Intraoperative gamma imaging of axillary sentinel lymph nodes in breast cancer patients

Sentinel lymph node (SLN) biopsy is now standard practice in the management of many breast cancer patients. Localization protocols vary in complexity and rates of success. The least complex involve only intraoperative gamma counting of radiotracer uptake or intraoperative visualization of blue-dye uptake; the most complex involve preoperative gamma imaging, intraoperative counting and intraoperative dye visualization. Intraoperative gamma imaging may improve some protocols. This study was conducted to obtain preliminary experience and information regarding intraoperative imaging. Sixteen patients were enrolled: 8 in a protocol that included intraoperative counting and dye visualization (probe/dye), 8 in a protocol that involved intraoperative imaging, counting and dye visualization (camera/probe/dye). Preoperative imaging of all 16 patients was performed using a GE 500 gamma camera with a LEAP collimator (300 cpm/μCi). The results of this imaging were not, however, given to the surgeon until the surgeon had completed the procedures required for the study. A Care Wise C-Trak probe was used for intraoperative counting. A Gamma Medica Inc. GammaCAM/OR (12.5 × 12.5 cm FOV) with a LEHR collimator (135 cpm/μCi) was used for intraoperative imaging. Times from start of surgery to external detection of a radioactive focus and to completion of excision of SLNs were recorded. Foci were detected preoperatively via imaging in 16/16 patients. Intraoperative external detection using the probe was accomplished in less than 4 min (mean = 1.5 min) in 15/16 patients, and via intraoperative imaging in 6/8 patients. The average time for completion of excision of nodes was 19 min for probe/dye and 28 min for camera/probe/dye. In one probe/dye case, review of the preoperative images prompted the surgeon to resume axillary dissection and remove one additional SLN.     

The reliability and accuracy of intraoperative imprint cytology of sentinel lymph nodes in breast cancer

OBJECTIVE: Sentinel lymph node (SLN) biopsy is a new component of the surgical treatment of breast cancer that accurately predicts axillary status. In this study the authors evaluated the accuracy of intraoperative imprint cytology (IC) in comparison with definitive histologic evaluation of SLN in breast cancer patients. METHODS: A total 413 women with breast carcinoma and clinically negative axillary nodes underwent breast surgery and SLN biopsy. Mapping of SLN involved injection of (99m)Technecium labelled human albumin nanocolloid particles and Patent Blue dye. At the Department of Pathology, SLNs were bisected along its major axis. Both halves were imprinted 2-4 times on the slides and immediate staining with Hemacolor (Merck Germany) was performed for intraoperative examination. Imprint node negative women underwent no further surgery, while node positive women proceeded to full axillary clearance. Histological analysis of the SLN involved serial sectioning of the whole node with H&E and immunostaining for cytokeratin. RESULTS: Definitive histology revealed metastases (pN+) in 159/413 patients (38.5%): 69 (16.7%) macro metastases, 57 (13.8%) micro metastases, and 33 (8%) women with only isolated IHC positive cells or positive cell groups smaller than 0.2 mm (pNO sn+). The other 254 women had negative SLN biopsy. Imprint cytology detected 54/69 macro metastases, and 4/57 micro metastases. In the group with negative SLN (254), 2 cases were 'false positives'. CONCLUSIONS: Imprint of SLN biopsy can identify a negative axilla with high accuracy (specificity 99.2%). Overall sensitivity is only 36.5%, but macrometastases are detected in 77% which is important for performing ALDN in one session with operation of primary tumour.     

SPECT-CT localization of axillary sentinel lymph nodes for radiotherapy of early breast cancer

PurposeTo evaluate the opportunities of single photon emission tomography/computerized tomography (SPECT-CT) for localization of axillary sentinel lymph nodes (ASLNs) and subsequent radiotherapy planning in women with early breast cancer.Material and methodsIndividual topography of ASLN was determined in 151 women with clinical T1-2N0M0 breast cancer. SPECT-CT visualization of ASLNs was initiated 120 min after intra-peritumoral injection of 99mTc-radiocolloids. Doses absorbed by virtual ASLNs after the whole breast irradiation with standard and extended tangential fields were calculated on a treatment planning station.ResultsSPECT-CT demonstrated a large variability of ASLN localization. They were detected in the central subgroup in 94 (61%) patients, in pectoral – in 77 (51%), and in interpectoral – in 4 (3%) patients. Sentinel lymph nodes “lying on the chest” were revealed in 35 (23%) cases.We found that with standard tangential fields coverage of ASLNs was obtained only in 20% of evaluated women. Extended tangential fields can effectively irradiate ASLNs localized in all axillary sub-regions with the exception of ASLNs “lying on the chest”.ConclusionSPECT-CT mapping of ASLNs in women with cT1-2N0M0 breast cancer reveals their variable localization. This information can be important for planning of radiation treatment in women that underwent breast conserving surgery without an axillary surgery.     

