Transmigration of lymph nodes by tumor cells

Association of tumor molecular factors with in-transit metastasis in primary cutaneous melanoma

BACKGROUND

In-transit metastases (ITM) are a form of locoregional relapse representing intralymphatic metastatic spread and occur in approximately 4-9% of patients with melanoma >1 mm Breslow thickness. Our objective was to evaluate a combination of clinicopathologic risk factors and gene expression biomarkers predictive of ITM risk.

METHODS

We used PCR to quantify gene expression in diagnostic biopsy tissue across a prospectively designed archival cohort of 854 consecutive thin and intermediate thickness primary cutaneous melanomas. The outcome of interest was ITM >90 days after a melanoma diagnosis. Cox proportional hazard models were fit to estimate each clinicopathologic and molecular characteristic's association with the risk of ITM.

RESULTS

The 5-year cumulative incidence of ITM was 3.2%. Clinical factors univariately associated with an increased risk of ITM were older age, greater Breslow thickness, greater mitotic rate, lower extremity location, ulceration, and a positive SLN biopsy. Of 108 genes tested, five were significantly upregulated and five significantly downregulated when evaluated in Cox models adjusted for age, Breslow thickness, mitotic rate, and lower extremity location. Among the upregulated genes, the strongest association was observed for interleukin-8 (IL8).

CONCLUSION

A subset of gene expression biomarkers was identified as independently associated with the risk of ITM after adjusting for key covariates. Once sufficiently validated, our results may lead the way to regional therapy trials for a small, selected group of high-risk patients.

A Short History of Bernard Fisher's Contributions to Randomized Clinical Trials

Dr. Bernard Fisher (1918-2019) was an early proponent of evidence-based medicine using the mechanism of prospective, multicenter, randomized clinical trials to test biological and clinical hypotheses. In this article, I trace how his early scientific work in striving to understand the nature of cancer metastasis through animal experiments led to a new, testable, clinical hypothesis: that surgery to remove only the tumor and a small amount of tissue around it was as effective as the more disfiguring operations that were then the standard treatment. Fisher's work with the National Surgical Adjuvant Breast and Bowel Project (NSABP) using large, randomized clinical trials to demonstrate the veracity of this hypothesis led to a new paradigm in which the emphasis was placed on how systemic therapies used at an early stage of disease could effectively eradicate breast cancer for many patients. This new therapeutic approach led to the successful development of new treatments, many of which are widely used today. Ultimately, the new paradigm led to successfully preventing breast cancer in women who were at high risk for the disease but who had not yet been diagnosed with the disease. Throughout his entire career, Fisher championed the use of large prospective, randomized clinical trials despite criticism from many in the medical community who strongly criticized his use of randomization as a mechanism for testing clinical hypotheses. The approach he and the NSABP employed is still considered to be the highest standard of evidence in conducting clinical studies.

Thorny ground, rocky soil: Tissue-specific mechanisms of tumor dormancy and relapse

Disseminated tumor cells (DTCs) spread systemically yet distinct patterns of metastasis indicate a range of tissue susceptibility to metastatic colonization. Distinctions between permissive and suppressive tissues are still being elucidated at cellular and molecular levels. Although there is a growing appreciation for the role of the microenvironment in regulating metastatic success, we have a limited understanding of how diverse tissues regulate DTC dormancy, the state of reversible quiescence and subsequent awakening thought to contribute to delayed relapse. Several themes of microenvironmental regulation of dormancy are beginning to emerge, including vascular association, co-option of pre-existing niches, metabolic adaptation, and immune evasion, with tissue-specific nuances. Conversely, DTC awakening is often associated with injury or inflammation-induced activation of the stroma, promoting a proliferative environment with DTCs following suit. We review what is known about tissue-specific regulation of tumor dormancy on a tissue-by-tissue basis, profiling major metastatic organs including the bone, lung, brain, liver, and lymph node. An aerial view of the barriers to metastatic growth may reveal common targets and dependencies to inform the therapeutic prevention of relapse.

Intranodal pressure of a metastatic lymph node reflects the response to lymphatic drug delivery system

Cancer metastasis to lymph nodes (LNs) almost certainly contributes to distant metastasis. Elevation of LN internal pressure (intranodal pressure, INP) during tumor proliferation is associated with a poor prognosis for patients. We have previously reported that a lymphatic drug delivery system (LDDS) allows the direct delivery of anticancer drugs into the lymphatic system and is a promising treatment strategy for early‐stage LN metastasis. However, methods for evaluating the treatment effects have not been established. Here, we used a mouse model of MXH10/Mo‐lpr/lpr, which develops a systemic swelling of LNs, and murine malignant fibrous histiocytoma‐like (KM‐Luc/GFP) cells or murine breast cancer (FM3A‐Luc) cells inoculated into the subiliac LN of mice to produce a tumor‐bearing LN model. The changes in INP during intranodal tumor progression and after treatment with cis‐dichlorodiammineplatinum(II) (CDDP) using an LDDS were measured. We found that tumor progression was associated with an increase in INP that occurred independently of LN volume changes. The elevation in INP was suppressed by CDDP treatment with the LDDS when intranodal tumor progression was significantly inhibited. These findings indicate that INP is a useful parameter for monitoring the therapeutic effect in patients with LN metastasis who have been given drugs using an LDDS, which will serve to manage cancer metastasis treatment and contribute to an improved quality of life for cancer patients.

Rare Treatment for a Rare Tumor: Cryoablation of a Granular Cell Tumor

Background

Granular cell tumors (GCTs) or Abrikossoff's tumors are rare neoplasms known to originate from Schwann cells in the peripheral nervous system. These lesions are usually benign; malignancy only occurs in 1-2% of cases. Surgical resection is the traditional treatment method for GCTs, but it poses several risks and disadvantages related to the surgical incompatibility of the patient, the extended recovery time, and the chance of relapse. Cryoablation is becoming an increasingly favored method of treatment for tumors, both benign and malignant, due to its minimal invasiveness, natural analgesic properties, and ability to stimulate antitumor immunity. Cryoablation may contribute to the prevention of secondary and metastatic tumor growth in cases of malignancy by preserving tumor-associated antigen molecules for recognition by cell-mediated immunity.

