Lymphatic Mapping in the Molecular Era

Preclinical Validation of a Single-Treatment Infusion Modality That Can Eradicate Extremity Melanomas

Isolated limb perfusion (ILP) with the chemotherapeutic agent melphalan is an effective treatment option for extremity in-transit melanoma but is toxic and technically challenging to deliver locoregionally. CBL0137 is an experimental clinical drug with broad anticancer activity in animal models, owing to its ability to bind DNA in a nongenotoxic manner and inactivate the FACT chromatin modulator essential for tumor cell viability. Here, we report that CBL0137 delivered by ILP in a murine melanoma model is as efficacious as melphalan, displaying antitumor activity at doses corresponding to only a fraction of the systemic MTD of CBL0137. The ability to bind DNA quickly combined with a favorable safety profile made it possible to substitute CBL0137 in the ILP protocol, using an intra-arterial infusion method, to safely achieve effective tumor suppression. Our findings of a preclinical proof of concept for CBL0137 and its administration via intra-arterial infusion as a superior treatment compared with melphalan ILP allows for locoregional treatment anywhere a catheter can be placed. Cancer Res; 76(22); 6620-30. ©2016 AACR.

Quinacrine for extremity melanoma in a mouse model of isolated limb perfusion (ILP)

PURPOSE

Quinacrine is a relatively non-toxic drug, once given almost exclusively for malaria. However, recent studies show that quinacrine can suppress nuclear factor-κB (NF-κB), and activate p53 signaling. We investigated the anti-cancer effect of quinacrine, using a novel mouse model of isolated limb perfusion (ILP) for extremity melanoma.

METHOD

Female C57BL/6 mice (22-25 g) were injected with B16 melanoma cells (1 × 10(5)) subcutaneously in the distal thigh. After 7 days of tumor establishment, mice were perfused with either PBS, melphalan (90 µg), or quinacrine (3.5 and 4.5 mg) through the superficial femoral artery for 30 min at either 37 or 42 °C in a non-oxygenated circuit. We analyzed morbidity, toxicity, tumor apoptosis, and responses.

RESULTS

Melanoma cell death following in vitro exposure to quinacrine was dose and time dependent. A significant decrease in mean tumor volume was observed after perfusion with low-dose and high-dose quinacrine (both P = 0.002) at 37 °C as well as after perfusion with low-dose quinacrine (P = 0.0008) at 42 °C.

CONCLUSION

Quinacrine has demonstrable efficacy against melanoma cells in vitro and in a clinically relevant model of ILP. Further studies to evaluate the optimal conditions for quinacrine usage are warranted.

Cutaneous malignancies: melanoma and nonmelanoma types

This article reviews melanoma and nonmelanoma cutaneous malignancies.

Isolated limb infusion for in-transit malignant melanoma of the extremity: a well-tolerated but less effective alternative to hyperthermic isolated limb perfusion

BACKGROUND

Isolated limb infusion (ILI) is a recently described minimally invasive technique developed in Australia for delivering regional chemotherapy. This study examined the efficacy and toxicity of ILI, compared to hyperthermic isolated limb perfusion (HILP), in treating extremity in-transit melanoma.

METHODS

Variables from a prospective single institution database of 120 regionally treated melanoma patients (1995-2007) were compared using chi-square analysis. This included 61 consecutive ILI treatments in 58 patients and 59 HILP treatments in 54 patients. Response was defined at 3 months using the response evaluation criteria in solid tumors (RECIST). ILI was performed using melphalan (LPAM) and dactinomycin for 30 min after limb temperature reached 37 degrees C. HILP was performed using LPAM for 60 min after limb temperature reached 38.5 degrees C.

RESULTS

For ILI (n = 61), the complete response (CR) rate was 30%, the partial response (PR) rate was 14%, and there was no response (NR) in 56% of patients. The median duration of CR was 12 months and 18% of patients experienced (grade >or=3) toxicity. HILP (n = 59) was associated with a better (P < 0.001) response rate (CR 57%, PR 31%, and NR 12%) however, more patients (32%) experienced grade >or=3 toxicity (P = 0.037). The dose of LPAM was corrected for ideal body weight (IBW) in 40 out of 61 ILI procedures, and 13 of 59 HILP procedures. This dosing modification was associated with decreased toxicity (P = 0.024) without diminishing response.

