The value of cytokeratin immunohistochemistry in the evaluation of axillary sentinel lymph nodes in patients with lobular breast carcinoma

In vivo lymph node CEST-Dixon MRI in breast cancer patients with metastatic lymph node involvement

PURPOSE

Axillary lymph nodes (LNs) often present a reservoir for metastatic breast cancer, yet metastatic LN involvement cannot be discerned definitively using diagnostic imaging. This study investigated whether in vivo CEST may discriminate LNs with versus without metastatic involvement.

METHODS

3T MRI was performed in patients with breast cancer before clinically-indicated mastectomy or lumpectomy with LN removal, after which LN metastasic involvement was determined using histological evaluation. Non-contrast anatomical imaging, as well as B0 and B1 field maps, were acquired in sequence with three-point CEST-Dixon (3D turbo-gradient-echo; factor = 25; TR/TE1/ΔTE = 851/1.35/1.1 ms; spatial-resolution = 2.5 × 2.5 × 6 mm; slices = 10; four sinc-gauss pulses with duty-cycle = 0.5, total saturation duration = 701.7 ms; B1  = 1.5 μT; saturation offsets = -5.5 to +5.5 ppm; stepsize = 0.2 ppm; scan duration = 6 min 30 s). The mean z-spectrum from LNs with (n = 20) versus without (n = 22) metastatic involvement were analyzed and a Wilcoxon rank-sum test (significance: p < 0.05) was applied to evaluate differences in B0, B1 , and magnetization transfer ratio (MTR) in differing spectral regions of known proton exchange (nuclear Overhauser effect [NOE], amide, amine, and hydroxyl) between cohorts.

RESULTS

No difference in axillary B1 (p = 0.634) or B0 (p = 0.689) was observed between cohorts. Elevated MTR was observed for the NOE (-1.7 ppm; MTR = 0.285 ± 0.075 vs. 0.248 ± 0.039; p = 0.048), amine (+2.5 ppm; MTR = 0.284 ± 0.067 vs. 0.234 ± 0.31; p = 0.005), and hydroxyl (+1 ppm; MTR = 0.394 ± 0.075 vs. 0.329 ± 0.055; p = 0.002) protons in LNs from participants with versus without metastatic involvement.

CONCLUSIONS

Findings are consistent with a unique metastatic LN microenvironment detectable by CEST-Dixon and suggest that CEST MRI may have potential for mapping LN metastasis non-invasively in vivo.

Update on Sentinel Lymph Node Methods and Pathology in Breast Cancer

Breast cancer stands out as the most commonly diagnosed cancer among women globally. Precise lymph node staging holds critical significance for both predicting outcomes in early-stage disease and formulating effective treatment strategies to control regional disease progression in breast cancer patients. No imaging technique possesses sufficient accuracy to identify lymph node metastases in the early stages (I or II) of primary breast cancer. However, the sentinel node procedure emerges as a valuable approach for identifying metastatic axillary nodes. The sentinel lymph node is the hypothetical first lymph node or group of nodes draining a cancer. In case of established cancerous dissemination, it is postulated that the sentinel lymph nodes are the target organs primarily reached by metastasizing cancer cells from the tumor. The utilization of the sentinel node technique has brought about changes in the assessment of lymph nodes. It involves evaluating the sentinel node during surgery, enabling prompt lymph node dissection when the sentinel node procedure is positive. Additionally, histological ultra-stratification is employed to uncover occult metastases. This review aims to provide an update of this valuable technique, with focus on the practical aspects of the procedure and the different histological protocols of sentinel node evaluation in breast cancer.

Updates in the Use of Immunohistochemical Stains in Breast and Gynecologic Pathology

CONTEXT.—

The use of immunohistochemical stains in breast and gynecologic pathology has become increasingly complex, with various diagnostic, prognostic, and predictive applications.

OBJECTIVE.—

To provide an update and review of immunohistochemical stains used in the practice of breast and gynecologic pathology. Established and new entities are reviewed, with descriptions of histomorphology and immunohistochemical staining patterns and discussion of interpretive pitfalls.

DATA SOURCES.—

Data were obtained from review of the English-language literature and firsthand experience of the authors in breast and gynecologic pathology.

CONCLUSIONS.—

Many entities in breast and gynecologic pathology benefit from evaluation with various immunohistochemical stains. These studies not only aid in the diagnosis and staging of tumors but also can provide prognostic and predictive information. Updated guidelines for recommended ancillary studies such as mismatch repair, p53, and human epidermal growth factor receptor 2 (HER2) studies in endometrium, as well as estrogen and progesterone receptors and HER2 in breast, are discussed. Finally, the use and interpretation of established and novel immunohistochemical stains are discussed in various breast and gynecologic malignancies.

Development and validation of a pre- and intra-operative scoring system that distinguishes between non-advanced and advanced axillary lymph node metastasis in breast cancer with positive sentinel lymph nodes: a retrospective study

Background

There are currently no scoring-type predictive models using only easily available pre- and intraoperative data developed for assessment of the risk of advanced axillary lymph node metastasis (ALNM) in patients with breast cancer with metastatic sentinel lymph nodes (SLNs). We aimed to develop and validate a scoring system using only pre- and intraoperative data to distinguish between non-advanced (≤ 3 lymph nodes) and advanced (> 3 lymph nodes) ALNM in patients with breast cancer with metastatic SLNs.

Methods

We retrospectively identified 804 patients with breast cancer (cT1-3cN0) who had metastatic SLNs and had undergone axillary lymph node dissection (ALND). We evaluated the risk factors for advanced ALNM using logistic regression analysis and developed and validated a scoring system for the prediction of ALNM using training (n = 501) and validation (n = 303) cohorts, respectively. The predictive performance was assessed using the receiver operating characteristic (ROC) curve, area under the curve (AUC), and calibration plots.

Results

Ultrasound findings of multiple suspicious lymph nodes, SLN macrometastasis, the ratio of metastatic SLNs to the total number of SLNs removed, and the number of metastatic SLNs were significant risk factors for advanced ALNM. Clinical tumor size and invasive lobular carcinoma were of borderline significance. The scoring system based on these six variables yielded high AUCs (0.90 [training] and 0.89 [validation]). The calibration plots of frequency compared to the predicted probability showed slopes of 1.00 (training) and 0.85 (validation), with goodness-of-fit for the model. When the cutoff score was set at 4, the negative predictive values (NPVs) of excluding patients with advanced ALNM were 96.8% (training) and 96.9% (validation). The AUC for predicting advanced ALNM using our scoring system was significantly higher than that predicted by a single independent predictor, such as the number of positive SLNs or the proportion of positive SLNs. Similarly, our scoring system also showed good discrimination and calibration ability when the analysis was restricted to patients with one or two SLN metastases.

Conclusion

Our easy-to-use scoring system can exclude advanced ALNM with high NPVs. It may contribute to reducing the risk of undertreatment with adjuvant therapies in patients with metastatic SLNs, even if ALND is omitted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02779-9.

