Heterogeneous Patterns of Lymphatic Drainage to Sentinel Lymph Nodes by Primary Melanoma From Different Anatomic Sites

A core-satellite micellar system against primary tumors and their lymphatic metastasis through modulation of fatty acid metabolism blockade and tumor-associated macrophages

Lymph nodes (LNs) are the initial sanctuary of various metastatic tumor cells, and thus a precise lymphatic drug delivery strategy is necessary for the effective inhibition of metastasis. However, the complex biological barriers have restrained the drug delivery to tumor-draining lymph nodes (TDLNs). Metastatic tumor cells would undergo metabolic adaptation towards fatty acid oxidation (FAO) upon reaching the lipid-rich LNs. Herein, to inhibit primary tumors and their lymphatic metastasis, a core-satellite matrix metalloproteinase 2 (MMP-2) responsive micellar system was developed for sequential delivery of paclitaxel (PTX) and the metabolism-regulating drug etomoxir (ET) to tumors and TDLNs, respectively. Upon arrival at the tumor microenvironment (TME), the small satellite micelle encapsulating ET was detached from the core micelle in response to MMP-2, which not only drained to TDLNs via tumor-draining lymphatic vessels and inhibited the FAO of metastatic tumor cells, but also blocked M2-like macrophage polarization in the TME. Meanwhile, the core micelle containing PTX could largely accumulate in the TME and kill tumor cells. In an orthotopic 4T1 breast cancer model, the tumor and TDLN dual-targeted core-satellite micellar system effectively inhibited the growth of the primary tumor and alleviated immune suppression by blocking macrophage polarization. More importantly, tumor lymphatic metastasis was suppressed through FAO metabolic regulation. This strategy provides a promising approach for TDLN targeted therapy against breast cancer and its lymphatic metastasis.

Application of an indocyanine green surgical fluorescence imaging system in sentinel lymph node biopsy of acral malignant melanoma

Background

Regional lymph node status is an independent influencing factor for the prognosis of acral malignant melanoma, and the accuracy of sentinel lymph node biopsy (SLNB) is directly related to the judgment of regional lymph node status. This study aimed to explore the application value of indocyanine green (ICG) surgical fluorescence imaging system in the SLNB of acral malignant melanoma.

Methods

A total of 34 patients with acral malignant melanoma were admitted to the Department of Burn and Plastic Surgery in Jiangsu Provincial People’s Hospital from January 2020 to March 2020. Among these patients, 22 required SLNB. ICG and methylene blue (MB) were combined to intraoperatively trace the sentinel lymph nodes (SLNs). The total number of SLNs detected during the operation was counted. We compared the number, detection rate, as well as the detection rate and false negative rate of positive SLNs of SLNs detected by ICG, MB, and ICG combined with MB.

Results

A total of 56 SLNs were detected in the 22 patients, among which 55 were detected by ICG (98%), 41 were detected by MB (71%), and 56 (100%) were detected by ICG combined with MB, and the average number of SLNs were 2.5, 1.64, and 2.55, respectively. A total of nine SLNs were detected, of which nine were detected by ICG (100%), seven by MB (78%), and nine by ICG combined with MB (100%). Patients with negative SLNs had no recurrence at the 6-month follow-up.

Conclusions

Compared with MB, the ICG fluorescent imaging system can improve the detection rate of SLNs in patients with acral malignant melanoma. Also, ICG combined with MB was superior to ICG alone.

Clinical Diagnosis and Classification: Including Biopsy Techniques and Noninvasive Imaging

Early detection of melanoma is important in improving patient survival. The treatment of melanoma is multidisciplinary and begins by obtaining an accurate diagnosis. The mainstays of melanoma diagnosis include examination of the lesion and surrounding areas and an excisional biopsy so that a pathologic diagnosis can be obtained. The pathology results will help guide treatment recommendations, and some information can be used for prognosis. Further workup of the patient may include laboratory studies and imaging for staging and surveillance.

Study of the physicochemical properties of drugs suitable for administration using a lymphatic drug delivery system

Lymph node (LN) metastasis is thought to account for 20‐30% of deaths from head and neck cancer. The lymphatic drug delivery system (LDDS) is a new technology that enables the injection of drugs into a sentinel LN (SLN) during the early stage of tumor metastasis to treat the SLN and secondary metastatic LNs. However, the optimal physicochemical properties of the solvent used to carry the drug have not been determined. Here, we show that the osmotic pressure and viscosity of the solvent influenced the antitumor effect of cisplatin (CDDP) in a mouse model of LN metastasis. Tumor cells were inoculated into the proper axillary LN (PALN), and the LDDS was used to inject CDDP solution into the subiliac LN (SiLN) to treat the tumor cells in the downstream PALN. CDDP dissolved in saline had no therapeutic effects in the PALN after it was injected into the SiLN using the LDDS or into the tail vein (as a control). However, CDDP solution with an osmotic pressure of ~ 1,900 kPa and a viscosity of ~ 12 mPa⋅s suppressed tumor growth in the PALN after it was injected into the SiLN using the LDDS. The high osmotic pressure dilated the lymphatic vessels and sinuses to enhance drug flow in the PALN, and the high viscosity increased the retention of CDDP in the PALN. Our results demonstrate that optimizing the osmotic pressure and viscosity of the solvent can enhance the effects of CDDP, and possibly other anticancer drugs, after administration using the LDDS.

