion coefficient (ADC), contrast-to-noise ratio (CNR) at DW imaging with b values of 0 and 600 sec/mm(2), and T2 signal effects (measured with CNR at b = 0 sec/mm(2)). Univariate and stepwise multivariate logistic regression modeling was performed to identify MR imaging features that optimally discriminated HNG from non-HNG DCIS. Discriminative abilities of models were compared by using the area under the receiver operating characteristic curve (AUC). HNG lesions exhibited larger mean maximum lesion size (P = .02) and lower mean CNR for images with b value of 600 sec/mm(2) (P = .004), allowing discrimination of HNG from non-HNG DCIS (AUC = 0.71 for maximum lesion size, AUC = 0.70 for CNR at b = 600 sec/mm(2)). Differences in CNR for images with b value of 0 sec/mm(2) (P = .025) without corresponding differences in ADC values were observed between HNG and non-HNG lesions. Peak initial enhancement was the only kinetic variable to approach significance (P = .05). No differences in lesion morphology (P = .11) or worst-curve delayed enhancement kinetics (P = .97) were observed. A multivariate model combining CNR for images with b value of 600 sec/mm(2) and maximum lesion size most significantly discriminated HNG from non-HNG (AUC = 0.81). The preliminary findings suggest that DCE and DW MR imaging features may aid in identifying patients with high-risk DCIS. Further study may yield a model combining MR characteristics with histopathologic data to facilitate lesion-specific targeted therapies. © RSNA, 2012.

Incidence and possible pathogenesis of sentinel node micrometastases in ductal carcinoma in situ of the breast detected using molecular whole lymph node assay

Background:The pathogenesis of lymph node metastases in preinvasive breast cancer – ductal carcinoma in situ (DCIS) – remains controversial. The one-step nucleic acid amplification (OSNA) assay is a novel molecular method that can assess a whole node and detect clinically relevant metastases. In this retrospective cohort study, we determined the performance of the OSNA assay in DCIS and the pathogenesis of node-positive DCIS.Methods:The subjects consisted of 623 patients with DCIS who underwent sentinel lymph node (SN) biopsy. Of these, 2-mm-sectioned nodes were examined using frozen-section (FS) histology in 338 patients between 2007 and 2009, while 285 underwent OSNA whole node assays between 2009 and 2011. The SN-positivity rate was compared between cohorts, and the characteristics of OSNA-positive DCIS were investigated.Results:The OSNA detected more cases of SN metastases than FS histology (12 out of 285, 4.2% vs 1 out of 338, 0.3%). Most of the metastases were micrometastases. The characteristics of high-risk DCIS (i.e., mass formation, size, grade, and comedo) and preoperative breast biopsy (i.e., methods or time to surgery) were not valid for OSNA assay–positive DCIS.Conclusion:The OSNA detects more SN metastases in DCIS than FS histology. Further examination of the primary tumours and follow-up of node-positive DCIS are needed to elucidate the pathogenesis.

Selective approach to radionuclide-guided sentinel lymph node biopsy in high-risk ductal carcinoma in situ of the breast

Ductal carcinoma in situ (DCIS) currently represents approximately 15-25% of all breast cancers detected. Although inherently a noninvasive disease, occult invasive disease can be found at definitive histology. The role of sentinel lymph node (SLN) biopsy in DCIS is still unclear. The aim of this study was to evaluate the clinical usefulness of SLN biopsy and the incidence of SLN metastases in selected patients with high-risk DCIS, who are at highest risk for being upstaged to invasive carcinoma. Twenty-three high-risk patients with DCIS proven on core biopsy (mean age, 50 years; median age, 48 years; age range, 37-78 years) were included in the study. SLN scintigraphy was performed 2-4 h before surgery by injecting Tc-99m-labeled nanocolloid intradermally in the periareolar region. The first lymph node to appear on the scan was labeled as SLN and was marked on the skin by using a γ probe. The lymph node was explored in the axilla using a γ probe. The SLN was identified in all patients (100% success rate). Of 23 cases of DCIS on core biopsy, seven patients (30%) were shown to have invasive ductal carcinoma on final histological specimen. Among these seven patients, three had minimal invasive carcinoma (<1 cm) and none of these patients had positive SLN for metastases. Among 23 cases, only one patient with (4%) SLN was positive for metastasis despite histopathological diagnosis of pure DCIS. Although the study population is small, our findings suggest that patients with high-risk DCIS have an increased risk of invasive disease, as approximately one-third of these patients had invasive component at the time of definitive operative procedure. Furthermore, the study also suggests that SLNB appears to be reliable in identifying axillary lymph nodes status of these patients.