CONCLUSION

ILI was found to be a well-tolerated alternative to HILP. While ILI does not appear to be as effective as HILP, it does seem to be associated with less morbidity.

Sentinel lymph node molecular ultrastaging in patients with melanoma: a systematic review and meta-analysis of prognosis

PURPOSE

Molecular biology-based ultrastaging of cancer is already part of the standard management of patients with hematologic malignancies, whereas the evidence for solid tumors is much more debated. Polymerase chain reaction (PCR) -based detection of melanoma cells in sentinel lymph nodes (SLN) of patients with melanoma represents an appealing prognostic tool. However, no consensus exists on the clinical implementation of this prognostic indicator for the management of these patients.

METHODS

Twenty-two studies enrolling 4,019 patients who underwent SLN biopsy for clinical stage I to II cutaneous melanoma were reviewed. Correlation of PCR status with TNM stage, disease recurrence rates, and survival was assessed by means of association statistics and formal meta-analysis, respectively.

RESULTS

PCR status correlated with both TNM stage (stage I to II v III; PCR positivity, 95.1% v 46.6%; P < .0001) and disease recurrence (PCR positive v negative; relapse rate, 16.8% v 8.7%; P < .0001). PCR positivity was also associated with worse overall (hazard ratio [HR], 5.08; 95% CI, 1.83 to 14.08; P = .002) and disease-free (HR, 3.41; 95% CI, 1.86 to 6.24; P < .0001) survival. Statistical heterogeneity was significant, underscoring the variability among overall effect estimates across studies; metaregression and subgroup analysis did not identify clear-cut sources of heterogeneity, although some study design variables were suggested as potential causes.

CONCLUSION

PCR status of SLN appears to have a clinically valuable prognostic power in patients with melanoma. Although the heterogeneity of the studies so far published warrants caution to avoid overestimating the favorable results of pooled data, our findings strongly support additional investigation in this field.

Randomized multicenter trial of hyperthermic isolated limb perfusion with melphalan alone compared with melphalan plus tumor necrosis factor: American College of Surgeons Oncology Group Trial Z0020

PURPOSE

To determine in a randomized prospective multi-institutional trial whether the addition of tumor necrosis factor alpha (TNF-alpha) to a melphalan-based hyperthermic isolated limb perfusion (HILP) treatment would improve the complete response rate for locally advanced extremity melanoma.

PATIENTS AND METHODS

Patients with locally advanced extremity melanoma were randomly assigned to receive melphalan or melphalan plus TNF-alpha during standard HILP. Patient randomization was stratified according to disease/treatment status and regional nodal disease status.

RESULTS

The intervention was completed in 124 patients of the 133 enrolled. Grade 4 adverse events were observed in 14 (12%) of 129 patients, with three (4%) of 64 in the melphalan-alone arm and 11 (16%) of 65 in the melphalan-plus-TNF-alpha arm (P = .0436). There were two toxicity-related lower extremity amputations in the melphalan-plus-TNF-alpha arm, and one disease progression-related upper extremity amputation in the melphalan-alone arm. There was no treatment-related mortality in either arm of the study. One hundred sixteen patients were assessable at 3 months postoperatively. Sixty-four percent of patients (36 of 58) in the melphalan-alone arm and 69% of patients (40 of 58) in the melphalan-plus-TNF-alpha arm showed a response to treatment at 3 months, with a complete response rate of 25% (14 of 58 patients) in the melphalan-alone arm and 26% (15 of 58 patients) in the melphalan-plus-TNF-alpha arm (P = .435 and P = .890, respectively).

CONCLUSION

In locally advanced extremity melanoma treated with HILP, the addition of TNF-alpha to melphalan did not demonstrate a significant enhancement of short-term response rates over melphalan alone by the 3-month follow-up, and TNF-alpha plus melphalan was associated with a higher complication rate.