Systemic Targeting of Lymph Node Metastasis through the Blood Vascular System by Using Size-Controlled Nanocarriers

Occult nodal metastases increase the risk of cancer recurrence, demoting prognosis and quality of life of patients. While targeted drug delivery by using systemically administered nanocarriers can potentially control metastatic disease, lymph node metastases have been mainly dealt by locally injecting nanocarriers, which may not always be applicable. Herein, we demonstrated that sub-50 nm polymeric micelles incorporating platinum anticancer drugs could target lymph node metastases in a syngeneic melanoma model after systemic injection, even after removing the primary tumors, limiting the growth of the metastases. By comparing these micelles with clinically used doxorubicin-loaded liposomes (Doxil) having 80 nm, as well as a 70 nm version of the micelles, we found that the targeting efficiency of the nanocarriers against lymph node metastases was associated with their size-regulated abilities to extravasate from the blood vasculature in metastases and to penetrate within the metastatic mass. These findings indicate the potential of sub-50 nm polymeric micelles for developing effective conservative treatments against lymph node metastasis capable of reducing relapse and improving survival.

Sentinel node studies in truncal melanoma: does an increased number of draining basins correlate with an increased risk of lymph metastasis?

OBJECTIVES

To assess whether an association exists between drainage to multiple basins and lymphatic metastasis in patients with truncal melanoma.

METHODS

We retrospectively reviewed 227 patients with primary malignant melanoma between January 2006 and December 2009. All patients received an intradermal injection of (99m)Tc-nanocolloid and lymphoscintigraphy followed by sentinel node biopsy. Pre-staging histology with Breslow thickness from excision biopsy was also obtained.

RESULTS

82/227 (36%) patients with primary truncal melanoma were identified. Nodal histology was positive for metastatic disease in 27/82 (32.9%) patients. Of these 27, 15 had 1 basin of drainage, 7 had 2 basins of drainage and 5 had 3 basins of drainage. Of the 55 node-negative patients, 35 had 1 basin, 18 had 2 basins and 2 had 3 basins of drainage. We found no significant correlation with sentinel node positivity and those that had ≥2 drainage basins. Breslow thickness was available in 65/82(79.2%) patients. Sentinel node biopsy was positive in 6/28 patients who had <1.5 mm thickness, 8/14 who had a 1.5-3.9 mm thickness and 9/23 who had ≥4 mm thickness. There was a significant correlation between Breslow thickness of ≥4 mm and nodal positivity (P = 0.03).

CONCLUSION

This study demonstrates no association between multiple drainage basins and sentinel node histology. Sentinel lymph node status did correlate with Breslow thickness.

[Melanoma of the head and neck region in material of Department of Oncological and Reconstructive Surgery in Center of Oncology IMSC in Gliwice]

INTRODUCTION

About 25% of melanomas are localized in head and neck skin, and this particular localization is most difficult to treat, and the prognosis is less favorable. The depth of melanoma infiltration (Clark and Breslau grade) into the skin is the main factor of local advancement of the disease. Surgical treatment is an essential therapeutic modality in patients with melanoma.

AIM

The aim of this study was to evaluate results of our surgical treatment of melanomas in head and neck localisation, treated from 1997 to 2007 in Department of Oncological and Reconstructive Surgery in Center of Oncology IMSC in Gliwice.

MATERIAL

We analysed group of 47 patients (aged 26 to 75 years, mean 49), treated by surgical excision of malignant melanoma in the head and neck region. Most of the patiens required to use free flaps or skin graft technique to close posexcisional defect, on basis of clinical considerations.

RESULTS

The 5-year total survival for all patients was 62% and were dependent on depht of melanoma infiltration and regional lymph node metastasis. The significant prognostic factors were: localization of primary focus, local progression of disease, free microscopical excision margins sex and age.

CONCLUSIONS

Prognosis in the patients with melanoma of the head and neck is unreliable and dependent on local advancement of disease and localization of primary focus. Surgical treatment is an essential therapeutic modality in patients with melanoma. Adiuvant radiotherapy after surgical treatment of melanoma of the head and neck is intended for the patiens with high risk of local or regional recurence of disease.

Identification of 6 sentinel lymph nodes in a case of malignant melanoma on the ungual region of the finger

We describe a case of malignant melanoma on the ungual region of the index finger with which 6 sentinel lymph nodes were detected in the axillary basin. Of these nodes, 1 of 3 brachial nodes and 2 of 3 central axillary nodes showed micrometastasis. Additional lymph nodes obtained at the subsequent complete axillary lymph node dissection showed no metastasis. Identification of as many as 6 sentinel lymph nodes was ascribed to a single lymph trunk that would branch off to afferent lymphatics draining to each nodal group; however, a gamma probe may have detected radioactive tracer passing to the sequential nodes as well as that remaining in true sentinel nodes.