Molecular subtype classification is a determinant of non-sentinel lymph node metastasis in breast cancer patients with positive sentinel lymph nodes

Background

Previous studies suggested that the molecular subtypes were strongly associated with sentinel lymph node (SLN) status. The purpose of this study was to determine whether molecular subtype classification was associated with non-sentinel lymph nodes (NSLN) metastasis in patients with a positive SLN.

Methodology and Principal Findings

Between January 2001 and March 2011, a total of 130 patients with a positive SLN were recruited. All these patients underwent a complete axillary lymph node dissection. The univariate and multivariate analyses of NSLN metastasis were performed. In univariate and multivariate analyses, large tumor size, macrometastasis and high tumor grade were all significant risk factors of NSLN metastasis in patients with a positive SLN. In univariate analysis, luminal B subgroup showed higher rate of NSLN metastasis than other subgroup (P = 0.027). When other variables were adjusted in multivariate analysis, the molecular subtype classification was a determinant of NSLN metastasis. Relative to triple negative subgroup, both luminal A (P = 0.047) and luminal B (P = 0.010) subgroups showed a higher risk of NSLN metastasis. Otherwise, HER2 over-expression subgroup did not have a higher risk than triple negative subgroup (P = 0.183). The area under the curve (AUC) value was 0.8095 for the Cambridge model. When molecular subtype classification was added to the Cambridge model, the AUC value was 0.8475.

Conclusions

Except for other factors, molecular subtype classification was a determinant of NSLN metastasis in patients with a positive SLN. The predictive accuracy of mathematical models including molecular subtype should be determined in the future.     

Tumour-induced immune modulation of sentinel lymph nodes

Sentinel lymph nodes (SLNs), being the first nodes to receive lymph from a primary tumour and the preferential site of initial tumour metastases, are intensively exposed to the bioactive products of tumour cells and other associated cells. This makes them ideal for studies of the factors that determine selective tissue susceptibility to metastases. We postulate that tumour-induced immune modulation of SLNs facilitates lymph-node metastases by inhibiting the generation of tumour-specific cytotoxic T cells that are active against tumour cells of primary and metastatic melanomas. Immune modulation of the lymph nodes can be reversed by granulocyte/macrophage colony-stimulating factor (GM-CSF), a finding that has implications for the future therapy of lymph-node metastases.     

Intraoperative evaluation of sentinel lymph nodes in breast cancer: comparison of frozen sections,imprint cytology and immunocytochemistry

M. Francz, K. Egervari and Z. Szollosi
Intraoperative evaluation of sentinel lymph nodes in breast cancer: comparison of frozen sections, imprint cytology and immunocytochemistry Objective: We analysed the utility of imprint cytology with rapid immunocytochemistry and frozen section analysis for the evaluation of sentinel lymph nodes in breast cancer patients. Methods: The sensitivity, specificity, and positive and negative predictive values have been calculated for each method individually, each pair and all three together. We compared these results with those of routinely processed paraffin sections. Results: The sensitivity and specificity of each of the three methods for detection of metastatic carcinoma were as follows: 69.4% and 97.8% for touch imprint cytology; 58.3% and 100% for frozen sections; 68.5% and 98.9% for rapid immunocytochemistry. When the methods were combined, the highest accuracy was achieved by touch imprint cytology, frozen sections, touch imprint cytology plus rapid immunocytochemistry, or touch imprint cytology frozen section analysis and rapid immunocytochemistry, each of these having identical sensitivity and specificity of 72.2% and 97.8%, respectively. Conclusions: In our study the combined accuracy of the three methods was the same as combining touch imprint cytology and frozen sections or touch imprint cytology plus rapid immunocytochemistry. Rapid immunocytochemistry provides an additional parameter and preserves tissue for permanent sections.     