Structure function relationships in the lymphatic system and implications for cancer biology

The lymphatic system, composed of lymphatic vessels, lymph, lymph nodes, and lymphocytes, is a distinctive vasculature (discontinuous basement membrane, open endothelial junctions, anchoring filaments, valves, and intrinsic contractility), different yet similar to the blood vasculature; an integral component of the plasma-tissue fluid-lymph circulation (the "blood-lymph loop"); and the center of the immunoregulatory network. Lymphatics are involved in diverse developmental, growth, repair, and pathologic processes both analogous to and distinct from those affecting the blood vasculature. Interference with the blood-lymph loop produces swelling [an imbalance between lymph formation (regulated by Starling's law of transcapillary fluid exchange) and lymph absorption], scarring, nutritional and immunodysregulatory disorders, as well as disturbances in lymph(hem)angiogenesis (lymphedema-angiodysplasia syndromes). The lymphatic system is also the stage on which key events during cancer development and progression are played out, and historically, also forms the basis for current evaluation, prognostication, and/or both operative and non-operative treatment of most cancers. Recent advances in molecular lymphology (e.g., discovery of lymphatic growth factors, endothelial receptors, transcription factors, genes, and highly specific immunohistochemical markers) and growing interest in lymphangiogenesis, combined with fresh insights and refined tools in clinical lymphology, including non-invasive lymphatic imaging, are opening up a window for translation to the clinical arena. Therefore, in cancer biology, attention to the multifaceted structure-function relationships within this vast, relatively unexplored system is long overdue.

The treatment of melanoma with an emphasis on immunotherapeutic strategies

Melanoma continues to be one of the most difficult to treat of all solid tumors. Many new advances have been made in the surgical management of melanoma, including new guidelines for margins of excision, as well as sentinel node biopsy for the diagnosis of lymph node micrometastases. The search continues for an effective adjuvant melanoma treatment that can prevent local and distant recurrences. Melanoma is one of the most immunogenic of all tumors, and several clinical trials testing the immunotherapy of melanoma have been conducted, including trials in interferon, interleukin-2, and melanoma vaccines. Here we discuss many of the recent clinical trials in the surgical management of melanoma, in addition to the advances that have been made in the field of immunotherapy. A new second-generation melanoma vaccine, DC-MelVac (patent # 11221/5), has recently been granted FDA approval for Phase I clinical trials and will be introduced in this review.

Assessment of the role of sentinel lymph node biopsy for primary cutaneous desmoplastic melanoma

BACKGROUND

The role of sentinel lymph node biopsy (SLNB) in the treatment of desmoplastic melanoma (DM) remains undefined. The purpose of this study was to evaluate the use of SLNB for DM.

METHODS

In all, 1850 patients with cutaneous melanoma underwent wide local excision and SLNB. Patients with DM were identified and stratified as 'pure' DM or 'mixed' DM (i.e., DM associated with at least one other common histologic subtype).

RESULTS

Of the 1850 patients, 65 (3.5%) had DM. Of these, 46 (70.8%) had pure DM and 19 (29.2%) had mixed DM. Patients with pure DM had a median tumor thickness of 3.5 mm and 6.5% were ulcerated. Compared with patients with pure DM, patients with either mixed DM or non-DM (n = 1785) had thinner primary tumors (median, 1.7 mm and 1.5 mm, respectively, each P < 0.001 vs. pure DM) that were more likely to be ulcerated (27.7% and 21.3%, respectively, each P < 0.05 vs. pure DM). Although the incidence of a positive SLN was similar in patients with mixed DM (15.8%) and non-DM (17.5%), patients with pure DM were less likely to have a positive SLN (2.2%) (each P < 0.01 vs. non-DM and mixed DM). At a median follow-up of 2.9 years, no patient with pure DM had recurred.

CONCLUSIONS

Despite having thicker primary tumors, patients with pure DM have a lower incidence of positive SLNs compared with patients with non-DM. Whereas the treatment approach for patients with mixed DM should be similar to that of other melanoma patients, patients with pure DM are unlikely to have metastatic disease in regional lymph nodes and SLNB may not be warranted.

Optimizing a Novel Regional Chemotherapeutic Agent against Melanoma: Hyperthermia-Induced Enhancement of Temozolomide Cytotoxicity

PURPOSE

Previous preclinical studies have shown that regional temozolomide therapy via isolated limb infusion is more effective than melphalan, the current drug of choice for regional chemotherapy for advanced extremity melanoma. The aim of this study was to determine whether hyperthermia could further augment the efficacy of temozolomide, an alkylating agent, against melanoma and improve its therapeutic index in a rat model of isolated limb infusion.

