The orderly progression of melanoma nodal metastases

Cancer metastasis through the lymphatic versus blood vessels

Whether cancer cells metastasize from the primary site to the distant sites via the lymphatic vessels or the blood vessels directly into the circulation is still under intense study. In this review article, we follow the journey of cancer cells metastasizing to the sentinel lymph nodes and beyond to the distant sites. We emphasize cancer heterogeneity and microenvironment as major determinants of cancer metastasis. Multiple molecules have been found to be associated with the complicated process of metastasis. Based on the large sentinel lymph node data, it is reasonable to conclude that cancer cells may metastasize through the blood vessels in some cases but in most cases, they use the sentinel lymph nodes as the major gateway to enter the circulation to distant sites.

Review on Lymph Node Metastases, Sentinel Lymph Node Biopsy, and Lymphadenectomy in Sarcoma

Soft tissue sarcomas (STS) originating from connective tissue rarely affect the lymph nodes. However, involvement of lymph nodes in STS is an important aspect of prognosis and treatment. Currently, there is no consensus on the diagnosis and management of lymph node metastases in STS. The key risk factor for nodal involvement is the histological subtype of sarcoma. Radiological and pathological evaluation seems to be the most effective method of assessing lymph nodes in these neoplasms. Thus, sentinel lymph node biopsy (SLNB), which has been shown to be valuable in the management of melanoma or breast cancer, may also be a beneficial diagnostic option in some high-risk STS subtypes. This review summarizes data on the risk factors and clinical characteristics of lymph node involvement in STS. Possible management and therapeutic options are also discussed.

Vascular regulation of disseminated tumor cells during metastatic spread

Cancer cells can travel to other organs via interconnected vascular systems to form new lesions in a process known as metastatic spread. Unfortunately, metastasis remains the leading cause of patient lethality. In recent years, it has been demonstrated that physical cues are just as important as chemical and genetic perturbations in driving changes in gene expression, cell motility, and survival. In this concise review, we focus on the physical cues that cancer cells experience as they migrate through the lymphatic and blood vascular networks. We also present an overview of steps that may facilitate organ specific metastasis.

The Evolution of the Sentinel Node Biopsy in Melanoma

The growing repertoire of approved immune-checkpoint inhibitors and targeted therapy has revolutionized the adjuvant treatment of melanoma. While the treatment of primary cutaneous melanoma remains wide local excision (WLE), the management of regional lymph nodes continues to evolve in light of practice-changing clinical trials and dramatically improved adjuvant therapy. With large multicenter studies reporting no benefit in overall survival for completion lymph node dissection (CLND) after a positive sentinel node biopsy (SLNB), controversy remains regarding patient selection and clinical decision-making. This review explores the evolution of the SLNB in cutaneous melanoma in the context of a rapidly changing adjuvant treatment landscape, summarizing the key clinical trials which shaped current practice guidelines.

Sentinel Lymph Node Biopsy in Cutaneous Melanoma, a Clinical Point of View

Sentinel lymph node biopsy (SLNB) is a surgical procedure that has been used in patients with cutaneous melanoma for nearly 30 years. It is used for both staging and regional disease control with minimum morbidity, as proven by numerous worldwide prospective studies. It has been incorporated in the recommendations of national and professional guidelines. In this article, we provide a summary of the general information on SLNB in the clinical guidelines for the management of cutaneous malignant melanoma (American Association of Dermatology, European Society of Medical Oncology, National Comprehensive Cancer Network, and Cancer Council Australia) and review the most relevant literature to provide an update on the existing recommendations for SLNB.

Therapeutic Value of Sentinel Lymph Node Biopsy in Patients With Melanoma: A Randomized Clinical Trial

Importance

Sentinel lymph node (SLN) biopsy is a standard staging procedure for cutaneous melanoma. Regional disease control is a clinically important therapeutic goal of surgical intervention, including nodal surgery.

Objective

To determine how frequently SLN biopsy without completion lymph node dissection (CLND) results in long-term regional nodal disease control in patients with SLN metastases.

Design, Setting, and Participants

The second Multicenter Selective Lymphadenectomy Trial (MSLT-II), a prospective multicenter randomized clinical trial, randomized participants with SLN metastases to either CLND or nodal observation. The current analysis examines observation patients with regard to regional nodal recurrence. Trial patients were aged 18 to 75 years with melanoma metastatic to SLN(s). Data were collected from December 2004 to April 2019, and data were analyzed from July 2020 to January 2022.

Interventions

Nodal observation with ultrasonography rather than CLND.

Main Outcomes and Measures

In-basin nodal recurrence.

Results

Of 823 included patients, 479 (58.2%) were male, and the mean (SD) age was 52.8 (13.8) years. Among 855 observed basins, at 10 years, 80.2% (actuarial; 95% CI, 77-83) of basins were free of nodal recurrence. By univariable analysis, freedom from regional nodal recurrence was associated with age younger than 50 years (hazard ratio [HR], 0.49; 95% CI, 0.34-0.70; P < .001), nonulcerated melanoma (HR, 0.36; 95% CI, 0.36-0.49; P < .001), thinner primary melanoma (less than 1.5 mm; HR, 0.46; 95% CI, 0.27-0.78; P = .004), axillary basin (HR, 0.61; 95% CI, 0.44-0.86; P = .005), fewer positive SLNs (1 vs 3 or more; HR, 0.32; 95% CI, 0.14-0.75; P = .008), and SLN tumor burden (measured by diameter less than 1 mm [HR, 0.39; 95% CI, 0.26-0.60; P = .001] or less than 5% area [HR, 0.36; 95% CI, 0.24-0.54; P < .001]). By multivariable analysis, younger age (HR, 0.57; 95% CI, 0.39-0.84; P = .004), thinner primary melanoma (HR, 0.40; 95% CI, 0.22-0.70; P = .002), axillary basin (HR, 0.55; 95% CI, 0.31-0.96; P = .03), SLN metastasis diameter less than 1 mm (HR, 0.52; 95% CI, 0.33-0.81; P = .007), and area less than 5% (HR, 0.58; 95% CI, 0.38-0.88; P = .01) were associated with basin control. When looking at the identified risk factors of age (50 years or older), ulceration, Breslow thickness greater than 3.5 mm, nonaxillary basin, and tumor burden of maximum diameter of 1 mm or greater and/or metastasis area of 5% or greater and excluding missing value cases, basin disease-free rates at 5 years were 96% (95% CI, 88-100) for patients with 0 risk factors, 89% (95% CI, 82-96) for 1 risk factor, 86% (95% CI, 80-93) for 2 risk factors, 80% (95% CI, 71-89) for 3 risk factors, 61% (95% CI, 48-74) for 4 risk factors, and 54% (95% CI, 36-72) for 5 or 6 risk factors.

