Axillary sentinel lymph nodes can be falsely positive due to iatrogenic displacement and transport of benign epithelial cells in patients with breast carcinoma

Ductal carcinoma in situ and sentinel lymph node metastasis in breast cancer

Background

The impact of sentinel lymph node biopsy on breast cancer mimicking ductal carcinoma in situ (DCIS) is a matter of debate.

Methods

We studied the rate of occurrence of sentinel lymph node metastasis in 255 breast cancer patients with pure DCIS showing no invasive components on routine pathological examination. We compared this to the rate of occurrence in 177 patients with predominant intraductal-component (IDC) breast cancers containing invasive foci equal to or less than 0.5 cm in size.

Results

Most of the clinical and pathological baseline characteristics were the same between the two groups. However, peritumoral lymphatic permeation occurred less often in the pure DCIS group than in the IDC-predominant invasive-lesion group (1.2% vs. 6.8%, p = 0.002). One patient (0.39%) with pure DCIS had two sentinel lymph nodes positive for metastasis. This rate was significantly lower than that in patients with IDC-predominant invasive lesions (6.2%; p < 0.001).

Conclusions

Because the rate of sentinel lymph node metastasis in pure DCIS is very low, sentinel lymph node biopsy can safely be omitted.

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.

Micrometastases or isolated tumor cells and the outcome of breast cancer

BACKGROUND

The association of isolated tumor cells and micrometastases in regional lymph nodes with the clinical outcome of breast cancer is unclear.

METHODS

We identified all patients in The Netherlands who underwent a sentinel-node biopsy for breast cancer before 2006 and had breast cancer with favorable primary-tumor characteristics and isolated tumor cells or micrometastases in the regional lymph nodes. Patients with node-negative disease were randomly selected from the years 2000 and 2001. The primary end point was disease-free survival.

RESULTS

We identified 856 patients with node-negative disease who had not received systemic adjuvant therapy (the node-negative, no-adjuvant-therapy cohort), 856 patients with isolated tumor cells or micrometastases who had not received systemic adjuvant therapy (the node-positive, no-adjuvant-therapy cohort), and 995 patients with isolated tumor cells or micrometastases who had received such treatment (the node-positive, adjuvant-therapy cohort). The median follow-up was 5.1 years. The adjusted hazard ratio for disease events among patients with isolated tumor cells who did not receive systemic therapy, as compared with women with node-negative disease, was 1.50 (95% confidence interval [CI], 1.15 to 1.94); among patients with micrometastases, the adjusted hazard ratio was 1.56 (95% CI, 1.15 to 2.13). Among patients with isolated tumor cells or micrometastases, the adjusted hazard ratio was 0.57 (95% CI, 0.45 to 0.73) in the node-positive, adjuvant-therapy cohort, as compared with the node-positive, no-adjuvant-therapy cohort.

CONCLUSIONS

Isolated tumor cells or micrometastases in regional lymph nodes were associated with a reduced 5-year rate of disease-free survival among women with favorable early-stage breast cancer who did not receive adjuvant therapy. In patients with isolated tumor cells or micrometastases who received adjuvant therapy, disease-free survival was improved.

Estrogen receptor immunohistochemistry for confirmation of sentinel lymph node metastasis in cases with equivocal cytokeratin positivity

Differentiation of true metastases from cytokeratin (CK)-positive nonepithelial cells by immunohistochemistry occasionally may be difficult in the evaluation of sentinel lymph nodes (SLNs) for occult breast carcinoma metastases. In this study, we evaluated estrogen receptor (ER) immunostaining superimposed on CK as a method for the confirmation of metastasis when CK immunostaining alone was equivocal. We performed sequential ER staining on previously CK-stained slides on 15 axillary SLNs from breast cancer patients: 5 SLNs with known metastatic carcinoma (positive controls), 6 known negative SLNs (negative controls), and 4 test cases (3 SLNs in which CK-positive cells were equivocal for malignancy and 1 SLN in which metastasis was obvious, but contained focal weakly CK-positive signet ring cells). The primary tumor in all cases expressed ER in >50% of cells. Only 3 of 5 positive controls showed metastatic cells with dual CK/ER staining. CK-positive reticulum cells in all negative controls were ER negative. Three test cases showed dual CK/ER staining in the equivocal cells. The case with signet ring cells showed strong ER staining in the nonsignet ring cells and weaker staining in the signet ring cells. We conclude that dual CK/ER staining can be useful in SLNs when CK staining alone is equivocal, particularly when the primary tumor is known to have high expression of ER. Although dual ER/CK positivity helps to confirm metastasis, negative ER staining does not exclude metastatic disease.