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology.

Sentinel lymph node biopsy in the pediatric population

BACKGROUND

Sentinel lymph node biopsy (SLNB) has only been recently used for childhood neoplasms.

METHODS

We reviewed all patients younger than 19 years who underwent SLNB for 5 years.

RESULTS

Twenty patients were identified (11 male, 9 female). Sentinel lymph node biopsy was performed for 10 sarcomas (5 synovial, 3 rhabdomyosarcoma, 1 epitheliod, 1 other); 9 skin neoplasms (4 melanomas, 3 Spitz nevi, 2 melanocytomas); and 1 acinic cell carcinoma. All patients underwent Technetium 99m sulfur microcolloid injection and 4-quadrant subdermal injection with Lymphazurin 1% (Autosuture, Norwalk, Conn). Six patients required either sedation for lymphoscintigraphy. Intraoperative gamma probe was used. Primary lesions were found in lower extremity (n = 8), upper extremity (n = 6), trunk (n = 3), and head and neck (n = 3). The lymphatic basins were inguinal (n = 8), axilla (n = 8), neck (n = 3), and both inguinal and axilla (n = 1). At least one lymph node was identified in each procedure. Of 20 patients, 5 (25%) had metastatic disease (4 skin neoplasms and 1 sarcoma). There were no complications in our series, and all patients are alive with no recurrence at an average follow-up of 2.2 years.

CONCLUSIONS

Sentinel lymph node biopsy allows for an accurate biopsy in children. However, some younger patients may require sedation, and it may be more challenging to isolate the sentinel node.

Immediate dynamic lymphoscintigraphy delivers no additional value to lymphoscintigraphy 3 hr after tracer injection in sentinel lymph node biopsy in breast cancer patients

OBJECTIVE

Immediate dynamic imaging enables accurate definition of sentinel lymph nodes, whereas imaging 3 hr after tracer injection may lead to overestimation of the number of sentinel lymph nodes. A study was performed to define the value of lymphoscintigraphy immediately versus 3 hr after tracer injection in sentinel lymph node biopsy for breast cancer management.

METHODS

In 165 sentinel lymph node biopsy procedures preoperative immediate and 3 hr post-injection lymphoscintigraphy was performed after intraparenchymal tracer administration.

RESULTS

Lymph node visualization occurred in 63 immediate procedures (38%) versus in 163 procedures 3 hr post-injection (99%). In 17 procedures (10%) in which immediate lymphoscintigraphy had visualized sentinel lymph nodes, additional nodes had been seen on 3 hr post-injection lymphoscintigraphy. In eight of these procedures (5%) all nodes were detected in the same draining lymph node basin. Non-axillary sentinel lymph nodes were identified by preoperative lymphoscintigraphy in 28 procedures (17%) and improved staging in three patients (5%).

CONCLUSION

The only impact of immediate lymphoscintigraphy was the possible omission of removal of 1-2 sec-echelon nodes per patient in 5% of patients. We consider this yield too low to continue immediate lymphoscintigraphy in breast cancer patients.

Lymphoscintigraphic drainage of acral limb skin to interval sentinel lymph nodes in healthy subjects

BACKGROUND AND OBJECTIVES

In the literature, drainage to epitrochlear and popliteal sentinel lymph nodes (SLN) are analyzed for whole or distal extremity (below elbow or knee) melanomas that are not topographically homogeneous with respect to tendency of drainage to interval SLNs. We hypothesize that acral (hand and foot) skin has a uniform frequency of drainage to interval SLNs, which is higher than reported for distal extremity melanomas.

METHODS

One hundred healthy subjects were enrolled. Fifty subjects had standard four extremity lymphoscintigraphies by radiocolloid injection into an interdigital web space as in lymphodynamic studies. On another 50 subjects, either targeted upper (n = 25) or lower (n = 25) extremity lymphoscintigraphies were performed utilizing injection sites that likely drain to interval SLNs. Acral skin drainage to interval SLNs was analyzed for interindividual variability and injection site dependence.

RESULTS

There was considerable interindividual variability in drainage of each injection site to interval SLNs. Hand skin had a uniform 50% frequency of drainage to epitrochlear-midhumeral SLNs with both injection sites. This frequency was higher than the epitroclear SLN frequencies reported for distal extremity melanomas. Foot skin had 10% and 90% frequencies of drainage to popliteal SLNs from standard and targeted injection sites, respectively. Foot skin largely simulates the tendency of drainage reported for distal extremity melanomas while lateral heel represents a limited zone that almost uniformly drains to popliteal SLNs.

CONCLUSIONS

Despite dissimilarities between hand and foot, acral skin drainage to interval SLNs is high enough to obligate a thorough interval SLN exploration in acral primaries.