The Biologic and Clinical Significance of Lymphatic Metastases in Breast Cancer

Lymph Nodes as Anti-Tumor Immunotherapeutic Tools: Intranodal-Tumor-Specific Antigen-Pulsed Dendritic Cell Vaccine Immunotherapy

Simple Summary

In the field of cancer therapy, lymph nodes are important not only as targets for metastases resection but also as prudent target organs for cancer immunotherapy. Lymph nodes comprise a complete structure for the accumulation of a large number of T cells and their distribution throughout the body after antigen presentation and activation of dendritic cells. This review highlights current topics on the importance of lymph node structure in antitumor immunotherapy and intranodal-antigen-presenting mature dendritic cell vaccine therapy. We also discuss the rationale behind intranodal injection methods and their applications in neoantigen vaccine therapy, a new cancer immunotherapy.

Abstract

Hundreds of lymph nodes (LNs) are scattered throughout the body. Although each LN is small, it represents a complete immune organ that contains almost all types of immunocompetent and stromal cells functioning as scaffolds. In this review, we highlight the importance of LNs in cancer immunotherapy. First, we review recent reports on structural and functional properties of LNs as sites for antitumor immunity and discuss their therapeutic utility in tumor immunotherapy. Second, we discuss the rationale and background of ultrasound (US)-guided intranodal injection methods. In addition, we review intranodal administration therapy of tumor-specific-antigen-pulsed matured dendritic cells (DCs), including neoantigen-pulsed vaccines.

The lymphatic vasculature: An active and dynamic player in cancer progression

The lymphatic vasculature has been widely described and explored for its key functions in fluid homeostasis and in the organization and modulation of the immune response. Besides transporting immune cells, lymphatic vessels play relevant roles in tumor growth and tumor cell dissemination. Cancer cells that have invaded into afferent lymphatics are propagated to tumor‐draining lymph nodes (LNs), which represent an important hub for metastatic cell arrest and growth, immune modulation, and secondary dissemination to distant sites. In recent years many studies have reported new mechanisms by which the lymphatic vasculature affects cancer progression, ranging from induction of lymphangiogenesis to metastatic niche preconditioning or immune modulation. In this review, we provide an up‐to‐date description of lymphatic organization and function in peripheral tissues and in LNs and the changes induced to this system by tumor growth and progression. We will specifically focus on the reported interactions that occur between tumor cells and lymphatic endothelial cells (LECs), as well as on interactions between immune cells and LECs, both in the tumor microenvironment and in tumor‐draining LNs. Moreover, the most recent prognostic and therapeutic implications of lymphatics in cancer will be reported and discussed in light of the new immune‐modulatory roles that have been ascribed to LECs.

Lymphovascular invasion and histologic grade are associated with specific genomic profiles in invasive carcinomas of the breast

Lymphovascular invasion (LVI) and histologic grade are clinical parameters of high prognostic value in breast cancer and indicate the level of tumor aggressiveness. Many studies have focused on the association of breast cancer subtypes with gene expression and chromosomal profiles, but considerably less genomic information is available regarding traditional prognostic factors such as histologic grade and LVI. We studied by array-CGH a group of 57 invasive ductal carcinomas of the breast to outline the DNA copy number aberration (CNA) profile linked to high histologic grades and LVI. Selected CNAs were validated using real-time quantitative PCR (qPCR). Furthermore, gene expression analysis was performed in a subset of 32 of these tumors, and findings were integrated with array-CGH data. Our findings indicated an accumulation of genomic alterations in high-grade breast tumors compared to low-grade samples. Grade III tumors showed higher number of CNAs and larger aberrations than low-grade tumors and displayed a wide range of chromosomal aberrations, which were mainly 5p, 8q, 10p, 17q12, and 19 gains, and 3p, 4, 5q proximal, 9p, 11p, 18q, and 21 losses. The presence of LVI, a well-established prognostic marker, was not significantly associated with increased genomic instability in comparison to breast tumors negative for LVI, considering the total number of chromosomal alterations. However, a slightly increase in the frequency of specific alterations could be detected in LVI-positive group, such as gains at 5p, 16p, 17q12, and 19, and losses at 8p, 11q, 18q, and 21. Three newly reported small-scale rearrangements were detected in high-risk tumors (LVI-positive grade III) harboring putative breast cancer genes (amplicons at 4q13.3 and 11p11.2, and a deletion at 12p12.3). Furthermore, gene expression analysis uncovered networks highlighting S100A8, MMP1, and MED1 as promising candidate genes involved in high-grade and LVI-positive tumors. In summary, a group of genomic regions could be associated with high-risk tumors, and expression analysis pinpointed candidate genes deserving further investigation. The data has shed some light on the molecular players involved in two highly relevant prognostic factors and may further add to the understanding of the mechanisms of breast cancer aggressiveness.

Lymphangiogenesis and lymphatic vessel remodelling in cancer

The generation of new lymphatic vessels through lymphangiogenesis and the remodelling of existing lymphatics are thought to be important steps in cancer metastasis. The past decade has been exciting in terms of research into the molecular and cellular biology of lymphatic vessels in cancer, and it has been shown that the molecular control of tumour lymphangiogenesis has similarities to that of tumour angiogenesis. Nevertheless, there are significant mechanistic differences between these biological processes. We are now developing a greater understanding of the specific roles of distinct lymphatic vessel subtypes in cancer, and this provides opportunities to improve diagnostic and therapeutic approaches that aim to restrict the progression of cancer.

Exploring molecular links between lymph node invasion and cancer prognosis in human breast cancer

BACKGROUND

Lymph node invasion is one of the most powerful clinical factors in cancer prognosis. However, molecular level signatures of their correlation are remaining poorly understood. Here, we propose a new approach, monotonically expressed gene analysis (MEGA), to correlate transcriptional patterns of lymph node invasion related genes with clinical outcome of breast cancer patients.

RESULTS

Using MEGA, we scored all genes with their transcriptional patterns over progression levels of lymph node invasion from 278 non-metastatic breast cancer samples. Applied on 65 independent test data, our gene sets of top 20 scores (positive and negative correlations) showed significant associations with prognostic measures such as cancer metastasis, relapse and survival. Our method showed better accuracy than conventional two class comparison methods. We could also find that expression patterns of some genes are strongly associated with stage transition of pathological T and N at specific time. Additionally, some pathways including T-cell immune response and wound healing serum response are expected to be related with cancer progression from pathway enrichment and common motif binding site analyses of the inferred gene sets.

CONCLUSIONS

By applying MEGA, we can find possible molecular links between lymph node invasion and cancer prognosis in human breast cancer, supported by evidences of feasible gene expression patterns and significant results of meta-analysis tests.

Hormone receptor status in breast cancer and its relation to age and other prognostic factors

BACKGROUND

Increasing evidence shows the importance of young age, estrogen receptor (ER), progesterone receptor (PR) status, and HER-2 expression in patients with breast cancers.