Imprint cytology of sentinel lymph nodes in breast cancer. Experience with rapid, intraoperative diagnosis and primary screening by cytotechnologists

OBJECTIVE: To evaluate the intraoperative imprint diagnoses of smears from sentinel lymph nodes that had been primary screened by cytotechnologists and to assess the most important causes of false negative (FN) imprint diagnoses. STUDY DESIGN: Material consisted of 429 imprints from sentinel lymph nodes in 211 breast cancer patients that were sent for frozen section examination over 13 months. RESULTS: The mean number of imprints/lymph nodes per patient was 2.02. The mean screening time per imprint was 3.6 minutes. Sixty-six sentinel nodes (16%) from 51 women (24%) were metastatic. Imprints and/or frozen sections were positive in 54 nodes (82%). Imprints were positive in 38 nodes, representing 70% of intraoperative positive nodes and 58% of the total number of positive nodes. Twenty-six of 28 (93%) FN imprints were due to suboptimal sampling. Four of 9 FN macrometastases did not contain diagnostic or suspicious cells/cell groups even on rescreening, whereas a few, and then only 1 diagnostic group were identified in 2/9. There were no false positives. CONCLUSION: Primary screening by experienced cytotechnologists is both rapid and reliable and enabled the diagnosing pathologist to concentrate on the frozen section. The major cause of false negative imprints is sampling, even in macrometastases.     

Sampling of sentinel lymph nodes: a simulation study

OBJECTIVE: To analyze the effects of various slicing schemes on the detection of metastases in lymph nodes. STUDY DESIGN: Use of an advanced computer simulation tool. RESULTS: Bisectioning along the longitudinal axis is an inadequate approach. Slicing ellipsoid lymph nodes along their longitudinal axis also results in a lower rate of detecting metastases since metastatic deposits have a predilection to localize subcapsularly. CONCLUSION: Ellipsoid lymph nodes must be sliced perpendicular to the longest axis to increase the rate of detecting metastases.     

Patterns of DNA copy number changes in sentinel lymph node breast cancer metastases

The sentinel lymph node (SLN) is considered to be the first axillary node that contains malignant cells in metastatic breast tumors, and its positivity is currently used in clinical practice as an indication for axillary lymph node dissection. Therefore, accurate evaluation of the SLN for the presence of breast metastatic cells is essential. The main aim of our study is to characterize the genomic changes present in the SLN metastatic samples with the ultimate goal of improving the predictive value of SLN evaluation. Twenty paired samples of SLN metastases and their corresponding primary breast tumors (PBT) were investigated for DNA copy number changes using comparative genomic hybridization (CGH). Non-random DNA copy number changes were observed in all the lesions analyzed, with gains being more common than losses. In 75% of the cases there was at least one change common to both PBT and SLN. The most frequent changes detected in both lesions were gains of 1pter-->p32, 16, 17, 19, and 20 and losses of 6q13-->q23 and 13q13-->q32. In the PBT group, alterations on chromosomes 1, 16, and 20 were the most frequent, whereas chromosomes 1, 6, and 19 were the ones with the highest number of changes in the SLN metastatic group. A positive correlation was found between the DNA copy number changes per chromosome in each of the groups. Our findings indicate the presence of significant DNA copy number changes in the SLN metastatic lesions that could be used in the future as additional markers to improve the predictive value of SLN biopsy procedure.     

The number distribution for involved lymph nodes in cancer

The number of involved lymph nodes exhibits considerable heterogeneity within populations. Here, the implications of population heterogeneity are explored with respect to the kinematics of nodal metastases. Data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program for 224656 breast, 12404 gastric, 18015 rectal, 4117 cervical and 2443 laryngeal cancers as well as 9118 melanomas were used to construct frequency distributions for the number of involved nodes which were then fitted to the negative binomial distribution. The negative binomial distribution described the heterogeneity in nodal involvement well. The patterns of nodal involvement can be explained by either of two models: one where involved nodes could seed further nodal metastases, the other where the number of nodal metastases in any individual was randomly distributed, with the deviations between patients accounted for by population heterogeneity. Since the number of sampled nodes similarly approximated a negative binomial distribution, random involvement with superimposed population heterogeneity would more credibly explain both sets of observations.     

Histoenzymological and ultrastructural changes of axillary lymph nodes with breast cancer metastases

Histoenzymatic and ultrastructural changes were studied in axillary lymph nodes from patients with breast cancer by comparison between lymph nodes without metastases, with incipient metastases and completely metastatically transformed. Metastases is preceded by intense macrophagic reactions of lymph nodes, and prepared by the development of vascular stroma. Neoplastic cells in course of invasion presented an intense respiratory activity, while those replacing the lymphoid elements an accentuated synthesis of glycoproteins.