Molecular detection of lymph node metastases in breast cancer patients: results of a multicenter trial using the one-step nucleic acid amplification assay

PURPOSE

Accurate assessment of metastasis in sentinel lymph nodes (SLN) of breast cancer is important but involves a heavy workload for the pathologist. We conducted a multicenter clinical trial in Japan to evaluate a new automated assay system for cytokeratin 19 mRNA, the one-step nucleic acid amplification (OSNA) assay (Sysmex), to detect lymph node metastasis of breast cancer.

EXPERIMENTAL DESIGN

Surgically obtained axillary lymph nodes were sectioned into four pieces, two of which were examined with the OSNA assay. The other two adjacent pieces were examined with H&E and immunohistochemical staining for cytokeratin 19. Serial sections at 0.2-mm intervals were used in trial 1 to determine the specificity of the OSNA assay, and three pairs of sections cut from the sliced surfaces of the pieces were used in trial 2 to compare the accuracy of the OSNA assay with that of a routine pathologic examination for SLNs in Japan.

RESULTS

In trial 1, the sensitivity and specificity were 95.0% [95% confidence interval (95% CI), 75.1-99.9%] and 97.1% (95% CI, 91.8-99.4%), respectively, for 124 axillary lymph nodes obtained from 34 patients. In trial 2, the agreement between findings of the assay and of the pathologic examination was 92.9% (95% CI, 90.1-95.1%) for 450 axillary lymph nodes obtained from 164 patients.

CONCLUSION

The OSNA assay can detect lymph node metastasis as accurately as can conventional pathology and thus can be an effective addition to or alternative for rapid intraoperative examination of SLNs.

Intraoperative consultation for axillary sentinel lymph node biopsy: an 8-year audit

To summarize the authors' 8-year institutional experience with intraoperative consultation via frozen section (FS) on sentinel lymph node biopsy (SLNB) in breast cancer patients we recorded the, complete operative procedure including additional surgery on the ipsilateral axilla and intraoperative consultation and permanent histopathologic processing for all cases with inoperative consultation on SLNB in breast cancer patients between the groups, chi(2) and Fisher's exact tests were used. Intraoperative consultation was positive in 116/706 cases (16.4%) and final pathology in 158/706 cases (22.4%); the false-negative rate was 26.6%, the false-positive rate was 0%, and the overall accuracy was 94%. False-negative rate was significantly associated with the size of metastasis (micro vs macrometastasis; P < .002) but not significantly associated with the histologic type (P = 0.76) or pathologist expertise (P = 0.08). The rate of spared second procedures was 92% when calculated exclusively for patients who ultimately underwent ALND. Intraoperative consultation via FS for SLNB is a safe practice that can reliably save clinically node-negative patients a second surgery.

Paracortical axillary sentinel lymph node ectopic breast tissue

Benign glandular inclusions in axillary lymph nodes are uncommon, and their presence in axillary sentinel lymph nodes is exceptionally rare. The possibility of over-staging due to misinterpretation of glandular inclusions as metastatic carcinoma is a concerning issue. We present a 54-year-old female with high grade ductal carcinoma in-situ undergoing simple mastectomy with sentinel lymph node biopsy. Permanent sections of the sentinel lymph node revealed scarce naked small glands without surrounding stroma scattered in the paracortex in the superficial level. Deeper levels showed glands spanning a much larger area (2mm), with bland ducts and tubules separated by abundant stroma. The myoepithelial layer was visible and was immunohistochemically confirmed. A final diagnosis of benign ectopic breast tissue within an axillary sentinel lymph node was rendered. Previous studies described axillary sentinel lymph nodes with glandular inclusions separated by stroma or subcapsular in location. It has been suggested that paracortical location and absence of stroma are characteristics of metastasis. As demonstrated in our report, benign inclusions may be paracortical and lack surrounding stroma. We recommend that glandular inclusions should be a diagnostic consideration for cases in which paracortically located naked glands do not histologically resemble the corresponding primary tumor.