PATIENTS AND METHODS

We organized an analytic cross-sectional study of 105 women diagnosed with breast cancer who have been operated on between 2008 to 2010. We evaluated age, size, hormone receptor status, HER-2 and P53 expression as possible indicator of lymph node involvement.

RESULTS

There is a direct correlation between positive progesterone receptor status and being younger than 40 (P < 0.05). Also, compared with older women, young women had tumors that were more likely to be large in size and have higher stages (P < 0.05). Furthermore patients with negative progesterone receptor status were more likely to have HER-2 overexpression (P < 0.05). The differences in propensity to lymph node metastasis between hormone receptor statuses were not statically significant.

CONCLUSIONS

Although negative progesterone receptor tumors were more likely to have HER-2 overexpression, it is possible that higher stage and larger size breast cancer in younger women is related to positive progesterone receptor status.

MiR-34a inhibits lymphatic metastasis potential of mouse hepatoma cells

MicroRNAs are small non-coding RNAs that regulate the expression of other genes in a post-transcriptional manner. MiR-34a can induce apoptosis, cell cycle arrest, and senescence. However, its role in tumor progress remains to be fully elucidated. In the present study, the role of miR-34a in lymphatic metastasis was investigated using mouse hepatocarcinoma cell lines Hca-F and Hepa1-6. MicroRNA profiling and Hairpin-RT-PCR analysis showed that the expression level of miR-34a was higher in Hepa1-6 cells (of no metastatic ability) than that in Hca-F cells (of high metastatic ability). Ectopic expression of miR-34a can inhibit cell growth and cell invasion in Hepa1-6 and Hca-F cells. Moreover, miR-34a triggers G1 arrest and down-regulates CyclinD1 and CDK6 in Hepa1-6 cells. Furthermore, we proved that miR-34a decreased adhesion of Hca-F cells to regional lymph node in vitro, reduced lymph nodes-metastasized burden, and inhibited tumor lymph node metastases in vivo. All these results suggest that miR-34a plays multiple tumor suppressive roles in murine hepatocarcinoma, not only inhibiting cell growth by cell cycle arrest, but also repressing metastasis, and may serve as a novel therapeutic target for hepatocarcinoma.

The role of lymph node metastasis in the systemic dissemination of breast cancer

BACKGROUND.: Lymphatic invasion is necessary for regional lymph node (RLN) metastasis in breast cancer (BC), while systemic metastasis requires blood vessel (BV) invasion. The site of BV invasion could be at the primary BC site or through lymphovascular anastomoses. The vague pathologic term "lymphovascular invasion" (LVI) encourages the belief that peri/intratumoral BV invasion may be common. We investigated the relative contribution of RLN metastasis to systemic metastasis by studying the relationship among LVI and RLN and/or systemic metastasis in a population-based cohort of breast cancer patients. METHODS.: Fisher's exact test was done to assess global associations among LVI and RLN and/or systemic metastasis in a prospective database of breast cancer patients undergoing RLN biopsy. Logistic regression was used to determine multivariable contributions of LVI to metastasis when controlling for available demographic, radiologic, and pathologic variables. RESULTS.: Of 1668 patients evaluated 25.4% were RLN positive and 10.4% had LVI. RLN metastasis was predicted by tumor size (P < .0001), HER-2/neu overexpression (P = .0022) and the interaction between LVI positive and HER-2/neu positive tumors (< .0001). Patients with LVI/HER-2-neu positive were 3 times as likely to have positive RLNs compared with patients LVI/HER-2-neu negative. Systemic metastasis was significantly (P = .0013) associated with LVI/ RLN positive, but not with LVI positive/RLN negative patients (P = .137). CONCLUSIONS.: LVI predicted RLN metastasis. LVI also significantly predicted systemic metastasis, but only when the RLN was also positive. Since RLN requires lymphatic invasion, these data support the hypothesis that primary breast cancers often invade lymphatics to gain access to the systemic circulation.

Cancer-associated fibroblasts and epithelial-mesenchymal transition in metastatic oral tongue squamous cell carcinoma

We examined cancer-associated fibroblasts (CAFs) and a panel of immunohistochemical markers of epithelial-mesenchymal transition (EMT) in 19 pair-matched oral tongue squamous cell carcinoma (SCC) and metastatic tumors to regional lymph nodes (RLNs). alpha-Smooth muscle actin (alpha-SMA) was studied to identify CAFs. EMT was studied with syndecan-1, Cadherin-11, fibroblast-specific protein (FSP)-1, secreted protein acidic and rich in cysteine (SPARC) and Twist. Triple immunostaining in RLNs was used to highlight the carcinoma cells (E-cadherin and Ki-67) and their relationship to the CAFs (alpha-SMA). We found that metastatic RLNs hosted CAFs similarly as in pair-matched primary tumors. Expression of EMT markers is common in both primary and metastatic tumors. We demonstrate that metastatic carcinoma cells (Ki-67 positive) downregulate E-cadherin expression at the periphery of cancer islands, where they are in direct contact with CAFs. The supporting connective tissue microenvironment also commonly expresses syndecan-1, Cadherin-11, FSP-1, and SPARC. In conclusion, CAFs are common to both primary and metastatic SCC. We hypothesize that CAFs not only promote tumor invasion but also facilitate metastases, either by cometastasizing and/or being recruited to lymph nodes. Evidence of EMT is common within primary tumors and metastatic SCC and may be further modulated by CAFs.

The role of lymph node metastasis in the systemic dissemination of breast cancer

BACKGROUND

Lymphatic invasion is necessary for regional lymph node (RLN) metastasis in breast cancer (BC), while systemic metastasis requires blood vessel (BV) invasion. The site of BV invasion could be at the primary BC site or through lymphovascular anastomoses. The vague pathologic term "lymphovascular invasion" (LVI) encourages the belief that peri/intratumoral BV invasion may be common. We investigated the relative contribution of RLN metastasis to systemic metastasis by studying the relationship among LVI and RLN and/or systemic metastasis in a population-based cohort of breast cancer patients.

METHODS

Fisher's exact test was done to assess global associations among LVI and RLN and/or systemic metastasis in a prospective database of breast cancer patients undergoing RLN biopsy. Logistic regression was used to determine multivariable contributions of LVI to metastasis when controlling for available demographic, radiologic, and pathologic variables.

RESULTS

Of 1668 patients evaluated 25.4% were RLN positive and 10.4% had LVI. RLN metastasis was predicted by tumor size (P < .0001), HER-2/neu overexpression (P = .0022) and the interaction between LVI positive and HER-2/neu positive tumors (< .0001). Patients with LVI/HER-2-neu positive were 3 times as likely to have positive RLNs compared with patients LVI/HER-2-neu negative. Systemic metastasis was significantly (P = .0013) associated with LVI/RLN positive, but not with LVI positive/RLN negative patients (P = .137).