Lack of Clinical Value for Immunohistochemistry for Sentinel Lymph Node Assessment in Invasive Lobular Carcinoma

BACKGROUND

The distinct histologic appearance of invasive lobular carcinoma (ILC) may pose diagnostic challenges for sentinel lymph node (SLN) analysis. We evaluated the impact of cytokeratin immunohistochemistry (IHC) on SLN assessment in ILC and its contribution to pathologic nodal upstaging.

METHODS

We identified ILC patients treated with SLN surgery at our institution between September 2008 and August 2021. IHC for SLN assessment was employed at the discretion of the pathologist. Differences between groups evaluated with and without IHC were compared using Chi-square tests.

RESULTS

Overall, 608 cases of ILC were identified in patients who underwent SLN surgery. IHC was used in 301 cases (49.5%) and was not associated with cT category, pT category, or tumor grade. Use of IHC increased detection of SLN+ disease when isolated tumor cells (ITCs) were included in the analysis (35.9% with IHC vs. 21.2% without IHC; p < 0.001). There was no effect on nodal upstaging to micrometastatic disease (pN1mi) or greater (21.9% with IHC vs. 21.2% without IHC; p = 0.82). IHC did not increase the number of positive SLNs detected (median 1 with and without IHC) nor did it increase axillary lymph node dissection (ALND) rates (11.6% with IHC vs. 15.3% without IHC; p = 0.18).

CONCLUSION

IHC improved detection of pN0(i+) disease among ILC patients undergoing SLN surgery. IHC did not increase upstaging to pN1mi or higher categories of nodal disease, detection of a greater number of positive SLNs, or ALND rates. Our data suggest routine use of IHC for SLN assessment in ILC patients does not add clinical utility.

Update on sentinel node pathology in breast cancer

Pathologic examination of the sentinel lymph nodes (SLNs) in patients with breast cancer has been impacted by the publication of practicing changing trials over the last decade. With evidence from the ACOSOG Z0011 trial to suggest that there is no significant benefit to axillary lymph node dissection (ALND) in early-stage breast cancer patients with up to 2 positive SLNs, the rate of ALND, and in turn, intraoperative evaluation of SLNs has significantly decreased. It is of limited clinical significance to pursue multiple levels and cytokeratin immunohistochemistry to detect occult small metastases, such as isolated tumor cells and micrometastases, in this setting. Patients treated with neoadjuvant therapy, who represent a population with more extensive disease and aggressive tumor biology, were not included in Z0011 and similar trials, and thus, the evidence cannot be extrapolated to them. Recent trials have supported the safety and accuracy of sentinel lymph node biopsy (SLNB) in these patients when clinically node negative at the time of surgery. ALND remains the standard of care for any amount of residual disease in the SLNs and intraoperative evaluation of SLNs is still of value for real time surgical decision making. Given the potential prognostic significance of residual small metastases in treated lymph nodes, as well as the decreased false negative rate with the use of cytokeratin immunohistochemistry (IHC), it may be reasonable to maintain a low threshold for the use of cytokeratin IHC in post-neoadjuvant cases. Further recommendations for patients treated with neoadjuvant therapy await outcomes data from ongoing clinical trials. This review will provide an evidence-based discussion of best practices in SLN evaluation.

Preoperative axillary nodal staging of invasive lobular breast cancer with ultrasound guided fine needle aspiration in patients with suspicious ultrasound findings versus aspiration in all patients - A retrospective single institutional analysis

INTRODUCTION

- At present, surgical strategies for breast cancer patients with >2 lymph nodes (LN) involved differ from those with no or lower degree of nodal involvement. Preoperative assessment of the axilla is less sensitive in patients with lobular carcinoma (ILC) than patients with other histological tumour types.

MATERIALS AND METHODS

- A retrospective analysis of axillary staging by palpation, axillary ultrasound (AXUS) and AXUS-guided fine-needle aspiration cytology (FNAC) of 153 patients with ILC diagnosed and operated on between January 2013 and December 2020 was performed. Patients had either sentinel node biopsy or axillary lymph node dissection according to current practice. In period 1, patients had FNAC only when AXUS suggested nodal involvement (n = 106), and in period 2, all ILC patients had axillary FNAC (n = 47).

RESULTS

- Of the factors associated with >2LNs involvement, logistic regression suggested only AXUS/FNAC based staging as independent variable for all patients. Patients with AXUS-guided FNAC had a significantly higher proportion of true negative and lower proportion of true positive cases in the P2 period (0 vs 55% and 72% vs 11% for >2 LNs involvement, respectively; both p < 0.0001).

CONCLUSIONS

- AXUS-guided FNAC of all ILC patients did not result in improved preoperative identification of patients with >2 metastatic LNs but increased the false-negative rate of the assessment by producing false-negative results in patients who would not have undergone a biopsy due to negative AXUS findings.

Axillary Nodal Metastases in Invasive Lobular Carcinoma Versus Invasive Ductal Carcinoma: Comparison of Node Detection and Morphology by Ultrasound

Background: Invasive lobular carcinoma is more subtle on imaging compared with invasive ductal carcinoma; nodal metastases may also differ on imaging between these. Objective: To determine whether invasive lobular carcinoma and invasive ductal carcinoma differ in the detection rate by ultrasound (US) of metastatic axillary nodes and in metastatic nodes' US characteristics. Methods: This retrospective study included 695 women (median age 53 years) with breast cancer in a total of 723 breasts (76 lobular, 586 ductal, 61 mixed), with biopsy-proven axillary nodal metastases and who underwent pretreatment US. A single breast radiologist reviewed US images in patients with suspicious nodes on US and classified node number, size, and morphology. Morphologic assessment used a previously described classification based on the relationship between node cortex and hilum. Nodal findings were compared between lobular and ductal carcinoma. A second radiologist independently classified node morphology in 241 cancers to assess interreader agreement. Results: A total of 99 metastatic axillary nodes (15 lobular, 66 ductal, 18 mixed) were not visualized on US and were diagnosed by surgical biopsy. The remaining 624 metastatic nodes (61 lobular, 520 ductal, 43 mixed) were visualized on US and diagnosed by US-guided FNA. Thus, US detected the metastatic nodes in 80.3% for lobular carcinoma versus 88.7% for ductal carcinoma (p=.04). Among metastatic nodes detected by US, retrospective review identified ≥3 abnormal nodes in 50.8% of lobular carcinoma versus 69.2% of ductal carcinoma (p=.003); node size was ≤2.0 cm in 65.6% for lobular carcinoma versus 47.3% for ductal carcinoma (p=.03); morphology was type III/IV (diffuse cortical thickening without hilar mass effect) rather than type V/VI (marked cortical thickening with hilar mass effect) in 68.9% for lobular carcinoma versus 28.8% for ductal carcinoma (p<.001). Interreader agreement assessment for morphology exhibited kappa coefficient of 0.63 (95% CI, 0.54-0.73). Conclusion: US detects a lower percentage of nodal metastases in lobular than ductal carcinoma. Nodal metastases in lobular carcinoma more commonly show diffuse cortical thickening and with less hilar mass effect. Clinical Impact: A lower threshold may be warranted to recommend biopsy of suspicious axillary nodes detected on US in patients with lobular carcinoma.