Conclusions and Relevance

This randomized clinical trial was the largest prospective evaluation of long-term regional basin control in patients with melanoma who had nodal observation after removal of a positive SLN. SLN biopsy without CLND cleared disease in the affected nodal basin in most patients, even those with multiple risk factors for in-basin recurrence. In addition to its well-validated value in staging, SLN biopsy may also be regarded as therapeutic in some patients.

Trial Registration

ClinicalTrials.gov Identifier: NCT00297895.

Molecular mechanisms of cancer metastasis via the lymphatic versus the blood vessels

Cancer metastasis is the process by which primary cancer cells invade through the lymphatic or blood vessels to distant sites. The molecular mechanisms by which cancer cells spread either through the lymphatic versus blood vessels or both are not well established. Two major developments have helped us to understand the process more clearly. First, the development of the sentinel lymph node (SLN) concept which is well established in melanoma and breast cancer. The SLN is the first lymph node in the draining nodal basin to receive cancer cells. Patients with a negative SLN biopsy show a significantly lower incidence of distant metastasis, suggesting that the SLN may be the major gateway for cancer metastasis in these cancer types. Second, the discovery and characterization of several biomarkers including VEGF-C, LYVE-1, Podoplanin and Prox-1 have opened new vistas in the understanding of the induction of lymphangiogenesis by cancer cells. Cancer cells must complete multiple steps to invade the lymphatic system, some of which may be enabled by the evolution of new traits during cancer progression. Thus, cancer cells may spread initially through the main gateway of the SLN, from which evolving cancer clones can invade the blood vessels to distant sites. Cancer cells may also enter the blood vessels directly, bypassing the SLN to establish distant metastases. Future studies need to pinpoint the molecules that are used by cancer cells at different stages of metastasis via different routes so that specific therapies can be targeted against these molecules, with the goal of stopping or preventing cancer metastasis.

Is skipped nodal metastasis a phenomenon of cutaneous melanoma?

BACKGROUND AND METHODS

Skipped nodal metastasis (SNM) is a recognized phenomenon of visceral cancers when metastases bypass the regional basin and skip to a distant nodal basin without evidence of distant metastases. Its occurrence is undocumented in cutaneous melanoma patients but of potential prognostic significance. We therefore assessed the frequency of SNM in a large series of patients with limb melanomas.

PATIENTS AND METHODS

We studied melanoma patients attending a tertiary oncology hospital in northwest England using two approaches. First, we systematically searched medical records of an unselected patient sample treated 2002-2015, and second, we studied lymphoscintigrams of all patients with limb melanoma who underwent sentinel node biopsy 2008-2019.

RESULTS

Of 672 melanoma patients whose clinical records were examined, 16 had regional nodal metastases without apparent visceral spread and one appeared to have SNM but further scans were uncovered that showed concurrent pulmonary metastases. Of 667 limb melanoma patients with lymphoscintigrams, 7 showed dual lymphatic drainage patterns to distal as well as regional nodal basins, but none had micro-metastases solely in the distant basin.

CONCLUSION

Occurrence of SNM in cutaneous melanoma is highly unlikely.

The lymphatic system and sentinel lymph nodes: conduit for cancer metastasis

The lymphatic system is a complicated system consisting of the lymphatic vessels and lymph nodes draining the extracellular fluid containing cellular debris, excess water and toxins to the circulatory system. The lymph nodes serve as a filter, thus, when the lymph fluid returns to the heart, it is completely sterile. In addition, the lymphatic system includes the mucosa-associated lymphoid tissue, such as tonsils, adenoids, Peyers patches in the small bowel and even the appendix. Taking advantage of the drainage system of the lymphatics, cancer cells enter the lymphatic vessels and then the lymph nodes. In general, the lymph nodes may serve as a gateway in the majority of cases in early cancer. Occasionally, the cancer cells may enter the blood vessels. This review article emphasizes the structural integrity of the lymphatic system through which cancer cells may spread. Using melanoma and breast cancer sentinel lymph node model systems, the spread of early cancer through the lymphatic system is progressive in a majority of cases. The lymphatic systems of the internal organs are much more complicated and difficult to study. Knowledge from melanoma and breast cancer spread to the sentinel lymph node may establish the basic principles of cancer metastasis. The goal of this review article is to emphasize the complexity of the lymphatic system. To date, the molecular mechanisms of cancer spread from the cancer microenvironment to the sentinel lymph node and distant sites are still poorly understood and their elucidation should take major priority in cancer metastasis research.

Spectrophotometric Assays for Sensing Tyrosinase Activity and Their Applications

Tyrosinase (TYR, E.C. 1.14.18.1), a critical enzyme participating in melanogenesis, catalyzes the first two steps in melanin biosynthesis including the ortho-hydroxylation of L-tyrosine and the oxidation of L-DOPA. Previous pharmacological investigations have revealed that an abnormal level of TYR is tightly associated with various dermatoses, including albinism, age spots, and malignant melanoma. TYR inhibitors can partially block the formation of pigment, which are always used for improving skin tone and treating dermatoses. The practical and reliable assays for monitoring TYR activity levels are very useful for both disease diagnosis and drug discovery. This review comprehensively summarizes structural and enzymatic characteristics, catalytic mechanism and substrate preference of TYR, as well as the recent advances in biochemical assays for sensing TYR activity and their biomedical applications. The design strategies of various TYR substrates, alongside with several lists of all reported biochemical assays for sensing TYR including analytical conditions and kinetic parameters, are presented for the first time. Additionally, the biomedical applications and future perspectives of these optical assays are also highlighted. The information and knowledge presented in this review offer a group of practical and reliable assays and imaging tools for sensing TYR activities in complex biological systems, which strongly facilitates high-throughput screening TYR inhibitors and further investigations on the relevance of TYR to human diseases.

Contemporary update of SPECT tracers and novelties in radioguided surgery: a perspective based on urology

Recent technical advances and implementation of novel radiotracers have further increased the potential of radioguided surgery for a broad variety of malignancies. Indeed, the possibilities for future applications of novel radiotracers in diverse oncological strategies has become more promising than ever. This literature review aims to provide a contemporary update on a selected group of radiotracers and evaluates the usability of radioguided surgery and sentinel node procedures, focusing on most promising advances. For example, the impact of targeted radiotracers on prostate specific membrane antigen (PSMA), CD206 receptor-targeted agents (^99mTc-tilmanocept), and hybrid tracers adding fluorescence to radioguidance (ICG-^99mTc-nanocolloid) as well as targeting hypoxia-induced carbonic anhydrase IX (CAIX) will be covered. Furthermore, future outlooks on the implementation of gold nanoparticles (AuNP's), but also technical advances in improved radiotracer detection by hybrid gamma devices will be discussed.