Methods

This article describes a novel method for GCT treatment using cryoablation. This technique exposes tumor tissue to extreme cold temperatures, effectively destroying tumor cells by irreversibly compromising their plasma membranes. To our knowledge, this is the first report in the literature of cryoablative techniques being used for GCT.

Results

Cryoablation of this mass was successful with no complications. CT images during the procedure demonstrated circumferential coverage of the entire lesion with no injury to the surrounding tissues.

Conclusion

Cryoablation can be used as an alternative to surgical intervention to treat malignant GCTs. This procedure is minimally invasive, less painful, and potentially effective in promoting antitumor immunity.

Histone deacetylase 11 inhibition promotes breast cancer metastasis from lymph nodes

Lymph node (LN) metastases correspond with a worse prognosis in nearly all cancers, yet the occurrence of cancer spreading from LNs remains controversial. Additionally, the mechanisms explaining how cancers survive and exit LNs are largely unknown. Here, we show that breast cancer patients frequently have LN metastases that closely resemble distant metastases. In addition, using a microsurgical model, we show how LN metastasis development and dissemination is regulated by the expression of a chromatin modifier, histone deacetylase 11 (HDAC11). Genetic and pharmacologic blockade of HDAC11 decreases LN tumor growth, yet substantially increases migration and distant metastasis formation. Collectively, we reveal a mechanism explaining how HDAC11 plasticity promotes breast cancer growth as well as dissemination from LNs and suggest caution with the use of HDAC inhibitors.

The prognosis of cancer patients with lymph node (LN) metastasis is worse than those without. Here, the authors report that while histone deacetylase 11 (HDAC11) inhibition suppresses tumor growth within the LN, it also promotes cancer cell migration out of the LN to form distant metastasis, and therefore suggest caution with HDAC inhibitors.

Treatment of false-negative metastatic lymph nodes by a lymphatic drug delivery system with 5-fluorouracil

Metastatic lymph nodes (LNs) may be the origin of systemic metastases. It will be important to develop a strategy that prevents systemic metastasis by treating these LNs at an early stage. False‐negative metastatic LNs, which are found during the early stage of metastasis development, are those that contain tumor cells but have a size and shape similar to LNs that do not host tumor cells. Here, we show that 5‐fluorouracil (5‐FU), delivered by means of a novel lymphatic drug delivery system (LDDS), can treat LNs with false‐negative metastases in a mouse model. The effects of 5‐FU on four cell lines were investigated using in vitro cytotoxicity and cell survival assays. The therapeutic effects of LDDS‐administered 5‐FU on false‐negative metastatic LNs were evaluated using bioluminescence imaging, high‐frequency ultrasound (US), and histology in MHX10/Mo‐lpr/lpr mice. These experimental animals develop LNs that are similar in size to human LNs. We found that all cell lines showed sensitivity to 5‐FU in the in vitro assays. Furthermore, a concentration‐dependent effect of 5‐FU to inhibit tumor growth was observed in tumor cells with low invasive growth characteristics, although a significant reduction in metastatic LN volume was not detected in MHX10/Mo‐lpr/lpr mice. Adverse effects of 5‐FU were not detected. 5‐Fluorouracil administration with a LDDS is an effective treatment method for false‐negative metastatic LNs. We anticipate that the delivery of anticancer drugs by a LDDS will be of great benefit in the prevention and treatment of cancer metastasis via LNs.

Is Axillary Sentinel Lymph Node Biopsy Required in Patients Who Undergo Primary Breast Surgery?

Local treatment of the axilla in clinically node-negative (cN0) early breast cancer patients with routine sentinel lymph node biopsy (SLNB) is debated for various reasons: i) pN staging information may not be necessary for the postoperative treatment decision regarding adjuvant systemic therapy in the great majority of patients; ii) the SLNB-positive rate is declining below 20% in specialized breast centers; iii) albeit being a minimally invasive procedure, SLNB causes a significant reduction in quality of life in 23% of patients; and iv) previous randomized trials from the pre-SLNB era did not show a disadvantage for patients without axillary surgery with regard to overall survival. These data support the hypothesis that avoiding axillary treatment in patients with clinically and sonographically unsuspicious lymph nodes seems to be a safe option, although omitting axillary surgery may increase the risk of locoregional recurrence. Currently, the information regarding node-positive status is essential to guide postoperative treatment such as systemic or radiation therapies in a non-negligible minority of patients. Three ongoing prospective European trials (SOUND, INSEMA, BOOG 2013-08) with axillary observation alone versus SLNB in cN0 patients and primary breast-conserving surgery have the objective to evaluate oncologic safety when omitting SLNB.

Lymph node metastasis in melanoma: a debate on the significance of nodal metastases, conditional survival analysis and clinical trials

While there is no doubt that regional lymph node metastases are an enormously important factor in melanoma staging and treatment, the biology behind this significance and its precise implications for treatment planning have been a leading controversy in melanoma and other solid tumors for over a century. Recent clinical data, including data from prospective randomized clinical trials have refined our understanding of the process of nodal metastases and the advantages and disadvantages of different clinical management strategies. This review presents two points of view in this debate and discusses the results of new data analyses as well as pivotal clinical trials informing the discussion.