CONCLUSIONS

LVI predicted RLN metastasis. LVI also significantly predicted systemic metastasis, but only when the RLN was also positive. Since RLN requires lymphatic invasion, these data support the hypothesis that primary breast cancers often invade lymphatics to gain access to the systemic circulation.

Characterization of tumor cell dissemination patterns in preclinical models of cancer metastasis using flow cytometry and laser scanning cytometry

The inability to sensitively detect metastatic cells in preclinical models of cancer has created challenges for studying metastasis in experimental systems. We previously developed a flow cytometry (FCM) method for quantifying circulating tumor cells (CTCs) in mouse models of breast cancer. We have adapted this methodology for analysis of tumor dissemination to bone marrow (BM) and lymph node (LN), and for analysis of these samples by laser scanning cytometry (LSC). Our objective was to implement these methodologies for characterization of tumor cell dissemination in preclinical models of cancer metastasis. Human cancer cells were injected into mice via mammary fat pad (MFP; spontaneous metastasis), tail vein (TV; targets lung), or intracardiac (IC; targets bone) routes. At several time points postinjection (4 h to 8 weeks), mice were sacrificed and blood, LNs, and BM were collected. Samples were immunomagnetically enriched and labeled with human leukocytic antigen-fluorescein isothiocyanate and CD45-PE antibodies (FCM/LSC), and propidium iodide (FCM) prior to quantitative analysis. Following MFP injection, CTCs increased over time, as did disseminated cells to the LN. Interestingly, tumor cells also spontaneously disseminated to BM, peaking at 2 weeks postinjection. Following TV injection, CTCs were initially high but decreased rapidly by 1 week before increasing to peak at endpoint. Combined with an observed concurrent increase in disseminated cells to LN and BM, this suggests that tumor cells may shed into the circulation from lung metastases that establish following initial cell delivery. Following IC injection, CTCs increased over time, peaking at 4 weeks. Tumor cells in the BM (most prevalent site of metastasis after IC injection) remained at moderate levels until peaking at endpoint. Combined use of FCM and LSC allows sensitive quantification of disseminated tumor cells in preclinical models of metastasis. These methods will be valuable for future studies aimed at testing new therapeutics in the metastatic setting.

Patterns of axillary surgical care for breast cancer in the era of sentinel lymph node biopsy

BACKGROUND

Population-based overall patterns of surgical management of the axilla in women with operable breast cancer during the era of adoption of sentinel lymph node biopsy (SLNB) were studied.

METHODS

Women with operable breast carcinoma residing in 14 geographic areas of the Surveillance, Epidemiology, and End Results (SEER) cancer registries (1998-2004, n=239,661) were assessed for axillary surgical patterns of care.

RESULTS

Use of SLNB increased from 11 to 59%. Use of no axillary surgery decreased from 14 to 6.6%. In pathologic node-negative women, use of axillary lymph node dissection (ALND) decreased from 94 to 36%. Independent factors most associated with failure to receive SLNB included diagnosis year (2000: 62%; 2004: 29%), surgery (mastectomy: 64%; breast-conserving surgery: 36%), tumor size (T3: 71%; T2: 56%; T1: 40%), age (>or= 70 years: 50%; <70 years: 45%), grade (high: 42%; low: 38%), urbanity (non-large metropolitan area: 49%; large metropolitan area: 42%), and, by quartile, poverty (highest: 47%; lowest: 35%), and white-collar employment (lowest: 56%; highest: 47%). In pathologic node-positive women who had SLNB, failure to undergo completion ALND increased from 20% in 1998 to 32% in 2004. Patients with smaller, lower-grade tumors, and those with smaller size of nodal metastasis, lack of extracapsular extension, age >or= 70 years, increased linguistic isolation, African-American or Hispanic race/ethnicity, and white-collar employment were less likely to undergo completion ALND.

CONCLUSIONS

Management of the axilla changed dramatically during the period of rapid adoption of SLNB. Patterns of care suggest both appropriate and inappropriate selection for SLNB and ALND.

Comparison of Her-2, EGFR and cyclin D1 in primary breast cancer and paired metastatic lymph nodes: an immunohistochemical and chromogenic in situ hybridization study

The significant advance in the development of molecular-targeting drugs has made an evaluation of Her-2, EGFR, and cyclin D1 an important clinical issue in breast cancer patients. This study compared the Her-2, EGFR, and cyclin D1 status of primary tumors as well as their matching lymph node metastases using immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH) in 73 breast cancer patients. Her-2, EGFR, and cyclin D1 protein showed a concordance between the primary lesion and the metastatic regional lymph nodes in 82%, 90%, and 63%, respectively. CISH also revealed 92%, 93%, and 85% concordance in the gene amplification status of Her-2, EGFR, and cyclin D1, showing a reasonable agreement between primary tumors and metastatic regional lymph nodes. Although a statistically significant agreement was found in Her-2 expression, a relatively high discordance rate (18%) raises a little concern. Our findings suggest that the Her-2 status can be reliably assessed on primary tumor but a possible difference can be found in Her-2, EGFR, and cyclin D1 status between the primary and the metastatic sites and this possibility should be concerned in patients considering molecular targeted therapy or patients with progress of disease.

How many sentinel lymph nodes are enough during sentinel lymph node dissection for breast cancer?

BACKGROUND

: It remains unclear how many sentinel lymph nodes (SLNs) must be removed to accurately predict lymph node status during SLN dissection in breast cancer. The objective of this study was to determine how many SLNs need to be removed for accurate lymph node staging and which patient and tumor characteristics influence this number.

METHODS

: The authors reviewed data for all patients in their prospective database with clinical tumor, lymph node, metastasis (TNM) T1 through T3, N0, M0 breast cancer who underwent lymphatic mapping at their institution during the years 1994 through 2006. There were 777 patients who had at least 1 SLN that was positive for cancer. Simple and multiple quantile regression analyses were used to determine which patient and tumor characteristics were associated with the number of positive SLNs. The baseline number of SLNs that needed to be dissected for detection of 99% of positive SLNs in the total group of patients also was determined.

RESULTS

: The mean number of SLNs removed in the 777 lymph node-positive patients was 2.9 (range, 1-13 SLNs). Greater than 99% of positive SLNs were identified in the first 5 lymph nodes removed. On univariate analysis, tumor histology, patient race, tumor location, and tumor size significantly affected the number of SLNs that needed to be removed to identify 99% of all positive SLNs. On multivariate analysis, mixed ductal and lobular histology, Caucasian race, inner quadrant tumor location, and T1 tumor classification significantly increased the number of SLNs that needed to be removed to achieve 99% recovery of all positive SLNs.

CONCLUSIONS

: In general, the removal of a maximum of 5 SLNs at surgery allowed for the recovery of >99% of positive SLNs in patients with breast cancer. The current findings indicated that tumor histology, patient race, and tumor size and location may influence this number.

