The lymphatic anatomy of the breast and its implications for sentinel lymph node biopsy: a human cadaver study.
ABSTRACT: BACKGROUND: Current understanding of the lymphatic system of the breast is derived mainly from the work of the anatomist Sappey in the 1850s, with many observations made during the development and introduction of breast lymphatic mapping and sentinel node biopsy contributing to our knowledge. METHODS: Twenty four breasts in 14 fresh human cadavers (5 male, 9 female) were studied. Lymph vessels were identified with hydrogen peroxide and injected with a lead oxide mixture and radiographed. The specimens were cross sectioned and radiographed to provide three dimensional images. Lymph (collecting) vessels were traced from the periphery to the first-tier lymph node. RESULTS: Lymph collecting vessels were found evenly spaced at the periphery of the anterior upper torso draining radially into the axillary lymph nodes. As they reached the breast some passed over and some through the breast parenchyma, as revealed in the cross-section studies. The pathways showed no significant difference between male and female specimens. We found also perforating lymph vessels that coursed beside the branches of the internal mammary vessels, draining into the ipsilateral internal mammary lymphatics. In some studies one sentinel node in the axilla drained almost the entire breast. In most more than one sentinel node was represented. CONCLUSION: These anatomical findings are discordant with our current knowledge based on previous studies and demand closer examination by clinicians. These anatomical studies may help explain the percentage of false-negative sentinel node biopsy studies and suggest the peritumoral injection site for accurate sentinel lymph node detection.
Project description:Tumor lymphangiogenesis promotes metastatic cancer spread to lymph nodes and beyond. However, the potential remodeling and functionality of tumor-draining lymphatic vessels has remained unclear. Thus, we aimed to develop non-invasive imaging methods for repeated quantitative imaging of lymphatic drainage and of contractile collecting lymphatic vessel function in mice, with colloidal near-infrared (NIR) tracers and a custom fluorescence stereomicroscope specially adapted for NIR sensitive imaging. Using these tools, we quantitatively determined pulse rates and valvular function of collecting lymphatic vessels with high resolution. Unexpectedly, we found that tumor-draining lymphatic vessels in a melanoma footpad model initially were dilated but remained functional, despite lower pulse rates. In two independent tumor models, impaired lymphatic function was detected once metastases were present in draining lymph nodes. Importantly, we found that lymphatic dysfunction, induced by metastatic tumor spread to sentinel lymph nodes, can lead to a rerouting of lymphatic flow away from the metastatic lymph node, via collateral lymphatic vessels, to alternate lymph nodes. These findings might have important clinical implications for the procedure of sentinel lymph node mapping that represents the standard of care for determining prognosis and treatment of melanoma and breast cancer patients.
Project description:Background: Metastatic tumor cells spread through lymphatic vessels and colonize draining lymph nodes (LNs). It is known that tumors induce lymphangiogenesis to enhance lymphatic metastasis and that metastatic cancer cells are carried by lymph flow to LNs. Methods and Results: Here, we investigated the molecular and cellular regulation of collecting lymphatic vessel contraction in vessels draining a metastatic tumor using intravital microscopy. In tumor-draining collecting lymphatic vessels, we found vessel contraction was suppressed. The infiltration of peritumor tissue by inducible nitric oxide synthase positive and CD11b+Gr1+ myeloid cells played a critical role in the suppression of lymphatic contraction. Depletion of Gr1+ cells with an anti-Gr1 antibody improved contraction of tumor-draining lymphatic vessels. In addition, inducing tumor cell death restored lymphatic contraction in nude mice. Conclusions: These findings indicate that tumors contribute to regulation of lymphatic transport in a reversible manner, warranting further investigation into the role of impaired lymphatic transport in cancer progression.
Project description:The purpose of this study was to present a novel surgical method for intraoperative precise sentinel lymph node biopsy (SLNB) and to determine its clinical efficacy and sensitivity in breast cancer patients. The sentinel lymph nodes (SLNs) were preoperatively evaluated by axillary ultrasound. The intraoperative detection of SLNs was guided by lymphatic drainage pathway. The lymphatic vessels and SLNs were visualized. During operation, we searched for all the true SLNs (trSLNs), para-SLNs (paSLNs) and post-SLNs (poSLNs) followed lymphatic drainage ducts. After precisely locating the lymphatic channels and lymph node, all the lymph nodes that firstly receive lymphatic drainage are designated as trSLNs. We precisely distinguished the trSLNs, paSLNs and poSLNs. We found the average number of trSLNs ranged from1 to 6. In addition, we assessed the novel technique in a total of 125 breast cancer patients. trSLNs were successfully identified in all patients (detection rate: 100 %). The accuracy of trSLNs is 99.2%. Data from our study strongly suggest that our method is a feasible and effective for the detection of precise trSLNs in breast cancer with real-time observations. (ClinicalTrials.gov number, NCT02651142).