Fine Tuning of the Van Nuys Prognostic Index (VNPI) 2003 by Integrating the Genomic Grade Index (GGI): New Tools for Ductal Carcinoma In Situ (DCIS)

Ductal carcinoma in situ (DCIS) is considered a heterogeneous premalignant condition of the breast with a certain probability for progressing to malignancy. There is no standard of care. The updated Van Nuys Prognostic Index (VNPI) 2003 is a clinical tool in treatment decision making. This study assessed the prognostic value of the VNPI after integration of proliferative biomarkers (GGI and Ki-67). DCIS samples were divided into three VNPI subgroups (low risk [score 4-6], intermediate risk [score 7-9], high risk [score 10-12]) based on nuclear grade ± necrosis, tumor size, margin width, and age. Nuclear grade was substituted by the genomic grade index (GGI) to generate the VNPI-GGI and combined with the Ki-67 to generate the VNPI-Ki67. Disease-free survival was calculated by Kaplan-Meier survival plots with log-rank significance. Multiple regression analysis was carried out using Cox proportional hazard regression analysis. A total of 88 cases (median age 54 years) with representative tissue were identified out of 168 DCIS patients. Median follow-up was more than 5 years. Ten patients developed an ipsilateral recurrence of whom nine were invasive: six patients were classified in the VNPI subgroup 2 and three patients in the VNPI subgroup 3. One non-invasive recurrence (DCIS) was classified in the VNPI subgroup III. A statistical association was observed between a high VNPI score and a higher risk of recurrence (HR = 7.72 [95% CI 1.01-58.91], p = 0.049). Ki-67 did not improve the prognostic value of VNPI (HR = 6.5, [95% CI 0.80-53.33], p = 0.08). In contrast, the VNPI-GGI could identify more accurately high-risk DCIS patients with early relapses within 5 years (HR = 18.14 [95% CI 1.75-188], p = 0.015). GGI incorporated into the VNPI improved its prognostic value for DCIS, especially for identifying early relapses. This method should be validated and incorporated in future prospective clinical DCIS trials.

Predictors of Invasion and Axillary Lymph Node Metastasis in Patients with a Core Biopsy Diagnosis of Ductal Carcinoma In Situ: An Analysis of 255 Cases

The diagnosis of ductal carcinoma in situ (DCIS) using core biopsy does not ensure the absence of invasion on final excision. We performed a retrospective analysis of 255 patients with DCIS who had subsequent excision. Clinical, radiologic, and pathologic findings were correlated with risk of invasion and sentinel lymph node (SLN) metastasis. Of 255 patients with DCIS, 199 had definitive surgery and 52 (26%) had invasive ductal carcinoma (IDC) on final excision. Extent of abnormal microcalcification on mammography, and presence of a radiologic/palpable mass and solid type of DCIS were significantly associated with invasion on final excision. Sentinel lymph node biopsy was performed in 131 (65.8%) patients of whom 18 (13.4%) had metastasis. Size of IDC and extent of DCIS on final pathology were significantly associated with positive SLN. Micrometastasis and isolated tumor cells comprised majority (71.4%) of the metastases in DCIS. SLN biopsy should be considered in those with high risk DCIS.