Chemotherapy and immunotherapy for recurrent and metastatic head and neck cancer: a systematic review

Head and neck cancer (HNC) is a fatal malignancy with an overall long-term survival of about 50% for all stages. The diagnosis is not rarely delayed, and the majority of patients present with loco-regionally advanced disease. The rate of second primary tumors after a diagnosis of HNC is about 3-7% per year, the highest rate among solid tumors. Currently, a single-modality or a combination of surgery, radiotherapy and chemotherapy (CHT), is the standard treatment for stage III-IV HNC. For the recurrent/metastatic setting, in the last 40 years great efforts have been made in order to develop a more effective CHT regimen, from the use of methotrexate alone, to the combination of cisplatin (CDDP) and 5-fluorouracile (5FU) or paclitaxel. Recently, the introduction of cetuximab, an anti-EGFR monoclonal antibody, to the CDDP-5FU doublet (EXTREME regimen) has improved the overall response rate, the progression-free survival and the overall survival (OS) compared to CHT alone. Nowadays, the EXTREME regimen is the standard of care for the first-line treatment of recurrent/metastatic head and neck carcinoma (RMHNC). In the last years, new promising therapies for RMHNC such as immune checkpoint inhibitors (ICIs), which have demonstrated favorable results in second-line clinical trials, gained special interest. Nivolumab and pembrolizumab are the first two ICIs able to prolong OS in the second-, later-line and platinum-refractory setting, with tolerable toxicities. This review summarizes the current state of the art in RMHNC treatment options.

Serial or Parallel Metastasis of Cutaneous Melanoma? A Study of the German Central Malignant Melanoma Registry

For more than a century the Halstedian hypothesis of contiguous metastasis from the primary tumor through the lymphatics to distant sites shaped lymph node surgery for melanoma. We challenge this dogma of serial metastatic dissemination. A single-center series of 2,299 patients with cutaneous metastatic melanoma was investigated to analyze overall survival and distant metastasis-free survival of stage IV patients with or without primary lymphatic metastasis. Results were then compared with those of 2,134 patients from three independent centers of the German Central Malignant Melanoma Registry. A multivariate binary logistic regression model was used to identify risk factors for the initial metastatic pathway. Distant metastasis-free survival (hazard ratio = 1.02; 95% confidence interval = 0.91-1.14; P = 0.76) and overall survival (HR = 1.09; 95% CI = 0.96-1.23; P = 0.177) did not differ between stage IV patients with primary hematogenous or primary lymphatic metastasis. Melanoma localization was the only significant risk factor for the initial metastatic pathway. These findings indicate that regional and distant metastases originate from the primary tumor itself in a rather parallel than serial fashion and could explain the lack of survival benefit associated with immediate complete lymph node dissection in sentinel lymph node-positive melanoma patients.

Paradigm Shift From Halstedian Radical Mastectomy to Personalized Medicine

Breast cancer management changed from radical mastectomy to precision medicine in a period longer than a century. The aims of these changes were to refrain from overdiagnoses and overtreatments as well as their harmful side effects and extra costs. Breast cancer is a heterogeneous disease and characterized by many morphological, clinical and molecular features. We now increasingly realise that a one-size-fits-all strategy does not apply to all breast cancer patients. Personalized medicine may be used for breast cancer screening, diagnosis and treatment. Individualized screening can decrease the number of unnecessary mammograms, additional radiologic studies, breast biopsies and false positivity rates. However, additional 15 to 20 years are necessary to reach the results of prospective randomized trials comparing low-risk and normal-risk women. We also should wait for outcomes of risk-based screening trials. The rates of overtreatment in patients with early-stage breast cancer have reached 40% in many studies. Personalized treatment has succeeded in reducing it substantially by using tumour genetic profiling and tumour receptors in early breast cancer patients. However, it has its limits and it is impossible to generalize it to all patients. New biomarkers and molecular classifications have also led to the development of novel therapies and treatment strategies. And, they can contribute to a more personalized management of breast cancer patients.

Study of fluid dynamics reveals direct communications between lymphatic vessels and venous blood vessels at lymph nodes of mice

Cancer cells metastasize to lymph nodes, with distant metastasis resulting in poor prognosis. The role of lymph node metastasis (LNM) in the spread of cancer to distant organs remain incompletely characterized. The visualization of flow dynamics in the lymphatic and blood vessels of MXH10/Mo-lpr/lpr mice, which develop systemic swelling of lymph nodes up to 10mm in diameter, has revealed that lymph nodes have the potential to be a direct source of systemic metastasis. However, it is not known whether these fluid dynamics characteristics are universal phenomena present in other strains of laboratory mice. Here we show that the fluid dynamics observed in MXH10/Mo-lpr/lpr mice are the same as those observed in C57BL/6J, BALB/cAJcl and NOD/ShiJic-scidJcl mice. Furthermore, when fluorescent solution was injected into a tumor-bearing lymph node, the flow dynamics observed in the efferent lymphatic vessels and thoracoepigastric vein depended on the type of tumor cell. Our results indicate that fluid dynamics in the lymphatic and blood vessels of MXH10/Mo-lpr/lpr mice are generalized phenomena seen in conventional laboratory mice. We anticipate our results can facilitate studies of the progression of lymphatic metastasis to hematogenous metastasis via lymph nodes and the early diagnosis and treatment of LNM.

Correlation of Tumoral Prognostic Factors by Sonoelastography Score in Patients to be Operated Due to Breast Cancer

Predictability of pre-op prognosis on patient with a diagnosis of breast cancer is quite valuable for the choice of both surgical technique and adjuvant therapy. With the aim of evaluation of sonoelastography score utility in this respect, correlation of tumoral prognostic factors by sonoelastography score in patients be operated due to breast cancer was analyzed on our study. Pre-op sonoelastography results and tumoral hystopathological properties of 60 patients operated with a diagnosis of breast cancer in 2011 at Adnan Menderes University Faculty of Medicine General Surgery Department were analyzed retrospectively. As an elastography scoring method, "Tsukuba scoring system" was used. Statistically significant differences(p < 0,05) were determined between tumor grade and Ki-67 analyzed as prognostic factor with tumors reported as sonoelastography score 4 and score 5, on the other hand there were no statistically significant differences between tumor size, positivity of axillary lymph nodes, significance of lymphovascular invasion, p-53 positivity, CerbB-2 positivity, hormone receptor positivity, tumor hysthologic type and applied surgical technique between tumors reported as elastography score 4 and score 5. (p > 0.005). Foresee ability of prognostic factors correlation by sonoelastography score will be guide way for the choice of surgery technique, determination of adjuvant therapy and patient follow-up.