The Effects of Modified Lymphoscintigraphy Techniques on Sentinel Lymph Node Biopsy Success During the COVID-19 Pandemic Period

BACKGROUND AND OBJECTIVE

Sampling of the sentinel lymph node (SLN) in breast cancer provides accurate information about the condition of the axilla in 95% of cases. Technically in detecting SLN; radioactive substance, dyers or both are used. During the COVID-19 (Coronavirus disease 2019) pandemic, delayed images were not taken in lymphoscintigraphy to reduce the risk of transmission by shortening the waiting time in our center. In this study, the effects of early and delayed lymphoscintigraphic images and only early images on our clinical practice were evaluated.

METHODS

We investigated the data of 147 patients in this study who underwent SLNB due to early-stage breast cancer at our institute during the COVID-19 pandemic period (PP) (March/April/May 2020) and within 3 months before the pandemic were evaluated.

RESULTS

Patients were divided into two groups, before pandemic (BP) and PP. BP consisted of patients whose early and delayed images were taken in lymphoscintigraphy whereas PP consisted of those with early images only. There were 74 patients in the BP group and 73 patients in the PP group. Early phase increased uptake was not observed in 23 patients, and increased uptake was obtained from 22 of these patients with delayed imaging in BP period. In PP, increased uptake was not observed in 12 patients. SLN was not detected in 2 patients in the BP group and 7 in the PP group. It was found that the sensitivity, NPV and accuracy of the SLNB procedure performed after taking delayed images was higher.

CONCLUSIONS

In the present study, we believe that if technically possible, delayed images taken during the lymphoscintigraphy can assist the surgeon in terms of SLN detection and the number of SLNs removed.

Clinicopathological Evaluation of the Potential Anatomic Pathways of Systemic Metastasis from Primary Breast Cancer Suggests an Orderly Spread Through the Regional Lymph Nodes

Background

Two conflicting hypotheses as to how breast cancer (BC) accesses the systemic circulation dominated the 20th century and affected surgical treatment. We hypothesized that tumor lymphovascular invasion (LVI) at the primary tumor site favors lymphatic and not blood vessel, capillaries, and systemic metastases (Smets) are dependent upon regional lymph node (RLN) mets.

Methods

Data from BC patients undergoing RLN biopsy was professionally abstracted and maintained in a prospective, precisely managed, single-institution database. Associations of RLN, LVI, and Smets were estimated by univariate and multivariate backward logistic regression models and patient-affiliated demographic, clinicopathologic, treatment type, and molecular marker data.

Results

Of 3329 patients, followed 1–22 years (mean 7.8), 463 of 3329 (13.9%) showed LVI, 742 of 3329 (22.3%) had RLN mets, and 262 of 3329 (7.9%) had Smets. Smets occurred in 52 of 252 (21% with LVI+/RLN+); 116 of 2301 (5% with LVI−/RLN−); 65 of 465 (14% with LVI−/RLN+); and 17 of 207 (8% with LVI+/RLN−), p = 0.021 for association between LVI and Smets for RLN+ patients but not for RLN− patients (p = 0.051). Positive RLN, larger tumor size, and higher grade (all p < 0.001) were predictive of Smets by the multivariable model, whereas positive LVI was not.

Conclusions

LVI predicts RLN mets in BC. RLN is critical to Smets from BC, whereas LVI on its own is not. Smets occur significantly more commonly when both LVI and RLN mets occur together. LVI is, thus, likely to be primarily lymphatic invasion, and rarely, blood vessel invasion, supporting the Halsted paradigm. LVI and RLN together predict clinical outcome better than either alone.

Graphic Abstract

A Review of Key Biological and Molecular Events Underpinning Transformation of Melanocytes to Primary and Metastatic Melanoma

Melanoma is a major public health concern that is responsible for significant morbidity and mortality, particularly in countries such as New Zealand and Australia where it is the commonest cause of cancer death in young adults. Until recently, there were no effective drug therapies for patients with advanced melanoma however significant advances in our understanding of the biological and molecular basis of melanoma in recent decades have led to the development of revolutionary treatments, including targeted molecular therapy and immunotherapy. This review summarizes our current understanding of the key events in the pathway of melanomagenesis and discusses the role of genomic analysis as a potential tool for improved diagnostic evaluation, prognostication and treatment strategies. Ultimately, it is hoped that a continued deeper understanding of the mechanisms of melanomagenesis will lead to the development of even more effective treatments that continue to provide better outcomes for patients with melanoma.

Sentinel Lymph Node Biopsy Was Associated With Favorable Survival Outcomes For Patients With Clinically Node-Negative Asian Melanoma

Purpose

Sentinel lymph node biopsy (SLNB) is the standard management for clinically node-negative cutaneous melanoma patients. This study aimed to evaluate the role of SLNB in Taiwanese melanoma patients and in particular, patients with acral lentiginous melanoma (ALM).

Patients and methods

We retrospectively analyzed the clinicopathological characteristics and survival outcomes of the patients who underwent primary surgery followed by either SLNB or nodal observation at the Linkou Chang Gung Memorial Hospital from January 2000 to December 2011.

Results

Among the total of 209 patients, 127 underwent SLNB and 51 underwent nodal observation only after primary surgery. There were no significant differences in clinicopathological features between the two groups except that patients who underwent SLNB were older and had a higher rate of ALM than those under nodal observation. The median follow-up time was 43.5 months until July 2013. The patients who underwent SLNB had significantly better disease-free survival (DFS) (57.1 vs 18.7 months, p < 0.01) and melanoma-specific survival (MSS) (112.4 vs 45.2 months, p < 0.01) than those under observation. Improvement in DFS (HR: 0.51, p < 0.01) and MSS (HR: 0.60, p = 0.03) was observed even after adjusting for age and disease pathology by multivariate analysis. This benefit of clinical outcomes persisted in patients with ALM, Breslow thickness ≤2 mm, or no ulceration, but not in patients with non-ALM, Breslow thickness >2 mm, or ulceration.

Conclusion

SLNB was associated with favorable outcomes in patients with clinically node-negative cutaneous melanoma, particularly in Taiwanese patients with ALM, Breslow thickness ≤2 mm, and nonulcerated melanoma.

[Sentinel node biopsy and lymph node dissection in the era of new systemic therapies for malignant melanoma]

BACKGROUND

Recently, adjuvant therapies with checkpoint inhibitors and BRAF/MEK inhibitors have become available for patients with malignant melanoma and microscopic nodal disease. Meanwhile the number of complete nodal dissections for a melanoma-positive sentinel node (SN) have decreased significantly.

OBJECTIVE

The authors discuss the significance of sentinel node biopsy (SNB) and early lymph node dissection in the era of adjuvant systemic therapy for stage III melanoma.

MATERIALS AND METHODS

Current publications and recommendations were evaluated.