Project description:Lymphatic vessels play a major role in cancer progression and in postsurgical lymphedema, and several new therapeutic approaches targeting lymphatics are currently being developed. Thus, there is a critical need for quantitative imaging methods to measure lymphatic flow. Indocyanine green (ICG) has been used for optical imaging of the lymphatic system, but it is unstable in solution and may rapidly enter venous capillaries after local injection. We developed a novel liposomal formulation of ICG (LP-ICG), resulting in vastly improved stability in solution and an increased fluorescence signal with a shift toward longer wavelength absorption and emission. When injected intradermally to mice, LP-ICG was specifically taken up by lymphatic vessels and allowed improved visualization of deep lymph nodes. In a genetic mouse model of lymphatic dysfunction, injection of LP-ICG showed no enhancement of draining lymph nodes and slower clearance from the injection site. In mice bearing B16 luciferase-expressing melanomas expressing vascular endothelial growth factor-C (VEGF-C), sequential near-IR imaging of intradermally injected LP-ICG enabled quantification of lymphatic flow. Increased flow through draining lymph nodes was observed in mice bearing VEGF-C-expressing tumors without metastases, whereas a decreased flow pattern was seen in mice with a higher lymph node tumor burden. This new method will likely facilitate quantitative studies of lymphatic function in preclinical investigations and may also have potential for imaging of lymphedema or improved sentinel lymph detection in cancer.
Project description:Proliferation of draining lymphatic vessels coupled with dynamic changes in lymph node volume and flow are characteristic features in rheumatoid arthritis (RA). Furthermore, impaired lymph egress from inflamed synovium is associated with joint flare in murine models of inflammatory-erosive arthritis. Unfortunately, advances towards a greater understanding of lymphatic changes in RA pathogenesis have been slow due to the absence of outcome measures to quantify lymphatic function in vivo. While lymphoscintigraphy is the current standard to assess lymphedema and sentinel lymph nodes in cancer patients, its sensitivity and specificity are inadequate to study lymphatics in RA. The emergence of high-resolution MRI, power Doppler ultrasound, and near-infrared imaging that permits real-time quantification of lymphatic function in animal models has been a major advance, and these techniques have produced a new paradigm of altered lymphatic function that underlies both acute arthritic flare and chronic inflammation. In acute flare, lymphatic drainage increases several fold, whereas no lymphatic contractions are detected in lymph vessels draining chronic arthritic joints. Moreover, these outcomes are now being adapted to study lymphatics in RA towards the development of novel biomarkers of arthritic flare and the discovery of new therapeutic targets. In particular, interventions that directly increase lymphatic egress from diseased joints by opening collateral lymphatic vessels, and that restore lymphatic vessel contractions, provide novel therapeutic approaches with potential for minimal toxicity and immunosuppression. To summarize the origins of this field, recent advances, and future directions, we herein review: current knowledge of lymphatics in RA based on classic literature; new in-vivo imaging modalities that have elucidated how lymphatics modulate acute versus chronic joint inflammation in murine models; and how these preclinical outcome measures are being translated to study lymphatic function in RA inflammation and how effective RA therapies alter lymphatic flow and lymph nodes draining flaring joints.ClinicalTrials.gov NCT02680067 . Registered 7 December 2015; ClinicalTrials.gov NCT01098201 . Registered 30 March 2010; and ClinicalTrials.gov NCT01083563 . Registered 8 March 2010.
Project description:Blood vessels are required for a tumor to grow and functional lymphatic vessels are required for it to disseminate to lymph nodes. In an attempt to eradicate both the primary tumor and its lymphatic metastasis, we targeted both blood and lymphatic vessels using two different tyrosine kinase inhibitors (TKIs): cediranib and vandetanib, which block vascular endothelial growth factor receptor (VEGFR)-2 and -3 in enzymatic assays. We found that although both cediranib and vandetanib slowed the growth rate of primary tumors and reduced blood vessel density, neither agent was able to prevent lymphatic metastasis when given after tumor cells had seeded the lymph node. However, when given during tumor growth, cediranib reduced the diameters of the draining lymphatic vessels, the number of tumor cells arriving in the draining lymph node, and the incidence of lymphatic metastasis. On the other hand, vandetanib had minimal effect on any of these variables, suggesting that vandetanib did not effectively block VEGFR-3 on lymphatic endothelial cells in our animal model. Collectively, these data indicate that the response of lymphatic vessels to a TKI can determine the incidence of lymphatic metastasis, independent of the effect of the TKI on blood vessels.