Oncologic outcomes of endometrial cancer in patients with low-volume metastasis in the sentinel lymph nodes: An international multi-institutional study

OBJECTIVE

To assess oncologic outcomes in endometrial cancer patients with low-volume metastasis (LVM) in the sentinel lymph nodes (SLNs).

METHODS

Patients with endometrial cancer and SLN-LVM (≤2 mm) from December 3, 2009, to December 31, 2018, were retrospectively identified from 22 centers worldwide. Patients with International Federation of Gynecology and Obstetrics (FIGO) stage IV, adnexal involvement, or unknown adjuvant therapy (ATx) were excluded.

RESULTS

Of 247 patients included, 132 had isolated tumor cell (ITC) and 115 had micrometastasis (MM). Overall 4-year recurrence-free survival (RFS) was 77.6% (95% CI, 70.2%-85.9%); median follow-up for patients without recurrence was 29.6 (interquartile range, 19.2-41.5) months. At multivariate analysis, Non-endometrioid (NE) (HR, 5.00; 95% CI, 2.50-9.99; P < .001), lymphovascular space invasion (LVSI) (HR, 3.26; 95% CI, 1.45-7.31; P = .004), and uterine serosal invasion (USI) (HR, 3.70; 95% CI, 1.44-9.54; P = .007) were independent predictors of recurrence. Among 47 endometrioid ITC patients without ATx, 4-year RFS was 82.6% (95% CI, 70.1%-97.2). Considering 18 ITC patients with endometrioid grade 1 disease, without LVSI, USI, or ATx, only 1 had recurrence (median follow-up, 24.8 months).

CONCLUSIONS

In patients with SLN-LVM, NE, LVSI, and USI were independent risk factors for recurrence. Patients with any risk factor had poor prognosis, even when receiving ATx. Patients with ITC and grade 1 endometrioid disease (no LVSI/USI) had favorable prognosis, even without ATx. Further analysis (with more patients and longer follow-up) is needed to assess whether ATx can be withheld in this low-risk subgroup.

Sentinel lymph node assessment in breast cancer-an update on current recommendations

Sentinel lymph node biopsy (SLNB) has become the preferred method of surgical pathological nodal staging of early breast cancer by the end of the nineties. As the most likely sites of metastasis, the SLNs allow a more precise staging, and indeed gross sectioning, step sectioning, immunohistochemistry, and molecular staging methods have been used to disclose metastatic involvement of these lymph nodes. This review summarizes the backgrounds of SLNB, trends in related surgery and pathology. It also gives an insight into European National recommendations related to SLN and divergent daily practices in European pathology departments, on the basis of replies to questionnaires from 84 pathologists from 38 European countries. The questionnaires revealed the post-neoadjuvant setting as an area where a significant minority of pathologists report less confidence in classifying residual nodal involvement into TNM categories. The review also summarizes the neoadjuvant therapy-related aspects of SLNB.

Development and Validation of a Preoperative Scoring System to Distinguish Between Nonadvanced and Advanced Axillary Lymph Node Metastasis in Patients With Early-stage Breast Cancer

BACKGROUND

It has been determined that axillary lymph node dissection after the detection of limited axillary lymph node metastasis does not improve the prognosis of patients with breast cancer. Thus, a need exists for less-invasive axillary surgery. However, it remains unclear whether a predictive model based on preoperative data would be sufficient to accurately predict the probability of pN2-N3 (> 3 lymph node metastases). We sought to develop an easy-to-use scoring system to distinguish between pN0-N1 (0-3 lymph node metastases) and pN2-N3 using only preoperative data and validate its predictive performance.

PATIENTS AND METHODS

We retrospectively identified 2687 patients diagnosed with cT1-3cN0-N1 who had undergone surgery in our hospital from 2013 to 2019. We evaluated the risk factors associated with pN2-N3 by logistic regression analysis and developed a scoring system. Predictive performance was assessed by calculating the receiver operating characteristic area under the curve (AUC) and was validated using K-fold cross-validation.

RESULTS

We identified 1987 patients with stage pN0, 522 with pN1, and 178 with pN2-N3. Multivariate analysis revealed tumor size, number of suspicious lymph nodes on axillary ultrasound examination, histologic type, histologic grade, and receptor status were significant risk factors for pN2-N3. The AUC value was 0.87, and the mean AUC of the 10-fold cross-validation was 0.88. When the cutoff score was set at 6, the negative predictive value for excluding patients with pN2-N3 was 98.4%.

CONCLUSION

Our easy-to-use scoring system could be useful to preoperatively identify patients at lower risk of pN2-N3 and avoid unnecessary axillary lymph node dissection.

Population-based study of the sensitivity of axillary ultrasound imaging in the preoperative staging of node-positive invasive lobular carcinoma of the breast

BACKGROUND

Preoperative staging of the axilla is important to allow decisions regarding neoadjuvant treatment and the management of the axilla. Invasive lobular carcinoma metastases are difficult to detect because of the infiltrative pattern of the nodal spread. In this study the sensitivity of preoperative axillary staging between invasive lobular (ILC) and ductal (IDC) carcinoma was compared.

METHODS

All women diagnosed with pure ILC or IDC in the West of Scotland in 2012-2014 were identified from a database maintained prospectively within the Managed Clinical Network. Pretreatment axillary ultrasound imaging (AUS), core biopsy and fine-needle aspiration cytology (FNAC) results were compared between ILC and IDC.

RESULTS

Some 602 women with ILC and 4199 with IDC had undergone axillary surgery, of whom 209 and 1402 respectively had nodal metastases. Pretreatment AUS sensitivity was significantly lower in ILC than in IDC (32·1 versus 50·1 per cent respectively, P < 0·001; OR 0·47, 95 per cent c.i. 0·34 to 0·64). Core biopsy had equally high sensitivity of 86 per cent in both subtypes; however, FNAC was significantly less sensitive in both ILC (55 per cent; P = 0·003) and IDC (75·6 per cent; P = 0·006). Multivariable analysis revealed that cT3-4 status and symptomatic presentation were both significant in predicting nodal metastasis in patients with ILC and false-negative AUS findings (OR 3·77, 95 per cent c.i. 1·69 to 8·42, P = 0·001; and OR 1·92, 1·24 to 2·98, P = 0·003, respectively).