Intraductal carcinoma arising in intraductal papilloma in an axillary lymph node: review of the literature and proposed theories of evolution

We report a case of an axillary lymph node containing benign glandular lesions, intraductal papilloma with florid and atypical duct hyperplasia, and ductal carcinoma in situ. We propose 2 theories for the development of the intraductal papilloma: from adjacent benign glandular inclusions, or from displaced epithelial cells from a previous intraductal papilloma in the ipsilateral breast. This case identifies yet another etiology for false-positive sentinel lymph nodes morphologically and by immunohistochemistry.

Lymphovascular invasion and lobular histology are associated with increased incidence of isolated tumor cells in sentinel lymph nodes from early-stage breast cancer patients

BACKGROUND

Isolated tumor cells (ITC) are more likely to be identified when serial sectioning and immunohistochemical staining are used to evaluate sentinel lymph nodes (SLN). Our goal was to identify clinicopathologic features associated with ITC in patients undergoing sentinel lymph node dissection (SLND).

METHODS

We reviewed clinicopathologic data for 3557 patients with no clinical evidence of lymph node metastases undergoing SLND between November 1993 and March 2007. Patients were staged according to the 6th edition of the American Joint Committee on Cancer staging system, with metastasis <or=.2 mm classified as ITC.

RESULTS

A SLN was identified in 3475 patients (97.7%), including 2518 (72.4%) with negative nodes and 169 (4.9%) with ITC. A statistically significant association existed between lobular histology and the identification of ITC; 13.6% of patients with ITC had lobular histology versus 7.3% of patients with a negative SLN (P = .003). The presence of lymphovascular invasion (LVI) was also associated with ITC; 18.3% of patients with ITC had LVI in the primary tumor versus 8.5% of patients with a negative SLN (P < .001). No difference existed between patients with and without ITC with respect to T stage, grade, estrogen receptor, progesterone receptor, HER2/neu status, or biopsy method.

CONCLUSION

The association between ITC and LVI, a known predictor of poor outcome, suggests ITC may have clinical relevance. The relationship between lobular histology and ITC is consistent with the known pattern of lobular metastases, which frequently present as small foci requiring immunohistochemistry for detection. Longer follow-up is needed to determine whether ITC have prognostic significance.

The role of sentinel node biopsy in ductal carcinoma in situ of the breast

AIM

Sentinel node biopsy (SNB) is an accepted alternative to lymphadenectomy in the case of invasive breast carcinoma, although the sentinel node's role in ductal carcinoma in situ (DCIS) diagnosed on core needle biopsy has not been well defined nevertheless guidelines recommend this procedure. The purpose of this study was to determine the diagnostic value of sentinel nodes in female patients with primary DCIS using core needle stereotactic biopsy.

MATERIAL AND METHODS

Between the years 2000 and 2005, 261 patients were diagnosed with DCIS by core needle biopsy. In this group, 183 patients underwent SNB to determine lymph node involvement. Those patients with metastases to the sentinel node underwent axillary lymphadenectomy.

RESULTS

In the group of 183 patients that underwent SNB, 10 patients (5.5%) showed metastases to the sentinel lymph node. Histopathological studies of the primary lesions of these 10 patients revealed invasive ductal carcinoma in 6 cases (3.5%) and 1 case (0.5%) of invasive lobular carcinoma. Only 3 of the patients (1.5%) were given a final diagnosis of DCIS with metastases to sentinel lymph nodes, of which 2 cases were DCIS and 1 case was DCIS with microinvasion. Axillary lymphadenectomy performed on patients with abnormal SNB showed involvement of other axillary lymph nodes in 4 patients.