RESULTS

Complete nodal dissection for a positive SN significantly reduces the risk of regional nodal relapse. However, neither SNB nor complete nodal dissection following a positive SN are associated with a benefit in survival. With the availability of novel adjuvant systemic treatment strategies for stage III melanoma, SNB has become an even more important part of modern staging diagnostics. Thus, detection of early dissemination of melanoma cells into the SN as well as the quantification of the tumor load are decisive for further therapy planning.

CONCLUSION

Accurate assessment of the regional lymph node status by SNB is becoming even more important in the era of novel effective adjuvant therapies for microscopic nodal disease. Whether complete lymph node dissection is performed in patients with a positive SN needs to be assessed individually. In the case of "active nodal surveillance" instead of surgery, long-term close follow-up in specialized centers, including ultrasonographic controls, is required.

Identification of novel, immune-mediating extracellular vesicles in human lymphatic effluent draining primary cutaneous melanoma

Epithelial tumors including melanoma often first metastasize to regional, sentinel lymph nodes (SLN). Thus, the presence of SLN metastases is a critical prognostic factor of survival. Prior to metastasis, accumulating evidence suggests the SLN is immunologically compromised; however, the process by which pre-metastatic niche formation occurs remains unknown. In this prospective study, freshly dissected, afferent lymphatic fluid was obtained during SLN biopsy in three patients with primary cutaneous melanoma. Lymphatic extracellular vesicles (L-EV) were visualized by transmission electron microscopy and proteomic cargo profiled by mass spectrometry. Flow cytometry assessed L-EV effects on autologous dendritic cell maturation in vitro. Immunogold electron microscopy and immunohistochemistry visualized expression of EV cargo within the primary tumor and SLN. Lymphatic extracellular vesicles from each afferent lymphatic channel demonstrated inhibition of autologous dendritic cell maturation. Proteomic profiling identified 81 peptides shared among the L-EV preparations including a signature of 18 immune-modulating proteins including previously established inhibitor of dendritic cell maturation, S100A9. Immunohistochemistry and immunogold electron microscopy confirmed S100A9 tracking along the lymphatic path, from keratinocytes in the primary tumor to sub-capsular macrophages in the SLN. Our findings suggest L-EV cargo may serve as early mediators of tumor-induced immune subversion in regional lymph nodes, by preceding malignant cells and trafficking within the lymphatic vasculature to harbor the first pre-metastatic niche.

Lymph node resection induces the activation of tumor cells in the lungs

Lymph node (LN) dissection is a crucial procedure for cancer staging, diagnosis and treatment, and for predicting patient survival. Activation of lung metastatic lesions after LN dissection has been described for head and neck cancer and breast cancer. Preclinical studies have reported that dissection of a tumor‐bearing LN is involved in the activation and rapid growth of latent tumor metastases in distant organs, but it is also important to understand how normal (non‐tumor‐bearing) LN resection influences secondary cancer formation. Here, we describe how the resection of tumor‐bearing and non‐tumor‐bearing LN affects distant metastases in MXH10/Mo‐lpr/lpr mice. Tumor cells were administered intravenously and/or intranodally into the right subiliac lymph node (SiLN) to create a mouse model of lung metastasis. Luciferase imaging revealed that tumor cells in the lung were activated after resection of the SiLN, irrespective of whether it contained tumor cells. No luciferase activity was detected in the lungs of mice that did not undergo LN resection (excluding the intravenous inoculation group). Our results indicate that resection of an LN can activate distant metastases regardless of whether the LN contains tumor cells. Hence, lung metastatic lesions are suppressed while metastatic LN are present but activated after LN resection. If this phenomenon occurs in patients with cancer, it is likely that lung metastatic lesions may be activated by elective LN dissection in clinical N0 cases. The development of minimally invasive cancer therapy without surgery would help to minimize the risk of activation of distant metastatic lesions by LN resection.

Sentinel Lymph Node Biopsy and Completion Lymph Node Dissection for Melanoma

OPINION STATEMENT

This review critically evaluates recent trials which have challenged the practice of completion lymph node dissection (CLND) for melanoma patients diagnosed with regional metastasis by positive sentinel lymph node biopsy (SLNB). Two trials in the last 2 years, DeCOG-SLT and MSLT-II, found no significant differences in melanoma-specific survival between patients, whether they received immediate CLND or observation after positive SLNB, despite decreases in nodal recurrence achieved by dissection. These trials together disfavor routine CLND in most patients after positive SLNB. However, their conclusions are limited by study populations which overall harbored a lower burden of SLN disease. Special attention needs to be given to patients who do have higher risk disease, with SLN tumor burdens exceeding 1 mm in diameter, for whom CLND may remain both prognostic and therapeutic. Current guidelines thus recommend either CLND or careful observation after positive SLNB after appropriate risk stratification of patients. While a decline in CLND is inevitable, treatment of stage III melanoma is witnessing the concurrent rise of effective adjuvant therapies. PD-1 inhibitors such as nivolumab, or combination BRAF/MEK inhibitors for V600E or K mutant melanoma, which were previously available to only trial patients with completely resected stage III disease, are now approved for use in patients with positive SLNB alone. Providers are better equipped than ever to treat clinically occult, regional metastatic disease with SLNB followed by adjuvant therapy for most patients, but should take steps to avoid undertreatment of high-risk patients who may proceed to disease relapse or progression.

Incidence and outcomes of pediatric extremity melanoma: A propensity score matched SEER study

BACKGROUND

There is a paucity of literature on treatment of melanoma in children with surgical management extrapolated from adult experience. The incidence and clinical outcomes of pediatric extremity melanoma were studied.

METHODS

SEER registry was analyzed between 1973 and 2010 for patients <20years old with extremity melanoma. Multivariate and propensity-score matched analyses were performed to identify independent predictors of survival.

RESULTS

Overall, 917 patients were identified with an age-adjusted incidence of 0.2/100,000 persons, annual percent change 0.96. Most had localized disease (77%), histology revealing melanoma-not otherwise specified (52%). Surgical procedures performed included wide local excision (50%), excisional biopsy (32%), lymphadenectomy (LA) (28%), and sentinel lymph node biopsy (SLNB) (15%). Overall, 30-year disease specific mortality was 7% with lower survival for extremity melanoma (90%), males (89%), nodular histology (69%), and distant disease (36%) (all P<0.05). Post-treatment multivariate analysis revealed localized disease (HR 9.76; P=0.006) as an independent prognosticator of survival; earlier diagnostic years 1988-1999 (HR 2.606; P=0.017) were a negative prognosticator of survival. Propensity-score matched analysis found no difference in survival between SLNB/LA vs no sampling for regional/distant disease.

CONCLUSIONS

Pediatric extremity melanoma in SEER demonstrate no survival advantage between children undergoing sampling procedures vs no sampling for regional/distant disease.