CONCLUSION

AUS is inferior in detecting axillary node metastasis in ILC compared with IDC. Women with cT3-4 lobular carcinoma may benefit from ultrasound-guided axillary biopsy regardless of the ultrasonographic appearance of the nodes.

Clinicopathologic features and prognoses of different histologic types of triple-negative breast cancer: A large population-based analysis

PURPOSE

To examine the clinicopathologic characteristics and survival outcomes of different histologic types of triple-negative breast cancer (TNBC).

METHODS

We used the SEER database to identify patients with TNBC diagnosed between 2010 and 2014. Our analysis focused on the seven most prevalent histologic types. Differences were compared between invasive carcinoma of no special type (NST) and the other six types.

RESULTS

Significant differences were observed in age at diagnosis, tumor grade, size, nodal status and treatment. As tumor size increased, the number of positive lymph nodes increased markedly in invasive lobular carcinoma (ILC) and mixed NST and lobular carcinoma (NST-ILC), while in metaplastic carcinoma the number only increased slightly. In multivariate survival analyses, compared with patients with invasive carcinoma NST, breast cancer-specific survival (BCSS) and overall survival (OS) were worse for those with NST-ILC (BCSS: hazard ratio [HR] 1.81, P < .001; OS: HR 1.56, P = .005) or metaplastic carcinoma (BCSS: HR 1.95, P < .001; OS: HR 1.73, P < .001). By contrast, patients with medullary (HR 0.40, P = .010) or apocrine carcinoma (HR 0.27, P = .008) showed better BCSS. Time-dependent receiver operating characteristic (ROC) analyses indicated that T category in ILC and N category in metaplastic carcinoma were of less prognostic value.

CONCLUSIONS

According to the histologic classification of TNBC, this heterogeneous disease can be divided into several entities with different clinicopathologic features and prognoses. In the era of molecular subtyping of breast cancer, the histologic classification of TNBC is still of considerable clinical significance.

Metas-Chip precisely identifies presence of micrometastasis in live biopsy samples by label free approach

Detecting the micrometastasis is a major challenge in patients’ survival. The small volume of the biopsied tissue results in limited number of histopathological samples and might reduce the rate of accurate diagnosis even by molecular technologies. We introduce a microelectronic biochip (named Metas-Chip) to detect the micrometastasis in unprocessed liquid or solid samples. It works based on the tendency of malignant cells to track single human umbilical vein endothelial cell (HUVEC)-sensing traps. Such cells detach themselves from the biopsied sample and invade the sensing traps by inducing membrane retraction and blebbing, which result in sharp changes in electrical response of the sensing elements. Metas-Chip identified the metastasis in more than 70 breast cancer patients, in less than 5 h. Moreover it detected the metastasis in lymph nodes of nine patients whom were missed by conventional pathological procedure. Multilevel IHC and real-time polymerase chain reaction (RT-PCR) tests confirmed the diagnosis.

Detecting metastatic cells in tumor/lymph node samples of breast cancer patients is extremely important for diagnosis. Here the authors develop a microelectronic biochip that detect the presence of invasive/metastatic cells in unprocessed biopsies and performs better than the current gold standards.

Comparison of CK-IHC assay on serial frozen sections, the OSNA assay, and in combination for intraoperative evaluation of SLN metastases in breast cancer

BACKGROUND

Intraoperative evaluations of sentinel lymph node (SLN) metastases are performed for providing appropriate and immediate axillary treatments in breast cancer patients who do not meet Z0011 criteria; however, standard intraoperative procedure has not yet been established.

METHODS

We consecutively performed intraoperative evaluation for SLN metastases using both a cytokeratin immunohistochemistry (CK-IHC) assay on serial frozen sections and a one-step nucleic acid amplification (OSNA) assay of the remaining whole node in patients with invasive breast cancer. In this article, we compared the intraoperative diagnostic ability of CK-IHC assay, the OSNA assay, and in combination.

RESULTS

Between August 2009 and May 2017, 1,103 SLNs from 499 consecutive clinically node-negative invasive breast cancers were intraoperatively evaluated for SLN metastases using an OSNA and CK-IHC assay. The detection rates of SLN metastases by the OSNA and CK-IHC assays and in combination were 11.8, 12.1, and 14.5%, respectively. The concordance rate between the intraoperative SLN findings of the OSNA and CK-IHC assays was 94.9% (95% confidence interval 93.6-96.2%). The false negative rate for the OSNA assay was 3.1% (30/973), including 3 (0.3%) macrometastases and 27 (2.8%) micrometastases, and for the CK-IHC assay was 2.7% (26/969), including 1 (0.1%) OSNA ++ and 25 (2.6%) OSNA +.

CONCLUSIONS

The CK-IHC assay and the OSNA assay have compatible diagnostic abilities in intraoperative evaluations for SLN metastases. The low incidence of false negative results with limited disease burden suggests that both assays can be reliable techniques for intraoperative diagnoses of SLN metastases in breast cancer patients.

Sentinel Lymph Nodes in Classic Invasive Lobular Carcinoma of the Breast: Cytokeratin Immunostain Ensures Detection, and Precise Determination of Extent, of Involvement

The assessment of sentinel lymph nodes (SLN) on hematoxylin and eosin (H&E)-stained sections in cases of classic type of invasive lobular carcinoma (cILC) is considered unreliable, particularly in cases with minimal involvement, that is by either isolated tumor cells (pN0i+) or micrometastases (pN1mi). Although the impact of minimal SLN involvement has been shown to be insignificant in most clinical trials (even though cILC was either under-represented or not separated in the respective cohorts), the results of MIRROR trial did emphasize the need for additional therapy in cases with minimally involved SLN to ensure improved disease-free survival. We sought to study the role of cytokeratin immunohistochemistry (CK-IHC) in evaluating SLN in cILC. A total of 582 cILC cases with SLN diagnosed over a 12-year period (2005 to 2016) were reviewed. In all, 394/582 (68%) cases had H&E(-)/CK(-) SLN. In total, 188/582 (32%) cases showed some degree of SLN involvement of which 143/582 (25%) cases had readily identifiable SLN involvement on H&E slides. Overall, 45/582 (7.7%) cases had H&E(-)/CK(+) SLN. The following data relate to the latter subset of 45 cases. Mean age of patients: 61 y (range: 32 to 86 y); right: 24 (53%), left: 21 (47%); multifocal and/or multicentric: 22 (49%); mean size: 2.0 cm (range: 0.25 to 4.4 cm); mean number of SLN: 2.5; mean number of involved SLN: 1.2; and cases with prior needle core or excisional biopsy: 45 (100%). CK(+) cells were identified in isolation or in loose clusters, either in subcapsular sinuses or nodal cortex or both. Overall, 30/45 (67%) showed ≤200 CK(+) cells (ie, pN0i+), and 15/45 (33%) showed >200 CK(+) cells (ie, pN1mi). In total, 15/45 (33%) cases underwent axillary lymph node dissection, of which 4/45 (9%) cases were positive. cILC recurred in 3/45 (7%) cases. On statistical analyses, the number of CK(+) cells (≤/>200) did not correlate with either axillary lymph node-positivity or with recurrence. Number of CK(+) cells (≤/>200) readily distinguished pN0i+ from pN1mi based on AJCC's numerical criteria. CK(+) cells could be quantified in linear terms (ie, AJCC's size criteria of pN0i+ and pN1mi was applicable) in only 2 cases. On the basis of these findings, the use of CK-IHC staining should be considered for SLN in cases of cILC to ensure detection, and precise determination of extent, of involvement; however, the prognostic significance of this procedure would have to await results of additional studies with long-term follow-up.