EXPERIMENTAL DESIGN

Athymic rats bearing s.c. human melanoma xenografts (DM6) in their hind limbs were randomized to a 15-minute isolated limb infusion procedure with or without temozolomide at room temperature, normothermic (37.5 degrees C), or hyperthermic (43 degrees C) conditions.

RESULTS

The concomitant administration of hyperthermia during an infusion with temozolomide led to the greatest increase in tumor growth delay, decreased proliferative index, and increased cell death. Isolated limb infusion treatment with a low dose (350 mg/kg) of temozolomide was ineffective at producing tumor growth delay (P = 0.07). Similarly, temozolomide infusion under normothermia yielded minimal tumor growth delay (P = 0.08). In contrast, the combination of hyperthermia plus temozolomide treatment produced marked tumor growth delay of 10.4 days (P = 0.02) with minimal toxicity. The addition of heat to temozolomide treatment yielded the smallest proliferative index (P = 0.001), while markedly increasing the level of apoptosis 48 hours after isolated limb infusion.

CONCLUSION

This study, the first to examine the interaction between hyperthermia and temozolomide, shows a strong, synergistic antitumor effect when hyperthermia is combined with temozolomide for regional treatment of melanoma confined to an extremity. The mechanism of this synergy seems to be through an augmentation, by hyperthermia, of the antiproliferative and proapoptotic effects of temozolomide.

Population-Based Assessment of Surgical Treatment Trends for Patients With Melanoma in the Era of Sentinel Lymph Node Biopsy

Purpose

The surgical staging of melanoma dramatically changed with the introduction of sentinel lymph node (SLN) biopsy. In this study, Surveillance, Epidemiology, and End Results (SEER) data were examined to determine how surgical treatment is being carried out and whether SLN biopsy is being performed in melanoma patients in conformance with National Comprehensive Cancer Network (NCCN) guidelines.

Patients and Methods

The SEER database (1998 to 2001) was searched for all patients with invasive melanoma. NCCN guidelines were used to define optimal stage-specific surgical treatment. Treatment trends in patients with stages I to III disease were summarized, and multivariate analyses were performed to identify factors associated with nonadherence with treatment guidelines.

Results

A total of 21,867 melanoma patients were identified; 18,499 of these patients met the inclusion criteria. The number of patients diagnosed with stage III melanoma increased by 55.7% over the study period, and this corresponded to a 53% increase in the number of SLN biopsies performed annually. The odds ratios for nonadherence were 2.32, 2.27, and 1.54 for stages IB, II, and III disease, respectively, compared with stage IA melanoma. Multivariate analyses revealed that age more than 65 years, marital status, minority populations, and primary tumor location were associated with nonadherence with guidelines. Treatment patterns among tumor registries also varied significantly.

Conclusion

Stage migration is evident in the SEER registries in consort with increasing use of SLN biopsy. Although treatment trends are improving, SLN biopsy continues to be underused, particularly in the elderly and minority populations, in patients with truncal and head/neck melanomas, and also in some geographic regions of the United States.

The new staging system for cutaneous melanoma in the era of lymphatic mapping

In 2002, the American Joint Committee on Cancer (AJCC) revised the staging system for cutaneous melanoma on the basis of a survival analysis of important melanoma prognostic factors. Features of the revised system include new strata for primary tumor thickness, incorporation of primary tumor ulceration as an important staging criterion in both the tumor (T) and node (N) classifications, revision of the N classification to reflect the prognostic significance of regional nodal tumor burden, and new categories for distant metastatic disease. These changes reflect evolving insight into melanoma arising from the results of numerous clinical investigations and database analyses. One of the most important recent changes in melanoma care is the establishment of lymphatic mapping and sentinel lymph node (SLN) biopsy as a highly accurate and minimally morbid technique for pathologic regional nodal staging. In this article, the salient features of the revised melanoma staging system are examined, with specific attention paid to its use in this era of lymphatic mapping and SLN biopsy.