Downregulation of osteopontin contributes to metastasis suppression by breast cancer metastasis suppressor 1

Breast cancer metastasis suppressor 1 (BRMS1) inhibits the ability of multiple human and murine cancer cell lines to metastasize to lymph nodes, bones and lungs. Comparison of mRNA expression in metastatic MDA-MB-435 human carcinoma cells (435) and metastasis-suppressed BRMS1 transfectants (435/BRMS1) showed a marked (>90%) reduction of osteopontin (OPN) mRNA and protein expression in BRMS1-overexpressing cells. OPN expression is associated with disease progression in patients, with higher levels of OPN produced by cancer cells associated with poorer patient survival. Furthermore, OPN has been suggested to promote survival of cancer cells in response to stress, although the mechanisms by which this may occur remain poorly understood. This study tested the hypothesis that re-expression of OPN in metastasis-suppressed 435/BRMS1 cells would reverse metastasis suppression and confer protection from stress-induced apoptosis. A stable pooled population of OPN overexpressing 435/BRMS1 cells was created (435/BRMS1/OPN). OPN re-expression did not affect in vitro cell growth rates; however, increased anchorage independent growth/survival and protection from hypoxia-induced apoptosis was observed (p < 0.05). In vivo, OPN re-expression in BRMS1 transfected cells did not affect in vivo primary tumor growth but did increase the incidence of spontaneous metastasis to lymph nodes and lungs in mice. These novel findings suggest that OPN downregulation by BRMS1 may be responsible, at least in part, for BRMS1-mediated metastasis suppression by sensitizing cancer cells to stress induced apoptosis. These studies clarify one mechanism by which BRMS1 can suppress metastasis.

Factors predicting additional disease in the axilla in patients with positive sentinel lymph nodes after neoadjuvant chemotherapy

BACKGROUND

The utility of sentinel lymph node (SNL) biopsy (SLNB) as a predictor of axillary lymph node status is similar in patients who receive neoadjuvant chemotherapy and patients who undergo surgery first. The authors of this study hypothesized that patients with positive SLNs after neoadjuvant therapy would have unique clinicopathologic factors that would be predictive of additional positive non-SLNs distinct from patients who underwent surgery first.

METHODS

One hundred four patients were identified who received neoadjuvant chemotherapy, had a positive SLN, and underwent axillary dissection between 1997 and 2005. At the time of presentation, 66 patients had clinically negative lymph nodes by ultrasonography, and 38 patients had positive lymph nodes confirmed by fine-needle aspiration. Eighteen factors were assessed for their ability to predict positive non-SLNs using chi-square and logistic regression analysis with a bootstrapped, backwards elimination procedure. The resulting nomogram was tested by using a patient cohort from another institution.

RESULTS

Patients with clinically negative lymph nodes at presentation were less likely than patients with positive lymph nodes to have positive non-SLNs (47% vs 71%; P=.017). On multivariate analysis, lymphovascular invasion, the method for detecting SLN metastasis, multicentricity, positive axillary lymph nodes at presentation, and pathologic tumor size retained grouped significance with a bootstrap-adjusted area under the curve (AUC) of 0.762. The resulting nomogram was validated in the external patient cohort (AUC, 0.78).

CONCLUSIONS

A significant proportion of patients with positive SLNs after neoadjuvant chemotherapy had no positive non-SLNs. The use of a nomogram based on 5 predictive variables that were identified in this study may be useful for predicting the risk of positive non-SLNs in patients who have positive SLNs after chemotherapy.

Hypoxia increases breast cancer cell-induced lymphatic endothelial cell migration

Because tumors are characterized by hypoxic environments, we used a novel in vitro noninvasive magnetic resonance imaging assay to examine the influence of invasive MDA-MB-231 breast cancer cells on the invasion and migration of human dermal lymphatic microvascular endothelial cells (HMVEC-dLy) under normoxic and hypoxic conditions. Nonmalignant immortalized MCF-12A human mammary epithelial cells instead of cancer cells or chambers with HMVEC-dLy alone were used as controls for comparison. HMVEC-dLy cells were labeled with a T(2) contrast agent (Feridex), and their invasion and migration through extracellular matrix under normoxic and hypoxic conditions were monitored using magnetic resonance imaging. A significant increase in the invasion and migration of HMVEC-dLy cells was detected in the presence of cancer cells, which further increased significantly under hypoxic conditions. HMVEC-dLy cells formed interconnecting strands extending toward the cancer cells under normoxic but not under hypoxic conditions. Following reoxygenation, these interconnecting strands, extending from HMVEC-dLy cells toward the cancer cells, were observed. These data demonstrate the importance of hypoxia in lymphatic endothelial cell invasion and migration through extracellular matrix in the presence of cancer cells.

Role of primary tumor characteristics in predicting positive sentinel lymph nodes in patients with ductal carcinoma in situ or microinvasive breast cancer

BACKGROUND

We determined the incidence of positive sentinel lymph nodes (SLNs) in patients with ductal carcinoma in situ (DCIS) or microinvasive breast cancer (MIC) and the predictive factors of SLN metastasis in these patients.

METHODS

Of 4,503 patients who underwent SLN dissection between March 1994 and March 2006 at our institution, we identified those with a preoperative diagnosis or final diagnosis of DCIS or MIC. Clinicopathologic factors were examined by logistic regression analysis.

RESULTS

Of the 624 patients with a preoperative diagnosis of DCIS or MIC, 40 had positive SLNs (6.4%). Of the 475 patients with a final diagnosis of DCIS or MIC, 9 had positive SLNs (1.9%). Clinical DCIS size >5 cm was the only independent predictor of positive SLN for patients with a preoperative diagnosis and patients with a final diagnosis of DCIS or MIC. Core biopsy as the method of preoperative diagnosis and DCIS size >5 cm were independent predictors for a final diagnosis of invasive carcinoma in the 149 patients who had a preoperative diagnosis of DCIS or MIC.

CONCLUSIONS

SLN dissection for patients with a diagnosis of DCIS should be limited to patients who are planned for mastectomy or who have DCIS size >5 cm. Patients who have a core-needle biopsy diagnosis of DCIS have a higher risk of invasive breast cancer on final pathologic assessment of the primary tumor. This information can be used in preoperative counseling of patients with DCIS regarding the timing of SLN biopsy.