TYPE OF STUDY

Retrospective, prognostic study.

LEVEL OF EVIDENCE

III.

Future perspectives: cancer metastases

The sentinel lymph node (SLN) is the initial metastatic site for the majority of solid cancers. In some cases, cancer cells may bypass the SLNs and enter the vascular channels directly to spread to the systemic sites. Metastatic progression is an orderly process. During the process of metastasis, complex biochemical and molecular mechanisms are involved being subjected to the host influence, in particular, the immune system. With more detailed understanding of the genomic and molecular characteristics of cancer both from the primary site and its metastases, the pathways of cancer growth and spread within the cancer microenvironment may be further elucidated.

Melanoma & nuclear medicine: new insights & advances

The contribution of nuclear medicine to management of melanoma patients is increasing. In intermediate-thickness N0 melanomas, lymphoscintigraphy provides a roadmap for sentinel node biopsy. With the introduction of single-photon emission computed tomography images with integrated computed tomography (SPECT/CT), 3D anatomic environments for accurate surgical planning are now possible. Sentinel node identification in intricate anatomical areas (pelvic cavity, head/neck) has been improved using hybrid radioactive/fluorescent tracers, preoperative lymphoscintigraphy and SPECT/CT together with modern intraoperative portable imaging technologies for surgical navigation (free-hand SPECT, portable gamma cameras). Furthermore, PET/CT today provides 3D roadmaps to resect 18F-fluorodeoxyglucose-avid melanoma lesions. Simultaneously, in advanced-stage melanoma and recurrences, 18F-fluorodeoxyglucose-PET/CT is useful in clinical staging and treatment decision as well as in the evaluation of therapy response. In this article, we review new insights and recent nuclear medicine advances in the management of melanoma patients.

Sentinel Lymphadenectomy in Cutaneous Melanoma

Aims and Background

In the last ten years validation of the sentinel lymph node (SLN) concept has led to modification of the surgical approach for patients with intermediate-risk cutaneous melanoma.

Methods and Study Design

Forty-eight patients affected by cutaneous melanoma with a Breslow thickness between 0.65 and 4 mm were enrolled in the study. Approximately 2 mCi of radiotracer and 1 mL of vital blue dye were injected in each patient around the site of the primary lesion. Lymphoscintigraphy was performed until the lymphatic basin and the respective SLN were localized. The whole surgical procedure consisted of enlargement of the surgical margins followed by localization and excision of the SLN(s) by using both radiotracer and vital dye. Whenever the SLN proved to be histologically positive for metastasis, complete regional lymphadenectomy was performed.

Results

Within 15 minutes of radiotracer administration the lymphatic basin was localized in all 48 patients by lymphoscintigraphy. Vital dye and radiotracer successfully allowed SLN localization and excision in 46 of 48 patients (97%); in one case the SLN was detected by radiotracer alone. The SLN proved to be metastatic in six (13%) of 46 evaluable patients; interestingly, in three of them the presence of metastatic cells was revealed only by immunohistochemistry. All patients with tumor-positive SLNs had primary lesions with a Breslow thickness = 2 mm.

Conclusions

Sentinel lymphadenectomy is able to identify lymph node involvement in patients with cutaneous melanoma with a Breslow thickness >1 mm, thus avoiding the risks associated with radical regional lymphadenectomy. Lymphoscintigraphy proved to be an important tool to obtain correct preoperative localization of the drainage basin, especially for melanomas located on the face and trunk.

Sentinel Node Biopsy and Selective Dissection for Melanoma Nodal Metastases

Background

Early detection of nodal metastases still represents an important goal in the management of melanoma patients. A sentinel node is defined as the first colored node in the regional lymphatic basin following injection of blue dye in the site of the primary melanoma. Sentinel node biopsy may represent a feasible technique for early identification of occult disease. A therapeutic dissection is then performed only in patients with proven nodal disease, thus introducing the concept of selective dissection.

Methods

At the National Cancer Institute of Milan from February 1994 to October 1996, 74 patients with a melanoma of the trunk or limbs and without clinically detectable node metastases were submitted to sentinel node biopsy and eventual selective dissection.

Results

The sentinel node was identified in 67 patients (90%). Nodal metastases were detected in 11 patients (16%); 5 of these were identified by an intraoperative frozen section examination. In all but one case, only the sentinel node was affected at radical dissection. Incidence of positive sentinel nodes was correlated with depth of infiltration of the primary lesion. Mapped nodal basin failures were observed in 3 patients with negative sentinel node biopsy. All patients but one, presenting distant metastases, are alive at this writing and free of disease with a follow-up ranging from 2 to 34 months.

Conclusions

Our study adds to accumulating evidence supporting the efficacy of sentinel node biopsy in detecting occult localizations and the potential of the technique to better select the group of patients that may benefit from nodal dissection.

Sentinel Node Biopsy for Malignant Melanoma: Analysis of a Four-Year Experience

Aims and background

Sentinel node (SN) biopsy has been introduced to solve the controversy concerning the effectiveness of prophylactic lymphadenectomy in intermediate thickness melanoma. The aim of this study was to evaluate the rate of metastases, the technical details of the procedure, and the main reasons of failure.

Methods

235 patients affected by intermediate thickness melanoma (tumor thickness >0.75 mm and <4 mm) without clinical signs of systemic spread (N0M0) were submitted to sentinel node biopsy between 1996 and 2000. Preoperative lymphoscintigraphy was routinely performed in the last 184 patients. Intraoperative mapping with gamma probe was combined with the use of vital dye for identification of sentinel nodes in the last 113 patients.

Results

The SN detection rate was 95.6%, with significant differences depending on the site of dissection and the use of a gamma probe. The overall rate of micrometastases was 14.7%, but relevant differences were recorded between different subgroups of patients (T2, 5.1%; T3a, 19.6%; T3b, 29%).

Conclusions

Sentinel node biopsy requires a multidisciplinary approach (surgery, pathology and nuclear medicine) for reliable results. The association of vital dye and intraoperative gamma probe for sentinel node harvesting has made the procedure more effective, less time-consuming and less invasive. Failures may be due not only to surgical mistakes, but also to improper nuclear medicine procedures or inaccurate histological evaluation of SNs. Methods for histological examination of the SN are still debated and not standardized but promising results have recently been obtained with molecular oncology techniques (RT-PCR).