Novel rapid-immunohistochemistry using an alternating current electric field for intraoperative diagnosis of sentinel lymph nodes in breast cancer

Axillary lymph node status and pathological diagnosis of sentinel lymph nodes (SLNs) is a prognostic factor that influences management of postoperative therapy. Recent reports indicate that one-step nucleic acid amplification and hematoxylin and eosin (HE)-stained frozen sections are effective for intraoperative diagnosis of SLNs. In the present study, we report a rapid-immunohistochemical staining (R-IHC) method that enables intraoperative detection of SLN metastases within 16 min using an anti-cytokeratin antibody. This is the first report on SLN diagnosis using R-IHC in patients with breast cancer. We prospectively examined 160 dissected SLNs from 108 breast cancer patients who underwent surgery at our institute. The dissected SLNs were sectioned and conventionally stained with HE or immunohistochemically labeled with anti-cytokeratin antibody using R-IHC procedures. Intraoperative R-IHC analyses were completed within 16 min, after which diagnoses were made by two pathologists. The total time required for intraoperative diagnosis was about 20 min. In this study series, R-IHC detected four metastatic SLNs that were undetected using conventional HE staining (4/20, 20.0%). Compared with subsequent permanent diagnosis, R-IHC offered 95.2% sensitivity and 100% specificity. These findings indicate R-IHC is a clinically applicable technique that enables precise and quick intraoperative detection of micro- and macrometastasis in breast cancer.

A comparison of the diagnostic accuracy of magnetic resonance imaging to axillary ultrasound in the detection of axillary nodal metastases in newly diagnosed breast cancer

Patients with a diagnosis of invasive breast cancer are increasingly undergoing breast magnetic resonance imaging (MRI) for preoperative staging including evaluation of axillary lymph node metastases (ALNM). This retrospective study aims to evaluate the utility of adding axillary ultrasound (AUS) in the preoperative setting when an MRI is planned or has already been performed. This IRB approved, HIPAA compliant study reviewed a total of 271 patients with a new diagnosis of invasive breast cancer at a single institution, between June 1, 2010 and June 30, 2013. The study included patients who received both AUS and MRI for preoperative staging. Data were divided into two cohorts, patients who underwent MRI prior to AUS and those who underwent AUS prior to MRI. AUS and MRI reports were categorized according to BI-RADS criteria as "suspicious" or "not suspicious" for ALNM. In the setting of a negative MRI and subsequent positive AUS, only one out of 25 cases (4%) were positive for metastases after correlating with histologic pathology. MRI detected metastatic disease in four out of 27 (15%) patients who had false-negative AUS performed prior to MRI. Our results indicate the addition of AUS after preoperative MRI does not contribute significantly to increased detection of missed disease. MRI could serve as the initial staging imaging method of the axilla in the setting that AUS is not initially performed and may be valuable in identification of lymph nodes not identified on AUS.

Is Pre-Operative Axillary Staging with Ultrasound and Ultrasound-Guided Fine-Needle Aspiration Reliable in Invasive Lobular Carcinoma of the Breast?

Axillary ultrasound (US) with US-guided fine-needle aspiration (US-FNA) for suspicious lymph nodes is important for pre-operative staging and planning of surgical management. Invasive lobular carcinoma (ILC) metastases were previously thought to be difficult to detect, but with a limited amount of evidence. This study investigated the ability of US and US-FNA to detect ILC metastases by assessing 142 patients with ILC. The sensitivity of US in detection of metastasis was 52.3%, and US was able to exclude 96% of N2 and N3 axillary metastases. The false-negative rate of US-FNA in detection of metastasis for suspicious lymph nodes on US was 34.8%, and lymph nodes with longer maximal dimensions were associated with false-negative US-FNA results. Multiplicity of breast lesions and maximal cortical thickness ≥3.1 mm of lymph nodes were independently associated with metastasis. Although pre-operative US in ILC can reliably exclude advanced axillary nodal disease, US-FNA results should be carefully interpreted.

Matrices of a hydrophobically functionalized hyaluronic acid derivative for the locoregional tumour treatment

A hyaluronic acid (HA) derivative bearing octadecylamine and acylhydrazine functionalities has been here employed for the production of a paclitaxel delivering matrix for locoregional chemotherapy. Through a strategy consisting in a powder compression and a plasticization with a mixture water/ethanol, a physically assembled biomaterial, stable in solutions with physiologic ionic strengths, has been produced. Two different drug loading strategies have been adopted, by using paclitaxel as chemotherapic agent, and obtained samples have been assayed in terms of release in enhanced solubility conditions and in vitro and in vivo tumoural cytotoxicity. In particular sample with the best releasing characteristics was chosen for an in vivo evaluation against a HCT-116 xenograft on mice. Local tumour establishment and metastatic diffusion was assayed locally at the site of xenograft implantation and at the tributary lymph nodes. Obtained results demonstrated how loading procedure influenced paclitaxel crystallinity into the matrix and consequently drug diffusion and its cytoreductive potential. Chosen paclitaxel loaded matrix was able to drastically inhibit HCT-116 establishment and metastatic diffusion.

A systematic review and economic evaluation of intraoperative tests [RD-100i one-step nucleic acid amplification (OSNA) system and Metasin test] for detecting sentinel lymph node metastases in breast cancer

BACKGROUND

In breast cancer patients, sentinel lymph node biopsy is carried out at the same time as the removal of the primary tumour to postoperatively test with histopathology for regional metastases in the sentinel lymph node. Those patients with positive test results are then operated on 2-4 weeks after primary surgery to remove the lymph nodes from the axilla (axillary lymph node dissection, ALND). New molecular tests RD-100i [one-step nucleic acid amplification (OSNA); based on messenger RNA amplification to identify the cytokeratin-19 (CK19) gene marker] (Sysmex, Norderstedt, Germany) and Metasin (using the CK19 and mammaglobin gene markers) (Cellular Pathology, Princess Alexandra Hospital NHS Trust, Harlow, UK) are intended to provide an intraoperative diagnosis, thereby avoiding the need for postoperative histopathology and, in positive cases, a second operation for ALND.