Estrogen receptor positive breast cancer metastasis: altered hormonal sensitivity and tumor aggressiveness in lymphatic vessels and lymph nodes

Breast cancers commonly spread to lymph nodes (LNs). If the primary tumors are estrogen receptor (ER) and/or progesterone receptor (PR) positive, then the likelihood that LN metastases express receptors exceeds 80%. However, due to lack of ER+ models, little is known about the role of hormones in breast cancer spread or the effects of the LN microenvironment on hormone responsiveness. We have developed metastasis models using ZsGreen labeled MCF-7 and T47D human breast cancer cells. Tumors are tracked in living mice by whole-body imaging, and macrometastases or micrometastases are detected by intravital imaging or fluorescence microscopy. Tumor growth is estrogen dependent and required for intratumoral lymphangiogenesis. Seventy-five percent of all tumors and >95% of larger tumors generate LN metastases. Occasionally more distant metastases are also observed. "Triads" of primary tumors, tumor-filled draining lymphatic vessels, and tumor-filled LNs from the same mouse show that (a) proliferation, as measured by 5-bromo-2'-deoxyuridine uptake, is higher in the LN than in the primary tumor. (b) High ER levels are extensively down-regulated by estradiol in primary tumors. However, there is partial failure of ER down-regulation in LNs associated with (c) reduced PR expression. This suggests that ER are dysfunctional in the LN microenvironment and perhaps hormone resistant. (d) CD44 is sparsely expressed in primary tumor cells but homogeneously overexpressed in cells transiting the lymphatics and populating LNs. We hypothesize that CD44 expression targets tumor cells for transport to, and uptake in, LNs. If so, the CD44 pathway could be targeted therapeutically to slow or prevent LN metastases.

Differentially expressed genes between primary cancer and paired lymph node metastases predict clinical outcome of node-positive breast cancer patients

The axillary lymph node status remains the most valuable prognostic factor for breast cancer patients. However, approximately 20-30% of node-positive patients remain free of distant metastases within 15-30 years. It is important to develop molecular markers that are able to predict for the risk of distant metastasis and to develop patient-tailored therapy strategies. We hypothesize that the lymph node metastases may represent the most metastatic fraction of the primary cancers. Therefore, we sought to identify the differentially expressed genes by microarray between the primary tumors and their paired lymph node metastases samples collected from 26 patients. A set of 79 differentially expressed genes between primary cancers and metastasis samples was identified to correctly separate most of primary cancers from lymph node metastases. And decreased expression of matrix metalloproteinase 2, fibronectin, osteoblast specific factor 2, collagen type XI alpha 1 in lymph node metastases were further confirmed by real-time RT-PCR performed on 30 specimen pairs. This set of genes also classified 35 primary cancers into two groups with different prognosis: "high risk group" and "low risk group." Patients in "high risk group" had a 4.65-fold hazard ratio (95% CI 1.02-21.13, P = 0.047) to develop a distant metastasis within 43 months comparing with the "low risk group." This suggested that the gene signature consisting of 79 differentially expressed genes between primary cancers and lymph node metastases could also predict clinical outcome of node-positive patients, and that the molecular classification based on the gene signature could guide patient-tailored therapy.

Role of the integrin-binding protein osteopontin in lymphatic metastasis of breast cancer

Although a primary route of breast cancer metastasis is believed to be via lymphatics, the molecular factors involved are poorly understood. We hypothesized that one such factor may be the integrin-binding protein osteopontin (OPN), and we investigated this clinically and experimentally. In breast cancer patients undergoing sentinel lymph node biopsy, OPN levels were significantly higher in lymph node metastases than in the primary tumor (P < 0.001). To test the functional contribution of OPN to lymphatic metastasis and to determine whether the RGD (Arg-Gly-Asp) integrin-binding sequence of OPN is important for this process, we transfected wild-type OPN or mutant OPN (lacking the RGD sequence) into MDA-MB-468 human breast cancer cells. In vitro, cells overexpressing OPN demonstrated increased anchorage-independent growth in soft agar (P = 0.001) and increased RGD-dependent adhesion (P = 0.045). Following mammary fat pad injection of nude mice, cells overexpressing OPN showed increased lymphovascular invasion, lymph node metastases, and lung micrometastases at earlier time points (P = 0.024). Loss of the RGD region partially abrogated this effect in the lymphatics (P = 0.038). These novel findings indicate that OPN is a key molecular player involved in lymphatic metastasis of breast cancer, potentially by affecting RGD-mediated adhesive interactions and by enhancing the establishment/persistence of tumor cells in the lymphatics.

Differential expression of a gene signature for scavenger/lectin receptors by endothelial cells and macrophages in human lymph node sinuses, the primary sites of regional metastasis

Sentinel lymph node biopsy for several cancers has shown that metastatic tumour cells are preferentially arrested in the lymph node sinuses. To study the molecular components of this sinusoidal trap, gene profiling of lymph node (sinuses) versus tonsil (no sinuses) was performed. Among other groups of molecules, an intriguing gene signature of scavenger and lectin-like receptors was identified. Nine of the 13 genes were preferentially expressed in sinusoidal cells by immunohistochemistry. Using stabilin-2 and monoclonal antibody 3A5 as exclusive endothelial cell (EC) and macrophage (Mvarphi) markers, respectively, lymph node sinusoidal ECs (stabilin-2+, LYVE-1+, DC-SIGNR+, MARCO+, stabilin-1+, MMR+) and sinusoidal Mvarphi (MMR+, DC-SIGN+, sialoadhesin+, CD163+, stabilin-1+ ) showed distinct, but overlapping expression patterns of the signature molecules by double labelling immunofluorescence. The number of stabilin-1+ sinusoidal Mvarphi, however, varied considerably between samples, indicating turnover/differentiation dynamics in this sinusoidal cell population. In the hepatic sinuses, LYVE-1 and CD36 were strongly up-regulated on both sinusoidal ECs and Mvarphi, while DC-SIGNR and DC-SIGN were strongly down-regulated; in contrast to lymph node sinusoidal ECs, MARCO was confined to Mvarphi (Kupffer cells) in the liver sinuses. As Mvarphi are not present in the wall and lumen of splenic sinuses, splenic sinuses expressed a considerably reduced repertoire of scavenger/lectin receptors lacking sialoadhesin, CD36, CD163, and MARCO; in addition, DC-SIGNR was absent from splenic sinusoidal ECs, while DC-SIGN and thrombomodulin were strongly expressed. Interestingly, most of the signature molecules are known to mediate tumour cell adhesion in addition to their functions as scavenger or pattern recognition receptors. This study establishes a gene and tissue database platform to test the hypothesis that additive expression of the lymph node sinus signature genes in sinusoidal ECs and Mvarphi may contribute to selective tumour cell metastasis in lymph nodes and liver including organ-specific mechanisms, such as intraluminal retention or transmigration, while sparing the spleen.

Is intraoperative touch imprint cytology of sentinel lymph nodes in patients with breast cancer cost effective?

BACKGROUND

Sentinel lymph nodes (SLNs) are generally evaluated postoperatively, requiring 5-7 days for assessment. SLNs can also be evaluated intraoperatively by using touch imprint cytology (TIC), thus providing the surgeon immediate feedback and allowing for concurrent completion node dissection (CND) for positive SLNs. The authors hypothesized that TIC, when compared with standard postoperative SLN assessment alone, would permit a cost-effective evaluation of SLNs in patients with clinically node-negative breast cancer.

METHODS

A decision-analysis model was created to compare TIC with standard postoperative SLN assessment alone. Sensitivity and specificity of TIC were determined prospectively from 342 patients who underwent SLN biopsy assessed by both techniques. Short-term health states associated with surgical staging were defined, and utilities were estimated using EuroQol-5D. Base-case analysis was performed to estimate quality-adjusted life years and the incremental cost-effectiveness ratio. Sensitivity analyses were performed to examine stability of model parameters.