State of the Art of Sentinel Node Biopsy in Oncology

Sentinel node biopsy has become a standard diagnostic procedure to assess lymph node status of various tumors. The combination of blue dye and a radioactive tracer offers the best chances of identifying the sentinel lymph node. Most progress in the technique of the sentinel node procedure has been made in melanoma and breast cancer. In melanoma, sentinel node biopsy has been introduced as a fundamental procedure for staging. Information on the lymphatic drainage from a melanoma can have a direct impact on the surgery. More recently, the technique has been successfully introduced in the management of breast cancer, in which a large number of unnecessary axillary dissections could be avoided. However, there are many other potential fields of application of the sentinel node biopsy (e.g. endometrial, vulvar, head and neck cancers) that are worthy of investigation. In any case, multicenter trials are required to standardize the procedures, taking into account several variables such as particle size and mode of delivery of the radiotracer, amount of radioactivity administered, number and location of injections, and choice of the hand-held probe. We briefly describe the technical and historical aspects of the sentinel node biopsy and summarize the main clinical trials proposed and/or performed in the field.

Detection of Melanoma Cells in Peripheral Blood and Sentinel Lymph Nodes by RT-PCR Analysis: A Comparative Study with Immunohistochemistry

The presence of lymph node metastases is the best prognostic factor for predicting relapse or survival in melanoma patients. It has been demonstrated that melanoma metastases spread through the first lymph node(s) draining the tumor (sentinel lymph node, SN) to the lymphatic system and that detection of melanoma cells in peripheral blood directly correlates with prognosis in melanoma.

To identify lymph node metastases and circulating melanocytes, we developed a single-step reverse transcriptase-polymerase chain reaction assay (RT-PCR) for detection of two melanoma-specific markers: the tyrosinase gene, which encodes an enzyme associated with melanin synthesis, and melanoma antigen-related T-cells, which are present in tumor infiltrating T-lymphocytes. This method detects two tumor cells in a background of 107 lymphocytes.

Thirty patients with stage I–IV cutaneous melanoma entered the study. Blood samples were taken preoperatively, one month after excision of the primary melanoma lesion and the SN or total lymphadenectomy, and before the start of chemotherapy and every three months thereafter in metastatic patients. SNs were collected from 22 patients, bisected and analyzed by RT-PCR and routine pathological and immunohistochemical tests. The preliminary results indicate that RT-PCR for melanoma markers is a sensitive and valuable method for the detection of micrometastases and for early diagnosis and staging of melanoma.

Sentinel Node Biopsy in Melanoma: The Experience of Brescia Civic Hospital

The accuracy of the sentinel node (SN) technique in the evaluation of lymph node involvement in melanoma was evaluated in 71 consecutive patients with localized disease and Breslow index >1 mm. Lymphoscintigraphy identified at least one SN in 70 of the 71 patients (98.5%). The following day 69 patients underwent selective SN excision. The SN was identified by portable probe. One hundred and twenty-two lymph nodes were removed, 14 (11.4%) of which were metastatic in 9 patients (13%). No metastases were found in 40 patients with Breslow <2 mm. Eight of the 9 patients with positive SNs underwent lymphadenectomy of the whole basin and in two patients new metastatic nodes were found. At 4–26 months’ follow-up 1 of the 60 patients with negative SN (scalp melanoma with Breslow 6.2 mm) developed bilateral cervical metastatic nodes. Two more patients with Breslow 3.7 and 5 mm, respectively, developed liver and lung metastases. The remaining 57 patients are still disease free. Among the 9 patients with tumor-positive SNs, 1 was lost to follow-up, 3 died and 5 are still alive. Our data confirm the clinical reliability of the SN technique in melanoma; we feel the technnique should be considered a standard tool in the evaluation of melanoma patients.

Mapping the Sentinel Lymph Node in Malignant Melanoma by Blue Dye, Lymphoscintigraphy and Intraoperative Gamma Probe

Eighty-eight consecutive patients (48 men and 40 women; mean age, 58.9 years; range, 16–84 years) with clinically localized cutaneous melanoma involving the trunk, extremities or head and neck underwent lymphatic mapping at our institution. The primary melanoma had a mean thickness of 2.74 mm (range, 0.95 to 9 mm). Patients were divided into two groups: group A (39 patients) underwent only vital blue dye (VBD) mapping, while group B (49 patients) underwent lymphatic mapping with VBD and radio-guided surgery (RGS) combined. In all patients 1-1.5 mL of VBD was injected subdermally around the biopsy scar 10–20 min before surgery. In group B 37 MBq in 150 μL of 99mTc-HSA nanocolloid was additionally injected intradermally 18 h before surgery (3–6 aliquots injected perilesionally). In all lymphatic basins where drainage was noted the sentinel lymph nodes (SNs) were identified and marked with a cutaneous marker. Final identification of the SN was then performed externally by a hand-held gamma probe. After the induction of anesthesia 0.5–1-0 mL of patent blue V dye was injected intradermally with a 25-gauge needle around the site of the primary melanoma. SNs were examined by routine hematoxylin and eosin (H&E) staining and immunohistochemistry. Patients with histologically positive SN(s) underwent standard lymph node dissection (SLND) in the involved lymph node basin.

The SN was identified in 37/39 patients (94.9%) of group A and in 48/49 patients (98.0%) of group B. Blue dye mapping failed to identify the SN in 5 of the 88 patients (5.8%), while the radioisotope method failed in only 1 of 49 patients (2.0%). Similar results were obtained with the combined use of the two probes. The average number of SNs harvested was 1.9 per basin sampled, which does not differ significantly from the numbers reported by other authors114. The SN was histologically positive in 18 patients (20.5%). None of the 12 patients with a Breslow thickness less than 1.5 mm had positive SNs, whereas 18 of the 77 patients (23.4%) with a Breslow index exceeding 1.5 mm showed metastatic SNs with H&E or immunohistochemistry. The latter all underwent SLND of the affected basin. In 10 patients (55.6%) the SN was the only site of tumor invasion; eight patients (44.4%) with positive SNs had one or more metastatic lymph nodes in the draining basin.

Sentinel Node Biopsy in Clinical Stage 1 Melanoma: Rationale for Restaging and Follow-Up

Lymph node involvement appears to be the most significant prognostic factor in patients affected by melanoma and has been shown to reduce the five-year survival by 40%. We studied 31 patients (15 M; 16 F; age range, 28–83 years) with clinical stage 1 (CS1) intermediate thickness (0.75–4 mm) melanoma. Scintigraphic examination of the nodes was performed in all patients, 29 of whom underwent surgical biopsy of the SN after 24 hours. Early images were acquired 5, 15 and 79 min and late images 60–180 min following perilesional injection of 2–4 microdoses of 99mTc-nanocolloid (15–20 MBq). A cobalt marker was used to project the SN on the skin surface which was later stained with indelible ink. For intraoperative localization we used a portable probe and perilesional injection of patent blue violet dye, which proved positive in 24/29 patients (83%). After surgery histological examination of the sentinel lymph nodes (SNs) (hematoxylin-eosin and immunohistochemistry) found positivity for metastatic cells in 6 patients. They all underwent elective lymph node dissection (ELND); five are N0+ and are currently undergoing supportive therapy with interferon alpha with an 8–24-month follow-up, while one N+ patient died 14 months after surgery. Follow-up (3–26 months) of NO- patients has not evidenced any locoregional recurrence so far. Only one case showed hematogenic metastases. This procedure might radically change the therapeutic approach to CS1 melanoma because it is simple, scarcely invasive, and shows a favorable cost-benefit ratio.

