A multicenter phase I dose escalation trial to evaluate safety and tolerability of intra-arterial temozolomide for patients with advanced extremity melanoma using normothermic isolated limb infusion

Molecular Aspects of the Isolated Limb Infusion Procedure

For decades, isolated limb infusion (ILI) and hyperthermic isolated limb perfusion (HILP) have been used to treat melanoma in-transit metastases and unresectable sarcoma confined to the limb utilizing the effect of loco-regional high-dose chemotherapy to the isolated limb. Both procedures are able to provide high response rates in patients with numerous or bulky lesions in whom other loco-regional treatments are becoming ineffective. In comparison to systemic therapies, on the other hand, ILI and HILP have the advantage of not being associated with systemic side-effects. Although in principle ILI and HILP are similar procedures, ILI is technically simpler to perform and differs from HILP in that it takes advantage of the hypoxic and acidotic environment that develops in the isolated limb, potentiating anti-tumour activity of the cytotoxic agents melphalan +/− actinomycin-D. Due to its simplicity, ILI can be used in both preclinical and clinical studies to test new cytotoxic regimens and combinations with the aim to overcome tumour resistance. In the future, administration of cytotoxic agents by ILI, in combination with systemic treatments such as BRAF/MEK/KIT inhibitors, immunotherapy (CTLA-4 blockade), and/or programmed death (PD-1) pathway inhibitors, has the potential to improve responses further by inducing increased tumour cell death while limiting the ability of the tumour to suppress the immune response.

Melanoma stem cell maintenance and chemo-resistance are mediated by CD133 signal to PI3K-dependent pathways

Melanoma stem cells (MSCs) are characterized by their unique cell surface proteins and aberrant signaling pathways. These stemness properties are either in a causal or consequential relationship to melanoma progression, treatment resistance and recurrence. The functional analysis of CD133⁺ and CD133^- cells in vitro and in vivo revealed that melanoma progression and treatment resistance are the consequences of CD133 signal to PI3K pathway. CD133 signal to PI3K pathway drives two downstream pathways, the PI3K/Akt/MDM2 and the PI3K/Akt/MKP-1 pathways. Activation of PI3K/Akt/MDM2 pathway results in the destabilization of p53 protein, while the activation of PI3K/Akt/MKP-1 pathway results in the inhibition of mitogen-activated protein kinases (MAPKs) JNK and p38. Activation of both pathways leads to the inhibition of fotemustine-induced apoptosis. Thus, the disruption of CD133 signal to PI3K pathway is essential to overcome Melanoma resistance to fotemustine. The pre-clinical verification of in vitro data using xenograft mouse model of MSCs confirmed the clinical relevance of CD133 signal as a therapeutic target for melanoma treatment. In conclusion, our study provides an insight into the mechanisms regulating MSCs growth and chemo-resistance and suggested a clinically relevant approach for melanoma treatment.

Locoregional management of in-transit metastasis in melanoma: an Ontario Health (Cancer Care Ontario) clinical practice guideline

Objective

The purpose of this guideline is to provide guidance on appropriate management of satellite and in-transit metastasis (itm) from melanoma.

Methods

The guideline was developed by the Program in Evidence-Based Care (pebc) of Ontario Health (Cancer Care Ontario) and the Melanoma Disease Site Group. Recommendations were drafted by a Working Group based on a systematic review of publications in the medline and embase databases. The document underwent patient- and caregiver-specific consultation and was circulated to the Melanoma Disease Site Group and the pebc Report Approval Panel for internal review; the revised document underwent external review.

Recommendations

"Minimal itm" is defined as lesions in a location with limited spread (generally 1-4 lesions); the lesions are generally superficial, often clustered together, and surgically resectable. "Moderate itm" is defined as more than 5 lesions covering a wider area, or the rapid development (within weeks) of new in-transit lesions. "Maximal itm" is defined as large-volume disease with multiple (>15-20) 2-3 cm nodules or subcutaneous or deeper lesions over a wide area.■ In patients presenting with minimal itm, complete surgical excision with negative pathologic margins is recommended. In addition to complete surgical resection, adjuvant treatment may be considered.■ In patients presenting with moderate unresectable itm, consider using this approach for localized treatment: intralesional interleukin 2 or talimogene laherparepvec as 1st choice, topical diphenylcyclopropenone as 2nd choice, or radiation therapy as 3rd choice. Evidence is insufficient to recommend intralesional bacille Calmette- Guérin or CO2 laser ablation outside of a research setting.■ In patients presenting with maximal itm confined to an extremity, isolated limb perfusion, isolated limb infusion, or systemic therapy may be considered. In extremely select cases, amputation could be considered as a final option in patients without systemic disease after discussion at a multidisciplinary case conference.■ In cases in which local, regional, or surgical treatments for itm might be ineffective or unable to be performed, or if a patient has systemic metastases at the same time, systemic therapy may be considered.

Isolated limb infusion: Institutional protocol and implementation

Patients with unresectable cutaneous and soft tissue malignancies confined to a limb have many treatment options. Isolated limb infusion (ILI) is one therapeutic option whereby the extremity is isolated and perfused with high-dose chemotherapy through a percutaneously placed catheter-based procedure. A detailed description of the ILI protocol at the Moffitt Cancer Center is given. We have shown that ILI is a safe and effective treatment strategy for malignancies confined to an extremity.