Importance of Adequate Lymphadenectomy in Gastrointestinal Cancer

One of the most important factors influencing cancer-specific survival in the field GI oncology is the presence of positive lymph nodes. Although it remains controversial, adequate lymph node examination is required for accurate staging such that patients can receive correct adjuvant treatments and for stratification in clinical trials. Nevertheless, wide variation in the quality of lymph node examination exists in the US and many centers are not meeting guideline treatment recommendations.

Techniques that accurately identify the sentinel lymph node in cancer

Sentinel lymph node (SLN) biopsy has become the gold standard for patients with melanoma and breast cancer but it’s clinical application in other solid tumor types such as cancers of the esophagus, stomach, colon and rectum, head and neck, penis, uterine cervix and endometrium has been somewhat limited. Commonly used mapping techniques utilizing the combination of radiocolloid and blue dye may result in reduced SLN detection and increased false negative rates when applied to cancers with more complex lymphatic drainage patterns. Novel localization techniques including near infrared fluorescence, high resolution imaging and molecular targeted agents have been developed to address the limitations of conventional SLN detection practices in many solid tumor types. This article reviews the indications, techniques and detection rates for SLN biopsy in several different solid tumor types as well as the promising novel techniques created to address the contemporary limitations of this procedure.

Sentinel lymph node metastases in cancer: causes, detection and their role in disease progression

Malignant tumors of ectodermal or endodermal origin may metastasize to the sentinel lymph node, the first lymph node encountered by tumor cells that enter lymphatics in the organ of origin. This pathway is enabled by the anatomy of the disease and the causes of metastasis are the result of complex interactions that include mechanical forces within the tumor and host tissues, and molecular factors initiated by tumor cell proliferation, elaboration of cytokines and changes in the tumor microenvironment. Mechanical stresses may influence complex biochemical, genetic and other molecular events and enhance the likelihood of metastasis. This paper summarizes our understanding of interacting molecular, anatomical and mechanical processes which facilitate metastasis to SLNs. Our understanding of these interacting events is based on a combination of clinical and basic science research, in vitro and in vivo, including studies in lymphatic embryology, anatomy, micro-anatomy, pathology, physiology, molecular biology and mechanobiology. The presence of metastatic tumor in the SLN is now more accurately identifiable and, based upon prospective clinical trials, paradigm-changing SLN biopsy has become the standard of clinical practice in breast cancer and melanoma.

A historical account of breast cancer surgery: beware of local recurrence but be not radical

In the late 19th century, William Halsted proposed the radical mastectomy, which became the standard surgical treatment of breast cancer for nearly 100 years. Later in this period, theories suggesting that breast cancer was a systemic disease at inception were championed by Bernard Fisher. This alternative hypothesis of biological predeterminism was based upon results of randomized clinical trials comparing breast conserving therapy with mastectomy, which showed similar overall survival outcomes. Nonetheless, data from meta-analyses suggest that inadequate local therapy can increase risk of local recurrence, which can subsequently increase mortality. In this review, the authors provide an historical account of how local therapy of breast cancer has evolved in the face of improved adjuvant therapies and better understanding of disease biology.

Clinical comparison of four types of skin incisions for skin-sparing mastectomy and immediate breast reconstruction

PURPOSE

Skin-sparing mastectomy (SSM) and immediate breast reconstruction (IBR) has become popular as an effective procedure for patients with early breast cancer. We herein report an overview of the four types of skin incisions used for SSM.

METHODS

The records of 111 consecutive breast cancer patients, who received SSM and IBR from 2003 to 2012, were reviewed retrospectively. Four types of skin incisions were used. Type A was the so-called tennis racquet incision, type B was a periareolar incision and mid-axillary incision, type C was the so-called areola-sparing with mid-axillary incision and type D was a small transverse elliptical incision and transverse axillary incision.

RESULTS

Twenty-six type A, 59 type B, 20 type C and six type D incisions were made. The average blood loss and average length of the operation during SSM were not significantly different between the four approaches. The average areolar diameter was 35 mm for type A, B and D incisions, and 45 mm for type C. There was a need for postoperative nipple-areolar complex plasty (NAC-P) in 75 % of the cases following type A, B and D incisions, and 35 % of the cases treated using type C incisions.

CONCLUSION

The type C incision is superior with regard to the cost and cosmetic outcomes, because fewer of these patients request postoperative NAC-P.

Platelets and cancer: a casual or causal relationship: revisited

Human platelets arise as subcellular fragments of megakaryocytes in bone marrow. The physiologic demand, presence of disease such as cancer, or drug effects can regulate the production circulating platelets. Platelet biology is essential to hemostasis, vascular integrity, angiogenesis, inflammation, innate immunity, wound healing, and cancer biology. The most critical biological platelet response is serving as "First Responders" during the wounding process. The exposure of extracellular matrix proteins and intracellular components occurs after wounding. Numerous platelet receptors recognize matrix proteins that trigger platelet activation, adhesion, aggregation, and stabilization. Once activated, platelets change shape and degranulate to release growth factors and bioactive lipids into the blood stream. This cyclic process recruits and aggregates platelets along with thrombogenesis. This process facilitates wound closure or can recognize circulating pathologic bodies. Cancer cell entry into the blood stream triggers platelet-mediated recognition and is amplified by cell surface receptors, cellular products, extracellular factors, and immune cells. In some cases, these interactions suppress immune recognition and elimination of cancer cells or promote arrest at the endothelium, or entrapment in the microvasculature, and survival. This supports survival and spread of cancer cells and the establishment of secondary lesions to serve as important targets for prevention and therapy.