CONCLUSIONS

SNB as a diagnostic tool in DCIS remains controversial as the number of cases of axillary lymph node metastases is minuscule. The biggest clinical challenge in this situation is a group of patients with primary diagnosis of DCIS in which invasive components are seen by mammotomic biopsy.

Novel intraoperative molecular test for sentinel lymph node metastases in patients with early-stage breast cancer

PURPOSE

An accurate, intraoperative sentinel lymph node (SLN) test could decrease delayed axillary dissections. Molecular tests may be more sensitive than current intraoperative tests but historically have not been rapid enough and have not been properly validated. We present the results from a large, prospective evaluation of the first rapid molecular SLN test, the Breast Lymph Node (BLN) Assay.

METHODS

A beta trial (n = 304) to determine the threshold levels of mammaglobin and cytokeratin 19 correlating with metastasis greater than 0.2 mm and a validation trial (n = 416) to validate the threshold cutoffs were conducted. Alternating portions from each SLN were processed for histology and the BLN Assay.

RESULTS

BLN Assay performance against extensive permanent-section histology verified by central pathology review was similar to that expected of standard permanent-section histology: sensitivity, 87.6%; specificity, 94.2%; positive predictive value, 86.2%; and negative predictive value (NPV), 94.9%. In 319 patients with both frozen-section hematoxylin and eosin results and BLN Assay results, the BLN Assay had higher sensitivity (95.6%) and NPV (98.2%) than frozen section (sensitivity, 85.6%; NPV, 94.5%). The assay can be performed in approximately 36 to 46 minutes for one to three nodes.

CONCLUSION

The BLN Assay allows a rapid evaluation of 50% of each SLN. Comparison with permanent-section histology on adjacent node pieces evaluated by expert pathologists indicated that the BLN Assay was more sensitive than current intraoperative techniques while maintaining high specificity. These data indicate that the assay may be clinically useful for intraoperative or postoperative axillary lymph node dissection decisions.

Sentinel node procedure in vulvar squamous cell carcinoma: a histomorphologic review of 32 cases. The significance of anucleate structures on immunohistochemistry

The sentinel lymph node (SLN) procedure is used in our institute in the setting of an observational multicenter study investigating the reliability of the sentinel node procedure in vulvar carcinoma (GROINSS-V: The Groningen International Study on Sentinel Nodes in Vulvar Cancer). One of our patients had a groin recurrence where the SLN had been reported as negative. After reviewing this SLN, it contained several anucleate, keratin-positive structures on immunohistochemistry, and in the same area on hematoxylin and eosin coloring, one single cell with a nucleus interpreted as a tumor cell. Our objective was to assess how frequently these anucleate structures occur and whether such nodes should be regarded as positive. The sentinel nodes from 32 patients with early-stage vulvar squamous cell carcinoma were reviewed. Seventy-seven SLN's were identified. In ten patients, the SLN was positive and a bilateral inguinofemoral lymph node dissection was subsequently performed. In two of these ten patients, both with a macrometastasis on SLN, further metastatic disease was present in the dissection specimen. Anucleate keratin-positive structures were seen on immunohistochemistry in 14 SLN's (18%), usually along with metastasis or single tumor cells, but in five nodes this was the only abnormality (mean follow-up period of 26.28 months). Anucleate keratin-positive structures are a common finding in immunohistochemical examination of SLN's. Our findings suggest that they are of no clinical significance and the SLN should be regarded as negative. When an atypical cell with a nucleus is present, the SLN should be classified as positive and further management should be accordingly