RESULTS

For each tumor stage, TIC was cost effective, and for patients with larger tumors (T3 and T4), TIC was the dominant strategy. The analysis was robust to changes in sensitivity and specificity of TIC, prevalence of metastasis, probability of complications, and cost. However, when utility associated with standard SLN assessment was 0.9 or greater, this became the preferred strategy.

CONCLUSIONS

TIC is cost effective for assessing SLN metastasis intraoperatively. For patients with larger tumors, it is not only more effective, but also less costly than standard SLN assessment alone. TIC may be particularly useful for patients who experience significant anxiety while awaiting results of standard SLN assessment.

A new model for lymphatic metastasis: development of a variant of the MDA-MB-468 human breast cancer cell line that aggressively metastasizes to lymph nodes

Breast cancer often spreads from the primary tumor to regional lymph nodes. Lymph node status provides clinically important information for making treatment decisions. Spread via lymphatics is also important for the biology of breast cancer, as tumor cells in lymph nodes may provide a reservoir of cells leading to distant, lethal metastases. Improved understanding of the biology of lymphatic spread thus is important for improved breast cancer survival. Advances towards understanding the interactions between tumors cells and lymphatic vessels have in part been limited by the lack of suitable cell lines and experimental models. We have addressed this need by developing a new model of lymphatic metastasis. Here we describe the establishment of 468LN cells, a variant of the MDA-MB-468 human breast adenocarcinoma cell line, which produces extensive lymph node metastasis following orthotopic injection of nude mice. 468LN cells are also more aggressive in vitro, produce more osteopontin and express different surface integrins compared to the parent line. The dramatic in vitro and in vivo phenotypic and molecular differences of 468LN and parental 468GFP cells make this pair of cell lines a unique model for the specific study of lymph node metastasis of breast cancer.

No common denominator for breast cancer lymph node metastasis

The axillary lymph node status is the most powerful prognostic factor for breast cancer patients to date. The molecular mechanisms that control lymph node metastasis, however, remain poorly understood. To define patterns of genes or gene regulatory pathways that drive breast cancer lymph node metastasis, we compared the gene expression profiles of 15 primary breast carcinomas and their matching lymph node metastases using microarrays. In general, primary breast carcinomas and lymph node metastases do not differ at the transcriptional level by a common subset of genes. No classifier or single gene discriminating the group of primary tumours from those of the lymph node metastases could be identified. Also, in a series of 295 breast tumours, no classifier predicting lymph node metastasis could be developed. However, subtle differences in the expression of genes involved in extracellular-matrix organisation and growth factor signalling are detected in individual pairs of matching primary and metastatic tumours. Surprisingly, however, different sets of these genes are either up- or downregulated in lymph node metastases. Our data suggest that breast carcinomas do not use a shared gene set to accomplish lymph node metastasis.

Association between RCAS1 expression and microenvironmental immune cell death in uterine cervical cancer

OBJECTIVE

: The presence of regional lymph node metastasis is one of the prognostic factors for uterine cervical cancer. The development of metastasis requires that cancer cells avoid lymphocyte attack. Impaired lymphocyte function is mediated by apoptotic factors including receptor-binding cancer antigen expressed on SiSo cells (RCAS1), Fas ligand (FasL), and tumor necrosis factor-alpha (TNF-alpha). Our aim was to evaluate the association between expression of these factors and microenvironmental lymphocyte apoptosis in this disease.

METHODS

: Immunohistochemical methods were used to determine the relationship between the expression of RCAS1, FasL, and TNF-alpha, and the number of apoptotic lymphocytes in primary lesions and metastatic lymph nodes in patients with cervical cancer.

RESULTS

: Expression of these apoptosis-inducing molecules was quite different in primary tumors and metastatic lymph nodes: RCAS1 expression in lymph nodes was significantly higher than that in primary lesions (P < 0.0001), whereas FasL and TNF-alpha expressions at these two locations were not significantly different. The number of cells with positive expression of RCAS1, but not of FasL or TNF-alpha, was significantly correlated with the number of apoptotic lymphocytes in uterine cervix and metastatic lymph nodes (P < 0.0001 for both).

CONCLUSION

: RCAS1 expression may be related to tumor cell evasion of immune surveillance via induction of lymphocyte apoptosis in primary lesions and metastatic lymph nodes in uterine cervical cancer.

Molekularbiologische Erklärungsansätze einer Lymphknotenmetastasierung

The spread of tumor cells of solid tumors to the regional lymph nodes is an important step in the progression of the disease and also an important prognostic factor. While the significance of the prognostic value of the lymphatic progression had been detected long ago, only increased knowledge of the molecular anatomy and mechanisms involved in the lymphatic spread of tumor cells provided a beginning insight into the understanding of lymphatic metastasis. One group of important molecular factors consists of proteins produced by the tumor cells inducing a proliferation of lymphatic vessels into the primary tumor. The vascular endothelial growth factors have been identified as key factors in this process. In addition there are hints for the fact that chemokines, which are cytokine-like proteins taking part in the regulation of processes of inflammation, and their chemokine receptors control cellular key steps of lymphatic metastasis of tumor cells such as migration, proliferation, and invasion. In conclusion new data point to the possible inhibition of lymphatic spread by selective blockade of growth factor receptors or chemokine receptors. The growing insight into cellular understanding of the mechanisms involved in the metastasis of tumor cells into the lymphatics and lymph nodes will hopefully facilitate the development of new diagnostic and therapeutic tools in the treatment of cancer patients.

Biochemical characterization of metastatic lymph nodes of breast cancer patients by in vitro 1H magnetic resonance spectroscopy: a pilot study

Using one-dimensional (1D) and two-dimensional (2D) proton nuclear magnetic resonance (NMR) methods, the perchloric acid extract of involved (n = 11) and noninvolved (n = 12) axillary lymph nodes (ALN) of breast cancer patients was investigated. Resonances from 40 metabolites such as lactate (Lac), glucose, several amino acids (alanine, lysine, glutamic acid, glutamine, etc.), nucleotides (adenosine triphosphate, guanosine triphosphate, uridine triphosphate, uridine monophosphate, etc.), membrane metabolites [glycerophosphocholine (GPC), phosphocoline (PC), phosphoethanolamine (PE), choline] were unambiguously assigned in both the involved and noninvolved ALN. The concentration of PC/GPC (p = 0.002) was significantly higher in the involved compared to noninvolved nodes. In addition, the concentration of glycolytic product Lac (p = 0.0001) was also found to be significantly higher in involved nodes. Increased concentration of membrane metabolites PC/GPC may be attributed to increased membrane synthesis in malignant cells and, therefore, suggests the presence of metastatic cells in lymph nodes. The higher concentration of Lac is indicative of the presence of malignant cells that derive energy via anaerobic glycolytic pathway. Present results demonstrate the potentials of in vitro proton NMR in detecting malignant cells in ALN and such studies may have an important bearing in determining the prognosis of breast cancer patients.