Landmark trials affecting the surgical management of invasive breast cancer

Significant progress has been made in the surgical management of breast cancer. Most women diagnosed with early stage invasive breast cancer can now be managed with breast-conserving therapy to include a segmental mastectomy followed by radiation. Axillary lymph nodes are routinely assessed by sentinel lymph node biopsy. Axillary lymph node dissection is reserved for patients with documented nodal metastasis; however, here too progress has been made because a population of low-risk patients has been identified in whom a complete dissection is not required even in the setting of a positive sentinel lymph node. This article details the landmark clinical trials that have guided the surgical management of breast cancer.

Emerging insights into head and neck cancer metastasis

The purpose of this review was to provide biological concepts of head and neck cancer metastasis. To attain this goal, we analyzed peer-reviewed articles related to head and neck cancer metastasis obtained though PubMed and archived articles. Articles related to the biologic principles of head and neck cancer metastasis were reviewed and summarized. As locoregional control has improved for patients with head and neck cancer, rates of distant metastasis have not decreased. As patients live longer, many will die of complications related to the development of disease at sites below the clavicles. Emerging evidence now suggests a more complicated framework of metastatic behavior for head and neck cancer. Here, we review the role of regional lymph nodes in containing advanced head and neck cancer, evidence for active as opposed to passive tumor cell metastasis, and clinical implications these concepts have on both treatment of head and neck cancer and future research.

Positive lymph nodes do not metastasize

Our understanding of the role of lymph nodes (LN) in the metastasization process (MET) is marginal. Positive LNs (pLN) are the most important prognostic factor and lymph node dissection (LND) is still standard practice in primary treatment. However, up to now, there is almost no evidence that elective LND has a survival benefit. Based on many clinical and experimental findings, we propose that tumor foci in regional LN are incapable of metastasization and can therefore not infiltrate further LN and organs. Available data demonstrate a very early infiltration of MET capable tumor cells from the primary tumor into regional LN, and thereafter an increased probability of subsequent LN infiltrations. Disparate growth rates of the first versus subsequent infiltrating tumors as well as the asymptotic growth and prognosis of large tumor foci in LN explain many clinical observations for solid tumors. The consequence of the hypothesis "pLN do not metastasize" would impact clinical treatment and research and contribute to understanding the mounting evidence against LND.

The connectivity of lymphogenous and hematogenous tumor cell dissemination: biological insights and clinical implications

Although tumor cells are found in the blood early after tumorigenesis, dissemination through the lymphatic system and in particular the formation of lymph node metastases has long been considered to be a driving force behind the formation of secondary tumors in distant vital organs. Contemporary experimental observations and clinical trial results suggest that this may not be the case. In this review we survey the evidence for both points of view, and examine the hypothesis that the prognostic relevance of lymph node metastases may lie in their ability to indicate that primary tumors are producing soluble factors that have the potential to promote metastasis at these distant sites, for example by releasing tumor cells from dormancy. Furthermore, the interconnectivity between the lymphatic and blood circulatory systems underscores the relevance of the analysis of the properties of circulating and disseminated tumor cells for prognostic evaluation, patient stratification and understanding the biology of metastasis. We therefore give an overview of the current state of the art in this field.

Importance of and adherence to lymph node staging standards in gastrointestinal cancer

In gastrointestinal oncology, one of the most important factors influencing cancer-specific survival is the presence of positive lymph nodes. Although it remains controversial, adequate lymph node examination is required for accurate staging such that patients can receive appropriate adjuvant treatments and for stratification in clinical trials. Nevertheless, wide variation exists in the quality of lymph node examination in the United States, and many centers are not meeting guideline treatment recommendations.

Retrospective comparison of non-skin-sparing mastectomy and skin-sparing mastectomy with immediate breast reconstruction

Background. We compared Skin-sparing mastectomy (SSM) with immediate breast reconstruction and Non-skin-sparing mastectomy (NSSM), various types of incision in SSM. Method. Records of 202 consecutive breast cancer patients were reviewed retrospectively. Also in the SSM, three types of skin incision were used. Type A was a periareolar incision with a lateral extension, type B was a periareolar incision and axillary incision, and type C included straight incisions, a small elliptical incision (base line of nipple) within areolar complex and axillary incision. Results. Seventy-three SSMs and 129 NSSMs were performed. The mean follow-up was 30.0 (SSM) and 41.1 (NSSM) months. Respective values for the two groups were: mean age 47.0 and 57; seven-year cumulative local disease-free survival 92.1% and 95.2%; post operative skin necrosis 4.1% and 3.1%. In the SSM, average areolar diameter in type A & B was 35.4 mm, 43.0 mm in type C and postoperative nipple-areolar plasty was performed 61% in type A & B, 17% in type C, respectively. Conclusion. SSM for early breast cancer is associated with low morbidity and oncological safety that are as good as those of NSSM. Also in SSM, Type C is far superior as regards cost and cosmetic outcomes.

Tumor cell seeding during surgery-possible contribution to metastasis formations

In spite of optimal local control in breast cancer, distant metastases can develop as a systemic part of this disease. Surgery is suspected to contribute to metastasis formation activating dormant tumor cells. Here we add data that seeding of cells during surgery may add to the risk of metastasis formation. The change in circulating epithelial tumor cells (CETC) was monitored in 66 breast cancer patients operated on with breast conserving surgery or mastectomy and during the further course of the disease, analyzing CETC from unseparated white blood cells stained with FITC-anti-EpCAM. An increase in cell numbers lasting until the start of chemotherapy was observed in about one third of patients. It was more preeminent in patients with low numbers of CETC before surgery and, surprisingly, in patients without involved lymph nodes. Patients with the previously reported behavior—Reincrease in cell numbers during adjuvant chemotherapy and subsequent further increase during maintenance therapy—were at increased risk of relapse. In addition to tumor cells already released during growth of the tumor, cell seeding during surgery may contribute to the early peak of relapses observed after removal of the primary tumor and chemotherapy may only marginally postpone relapse in patients with aggressively growing tumors.

Axillary lymph node dissection in early-stage invasive breast cancer: is it still standard today?