OBJECTIVE

To evaluate the clinical effectiveness and cost-effectiveness of using OSNA and Metasin in the NHS in England for the intraoperative diagnosis of sentinel lymph nodes metastases, compared with postoperative histopathology, the current standard.

DATA SOURCES

Electronic databases including MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library and the Health Economic Evaluations Database as well as clinical trial registries, grey literature and conference proceedings were searched up to July 2012.

REVIEW METHODS

A systematic review of the evidence was carried out using standard methods. Single-gate studies were used to estimate the accuracy of OSNA with histopathology as the reference standard. The cost-effectiveness analysis adapted an existing simulation model of the long-term costs and health implications of early breast cancer diagnostic outcomes. The model accounted for the costs of an extended first operation with intraoperative testing, the loss of health-related quality of life (disutility) from waiting for postoperative test results, disutility and costs of a second operation, and long-term costs and disutility from lymphoedema related to ALND, adjuvant therapy, locoregional recurrence and metastatic recurrence.

RESULTS

A total of 724 references were identified in the searches, of which 17 studies assessing test accuracy were included in the review, 15 on OSNA and two on Metasin. Both Metasin studies were unpublished. OSNA sensitivity of 84.5% [95% confidence interval (CI) 74.7% to 91.0%] and specificity of 91.8% (95% CI 87.8% to 94.6%) for patient nodal status were estimated in a meta-analysis of five studies [unadjusted for tissue allocation bias (TAB)]. At these values and a 20% node-positive rate, OSNA resulted in lifetime discounted cost-savings of £498 and a quality-adjusted life-year (QALY) loss of 0.048 relative to histopathology, that is, £4324 saved per QALY lost. The most favourable plausible scenario for OSNA in terms of the node-positive rate (range 10-40%), diagnostic accuracy values (91.3% sensitivity and 94.2% specificity, from three reports that adjusted for TAB), the costs of histopathology, OSNA and second surgery, and long-term costs and utilities resulted in a maximum saving per QALY lost of £10,500; OSNA sensitivity and specificity would need to be ≥ 95% for this figure to be ≥ £20,000.

LIMITATIONS

There is limited evidence on the diagnostic test accuracy of intraoperative tests. The quality of information on costs of resource utilisation during the diagnostic pathway is low and no evidence exists on the disutility of waiting for a second surgery. No comparative studies exist that report clinical outcomes of intraoperative diagnostic tests. These knowledge gaps have more influence on the decision than current uncertainty in the performance of postoperative histopathology in standard practice.

CONCLUSIONS

One-step nucleic acid amplification is not cost-effective for the intraoperative diagnosis of sentinel lymph node metastases. OSNA is less accurate than histopathology and the consequent loss of health benefits in this patient group is not compensated for by health gains elsewhere in the health system that may be obtained with the cost-savings made. The evidence on Metasin is insufficient to evaluate its cost-effectiveness.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012002889.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Is axillary sonographic staging less accurate in invasive lobular breast cancer than in ductal breast cancer?

OBJECTIVES

The purpose of this study was to determine whether axillary sonography is less accurate in invasive lobular breast cancer than in ductal breast cancer.

METHODS

Patients with invasive breast cancer were retrospectively identified from histologic records from 2010 to 2012. Staging axillary sonograms from 96 patients with primary breast cancer in each of 2 subgroups, invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC), were reviewed. Preoperative sonographically guided 14-gauge core biopsy was performed on morphologically abnormal lymph nodes.

RESULTS

Thirty-one of 96 patients (32%) in each subgroup were node positive on final postoperative histopathologic analysis. Axillary staging sensitivity was 17 of 31 patients (54%) in the IDC subgroup and 15 of 31(48%) in the ILC subgroup. Further analysis of the data showed no statistically significant differences between these subgroups.

CONCLUSIONS

We found that there was no statistically significant difference in the accuracy of axillary sonographic staging between ILC and IDC.

Predicting the extent of nodal disease in early-stage breast cancer

BACKGROUND

The role of regional nodal ultrasound (US) has been questioned since publication of the American College of Surgeons Oncology Group (ACOSOG) Z0011 data. The goal of this study was to determine if imaging and clinicopathologic features could predict the extent of axillary nodal involvement in breast cancer.

STUDY DESIGN

Patients with T1-T2 tumors who underwent regional nodal US and axillary lymph node dissection from 2002 to 2012 were identified from a prospective database excluding those who received neoadjuvant chemotherapy. Patients whose metastases were identified by US confirmed by needle biopsy were compared with those identified by sentinel lymph node dissection (SLND) after a negative US.

RESULTS

Metastases were identified by US in 190 patients, and by SLND in 518 patients. SLND patients had fewer positive nodes (2.2 vs. 4.1; p < 0.0001), smaller metastases (5.3 vs. 13.8 mm; p < 0.0001), and a lower incidence of extranodal extension (24 vs. 53 %; p < 0.0001) than the US group. Even when US identified ≤2 abnormal nodes, patients were still more likely to have ≥3 positive nodes (45 %) than SLND patients (19 %; p < 0.001). After adjusting for tumor size, receptor status, and histology, multivariate analysis revealed that metastases identified by US [odds ratio (OR) 4.01; 95 % confidence interval (CI) 2.75-5.84] and lobular histology (OR 1.77; 95 % CI 1.06-2.95) predicted having ≥3 positive nodes.

CONCLUSIONS

Imaging and clinicopathologic features can be used to predict the extent of nodal involvement. Patients with US-detected metastases, even if small volume, have a higher burden of nodal involvement than patients with SLND-detected metastases and may not be comparable with patients in the ACOSOG Z0011 trial.

An improved axillary staging system using the OSNA assay does not modify the therapeutic management of breast cancer patients

The one-step nucleic acid amplification (OSNA) assay is a molecular procedure that can identify deposits of breast cancer (BC) cells in the sentinel lymph node (SLN). We examined the consistency of the OSNA assay with a classic hematoxylin-eosin (H&E)-based immunohistochemistry (IHC) study and evaluated how OSNA-based axillary staging might impact the therapeutic management of BC patients. SLN biopsy results were considered to be positive in 60 patients (40%) in the OSNA group (N = 148) and in 43 (28%) patients in the IHC cohort (N = 153, p = 0.023). There was no difference in the macrometastasis (22% for OSNA, 15% for H&E, p = 0.139) or micrometastasis (19% for OSNA, 13% for H&E, p = 0.166) rates, but we found statistically significant differences in the number of isolated tumor cells (1% for OSNA, 11% for H&E, p < 0.001). There were no differences in the administration rate of adjuvant systemic therapy between the OSNA (66% in the SLN(+) patients) and the H&E (74% in the SLN(+) patients) groups (p = 0.159). The OSNA assay allows for the detection of SLN metastases more precisely than conventional pathologic methods but does not alter the therapeutic management of SLN(+) BC patients.