Stratifying SLN incidence in intermediate thickness melanoma patients

BACKGROUND

Guidelines for melanoma recommend sentinel lymph node biopsy (SLNB) in patients with melanomas ≥1 mm thickness. Recent single institution studies have found tumors <1.5 mm a low-risk group for positive SLNB.

METHODS

A retrospective review of the Sentinel Lymph Node Working Group multicenter database identified patients with intermediate thickness melanoma (1.01-4.00 mm) who had SLNB, and assessed predictors for positive SLNB.

RESULTS

3460 patients were analyzed, 584 (17%) had a positive SLNB. Univariate factors associated with a positive SLNB included age <60 (p < .001), tumor on the trunk/lower extremity (p < .001), Breslow depth ≥2 mm (p < .001), ulceration (p < .001), mitotic rate ≥1/mm² (p = .01), and microsatellitosis (p < .001). Multivariate analysis revealed age, location, and Breslow depth as significant predictors. Patients ≥75 with lesions 1.01-1.49 mm on the head/neck/upper extremity and 1.5-1.99 mm without high-risk features had <5% risk of SLN positivity.

CONCLUSIONS

Intermediate thickness melanoma has significant heterogeneity of SLNB positivity. Low-risk subgroups can be found among older patients in the absence of high-risk features.

Metastases of malignant neoplasms: Historical, biological, & clinical considerations

The metastasis of neoplastic cells from their site of origin to distant anatomic locations continues to be the principal cause of death from malignant tumors, and that fact has been recognized by physicians for over a century. After the work done by Halsted in the treatment of breast cancer in the 1880s, accepted surgical canon held that metastasis occurred in a linear fashion, with centrifugal "growth in continuity" from the primary neoplasm that first involved regional lymph nodes. Those structures were considered to then be the sources of more distant, visceral metastases. With that premise in mind, radical and "ultra-radical" surgical procedures were devised to remove as many lymph nodes as possible in the treatment of carcinomas and melanomas. However, such interventions were ineffective in altering tumor-related mortality. This review considers the details of the historical material just mentioned. It also reviews currently-held concepts on biological mechanisms of metastasis, the "sentinel" lymph node biopsy technique, and the important topic of metastatic tumor "dormancy" as the cause of surgical treatment failure. Finally, predictive models of tumor behavior are discussed, which are based on gene signatures. These will likely be the key to identifying malignant lesions of low surgical stage that ultimately prove fatal through later manifestation of metastasis.

Impact of Time Between Diagnosis and SLNB on Outcomes in Cutaneous Melanoma

BACKGROUND

Hypothetically, delay between melanoma diagnosis and SLNB could affect outcomes, either adversely by allowing growth and dissemination of metastases, or beneficially by allowing development of an anti-melanoma immune response. Available data are conflicting about the effect of SLNB delay on patient survival. Our objective was to determine whether delay between initial diagnosis and SLNB affects outcomes in patients with cutaneous melanoma.

STUDY DESIGN

We performed query and analysis of a large prospectively maintained database of patients with primary cutaneous melanomas undergoing SLNB. An independent dataset from MSLT-1 (Multicenter Selective Lymphadenectomy Trial-1) was used for validation. Primary outcomes included disease-free survival and melanoma-specific survival.

RESULTS

Early and delayed SLNB were defined as less than 30 and 30 or more days from initial diagnosis, respectively. There were 2,483 patients that met inclusion criteria. Positive sentinel lymph nodes were identified in 17.4% (n = 432). Among all patients, 42% had SLNB 30 or more days after diagnosis and 37% of positive sentinel lymph nodes were at 30 or more days. No differences in sex, anatomic site, or histopathologic features were identified between the 2 groups. There was no difference in melanoma-specific survival or disease-free survival between those undergoing early or delayed SLNB. Examination of MSLT-1 trial data similarly demonstrated no difference in survival outcomes.

CONCLUSIONS

This, the largest study on this subject to date, found no adverse impact on long-term clinical outcomes of patients due to delay of SLNB beyond 30 days. The MSLT-1 data confirm this result. Patients can be reassured that if the operation is performed 30 or more days after diagnosis, it will not cause harm.

Sentinel Lymph Node Biopsy in Cutaneous Melanoma: Standard and New Technical Procedures and Clinical Advances. A Systematic Review of the Literature

Melanoma is an important public health problem, and its incidence is increasing worldwide. The disease status of regional lymph nodes is the most important prognostic factor in early-stage melanoma patients. Sentinel lymph node biopsy (SLNB) was introduced in the early 1990s as a less invasive procedure than complete lymph node dissection to allow histopathologic evaluation of the "sentinel lymph node" (SLN), which is the first node along the lymphatic pathway from a primary tumor. Sentinel lymph node biopsy has minimal complication risks compared with standard complete lymph node dissection. Currently, SLNB is the accepted method for staging patients with clinically node-negative cutaneous melanoma and provides the most powerful prognostic information by evaluating the nodal basin status. The current practice of SLNB consists of the injection of Tc-labeled radiopharmaceutical, preoperative lymphoscintigraphy with the possibility of using the SPECT/CT hybrid imaging, and intraoperative SLN localization using a handheld gamma probe with or without the use of blue dye. Recently, the SLN localization and detection have been enhanced with the use of new tracers and new intraoperative devices, which have demonstrated to be particularly useful in melanomas of the head and neck region and in area of complex anatomy. Despite these important advances in the technology and the increasing experience in SLN mapping, major research centers have reported a false-negative rate higher than 15%. This relatively high false-negative rate, greater than those reported in the initial validation studies, points out the importance for the nuclear medicine community to continuously improve their knowledge on the biological behavior of melanoma and to improve the technical aspects that may allow more precise staging. For the SLNB procedure to be accurate, it is of critical importance that all "true" SLNs are identified and removed for examination. The aim of this article is to provide general information about the SLNB procedure in clinical practice highlighting the importance of standardization and accuracy of SLN identification in the light of the most recent technical innovations.

10 % fluorescein sodium vs 1 % isosulfan blue in breast sentinel lymph node biopsy

Background

Sentinel lymph node biopsy (SLNB) is well accepted to be a standard procedure in breast cancer surgery with clinically negative lymph nodes. Isosulfan blue is the first dye approved by the USA Food and Drug Administration for the localization of the lymphatic system. Few alternative tracers have been investigated. In this study, we aimed to compare the differences between 10 % fluorescein sodium and 1 % isosulfan blue in breast sentinel lymph node biopsy and to investigate the feasibility of using 10 % fluorescein sodium as a new dye for breast sentinel lymph node biopsy.