Evaluation of axillary lymph node status by sentinel lymph node biopsy (SLNB) and complete axillary lymph node dissection (ALND) are an inherent part of breast cancer treatment. Increased understanding of tumor biology has changed the prognostic and therapeutic impact of lymph node status. Non-invasive imaging techniques like axillary ultrasound, FDG-PET, or MRI revealed moderate sensitivity and high specificity in evaluation of lymph node status. Therefore, they are not sufficient for lymph node staging. Otherwise, the impact of remaining micrometastases and even macrometastases for prognosis and treatment decisions is overestimated. Considering tumor biology, the distinction of axillary metastases in isolated tumor cells (ITC, pN0(i+)); micrometastases (pN1mi), and macrometastases (pN1a) is not comprehensible. Increasing data support the thesis that remaining axillary metastases neither increase the axillary recurrence rate nor decrease overall survival. It is doubtful that axillary tumor cells are capable to complete the complex multistep metastatic process. If applied, axillary metastases are sensitive to systemic treatment and are targeted by postoperative tangential breast irradiation. Therefore, the controversy about the clinical relevance of tumor cell clusters or micrometastases in SLN is a sophisticated but not contemporary discussion. Currently, there is no indication for axillary surgery in elderly patients with favorable tumors and clinically tumor-free lymph nodes. Nonetheless, a rational and evidence-based approach to the management of clinically and sonographically N0 patients with planned breast-conserving surgery and limited tumor size is needed now.

Distant metastases do not metastasize

Distant metastases (MET) are for most solid cancers decisive life-threatening events. Data about MET-free survival and survival after MET show a strong dependency on the kind of cancer and the prognostic features. Nonetheless, within biological subgroups, the MET process is very homogenous. Therefore, the growth rate can be estimated from initiation of MET to MET diagnosis and to time of death. Based on the known volume doubling time of breast cancer, the time of the first possible dissemination can also be estimated. Important consequences of these MET-initiation estimates are the hypotheses that almost all MET are initiated before removal of the primary tumor and that MET do not metastasize in a clinically relevant magnitude. Although breast cancer data were primarily used to form these hypotheses, the discussed MET process can be generalized to all solid cancers. The impact of these hypotheses on diagnostic, curative and palliative treatment, aftercare, and especially on clinical research would be important.

Tumor lymphatics

In this article we survey more than three centuries of observation and research into tumor-associated lymphatic vessels, and their role in the metastatic spread of cancer. This historical overview documents how questions regarding tumor lymphatics have been central to concepts about the process of metastasis, and how this has subsequently influenced the clinical treatment of cancer. In turn, we show how analysis of the efficacy of these treatments has challenged long-standing notions regarding the tumor lymphatics. Starting with the discovery of VEGFR-3 and its ligands VEGF-C and VEGF-D, we also review how the rapid developments over the last 15 years in the molecular analysis of the lymphatic system and in particular lymphangiogenesis have contributed to this debate. Finally we speculate on how apparently paradoxical bodies of evidence regarding the role of tumor lymphatics in determining patterns of metastatic spread might be reconciled.

Management of the axilla in women with breast cancer

The approach towards axillary surgery should be selective and flexible, with its management tailored to patient choice and tumour characteristics, and concordant with local practice guidelines and available resources. Sentinel-lymph-node biopsy has been embraced as a standard of care in many centres around the world and has revolutionised management of the axilla during the past decade. Nonetheless, data for long-term outcomes remain scarce, and there are persistent variations in practice and inconsistencies in methodology. An international perspective has been sought on important issues relating to management of the axilla, which includes not only the indications and techniques for sentinel-lymph-node biopsy, but also lymph-node sampling, axillary-lymph-node dissection, and observation alone. In this Review, we initially present an overview, which focuses on biological models of lymphatic networks within the breast and patterns of tumour dissemination. A set of key questions are posed with preliminary comments from the authors, followed by a series of collective viewpoints from experts within several different countries.

Regional lymph node metastases; a singular manifestation of the process of clinical metastases in cancer: contemporary animal research and clinical reports suggest unifying concepts

Research results from laboratory animals and human clinical reports provide insight into cancer cell disseminations and elaborate the complex metastatic cascade of cells into both regional lymph nodes and other distant organs. Critical appraisal of clinical trials indicates that lymph node metastases are themselves non-lethal, but indicate prognosis, confirming laboratory conclusions. Distant vital organ metastases can be resected with long term survival in highly selective situations, demonstrating metastatic specificity in oligometastatic disease. Appreciating lymphatic system embryology, anatomy, and physiology is necessary for understanding lymph node metastases. The primary lymphatic system function was to return interstitial fluid to the circulation. Later evolutionary insertion of lymphocyte collections in lymph nodes interrupting lymph flow completed a system of analyzing external antigens to enable adaptive immunologic responses. Human cancers seldom elicit major immunological responses; they are not generally "foreign" enough. Therefore, lymphatic metastases have little meaning in evolutionary terms. Organ specificity of both lymphatic and distant metastases occurs as metastatic cells lie dormant, but grow selectively only in liver, lung, bone, or lymph nodes. These organ specific metastatic cells have little ability to produce different organ site clinical metastases. Thus, laboratory findings and clinical correlations emphasize that surgical lymph node removal should be de-emphasized or omitted. More physiological approaches to the highly manipulable multi-step processes of clinical metastases arising from host microenvironments will eventually prevail.