Coincidence of mammary and sentinel lymph node papilloma

This report describes an unusual case of mammary intraductal papillomas coexistent with sentinel lymph node papilloma. A 47-year-old Japanese female underwent 5 needle manipulations and 2 surgical biopsies for recurring papillomas in the right breast over 5 years before having a simple mastectomy. During the mastectomy, the ipsilateral sentinel node was found to be extensively occupied by completely benign papilloma that measured 6 mm in its greatest dimension. The clinical history led us to put forward the working hypothesis that the nodal papillary lesion may develop from the epithelial cells that are displaced from the mammary papillomas during needle procedures and mechanically transported to the sentinel lymph node. To test the hypothesis, we retrieved surgical biopsies (dochectomy and excisional biopsy), mastectomy, and sentinel lymph node specimens for histopathologic, immunohistochemical, and molecular studies. The presence of myoepithelial layer in each papillary tumor was confirmed by immunostains with specific myoepithelial markers, p63 and CD10. The excisional biopsy specimen exhibited displaced fragments of benign epithelial cells within granulation tissue at the needle manipulation site, indicating that iatrogenic epithelial cell displacement did occur in this case. However, loss of heterozygosity at 16p13 and 16q21 was only observed in the papillomas of the dochectomy and the excisional biopsy; no loss of heterozygosity was detected in the papillomas of the mastectomy and the sentinel lymph node. It remains undetermined whether the nodal papilloma was derived from the papilloma of the mastectomy or if it arose de novo from the breast tissue inclusion of the sentinel node.

Minimal disease in sentinel nodes

Isolated tumor cells and micrometastases represent low-volume or minimal disease in the regional lymph nodes of breast cancer patients as compared to macrometastases. Sentinel lymph node biopsy is a functional selection and removal of the most likely site of regional metastasis, and gives pathologists the opportunity to concentrate detection techniques on a limited number of lymph nodes. Consequently, more lesions belonging in the two mentioned staging categories are discovered in sentinel lymph nodes. Despite some publications contradicting stochastic models of breast cancer, micrometastases seem to reflect a prognosis intermediate between the node-negative and macrometastatic nodal status, and they also reflect a risk of non-sentinel node involvement slightly higher than that associated with a node-negative status. Data are more contradictory as concerns isolated tumor cells. This minireview summarizes the definitions, their inconsistencies, pathological protocols aiming at the detection of minimal nodal disease, the prognostic impact and non-sentinel node involvement related risk of such nodal lesions, and their therapeutic consequences.

Meta-analysis of sentinel node biopsy in ductal carcinoma in situ of the breast

BACKGROUND

The need for sentinel lymph node (SLN) biopsy in patients with a preoperative diagnosis of ductal carcinoma in situ (DCIS) is debated. Advocates recommend such biopsy based on a high incidence of SLN involvement in some series. Opponents discourage SLN biopsy based on a perceived low incidence of nodal involvement in this setting. These contradictory arguments are generally based on small studies. The present study is a meta-analysis of the reported data on the incidence of SLN metastasis in patients with DCIS.

METHODS

A search of electronic databases identified studies reporting the frequency of SLN metastases in DCIS. The random-effects method was used to combine data.

RESULTS

Twenty-two published series were included in the meta-analysis. The estimate for the incidence of SLN metastases in patients with a preoperative diagnosis of DCIS was 7.4 (95 per cent confidence interval (c.i.) 6.2 to 8.9) per cent compared with 3.7 (95 per cent c.i. 2.8 to 4.8) per cent in patients with a definitive (postoperative) diagnosis of DCIS alone. This was a significant difference with an odds ratio of 2.11 (95 per cent c.i. 1.15 to 2.93).

CONCLUSION

Patients with a preoperative diagnosis of DCIS should be considered for SLN biopsy.

Promoter hypermethylation in sentinel lymph nodes as a marker for breast cancer recurrence

PURPOSE

Promoter methylation of tumor suppressor genes in histologically negative sentinel lymph nodes (HNSN) of early stage breast cancer patients has not been extensively studied. This study evaluates the methylation frequency and pattern in HNSN to determine if detection of hypermethylation of one or more genes is associated with an increased recurrence risk in node negative breast cancer.

EXPERIMENTAL DESIGN

In 1998, a prospective study of patients with early stage breast cancer and HNSN was initiated in order to correlate sentinel node analysis with clinical outcome. Nodal tissue was selected from 120 HNSN patients for methylation analysis in at least one and up to six sentinel nodes using a panel of nine genes. Corresponding primary breast tumors from 79 patients were also evaluated for hypermethylation. Methylation analysis was performed using nested Methylation Sensitive PCR (n-MSP). Logistical regression was used to evaluate the relationship between clinical recurrence and methylation status.