Methods

A total of 30 New Zealand rabbits were randomly divided into the fluorescein sodium group and the isosulfan blue group (15 rabbits per group). Fluorescein sodium or isosulfan blue was injected subcutaneously into the second pair of mammary areolas.

Results

The average fading time of the second lymph nodes in the isosulfan blue group was significantly shorter than that in the fluorescein sodium group. Moreover, the detection rates of SLNs were higher in the fluorescein sodium group than in the isosulfan blue group. No significant differences between the fluorescein sodium group and isosulfan blue group were observed regarding the distances between the detected sentinel lymph nodes and second pair of mammary areolas, the distances between the second lymph nodes and second pair of mammary areolas, the number of detected sentinel lymph nodes and second lymph nodes, the average dyeing time of the sentinel and the second lymph nodes, and the average fading time of the second lymph nodes.

Conclusions

In summary, we first reported that fluorescein sodium is a potential new tracer for breast sentinel lymph node biopsy.

Nodular Histologic Subtype and Ulceration are Tumor Factors Associated with High Risk of Recurrence in Sentinel Node-Negative Melanoma Patients

Background

Since its introduction, the sentinel lymph node biopsy (SLNB) has become the standard staging procedure in clinical node-negative melanoma patients. A negative SLNB, however, does not guarantee a recurrence-free survival. Insight into metastatic patterns and risk factors for recurrence in SLNB negative melanoma patients can provide patient tailored guidelines.

Methods

Data concerning melanoma patients who underwent SLNB between 1996 and 2015 in a single center were prospectively collected. Cox regression analyses were used to determine variables associated with overall recurrence and distant first site of recurrence in SLNB-negative patients.

Results

In 668 patients, SLNBs were performed between 1996 and 2015. Of these patients, 50.4 % were male and 49.6 % female with a median age of 55.2 (range 5.7–88.8) years. Median Breslow thickness was 2.2 (range 0.3–20) mm. The SLNB was positive in 27.8 % of patients. Recurrence rates were 53.2 % in SLNB-positive and 17.9 % in SLNB-negative patients (p < 0.001). For SLNB-negative patients, the site of first recurrence was distant in 58.5 %. Melanoma located in the head and neck region (hazard ratio 4.88, p = 0.003) and increasing Breslow thickness (hazard ratio 1.15, p = 0.013) were predictive for distant first site of recurrence in SLNB-negative patients. SLNB-negative patients with a nodular melanoma and ulceration had a recurrence rate of 43.1 %; the site of recurrence was distant in 64 % of these patients.

Conclusions

The recurrence rates of SLNB-negative nodular ulcerative melanoma patients approach those of SLNB-positive patients. Stringent follow-up is recommended in this subset of patients.

Sentinel Lymph Node Biopsy in Breast Cancer: Indications, Contraindications, and Controversies

Axillary lymph node status, a major prognostic factor in early-stage breast cancer, provides information important for individualized surgical treatment. Because imaging techniques have limited sensitivity to detect metastasis in axillary lymph nodes, the axilla must be explored surgically. The histology of all resected nodes at the time of axillary lymph node dissection (ALND) has traditionally been regarded as the most accurate method for assessing metastatic spread of disease to the locoregional lymph nodes. However, ALND may result in lymphedema, nerve injury, shoulder dysfunction, and other short-term and long-term complications limiting functionality and reducing quality of life. Sentinel lymph node biopsy (SLNB) is a less invasive method of assessing nodal involvement. The concept of SLNB is based on the notion that tumors drain in an orderly manner through the lymphatic system. Therefore, the SLN is the first to be affected by metastasis if the tumor has spread, and a tumor-free SLN makes it highly unlikely for other nodes to be affected. Sentinel lymph node biopsy has become the standard of care for primary treatment of early breast cancer and has replaced ALND to stage clinically node-negative patients, thus reducing ALND-associated morbidity. More than 20 years after its introduction, there are still aspects concerning SLNB and ALND that are currently debated. Moreover, SLNB remains an unstandardized procedure surrounded by many unresolved controversies concerning the technique itself. In this article, we review the main indications, contraindications, and controversies of SLNB in breast cancer in the light of the most recent publications.

Detection of Metastases in Patients with Cutaneous Melanoma Using FDG-PET/CT

This study aimed to detect metastases in patients with stage III or IV cutaneous melanoma by 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT). Thirty-nine patients with clinically evident stage III or IV melanoma underwent whole-body FDG-PET/CT scans for metastatic disease and these results were compared with those of biopsy. Scans for 38 of the patients were evaluated; one patient's scan could not be evaluated. There were 11 true-positive, two false-positive, 24 true-negative and one false-negative scans for the detection of melanoma metastases, with sensitivity 91%, specificity 92%, accuracy 92%, and positive and negative predictive values 84% and 96%, respectively. False-positive FDG-PET/CT scans were due to sarcoidosis in the lung and infected cyst in the liver. It is concluded that FDG-PET/CT scanning has high sensitivity and specificity for detecting stage III or IV metastatic melanoma.

Assessment of laparoscopic stomach preserving surgery with sentinel basin dissection versus standard gastrectomy with lymphadenectomy in early gastric cancer-A multicenter randomized phase III clinical trial (SENORITA trial) protocol

Background

Along with the marked increase in early gastric cancer (EGC) in the Eastern countries, there has been an effort to adopt the sentinel node concept in EGC to preserve gastric function and reduce the occurrence of postoperative complications. Based on promising results from a previous quality control study, this prospective multicenter randomized controlled phase III clinical trial aims to elucidate the oncologic safety of laparoscopic stomach-preserving surgery with sentinel basin dissection (SBD) compared to a standard laparoscopic gastrectomy.

Methods/Design

This trial is an investigator-initiated, open-label, multicenter randomized controlled phase III trial with a non-inferiority design. Patients diagnosed with a single lesion of clinical stage T1N0M0 gastric adenocarcinoma, with a diameter of 3 cm or less are eligible for the present study. A total of 580 patients (290 per group) will be randomized to either laparoscopic stomach-preserving surgery with SBD or standard surgery. The primary end-point is 3-year disease-free survival (DFS) and the secondary endpoints include postoperative morbidity and mortality, quality of life, 5-year DFS, and overall survival. Qualified investigators who completed the prior quality control study are exclusively allowed to participate in this phase III clinical trial.

Discussion

The proposed trial is expected to verify whether laparoscopic stomach-preserving surgery with SBD achieves similar oncologic outcomes and improved quality of life compared to a standard gastrectomy in EGC patients.

Trial registration

This study was registered at the NIH ClinicalTrial.gov database (NCT01804998) on March 4th, 2013.