Regional lymph node metastases, a singular manifestation of the process of clinical metastases in cancer: contemporary animal research and clinical reports suggest unifying concepts

The multistep complex metastatic cascade in cancer has been extensively studied in recent years. In addition, the concept of metastatic organ specificity has been elaborated. Histological studies in clinical situations have become far more sophisticated, enabling the frequent discovery of minor collections of cells in bone marrow and lymph nodes. Pertinent clinical evidence of the selective nodal metastatic pattern exists in differentiated thyroid cancer in younger, low-risk patients, yet none of the published risk group definitions indicate that lymph node metastases have a relationship to thyroid cancer survival. This unique clinical situation with very frequent nodal metastases but excellent survival is replicated in carcinoid cancers of the gastrointestinal tract. The lymph node metastatic frequency without distant organ metastases in these two human cancers help cement the understanding gained from laboratory and animal research regarding metastatic specificity and hopefully will help place the role of lymph node metastases generally and their surgical removal on a more scientifically and logically based understanding. More broadly, the elaboration of the frequency of metastatic cell dissemination to distant organs as well as lymph nodes, and comprehension of the metastatic cascade with metastatic specificity may reorient our understanding of the evolution from metastatic cells to clinical metastatic disease. Additionally, these concepts reemphasize that lymph node metastases are indicators, not governors, of distant metastases and survival, and add the assumption that metastatic tumor cells and tumor cell clusters, and perhaps even micrometastases in other organs, are themselves only indicators and not governors of distant metastases and survival in human cancers since they represent dormant metastases prior to their host microenvironmental changes that, on rare occasions, lead to angiogenesis and clinical metastases. Thus, the future may allow us to abandon some aspects of our surgical or systemic attack on clinical cancer metastases, such as lymph node removal or use of toxic chemotherapy, but open the door to more physiological and hopefully less traumatic approaches to the highly manipulable multistep genetic and physiological process of metastatic development. The future biological models of clinical cancer behavior will have to incorporate aspects of understanding the intricate metastatic cascade, and particularly the host microenvironmental factors that permit or prevent progressive growth of dormant cells or cell clusters to clinical metastases.

Clinical patterns of metastasis

In human solid cancer, lymph node status is the most important indicator for clinical outcome. Recent developments in the sentinel lymph node concept and technology have resulted in a more precise way of examining micrometastasis in the sentinel lymph node and the role of lymphovascular system in the facilitation of cancer metastasis. Different patterns of metastasis are described with respect to different types of solid cancer. Expect perhaps for papillary carcinoma and sarcoma, the overwhelming evidence is that solid cancer progresses in an orderly progression from the primary site to the regional lymph node or the sentinel lymph node in the majority of cases with subsequent dissemination to the systemic sites. The basic mechanisms of cancer metastasis through the lymphovascular system form the basis of rational therapy against cancer. Beyond the clinical patterns of metastasis, it is imperative to understand the biology of metastasis and to characterize patterns of metastasis perhaps due to heterogeneous clones based on their molecular signatures.

Cutaneous melanoma: therapeutic lymph node and elective lymph node dissections, lymphatic mapping, and sentinel lymph node biopsy

Early clinical observation in cancer patients suggested that tumors spread in a methodical, stepwise fashion from the primary site, to the regional lymphatics, and only then to distant locations. Based on these observations, the regional lymphatics were believed to be mechanical barriers, at least temporarily preventing the widespread dissemination of tumor. Despite evidence now available disputing its validity, this barrier theory has guided the surgical management of the regional lymphatics in cancer patients for more than a century, influencing the use of such surgical modalities as therapeutic lymph node dissection, elective lymph node dissection, and most recently lymphatic mapping and sentinel lymph node biopsy. No published randomized controlled trial exists that demonstrates improved overall patient survival for cancer of any type, including melanoma, after surgical excision of regional lymphatics. This article will review the biology of lymphatics as it relates to regional tumor metastasis, and based on available information, offer practical recommendations for the clinical dermatologist and their patients who have cutaneous melanoma.

The safety and accuracy of sentinel-node biopsy in early-stage invasive breast cancer--Turkish experience

The purpose of this prospective study was to investigate the correlation of sentinel lymph node (SLN) and axillary lymph node (ALN) metastasis in early-stage invasive breast cancer in a single institution. One hundred and fifteen patients with early-stage invasive breast cancer first underwent SLND followed by an appropriate surgical procedure (modified radical mastectomy, lumpectomy + axillary dissection, simple mastectomy + mammoplasty). In this series, a radioactive agent (technetium) was used to investigate the sentinel lymph node/nodes. In 28 (24.3%) patients, metastases were found in both SLN and axillary dissections. There were no metastases in either of these procedures in 69 (60%) patients. SLN metastasis was found in 13 (11.3%) patients, but no axillary metastasis was found. No skip metastasis was detected. Five patients in whom the sentinel node was not found were also negative for axillary metastasis. As the studies progress in this direction, it might be possible to avoid axillary dissection in patients with early breast cancer in whom metastasis in SLN cannot be detected. We believe this will reduce morbidity from breast cancer surgeries.

The management of regional lymph nodes in cancer

Early clinical observation in cancer patients suggested that tumours spread in a methodical, stepwise fashion from the primary site to the regional lymphatics, and only then to distant locations. Based on these observations, the regional lymphatics were believed to be mechanical barriers preventing the widespread dissemination of tumour. Despite evidence now available disputing its validity, this barrier theory has guided the surgical management of the regional lymphatics for more than a century, influencing the use of such surgical modalities as therapeutic lymph node dissection, elective lymph node dissection and most recently sentinel lymph node biopsy. No published randomized controlled trial exists that demonstrates improved overall survival for patients with cancer of any type undergoing surgery of the regional lymphatics. We believe the presence of tumour in the regional lymphatics indicates the presence of systemic disease, and therapeutic interventions should be directed accordingly.