RESULTS

Over a median follow-up of 79 months, 13 of the 120 patients had clinical recurrence. Hypermethylation of genes was frequently observed in HNSN, but there was no correlation of methylation pattern and clinical recurrence. However, increased frequency of gene methylation of the primary tumor correlated with clinical recurrence.

CONCLUSIONS

Although hypermethylation of multiple genes occurs frequently in HNSN of breast cancer patients, it is not associated with breast cancer recurrence in the first 7 years of clinical follow-up.

Application of immunohistochemistry to breast lesions

CONTEXT

Immunohistochemistry has an expanding role in mammary pathology that has been facilitated by a growing list of available antibodies and a better understanding of biology.

OBJECTIVE

To explore the key role of immunohistochemistry in guiding adjuvant therapy decisions and sentinel node staging in breast cancer, as well as the role of immunohistochemistry as an aid to distinguishing usual ductal hyperplasia from atypical ductal hyperplasia/low-grade carcinoma in situ; subtyping a carcinoma as ductal or lobular, basal or luminal; ruling out microinvasion in extensive intraductal carcinoma; distinguishing invasive carcinoma from mimics; and establishing that a metastatic carcinoma of unknown primary site has originated in the breast.

DATA SOURCES

Current literature is reviewed, including clinical and pathologic journals.

CONCLUSIONS

As new, targeted treatments for breast cancer are developed, pathologists can expect additional immunohistochemistry applications in the future.

A model for predicting non-sentinel lymph node metastatic disease when the sentinel lymph node is positive

BACKGROUND

Women with axillary sentinel lymph node (SLN)-positive breast cancer usually undergo completion axillary lymph node dissection (ALND). However, not all patients with positive SLNs have further axillary nodal disease. Therefore, in the patients with low risk of further disease, completion ALND could be avoided. The Memorial Sloan-Kettering Cancer Center (MSKCC) developed a nomogram to estimate the risk of non-SLN disease. This study critically appraised the nomogram and refined the model to improve predictive accuracy.

METHODS

The MSKCC nomogram was applied to 118 patients with a positive axillary SLN biopsy who subsequently had completion ALND. Predictive accuracy was assessed by calculating the area under the receiver-operator characteristic (ROC) curve. A further predictive model was developed using more detailed pathological information. Backward stepwise multiple logistic regression was used to develop the predictive model for further axillary lymph node disease. This was then converted to a probability score. After k-fold cross-validation within the data, an inverse variance weighted mean ROC curve and area below the ROC curve was calculated.

RESULTS

The MSKCC nomogram had an area under the ROC curve of 68 per cent. The revised predictive model showed the weighted mean area under the ROC curve to be 84 per cent.

CONCLUSION

The modified predictive model, which incorporated size of SLN metastasis, improved predictive accuracy, although further testing on an independent data set is desirable.

Sentinel node biopsy: interpretation and management of patients with immunohistochemistry-positive sentinel nodes and those with micrometastases

The sentinel node procedure is an adequate tool to identify lymph node metastasis in breast cancer. Sentinel nodes are generally examined with greater attention mainly to exclude, as reliably as possible, lymph node metastasis. To achieve this, many protocols are used, resulting in different rates of micrometastasis or isolated tumor cells encountered. Since the prognostic significance of isolated tumor cells or micrometastasis in the sentinel nodes, and the risk of further axillary lymph node involvement in patients with isolated tumor cells, is uncertain and at most limited, these findings may pose difficulties for clinicians in clinical decision making. Protocols that identify lymph node metastasis, from which the clinical relevance is known, are warranted. Unnecessary lymph node dissections should be avoided.