Detection of metastases in sentinel lymph nodes of breast cancer patients by multiple mRNA markers

Disseminated breast tumour cells in sentinel lymph nodes (SNs) were evaluated by quantitative real-time PCR and the sensitivity of this assay was compared to the routine histological analysis. First, several candidate marker genes were tested for their specificity in axillary lymph nodes (ALN) of 50 breast cancer patients and 43 women without breast cancer. The marker gene panel selected, designed to detect the mRNA of CK19, p1B, EGP2 and SBEM, was subsequently applied to detect metastases in 70 SNs that were free of metastases as determined by standard histological evaluation. Remarkably, seven negative SNs showed increased marker gene expression, suggesting the presence of (micro) metastases. Four of these seven SNs positive by real-time PCR proved to contain tumour deposits after careful review of the slides or further sectioning of the paraffin-embedded material. In three PCR positive SNs, however, no tumour cells were found by haematoxylin and eosin staining (H&E) and immunohistologically analysis. The quantitative real-time PCR assay with multiple mRNA markers for the detection of disseminated breast cancer cells in SNs thus resulted in an upstaging of SNs containing metastastic disease of 10% compared to the routine histological analysis. The application of this technique may be of clinical relevance, as it is suggested that micrometastatic disease in SNs are associated with further nodal non-SN metastases in breast cancer.

Insights into the mechanisms of lymph node metastasis

The mechanisms by which malignant tumors leave the primary tumor site, invade lymphatics, and metastasize to regional lymph nodes (RLNs) are complex and interrelated. Although the phenomenon of lymph node metastasis has been recognized for over 200 years, the exact mechanisms have only recently been the subject of intense interest and sophisticated experimentation. Sentinel lymph node biopsy has rapidly entered the clinical mainstream for melanoma and breast carcinoma, and this technique has provided confirmation of the orderly anatomic progression of tumor cells from primary site to the RLNs through lymphatic capillaries and trunks. Exciting studies involving the pathophysiology of interstitial fluid pressure in tumors and the peritumoral extracellular matrix have focused on lymphatic flow and tumor microenvironment and microcirculation. Molecular techniques have led to the definition of unique markers found on lymphatic endothelial cells. These markers have enabled scientists to identify peritumoral and intratumoral lymphatics and to visualize the ingrowth of tumor cells into the lumena of lymphatic capillaries. Tumor-secreted cytokines, such as vascular endothelial growth factors (VEGF)-C and -D, bind to VEGF receptors on lymphatic endothelial cells and induce proliferation and growth of new lymphatic capillaries; this process is similar to the well-known mechanism of angiogenesis, which results from the proliferation of new blood vessel capillaries. Lymphangiogenesis is associated with an increased incidence of RLN metastasis, and it is possible that this step is essential to the metastatic process. Directional movement toward lymphatics and lymph nodes appears to follow a chemokine gradient, and it is likely that some tumor cells that express certain types of chemokine receptors are more likely to metastasize to the RLNs. In contrast, tumor cells that do not express specific receptors that are responsive to lymphatic chemokines may not metastasize. New knowledge regarding the molecules involved in these processes should enable improvements in prognostic and possibly therapeutic approaches to the management of malignant tumors.

Accuracy of intraoperative touch imprint cytologic analysis of sentinel lymph nodes in breast cancer

BACKGROUND

Eliminating full axillary dissection (AD) in the face of negative sentinel lymph nodes (SLN) has become increasingly popular. We sought to evaluate the accuracy of intraoperative touch imprint cytology in detecting clinically significant metastatic involvement of the SLN.

METHODS

Retrospective review of intraoperative cytology and final hematoxylin-eosin stain evaluation of sentinel nodes examined in a community hospital from 1997 to 2002.

RESULTS

During that period 1,585 patients underwent axillary dissection; 380 had SLN identification with 142 patients undergoing intraoperative cytologic evaluation of 446 SLNs. Fourteen patients with negative intraoperative cytology had involvement of a SLN on final hematoxylin-eosin examination, for a sensitivity of 75%, specificity of 100%, negative predictive value of 95%, and a false negative rate of 4.9%. In all but 1 case the metastasis was microscopic and measured 2 mm or less. Seven patients went on to completion axillary dissection (50%) with no additional nodal involvement found.

CONCLUSIONS

Intraoperative touch imprint cytology is accurate in predicting clinically significant SLN pathology. Although the false negative rate in this series was 4.9%, in all but 1 case it represented micrometastatic disease that may not necessarily require completion axillary dissection.

Association between extent of axillary lymph node dissection and patient, tumor, surgeon, and hospital factors in patients with early breast cancer

BACKGROUND AND OBJECTIVES

Axillary lymph node dissection (ALND) in patients with breast cancer is crucial for accurate staging, provides excellent regional tumor control, and is included in the standard of care for the surgical treatment of breast cancer. However, the extent of ALND varies, and the extent of dissection and the number of lymph nodes that comprise an optimal axillary dissection are under debate. Despite conflicting evidence, several studies have shown that improved survival is correlated with more lymph nodes removed in both node-negative and node-positive patients. The purpose of this study is to determine which patient, tumor, surgeon, and hospital characteristics are associated with the number of nodes excised in early breast cancer patients.

METHODS

A random sample of 938 women with node-negative breast cancer was drawn from the Ontario Cancer Registry and the data supplemented with chart reviews. The extent of axillary dissection was studied by examining the number of nodes examined in relation to the patient, tumor, surgeon, and hospital factors.

RESULTS

The mean number of lymph nodes excised was 9.8 (SD = 4.8; range, 1-31), and 49% of patients had >/=10 nodes excised. Lower patient age was associated with the excision of more lymph nodes (>/=10 nodes: 63% of patients <40 years vs. 38% of patients >/=80 years). Surgeon academic affiliation and surgery in a teaching hospital were highly correlated with each other and were significantly associated with the excision of >/=10 nodes. The number of nodes excised was not associated with any tumor factors, nor with the breast operation performed. These results were confirmed with multivariable models.

CONCLUSIONS

Even though the number of lymph nodes found in the pathologic specimen can be influenced by factors other than surgical technique (e.g., number of nodes present, specimen handling, and pathologic examination), this study shows significant variation of this variable and an association with several patient and surgeon/hospital factors. This variation and the association with survival warrant further study and effort at greater consistency.

Increased mammography use and its impact on earlier breast cancer detection in Vermont, 1975-1999

BACKGROUND

A trend toward earlier breast carcinoma detection in the United States has been attributed to screening mammography, although direct evidence linking this trend to the increased use of mammography in a general population is lacking. This study examined the effects of mammography on tumor size and axillary lymph node metastasis in Vermont over 25 years.