Theranostic and molecular classification of breast cancer

CONTEXT

Despite advances in breast cancer management, women continue to relapse and die of breast cancer. Traditionally, evaluation for hormone receptors (estrogen and progesterone), as well as HER2 overexpression, have guided therapy-related decision-making because they are both prognostic and predictive indicators. However, there are limitations with those studies, which can lead to improper treatment. Gene signatures have recently been shown to be of value in identifying molecular portraits of breast carcinoma and are beginning to play role in management and treatment algorithms.

OBJECTIVE

To provide a summary of the prognostic and predictive indicators of breast cancer, such as hormone receptors, HER2, and molecular gene signatures that currently help guide clinical decision making.

DATA SOURCES

Published articles from peer-reviewed journals in PubMed (US National Library of Medicine).

CONCLUSIONS

Emerging evidence shows promise that, in addition to hormone receptors and HER2 studies, evaluating tumors with gene expression profiling can provide additional prognostic and predictive information, further aiding clinical management and leading to a more personalized approach to treating breast cancer.

The role of OCT4 immunohistochemistry in evaluation of retroperitoneal lymph node dissections: a pilot study

We investigated the role of OCT4 immunohistochemical staining in detecting germ cell tumor lymph node metastases. Retroperitoneal lymph node dissection is important for staging and treatment of testicular germ cell tumors, and OCT4 is sensitive and specific for pluripotent testicular germ cell tumors; however, micrometastases, particularly from seminoma, can be difficult to detect. We examined 262 lymph nodes in 45 retroperitoneal lymph node dissection specimens from germ cell tumor patients. Specimens were categorized as postchemotherapy and untreated retroperitoneal lymph node dissection with or without clinical suspicion, based on lymphadenopathy or elevated serum germ cell tumor markers. Sections were stained with anti-OCT4 antibody. Twenty-one additional positive lymph nodes in 12 cases were detected to harbor scattered seminoma cells, singly and in small clusters, from 256 previously considered benign in: untreated retroperitoneal lymph node dissection with clinical suspicion (13% increase), postchemotherapy retroperitoneal lymph node dissection (7%), and untreated retroperitoneal lymph node dissection without suspicion (4%). However, no patient with an entirely negative dissection specimen was reclassified as positive. OCT4 immunohistochemistry detected scattered seminoma cells and small clusters of seminoma cells in lymph nodes previously considered to be benign for an overall increase of 8%, greatest in the setting of untreated retroperitoneal lymph node dissection with clinical suspicion. However, immunohistochemistry did not convert any entirely negative specimen to positive. Future studies will be useful to determine whether the small volume of disease detected by immunohistochemistry has the same impact as routinely detected lymph node metastases.

Metasin-an intra-operative RT-qPCR assay to detect metastatic breast cancer in sentinel lymph nodes

Nodal status is one of the most important prognostic factors in breast cancer. Established tests such as touch imprint cytology and frozen sections currently used in the intra-operative setting show variations in sensitivity and specificity. This limitation has led to the development of molecular alternatives, such as GeneSearch, a commercial intra-operative real-time quantitative Polymerase Chain Reaction (RT-qPCR) assay that allows the surgeon to carry out axillary clearance as a one-step process. Since GeneSearch has been discontinued, we have developed the replacement Metasin assay, which targets the breast epithelial cell markers CK19 and mammaglobin mRNA and identifies metastatic disease in sentinel lymph nodes. The optimised assay can be completed within 32 min (6 min for RNA preparation and 26 min instrument run time), making its use feasible in the intraoperative setting. An analysis by Metasin of 154 archived lymph node homogenates previously analysed by both parallel histology and GeneSearch showed concordance for 148 cases. The sensitivity and specificity of Metasin compared with GeneSearch were 95% (CI 83%–99%) and 97% (CI 91%–99%) respectively; compared with histology they were 95% (CI 83%–99%) and 97% (CI 91%–99%), respectively. The sensitivity and specificity of GeneSearch compared with histology were 90% (CI 77%–96%) and 97% (CI 93%–99%) respectively. The positive predictive value of Metasin was 90% and negative predictive value was 98% for both histology and GeneSearch. The positive predictive value of GeneSearch was 92% and the negative predictive value was 97% compared to histology. The discordance rates of Metasin with both GeneSearch and histology were 3.89%. In comparison, the discordance rate of GeneSearch with histology was 4.5%. Metasin’s robustness was independently evaluated on 193 samples previously analysed by GeneSearch from the Jules Bordet Institute, where Metasin yielded comparable results.

Three-dimensional quantitative ultrasound for detecting lymph node metastases

PURPOSE

Detection of metastases in lymph nodes (LNs) is critical for cancer management. Conventional histological methods may miss metastatic foci. To date, no practical means of evaluating the entire LN volume exists. The aim of this study was to develop fast, reliable, operator-independent, high-frequency, quantitative ultrasound (QUS) methods for evaluating LNs over their entire volume to effectively detect LN metastases.

METHODS

We scanned freshly excised LNs at 26 MHz and digitally acquired echo-signal data over the entire three-dimensional (3D) volume. A total of 146 LNs of colorectal, 26 LNs of gastric, and 118 LNs of breast cancer patients were enrolled. We step-sectioned LNs at 50-μm intervals and later compared them with 13 QUS estimates associated with tissue microstructure. Linear-discriminant analysis classified LNs as metastatic or nonmetastatic, and we computed areas (Az) under receiver-operator characteristic curves to assess classification performance. The QUS estimates and cancer probability values derived from discriminant analysis were depicted in 3D images for comparison with 3D histology.

RESULTS

Of 146 LNs of colorectal cancer patients, 23 were metastatic; Az = 0.952 ± 0.021 (95% confidence interval [CI]: 0.911-0.993); sensitivity = 91.3% (specificity = 87.0%); and sensitivity = 100% (specificity = 67.5%). Of 26 LNs of gastric cancer patients, five were metastatic; Az = 0.962 ± 0.039 (95% CI: 0.807-1.000); sensitivity = 100% (specificity = 95.3%). A total of 17 of 118 LNs of breast cancer patients were metastatic; Az = 0.833 ± 0.047 (95% CI: 0.741-0.926); sensitivity = 88.2% (specificity = 62.5%); sensitivity = 100% (specificity = 50.5%). 3D cancer probability images showed good correlation with 3D histology.

CONCLUSIONS

These results suggest that operator- and system-independent QUS methods allow reliable entire-volume LN evaluation for detecting metastases. 3D cancer probability images can help pathologists identify metastatic foci that could be missed using conventional methods.