Clinical Applications of Sentinel Lymph Node Biopsy in Ductal Carcinoma in situ of the Breast: A Dilemma

Breast cancer is the fifth most common cause of cancer deaths in the world, which often spreads first to the axillary lymph nodes (ALN) from the primary tumor. ALN helps clinician stage breast cancer. In addition, it is one of the key prognostic factors for patients with invasive breast cancer. The sentinel lymph node (SLN) is defined as the first regional lymph node to receive lymphatic fluid from a malignant tumor. As a result, it seems possible to assess the complete nodal status with sentinel lymph node biopsy (SLNB), which is attractive and reliable approach for identifying lymph node metastasis. Ductal carcinoma in situ (DCIS) is the most common type of non-invasive breast cancer. However, the role of SLNB in DCIS is controversial because DCIS does not cause invasion and metastasis theoretically. In this review, clinical applications of SLNB in DCIS will be discussed. The potential benefit of accurately upstaging patients with DCIS and the minimal invasiveness of SLNB justify use of SLNB in selected high-risk DCIS patients. At least DSIS with microinvasion, have DCIS of sufficient extent on mammography or MRI, or indicated invasive or microinvasive focus by final histological examination, are recommended for SLNB. Moreover, large randomized trials to evaluate the usefulness of SLNB in DCIS patients after long-term follow-up on local control and survival are required for further evaluation.

Sentinel lymph node biopsy and management of the axilla in ductal carcinoma in situ.

Ductal carcinoma in situ (DCIS) of the breast historically has been a disease detected by physical examination, diagnosed by open surgical biopsy, and treated by mastectomy and axillary dissection. It is now increasingly detected by screening mammography, diagnosed by needle core biopsy, and treated by lumpectomy, with axillary dissection having been abandoned and sentinel node biopsy being used in axillary staging. However, outcomes related to sentinel node biopsy in DCIS have not been validated in well-controlled clinical trials. Current guideline recommendations are to use sentinel node biopsy when needle core biopsy is highly suspicious for invasive cancer or where there is a high-risk DCIS when lumpectomy identifies invasive breast cancer with the DCIS, or when mastectomy is performed for extensive DCIS. Routine use of sentinel node biopsy for DCIS is not supported.

Can galactography-guided stereotactic, 11-gauge, vacuum-assisted breast biopsy of intraductal lesions serve as an alternative to surgical biopsy?

The purpose of this study was to determine the value of galactography-guided, stereotactic, vacuum-assisted breast biopsy (VABB) for the assessment of intraductal breast lesions and its potential as a therapeutic tool that could eliminate the need for surgical excision. Eighteen patients (median age 64 years, range 37-80) with nipple discharge and galactography-verified intraductal lesions underwent galactography-guided, stereotactic, 11-gauge VABB followed by surgery. Histopathology findings from VABB and subsequent surgery were compared. Underestimation and false-negative rates were assessed. After VABB, histopathology revealed invasive ductal carcinoma (IDC) in three (17%), ductal carcinoma in situ (DCIS) in six (33%), high-risk lesions in six (33%) and benign lesions in three (17%) cases. After surgical biopsy, histopathology confirmed the previously established diagnosis in 11 lesions (61%). The underestimation rate for high-risk lesions and DCIS was 50% (6/12). The false-negative rate was 7% (1/14). Histopathology examination after surgery showed that not a single lesion had been completely removed at VABB. Galactography-guided VABB is a feasible diagnostic tool. However, its value as a therapeutic procedure is limited because of the high number of underestimated and missed lesions and because of the histopathological detection of lesions' remnants in every case. Surgical excision should be the therapeutic gold standard in cases of pathological nipple discharge and galactography abnormalities.

Development of Vaccines for High-Risk Ductal Carcinoma In situ of the Breast

Certain ductal carcinoma in situ (DCIS) lesions overexpress the HER-2/neu receptor at this early stage of breast cancer development. Recently, we showed that a HER-2-targeted dendritic cell vaccine could be used to eliminate HER-2-overexpressing cells in patients that harbor these high-risk DCIS lesions. Our findings suggest that vaccinating such patients might diminish the risk of recurrence, protect against the development of invasive breast cancer, and minimize morbidity associated with current treatments. We discuss several implications of this work for developing effective cancer vaccines.