METHODS

Pathology and mammography data from 3499 Vermont women who were diagnosed with invasive breast carcinoma during 1975-1984, 1989-1990, and 1995-1999 were compared. Logistic regression analysis was used to estimate the effects of age, mammography use, and period on the odds of a tumor < or = 2 cm and the odds of negative lymph nodes.

RESULTS

The proportion of breast tumors that were detected by screening mammography increased from 2% during 1974-1984 to 36% during 1995-1999 (P < 0.001), and these tumors were more likely to measure < or = 2 cm than tumors that were detected by other methods. Among women age > 50 years, the odds ratio (OR) was 4.5, with a 95% confidence interval (95% CI) of 3.5-6.4. The effect was smaller in younger women (OR, 1.8; 95% CI, 1.1-3.0). Mammographic detection increased the odds of negative lymph nodes by a similar amount in both age groups, although women age > 50 years were more likely to have negative lymph nodes than younger women (OR, 1.3; 95% CI, 1.1-1.6). Tumor size and lymph node metastasis also were related to the number of mammograms and to the mammographic interval.

CONCLUSIONS

Most of the trend toward earlier detection in Vermont was due to mammography. Mammography had a lesser effect on tumor size among younger women, which may be related to less frequent screening, although its effect on lymph node metastasis was not age dependent. Women age < 50 years were more likely to have positive lymph nodes, independent of the method of detection or the frequency of mammography.

Biologic and clinical significance of lymphadenectomy

Interest in the lymphatic system and its relationship to metastases has developed owing to renewed interest in sentinel node biopsy. This article summarizes the anatomy, physiology, and biology of the lymphatic system and lymph node metastases, and reviews studies of lymph node metastases and surgical resection of cancers in different anatomic sites. On the basis of these studies, the authors conclude that lymph node metastasis functions as an indicator of prognosis, not the controlling or determining factor of prognosis. Thus, varying degrees of treatment of regional lymph nodes and metastases do not seem to be controlling factors in the outcome of cancer.

Axillary dissection in the context of the biology of lymph node metastases

BACKGROUND

Modern breast surgery, as the primary treatment of invasive breast carcinoma, has been evolving over the last century. Aggressive radical surgery, which included chest wall resection, complete axillary clearance and internal mammary node dissection, has slowly changed to a less aggressive approach. This has been based on an improved understanding of the biology of the disease. Over the years, randomized prospective trials, performed at centers all over the world, have demonstrated that axillary dissection does not impact on the overall survival while it helps with loco-regional control of breast cancer. Its major role, at the present time, is limited to staging and prognostication; functions that are equally well served by the limited approach of a sentinel node biopsy.

SOURCES

This review is based on the available medical literature involving the biology and organ specificity of the metastatic process, not only in breast cancer but also in other malignancies. In addition, studies pertaining to clinical breast cancer, and the role of surgery in its treatment, were reviewed. The ongoing trials on the role of sentinel node biopsy in the management of the clinically node negative patients are discussed.

CONCLUSIONS

This review covers the history, pathophysiology, and clinical basis of the current role of axillary dissection for invasive breast cancer. From the data presented we hope that the medical community will agree that there is no therapeutic role for extended axillary dissection at the current time.

Reliability of the sentinel node procedure in melanoma patients: analysis of failures after long-term follow-up

BACKGROUND

The sentinel node (SN) concept assumes that early lymphatic metastases, if present, always are found first in the SN. The aim of this study was to determine the reliability of this procedure by establishing the success rate and number of failed procedures during a follow-up period of at least 2 years.

METHODS

From August 1993 to November 1996, 204 consecutive patients with stage I and II cutaneous melanoma underwent SN biopsy by a triple technique. Preoperatively, all patients underwent (dynamic) lymphoscintigraphy. A gamma probe and blue dye helped localize the SN(s) during surgery, and these nodes subsequently were excised. These lymph nodes were step-sectioned and examined by routine and immunohistochemical staining. If the SN contained tumor cells, a lymphadenectomy was performed at a later date.

RESULTS

The median follow-up time was 42 months. The success rate was 99%. Three patients developed a recurrence in the negative SN basin during follow-up, without simultaneous appearance of (locoregional) metastases.

CONCLUSIONS

With a 99% success rate and a 1.5% rate of failed SN procedures (7% false-negative rate) after a median follow-up of 3.5 years, we concluded that the combined triple technique approach of detecting the SN was a reliable method to accurately identify and retrieve the SN.

Unfiltered sulfur colloid and sentinel node biopsy for breast cancer: technical and kinetic considerations

BACKGROUND

There are few clinical data on technical limitations and radiocolloid kinetics related to sentinel lymph node (SLN) biopsy for breast cancer.

METHODS

In 70 clinical node-negative patients, unfiltered 99mTc sulfur-colloid was injected peritumorally and cutaneous hot spots were mapped with a gamma probe. SLN biopsy was performed followed by axillary lymph node dissection. Missed radioactive nodes (nodes not under hot spots) were removed from axillary lymph node dissection specimens and submitted separately.

RESULTS

At least one hot spot was mapped in 69 patients (98%) and SLNs were retrieved in 62 (89%). No radiolabeled nodes were found in five (7%) and only nodes not under hot spots were retrieved in three patients (4%). Residual nodes not under hot spots were retrieved in 17 patients (24%) in whom at least one SLN specimen had been found. Diffuse radioactivity around the radiocolloid injection site impeded identification of all radiolabeled nodes during SLN biopsy, and was responsible for one of two false negatives (20 node-positive patients; false-negative rate 10%). Hot spot radioactivity, number of radiolabeled nodes, and nodal radioactivity did not change with time interval from radiocolloid injection to surgery (0.75-6.25 hours).

CONCLUSIONS

Although SLN localization rate is high, intraparenchymal injection may predispose to failure of radiocolloid migration, failure to identify SLNs because of high radiation background, and false-negative outcomes. Alternative routes of radiocolloid administration should be explored.

Sentinel lymph node biopsy and axillary staging of T1-T2 N0 breast cancer: a multicenter study

From December 1996 to May 1998, 84 T1-T2 NO breast cancer patients were recruited for a multicenter study on the lymphoscintigraphic search of the axillary sentinel lymph node (SLN). The SLN was searched intraoperatively with a sodium iodide hand-held gamma-detecting probe (GDP) and excised before the standard axillary dissection was performed. Lymphoscintigraphy was unsuccessful in 8 of 84 cases (9.5%). In 73 of 76 patients with positive lymphoscintigraphy, SLN were found and excised (96%). The SLN proved to be predictive of axillary status in 71 of 73 cases (97.2%). Thirty of 41 patients had axillary metastases: in 16 cases, the SLN was the only site of the metastases (50%). In two cases, the SLN (reactive) did not match with the axillary status (2 of 63 reactive SLN, 4.6% of "skip" metastases). Age, tumor diameter, and histology seem to have little importance in affecting the predictivity of SLN biopsy. These results demonstrate the applicability of the lymphatic mapping techniques to a multicenter setting.