Axillary Dissection in the Case of Positive Sentinel Lymph Nodes: Results of the Innsbruck Consensus Conference

The prognosis of breast cancer is most heavily influenced by the status of the axillary nodes. Until a few years ago, this knowledge was gained through radical axillary lymph node clearance. In the meantime, sentinel lymph node clearance has become an established part of the surgical treatment of breast cancer. With the development of this procedure, the morbidity caused by axillary dissection has been reduced significantly. Although comprehensive prospective, randomised data regarding the safe use of the sentinel concept are only now available, the focus currently, however, is on the question of whether in the case of positive sentinel lymph nodes, an axillary dissection can be done away with altogether without having any negative impact on the risk of loco-regional recurrence or on progression-free survival and overall survival. The results of the American ACOSOG-Z001 study have changed the fundamental perspective of this. In this study on the advantages of axillary dissection following the confirmation of tumour tissue in the sentinel lymph nodes, there were no statistically significant advantages from axillary dissection for women with a favourable overall risk profile who had received radiotherapy and systemic therapy. If this concept takes hold, the surgical treatment of node-positive breast cancer, at least in the axilla, would be reduced to a minimum, and the focus of treatment would in future lie more on the systemic treatment of this condition. As part of an interdisciplinary consensus meeting, a standardised approach for Austria with regard to this question was decided upon.

Development, anatomy, histology, lymphatic drainage, clinical features, and cell differentiation markers of canine mammary gland neoplasms

Mammary neoplasms are the most common neoplasm in female dogs. This article describes the embryologic development, normal anatomy, and histology of the canine mammary gland from the onset of first estrous and the changes that occur in the mammary gland during the estrus cycle. The clinical features of canine mammary gland tumors and their relation to prognosis are discussed, including age, hormones, breed, diet, and obesity. Additional clinical prognostic factors including clinical presentation, tumor size, and lymph node status at the time of presentation are discussed in relation to diagnosis and tumor staging. Immunohistochemical evaluation of the cell differentiation markers of the normal and neoplastic canine mammary gland is described and compared with similar studies in humans; the ways these markers may be used to assist with the prognosis of canine mammary neoplasms are discussed.

Accurate classification of sentinel lymph node metastases in patients with lobular breast carcinoma

Among pathologists there is low reproducibility in classifying small volume metastases in sentinel lymph node particularly in cases of invasive lobular carcinoma. We postulate that strict adherence to American Joint Commission on Cancer (AJCC) 2003 criteria may result in inaccurate staging of lobular carcinoma patients. We reviewed cases of metastatic lobular carcinoma in sentinel lymph node biopsies between 1998 and 2008. All sentinel lymph nodes were reassessed using strict adherence to AJCC 2003 criteria. Subsequent axillary lymph node dissection and clinical follow-up were reviewed. Fifty-one patients met our inclusion criteria and were originally classified by the primary pathologist as follows: 10 isolated tumor cells, 8 micrometastases, 27 macrometastases, and 6 'positive' cases without further classification. Cases were re-classified using strict adherence to AJCC 2003 criteria as follows: 21 isolated tumor cells, 2 micrometastases, and 28 macrometastases. Twelve isolated tumor cells cases underwent full axillary dissection, and 3 (25%) had additional macrometastases. All micrometastatic cases underwent axillary dissection; all were negative. Twenty-two macrometastatic cases underwent full axillary dissection and 16 (73%) had additional macrometastases. Diffuse single cells or small clusters should not be interpreted as isolated tumor cells in invasive lobular carcinoma sentinel lymph nodes. The criteria for assessing small volume metastases in the sentinel lymph node of patients with invasive lobular carcinoma need to be more clearly defined.

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.

[Sentinel node biopsy in breast cancer: pathological analysis and interpretation]

This overview examines how the introduction of sentinel lymph node biopsy (SLNB) has changed the pathological staging of breast cancer. The more intensive analysis of the sentinel lymph nodes (gross slicing, step sections, immunohistological or molecular analysis) has lead to stage shifting in breast cancer. Regarding the rate of up-staging by positive results of SLNB, there are significant differences between institutes, some method-related, some related to the interpretation of results. Methodological differences should be reduced by means of reliable guidelines with the goal of systematically identifying metastases of a particular size (a macrometastasis over 2 mm being the minimum criterion). The next review of the TNM classification should result in a reduction in interobserver variability as a result of better definitions of staging categories for isolated tumor cells and micrometastases. In addition, a staging category is expected for metastases which have been identified by calibrated quantitative molecular tests only and which are larger than isolated tumors. Even in settings where nodal staging by SLNB is based on molecular tests at least a proportion of the lymph node should be investigated histologically.

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.

Non-sentinel lymph node metastases associated with isolated breast cancer cells in the sentinel node

There are many reports on the frequency of non-sentinel lymph node involvement when isolated tumor cells are found in the sentinel node, but results and recommendations for the use of an axillary lymph node dissection differ among studies. This systematic review was conducted to give an overview of this issue and to provide recommendations for the use of an axillary lymph node dissection in these patients. We searched Medline, Embase, and Cochrane databases from January 1, 2002, through November 27, 2007, for articles on patients with invasive breast cancer who had isolated tumor cells in the sentinel lymph node (according to the sixth edition of the Cancer Staging Manual of the American Joint Committee on Cancer) and who also underwent axillary lymph node dissection. Of 411 selected articles, 29 (including 836 patients) were included in this review. These 29 studies were heterogeneous, reporting a wide range of non-sentinel lymph node involvement (defined as the presence of isolated tumor cells or micro- or macrometastases) associated with isolated tumor cells in the sentinel lymph node, with an overall pooled risk for such involvement of 12.3% (95% confidence interval = 9.5% to 15.7%). This pooled risk estimate was marginally higher than the risk of a false-negative sentinel lymph node biopsy examination (ie, 7%-8%) but marginally lower than the risk of non-sentinel lymph node metastases in patients with micrometastases (ie, approximately 20%) who are currently eligible for an axillary lymph node dissection. Because 36 (64%) of the 56 patients with isolated tumor cells in their sentinel lymph node also had non-sentinel lymph node macrometastases, those patients with isolated tumor cells in the sentinel lymph node without other indications for adjuvant systemic therapy might be candidates for axillary lymph node dissection.

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.

Variations in sentinel node isolated tumour cells/micrometastasis and non-sentinel node involvement rates according to different interpretations of the TNM definitions

Breast cancers with nodal isolated tumour cells (ITC) and micrometastases are categorised as node-negative and node-positive, respectively, in the tumour node metastasis (TNM) classification. Two recently published interpretations of the TNM definitions were applied to cases of low-volume sentinel lymph node (SLN) involvement and their corresponding non-SLNs for reclassification as micrometastasis or ITC. Of the 517 cases reviewed, 82 had ITC and 435 had micrometastasis on the basis of one classification, and the number of ITC increased to 207 with 310 micrometastases on the basis of the other. Approximately 24% of the cases were discordantly categorised. The rates of non-SLN metastases associated with SLN ITCs were 8.5% and 13.5%, respectively. Although the second interpretation of low-volume nodal stage categories has better reproducibility, it may underestimate the rate of non-SLN involvement. The TNM definitions of low-volume nodal metastases need to be better formulated and supplemented with visual information in the form of multiple sample images.