Project description:In individuals with mammary carcinoma, the most relevant prognostic predictor of distant organ metastasis and clinical outcome is the status of axillary lymph node metastasis. Metastases form initially in axillary sentinel lymph nodes and progress via connecting lymphatic vessels into postsentinel lymph nodes. However, the mechanisms of consecutive lymph node colonization are unknown. Through the analysis of human mammary carcinomas and their matching axillary lymph nodes, we show here that intrametastatic lymphatic vessels and bulk tumor cell invasion into these vessels highly correlate with formation of postsentinel metastasis. In an in vitro model of tumor bulk invasion, human mammary carcinoma cells caused circular defects in lymphatic endothelial monolayers. These circular defects were highly reminiscent of defects of the lymphovascular walls at sites of tumor invasion in vivo and were primarily generated by the tumor-derived arachidonic acid metabolite 12S-HETE following 15-lipoxygenase-1 (ALOX15) catalysis. Accordingly, pharmacological inhibition and shRNA knockdown of ALOX15 each repressed formation of circular defects in vitro. Importantly, ALOX15 knockdown antagonized formation of lymph node metastasis in xenografted tumors. Furthermore, expression of lipoxygenase in human sentinel lymph node metastases correlated inversely with metastasis-free survival. These results provide evidence that lipoxygenase serves as a mediator of tumor cell invasion into lymphatic vessels and formation of lymph node metastasis in ductal mammary carcinomas.
Project description:In addition to axillary lymph node (ALN), internal mammary lymph node (IMLN) could also provide important prognostic information. In this paper, we will introduce a case of breast cancer patient whose preoperative lymphoscintigraphy revealed that there were "hot-spots" in bilateral intercostal space. The bilateral IMLN found by preoperative lymphoscintigraphy is a rare phenomenon. She received ipsilateral internal mammary sentinel lymph node biopsy (IM-SLNB) and IMLN dissection and contralateral IM-SLNB. She was diagnosed as pT2N3bM1 breast cancer based on the positive IMLN and positive ALN. After performing surgery, the pathology indicated: (left breast) invasive ductal carcinoma (3.0×3.0 cm2), ALN (3/30), ipsilateral internal mammary sentinel lymph node (IMSLN) (1/2), IMLN (0/2); contralateral IMSLN (1/1). After performing IMLN surgery, the pathology staging increased from pT2N1aM0 to pT2N3bM1. And the irradiation therapy choice had been changed, she received irradiation therapy include chest wall, supraclavicular region, ipsilateral IMLN and contralateral IMLN. The treatment benefit had been increased. When the ipsilateral internal mammary lymphatic vessels were obstructed, deep lymphatic system might drain from ipsilateral IMLN to contralateral IMLN. The contralateral IMLN metastasis belongs to distant metastasis. The IMLN irradiation therapy should be tailored and balanced based on the statues of IMLN. With effective application of systemic therapy, the localized treatment advantage benefited from IMLN surgery might be transferred to survival benefit.
Project description:Detection of sentinel lymph node (SLN) using photoacoustic imaging is an emerging technique for noninvasive axillary staging of breast cancer. Due to the absence of intrinsic contrast inside the lymph nodes, exogenous contrast agents are used for photoacoustic detection. In this work, we have demonstrated near infrared detection of SLN with gold nanobeacons (GNBs) providing the photoacoustic contrast in a rodent model. We found that size dictates the in vivo characteristics of these nanoparticles in SLN imaging. Larger nanobeacons with high payloads of gold were not as efficient as smaller size nanobeacons with lower payloads for this purpose. Colloidal GNBs were designed as a nanomedicine platform with "soft" nature that is amenable to bio-elimination, an essential feature for in vivo efficacy and safety. The GNBs were synthesized as lipid- or polymer-encapsulated colloidal particles incorporating tiny gold nanoparticles (2-4 nm) in three tunable sizes (90 nm, 150 nm and 290 nm). Smaller GNBs were noted trafficking through the lymphatic system and accumulating more efficiently in the lymph nodes in comparison to the bigger nanoagents. At 20 min, the GNBs reached the SLN and were no longer observed within the draining lymphatic vessel. Within 1 h post-injection, the contrast ratio of the lymph nodes with the surrounding blood vessels was 9:1. These findings were also supported by analytical measurements of the ex vivo tissue samples. Results indicate that cumulative nanoparticle deposition in lymph nodes is size dependent and that high payloads of gold, although offering greater contrast in vitro, may yield nanoagents with poor intradermal migration and lymphatic transport characteristics.
Project description:Tumor lymphangiogenesis is accompanied by a higher incidence of sentinel lymph node metastasis and shorter overall survival in several types of cancer. We asked whether tumor lymphangiogenesis might also occur in distant organs with established metastases and whether it might promote further metastatic spread of those metastases to other organs. Using mouse metastasis models, we found that lymphangiogenesis occurred in distant lung metastases and that some metastatic tumor cells were located in lymphatic vessels and draining lymph nodes. In metastasis-bearing lungs of melanoma patients, a higher lymphatic density within and around metastases and lymphatic invasion correlated with poor outcome. Using a transgenic mouse model with inducible expression of vascular endothelial growth factor C (VEGF-C) in the lung, we found greater growth of lung metastases, with more abundant dissemination to other organs. Our findings reveal unexpected contributions of lymphatics in distant organs to the promotion of growth of metastases and their further spread to other organs, with potential clinical implications for adjuvant therapies in patients with metastatic cancer.