Factors influencing cosmetic results after breast conserving management (Turkish experience)

We aimed to determine predictive factors affecting cosmetic results after breast conserving management in breast cancer. Data on 96 patients with 97 breast cancer cases, who had been admitted to Uludağ University M.A. Radiotherapy Center between October 1995 and December 1998 and managed with breast-conserving treatment, were analysed to determine the factors affecting cosmetic outcome. Possible factors affecting cosmesis were grouped as patient-related, tumor-related and treatment-related. Mann-Whitney U test was used in univariate analyses whereas logistic regression was used in multivariate analyses. Median follow-up time was 29.5 months ranging between 11 and 53 months and median age at admission was 50 (range 22-84). Cosmetic results were grouped in five categories; excellent; good; fair; poor and, very poor, using criteria, such as presence of fibrosis, telangiectasia, shape of breast, asymmetry, status of areola, pigmentation. Treated breasts were scored by the patients, three radiation oncologists and a breast surgeon independently. In the analysis performed using scores given by the patients, cases with scores 3 and above (unsatisfactory) were compared with cases with scores below 3 (satisfactory). Eighty-two patients (84%) considered cosmetic result as satisfactory (excellent/good) whereas 15 patients (16%) considered unsatisfactory (fair/poor/very poor). In univariate analysis using Mann-Whitney U test, type of surgery (P=0.0655) was the statistically significant factors affecting cosmetic results. In multivariate analysis using logistic regression, tumor quadrant (P=0.0060) and elapsed radiation therapy days (P=0.0090) were the most significant factors. Median values were taken into consideration for the scores given by the physicians and cases with scores 3 and above (unsatisfactory) were compared with cases with scores below 3 (satisfactory). Eighty-two cases were evaluated as satisfactory (84%) whereas 15 cases were unsatisfactory (16%). In this set of data, patient age (P=0.0144), menopausal status (P=0.0111), institution which surgery was performed (P=0.0045), type of surgery (P=0.0044), placement of metallic clips (P=0.0083) and skin fibrosis (P=0.038) were found to be significant in univariate analysis using Mann-Whitney U test. In multivariate analysis using logistic regression, institution where surgery took place (P=0.0015), menopausal status (P=0.0087) and telangiectasia (P=0.0657) were the most significant factors.

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.

Surgical considerations for invasive breast cancer

The 1992 NIH Consensus Development Conference reported that "breast conservation treatment is an appropriate method of primary therapy for the majority of women with stage I and II breast cancer and is preferable because it provides survival equivalent to total mastectomy and axillary dissection while preserving the breast." This conclusion has been solidly confirmed by recent updates of all of the prospective clinical trials performed. The uneven utilization of this BCS indicates the personal discomfort of some surgeons in recommending it or in communicating their recommendations to patients. The appropriate candidate for mastectomy is the patient in whom it is evident that BCS will not control the tumor. This conclusion may be drawn after one or even two attempts at revision have shown more extensive microscopic disease. The experience with preoperative chemotherapy programs such as NSABP Protocol B-18 shows that even for larger tumors primary excision or excision after preoperative chemotherapy provides reasonable rates of local control with no evidence of diminished distant control or survival. Very large tumors, often accompanied by other grave signs, are best treated by primary chemotherapy, because they are essentially not stage I or stage II disease. Although recognizing that better long-term cure rates are a function of the treatment of micrometastases with adjuvant chemotherapy, surgeons should remember the need to balance cosmetic factors with techniques required for good local control. Cosmetic factors are always important, but the primary concern is adequate removal of the primary tumor with pathologically negative margins. The best way to prevent the need for a salvage mastectomy following local recurrence is to obtain adequate control at the initial procedure, but this does not mean that aggressive local surgery is needed, and it certainly does not mean that a primary mastectomy is needed except in unusual cases.

High-malignancy orthotopic nude mouse model of human prostate cancer LNCaP

BACKGROUND

An animal model of human prostate cancer LNCaP demonstrating high rates of spontaneous metastasis from the orthotopic site after tumor implantation would be very valuable for mechanistic and drug discovery studies. We previously developed microsurgical techniques to implant histologically intact tumor tissues orthotopically in nude mice in order to develop high metastatic mouse models of human cancer.

METHODS

Intact tissue of the androgen-dependent human prostate cancer cell line, LNCaP, was implanted on the ventral lateral lobes of the prostate gland by surgical orthotopic implantation (SOI) in a series of 20 nude mice. Mice were autopsied, and histopathological examination of primary tumors and relevant organs was done to identify and quantitate micrometastasis.

RESULTS

Eighteen of 20 animals transplanted with LNCaP by SOI had tumor growth. Mean primary tumor weight in the prostate was 9.24 g at time of necropsy. Sixty-one percent of the transplanted animals had lymph node metastasis. Forty-four percent had lung metastasis. Mean survival time was 72 days, indicating a high degree of malignancy of the tumor.

CONCLUSIONS

The extensive and widespread lung metastasis as well as lymph node metastasis following orthotopic implantation of LNCaP in nude mice and the short survival time provide a high-malignancy nude model of the LNCaP human prostate tumor.

Surgical orthotopic implantation allows high lung and lymph node metastatic expression of human prostate carcinoma cell line PC-3 in nude mice

BACKGROUND

Prostate cancer is the second leading cause of male death in the United States. When diagnosed, nearly half the cases have metastatic lesions. An animal model of human prostate cancer demonstrating spontaneous metastasis from the orthotopic site after tumor implantation should be of great help for us to understand the disease and to formulate treatment strategy. We report here a high metastatic model of human prostate cancer PC-3.

METHODS

We developed microsurgical techniques, termed surgical orthotopic implantation (SOI), to implant histologically intact tumor tissues orthotopically in immunodeficient mice. In this study intact tissue of the human prostate cancer cell line PC-3, harvested from a subcutaneous tumor in a nude mouse, was implanted to the ventral lateral lobes of the prostate gland in a series of nude mice. Mice were sacrificed when found moribund, and autopsy and histology were performed subsequently.

RESULTS

A high frequency of lymph node and lung metastasis was noted upon histological examination. The extensive and widespread lung metastasis following orthotopic implantation of PC-3 is, to the best of our knowledge, the first report in the literature.

CONCLUSIONS

In contrast to orthotopic injection of cell suspensions, no multiple metastatic cell selection was necessary after SOI for significant expression of the metastatic potential of PC-3. We conclude that the stromal tissue architecture maintained in the implanted tumor played a critical role in tumor growth and progression.