Role of sentinel lymph node biopsy in high-risk ductal carcinoma in situ patients

Background The role of sentinel lymph node biopsy (SLNB) for ductal carcinoma in situ (DCIS) is poorly defined. However, up to 20% of patients with DCIS will have invasive carcinoma; these patients require staging for axillary metastasis. The aim of this study was to identify patients with a core biopsy diagnosis of DCIS who may benefit from SLNB. Methods In a prospective study, we performed SLNB on patients with a preoperative diagnosis of >2.5 cm of high-grade DCIS or DCIS when mastectomy was indicated. Results Sixty-two patients underwent surgery for high-grade DCIS, and 35 of these patients underwent SLNB. Postsurgical excision histology revealed invasive disease in 20 patients, 19 of whom had undergone SLNB. Before the adoption of SLNB in selected DCIS patients, all 20 with occult invasive disease would have required second surgery axillary staging ( P < .01, chi-square test). Conclusions SLNB should not be performed routinely for all patients with an initial diagnosis of DCIS. However, selective lymphadenectomy may be a useful clinical adjuvant in selected high-risk DCIS patients.

Outcomes for Women With Ductal Carcinoma-in-Situ and a Positive Sentinel Node: A Multi-Institutional Audit

A positive sentinel lymph node (SLN) has been reported in 6% to 13% of patients with ductal carcinoma in situ (DCIS). Although it is well established that nodal status for invasive disease is prognostically important, the clinical relevance of a positive SLN in patients with DCIS remains undetermined. SLN biopsy was performed on 470 high-risk patients with DCIS (22% of all patients with DCIS) at 3 institutions. Of these, 43 (9%) had SLN metastases. Pathology findings of positive cases were reviewed, and follow-up was obtained. At 2 of the 3 institutions, data were also collected on DCIS patients who had negative findings on SLN biopsy. For these 414 patients, univariate analyses of tumor characteristics were performed to identify factors associated with node positivity. Extensive disease requiring mastectomy (p = 0.02) and the presence of necrosis (p = 0.04) were associated with an increased risk of nodal positivity. Three (7%) of the 43 SLN-positive patients had macrometastases (pN1), 4 (9%) had micrometastases (pN1mi), and 36 (84%) had single tumor cells or small clusters (pN0(i+)). Of the 25 women that underwent completion axillary dissection, one was found to have a macrometastasis. On pathological review of the primary lesion, 2 (5%) of 43 patints were found to have microinvasion, and 2 (5%) lymphovascular invasion. Nine of 43 (21%) high-risk DCIS patients with a positive SLN and 9/470 (2%) of all high-risk DCIS patients were upstaged to AJCC stage I or II as a result of the SLN biopsy. At a median (range) follow-up of 27 (3-88) months, 1 patient had developed hepatic metastases. This patient had immunohistochemistry detected isolated tumor cells in her SLN (N0(i+)), and upon pathologic review, was found to have high-grade DCIS with microinvasion. SLN biopsy for high-risk DCIS patients is a mean of detecting those who may have unrecognized invasive disease and therefore are at risk for distant disease.

Is there an indication for sentinel node biopsy in patients with ductal carcinoma in situ of the breast? A review

Ductal carcinoma in situ (DCIS) of the breast is defined as a proliferation of malignant epithelial cells within breast ducts without evidence of invasion through the basement membrane. The detection rate of DCIS of the breast has dramatically increased since the mid-1980s as the result of the widespread use of screening mammography. DCIS currently represents about 15–25% of all breast cancers detected in population screening programmes. Although inherently a non-invasive disease, occult invasion with the potential of lymph node metastases may occur. Where performing an axillary lymph node dissection-or-not for DCIS used to be an important dilemma, the same now holds for the sentinel node biopsy. This article reviews the potential role of the sentinel node biopsy (SNB) in patients with DCIS. We conclude that based on the current literature, there is in general no role for a SNB in DCIS. A SNB should only be considered in patients with an excisional biopsy diagnosis of high risk DCIS (grade III with palpable mass or large tumour area by imaging) as well as in patients undergoing mastectomy after a core or excisional biopsy diagnosis of DCIS, although SNB may be contraindicated in many of the latter patients because of lesion size and/or multifocality. Even in these patients the value of a positive SN, containing mostly isolated tumour cells, is questionable.

Is it possible to refine the indication for sentinel node biopsy in high-risk ductal carcinoma in situ?