Nodal Stage Classification for Breast Carcinoma: Improving Interobserver Reproducibility Through Standardized Histologic Criteria and Image-Based Training

Purpose

Reliable pathologic stage classification of axillary lymph nodes is an important determinant of prognosis and therapeutic decision making for patients with invasive breast cancer. Pathologists' distinction between micrometastasis (pN1mi) and isolated tumor cells [ITC; pN0(i+)] is variable using the American Joint Committee on Cancer (AJCC) Staging Manual (Sixth Edition). We sought to determine whether a set of clearly defined histologic criteria could lead to reproducible nodal classification by pathologists.

Patients and Methods

Digital images of sentinel lymph node biopsies from 56 patients with small-volume nodal metastases were examined by six experienced breast pathologists (MDs), first as a pre-test, and again as a post-test after studying a training program that outlined and illustrated the classification criteria.

Results

Post-test results, after study of the training program, were significantly improved. Compared with the reference MD, agreement improved from 76.2% (pre-test κ = 0.575; standard deviation [SD], 0.25) to 97.3% (post-test κ = 0.947; SD, 0.049). Multirater analysis of agreement among the six MDs improved from 71.5% (pre-test κ = 0.487; ASE, 0.039) to 95.7% (post-test κ = 0.915; ASE, 0.037). Agreement on lobular carcinoma metastasis classification improved from 55% (23 of 42; pre-test) to 100% (42 of 42; post-test) (P < .001), and agreement on ITC classification in nodal parenchyma improved from 67.6% (69 of 102; pre-test) to 98.0% (100 of 102; post-test; P < .001).

Conclusion

Application of current definitions for classification of small-volume nodal metastases are inconsistent, leading to variable classification of ITC and micrometastases. Reproducibility of pathologic nodal stage classification is achievable through study of a training set to clarify the AJCC criteria.

Decision analysis to assess the efficacy of routine sentinel lymphadenectomy in patients undergoing prophylactic mastectomy

BACKGROUND

Patients who have invasive breast cancer identified after prophylactic mastectomy (PM) require axillary lymph node dissection (ALND) for lymph node staging (ie, directed ALND). Because the majority of these patients will be lymph node negative, sentinel lymphadenectomy (SLND) has been advocated at the time of PM to avoid the sequelae of unnecessary ALND. The objective of this study was to compare the efficacy of 2 surgical strategies, routine SLND versus directed ALND, in PM patients.

METHODS

A decision-analytic model was created to compare the 2 surgical strategies. Model estimates were derived from a systematic literature review. The endpoints that were examined to compare the 2 strategies were the number of SLNDs performed per breast cancer detected, the number of SLNDs attempted to avoid 1 ALND in a lymph node-negative patient with occult invasive cancer, and the number of axillary complications associated with each strategy.

RESULTS

The prevalence of invasive cancer in patients undergoing PM was estimated at 1.9%. At this rate, 37 SLNDs were performed per 1 breast cancer detected, and 73 SLNDs were required to avoid 1 ALND in a lymph node-negative PM patient. In 1 model scenario, the probability of complications per breast cancer detected was 9-fold greater with the SLND strategy than with the directed ALND strategy (2.7 vs 0.3). The complication rates for the 2 strategies become equivalent in the model scenario when the prevalence of occult invasive cancer was projected to 28%.

CONCLUSIONS

Routine SLND for patients undergoing PM is not warranted given the large number of procedures required to benefit 1 patient and the potential complications associated with performing SLND in all patients.

Sentinel node biopsy with intraoperative diagnosis in patients undergoing skin-sparing mastectomy and immediate breast reconstruction

AIMS

False negative cases in the intraoperative assessment of sentinel node (SN) metastases in breast cancer prompt for a secondary axillary lymph node dissection (ALND). Such ALND is technically demanding and prone to complications in patients with immediate breast reconstruction (IBR) if there is a microvascular anastomosis or the thoracodorsal pedicle of a latissimus dorsi flap in the axilla. This study aims to evaluate the feasibility of the intraoperative diagnosis of sentinel node biopsy (SNB) in breast cancer patients undergoing IBR.

METHODS

Sixty-two consecutive breast cancer patients undergoing SNB with the intraoperative diagnosis of SN metastases simultaneously with mastectomy and IBR between 2004 and 2006 were included in this study. Results of the SNB and especially the false negative cases in the intraoperative diagnosis were evaluated.

RESULTS

Eleven patients had tumor positive SN. Nine of these cases were detected intraoperatively. The two false negative cases in the intraoperative diagnosis constituted of isolated tumor cells only.

CONCLUSIONS

Our present study suggests that SNB with intraoperative diagnosis of SN metastases is feasible in patients undergoing IBR if the risk of nodal metastasis is low and the sensitivity of intraoperative SNB diagnosis is high.

Pathological classification of ductal carcinoma in situ of the breast correlates with surgical treatment and may be predicted by mammography

In order to assess the correlation of pathological and radiological features of ductal carcinoma in situ (DCIS) of the breast and their association with surgical outcome, a consecutive series of 150 patients was retrospectively examined. Pathological slides from all patients were divided into three categories according to the pathological EPWG (European Pathologist Working Group) and DIN (Ductal Intraepithelial Neoplasia) classifications, which showed very good inter-correlation (r=0.99) (whole series). Mammographic images from 46 of these cases were blindly classified into five categories according to the level of radiological suspicion (R), morphology of calcifications (Ca) and preoperative results of needle biopsy (C/B) (limited series). No significant differences in the distribution of clinical and pathological variables were detected among whole and limited series. The lesions were grouped into two (low versus high) pathological (PRG), radiological (RRG and CaRG) and needle biopsy (C/BRG) risk groups. PRG was associated with both RRG (p=0.002) and CaRG (p=0000), but not with C/BRG. Correlations with surgical outcome were also explored, with lesions of high PRG being more likely to undergo re-excision for inadequate first wide local excision [odds ratio (OR)=2.1], mastectomy (OR=2.6) and nodal staging procedures (OR=3.8) in the whole series. Conversely, no significant correlation was found between PRG, RRG, CaRG and C/BRG with surgical outcome in the limited series. We suggest that pathological features of DCIS are associated with surgical outcome and may be predicted by mammography.

Sentinel node biopsy is important in mastectomy for ductal carcinoma in situ

BACKGROUND

There is uncertainty about the utility of sentinel node biopsy (SNB) for ductal carcinoma in situ (DCIS) and its potential to avoid axillary lymph node dissection (ALND) in patients undergoing mastectomy for DCIS.

METHODS

A review was conducted of 179 patients who underwent mastectomy with sentinel node biopsy for DCIS without invasion or microinvasion on premastectomy pathology review.

RESULTS

The sentinel node identification rate was 98.9% (177/179). Twenty (11.3%) of 177 mastectomies for DCIS had a positive SNB: two micrometastasis (pN1mi) and 18 isolated tumor cells [pN0(i+)]. Unsuspected invasive cancer was found in 20 (11.2%) of 179 mastectomies, eight T1mic, five T1a, three T1b, and four T1c tumors. Sentinel nodes were identified in 19 of 20 patients with invasive cancer and four were positive: one pN1mi and three pN0(i+). Eighteen of 19 patients with unsuspected invasive cancer were able to avoid axillary dissection on the basis of SNB results. Of the 159 patients whose final pathology revealed DCIS without invasion, a sentinel node was identified in 158 (99.4%). The SNB was positive in 16 patients (10.1%): one pN1mi and 15 pN0(i+). Three patients underwent ALND on the basis of positive SNBs and in each the SNB was the only positive node.

CONCLUSIONS

11% of patients undergoing mastectomy for DCIS were found to have invasive cancer on final pathology. The use of SNB during mastectomy for DCIS allowed nearly all such patients to avoid axillary dissection. These results support routine use of SNB during mastectomy for DCIS.

Ductal carcinoma in situ--current management

This article summarizes the modern evidence-based management of ductal carcinoma in situ. The data addressing the surgical issues, including indications for mastectomy and the use of sentinel node biopsy, are presented. The randomized trials examining the role of radiation therapy after breast-conserving surgery and the use of tamoxifen in ductal carcinoma in situ are discussed. Factors to consider in developing a management strategy for the individual patient are elucidated in the final section.