The indication for sentinel node biopsy (SNB) has not been fully established yet for patients with ductal carcinoma in situ (DCIS). To relate the conversion rate to invasive carcinoma with sentinel node positivity in high risk DCIS, and to refine the clinical presentation analysis in order to better select patients for SNB. For this purpose, a risk score was devised. From 1998 to 2005, 151 high-risk DCIS patients from six clinical centres were included in a prospective sentinel node database. The conversion rate to invasive carcinoma was 39%. Ten of 142 (7%) successful SNBs showed a positive sentinel node (eight micrometastatic). The sentinel node was positive in 1% of pure DCIS, in 5.5% of DCIS with micro-invasion, and in 19.5% of invasive carcinoma. Both clinical presentation and corresponding risk score were closely related to conversion to invasive carcinoma. The association of risk score and sentinel node positivity approached but did not reach statistical significance (P=0.06); therefore a subset of further selected higher risk patients could not be defined. The relevance of SNB positivity cannot be overlooked in high-risk DCIS patients, however, because SNB is not free from morbidity and cost, more studies are needed to refine its final indication.

Evaluation of MUC1 splice variants as prognostic markers in patients with ductal carcinoma in situ of the breast

Despite intense research in the field of breast cancer it still remains the most common cancer in women in the Western world. A decreasing trend in mortality was mainly achieved by improved early detection which led to an increased incidence of ductal carcinoma in situ (DCIS) of the breast. For the patient's prognosis and the administration of a patient-tailored therapy strategy it is crucial to identify diagnostic and prognostic markers for high-risk DCIS patients. MUC1 is associated with tumour aggressiveness in human breast cancer. Recent studies used MUC1 splice variant A to identify malignant thyroid cancer. In the present study we have examined the usefulness of MUC1 splice variants as prognostic markers in DCIS. We used laser capture microdissection of paraffin-embedded tissue to isolate RNA from isolated tumour cells and determined the MUC1 splice variant distribution by RT-PCR. In the majority of cases variant B was more highly expressed than variant A. This was true for pure DCIS (66%) as well as for DCIS with adjacent invasive cancer (66%). In 7 out of 18 cases (38%) of pure DCIS variant A was not expressed at all. In DCIS with adjacent invasive cancer only 2 samples out of 12 showed this expression pattern (16%). The situation that variant A was more highly expressed than B, or that variant B was not expressed at all, was similar for pure DCIS (27%) and for DCIS with adjacent invasive cancer (33%). The present study describes the differences of MUC1 splice variant expression in pure DCIS compared to DCIS with adjacent invasive cancer. A discriminating pattern of MUC1 splice variants could not be demonstrated.

Sentinel lymph node biopsy: is it indicated in patients with high-risk ductal carcinoma-in-situ and ductal carcinoma-in-situ with microinvasion?

Axillary lymph node status is the strongest prognostic indicator of survival for women with breast cancer. The purpose of this study was to determine the incidence of sentinel node metastases in patients with high-risk ductal carcinoma-in-situ (DCIS) and DCIS with microinvasion (DCISM). From November 1997 to November 1999, all patients who underwent sentinel node biopsy for high-risk DCIS (n = 76) or DCISM (n = 31) were enrolled prospectively in our database. Patients with DCIS were considered high risk and were selected for sentinel lymph node biopsy if there was concern that an invasive component would be identified in the specimen obtained during the definitive surgery. Patients underwent intraoperative mapping that used both blue dye and radionuclide. Excised sentinel nodes were serially sectioned and were examined by hematoxylin and eosin and by immunohistochemistry. Of 76 patients with high-risk DCIS, 9 (12%) had positive sentinel nodes; 7 of 9 patients were positive for micrometastases only. Of 31 patients with DCISM, 3 (10%) had positive sentinel nodes. 2 of 3 were positive for micrometastases only. Six of nine patients with DCIS and three of three with DCISM and positive sentinel nodes had completion axillary dissection; one patient with DCIS had an additional positive node detected by conventional histological analysis. This study documents a high incidence of lymph node micrometastases as detected by sentinel node biopsy in patients with high-risk DCIS and DCISM. Although the biological significance of breast cancer micrometastases remains unclear at this time, these findings suggest that sentinel node biopsy should be considered in patients with high-risk DCIS and DCISM.