MGMT methylation correlates with melphalan pelvic perfusion survival in stage III melanoma patients: a pilot study

Approximately 25% of melanoma patients with locoregional metastases are nonresponsive to new molecular target therapy and immunotherapy. When metastases are located in the pelvis, melphalan hypoxic perfusion can be an optional treatment. Because methylation of MGMT promoter increases the efficacy of alkylating agents, studies on melanoma outcome of patients treated with melphalan regional chemotherapy should consider this epigenetic change. This study aims to evaluate whether the survival of stage III melanoma patients treated with melphalan regional chemotherapy may be correlated with MGMT methylation status. The metastatic tissues of 27 stage III melanoma patients with locoregional metastases located in the pelvis subjected to melphalan hypoxic pelvic perfusion were examined. The methylation status of the MGMT promoter was investigated by MS-MLPA probes analysis and the presence of the BRAF V600E mutation was analyzed by CAST-PCR. The median survival times were estimated using the Kaplan–Meier curves and were stratified according to the clinicopathological characteristics of patients and lesions. The overall median survival time was 17 months. The 1-year, 3-year, and 5-year survival rates were 66.7, 18.5, and 7.4%, respectively. Disease stage, burden, and percentage of MGMT methylation significantly affected survival. We estimated an MGMT promoter methylation cut-off of at least 14%, which was significantly associated with a longer survival after melphalan regional chemotherapy. Our data suggest that MGMT promoter methylation could be an important factor in determining which melanoma patients should receive melphalan regional chemotherapy, but its prognostic significance in the routine clinical setting needs to be clarified in a larger study.

Clinical and Prognostic Significance of O6-Methylguanine-DNA Methyltransferase Promoter Methylation in Patients with Melanoma: A Systematic Meta-Analysis

Tumor suppressor gene O⁶-methylguanine-DNA methyltransferase (MGMT) promoter methylation has been reported in melanoma. However, the clinical and prognostic significance of MGMT promoter methylation in patients with melanoma remained to be determined. A systematic search was performed to identify eligible papers published. The overall odds ratios (ORs) or hazard ratios and their 95% confidence intervals were calculated. Final 12 eligible publications involving Caucasian population were performed in this study, including 1,071 metastatic melanoma patients, 154 primary melanoma patients, and 211 normal controls. MGMT promoter methylation was significantly higher in primary or metastatic melanoma than in normal controls (p<0.05). No difference of MGMT promoter methylation was found in primary and metastatic melanoma (p=0.432). When metastatic melanoma was compared to normal controls, subgroup analysis showed the correlation between MGMT promoter methylation and different sample materials (tissue: OR=7.01, p<0.001 and blood: OR=12.04, p=0.005). MGMT promoter methylation was not associated with response to drug therapy and the prognosis in overall survival and progression-free survival for multivariate analysis. Our results show that MGMT promoter methylation may be correlated with the increased risk of primary or metastatic melanoma. Based on blood samples, MGMT promoter methylation may become a noninvasive biomarker for the detection of metastatic melanoma. Further additional clinical studies are necessary.

18F-FDG PET/CT and Melanoma: Value of Fourth and Subsequent Posttherapy Follow-up Scans for Patient Management

PURPOSE

We aimed to evaluate the added value of performing fourth and subsequent follow-up F-FDG-PET/CT scans to clinical assessment and impact on the patient's management in patients with melanoma.

METHODS

This was a retrospective study of 232 biopsy-proven melanoma patients who underwent F-FDG-PET/CT scans. Of these, 71 patients had 4 or more follow-up F-FDG-PET/CT scans after completion of primary treatment, with a total of 246 fourth or subsequent follow-up PET/CT scans. The added value of each follow-up PET/CT scan to the patient's clinical assessment and treatment management was established. Kaplan-Meier plots with a Mantel-Cox log-rank test were used to establish the patient's overall survival.

RESULTS

Of the 246 fourth and subsequent follow-up PET/CT scans, 61% (150/246) were negative for malignancy, and 39.0% (96/246) were positive for recurrence/metastases. FDG-PET/CT was helpful in identifying malignancy in 6.5% of the scans performed without prior clinical suspicion, which ruled out malignancy in 28.5% of the scans obtained with prior clinical signs suggestive of recurrence or for secondary therapy assessment. The PET/CT scan resulted in change of the patient's management in approximately 16.7% (41/246) of the scans. Change in management was significantly greater in patients whose scans were done with prior clinical signs suggestive of malignancy, or for therapy assessment than without prior clinical suspicion (29.3% vs 4.1%; P < 0.0001). Statistically significant difference was seen in the overall survival between patients with at least 1 positive and all negative fourth and subsequent follow-up PET/CT scans at patient level (P = 0.001).

CONCLUSIONS

The fourth and subsequent F-FDG-PET/CT scans obtained after completion of primary treatment added value to clinical assessment in patients with melanoma. Patients with clinical signs suggestive of recurrence or metastases or being monitored for treatment response are more likely to benefit from the fourth or subsequent FDG PET/CT than those without prior clinical suspicion.

Evaluating the cytotoxic effects of the water extracts of four anticancer herbs against human malignant melanoma cells

Malignant melanoma (MM) is the most dangerous type of skin cancer, killing more than 1,100 people each year in Canada. Prognosis for late stage and recurrent MM is extremely poor due to insensitivity to chemotherapy drugs, and thus many patients seek complementary and alternative medicines. In this study, we examined four commonly used anticancer herbs in traditional Chinese medicine, Hedyotis diffusa, Scutellaria barbata, Lobelia chinensis, and Solanum nigrum, for their in vitro antitumor effects toward human MM cell line A-375. The crude water extract of S. nigrum (1 g of dry herb in 100 mL water) and its 2-fold dilution caused 52.8%±13.0% and 17.3%±2.7% cytotoxicity in A-375 cells, respectively (P<0.01). The crude water extract of H. diffusa caused 11.1%±12.4% cytotoxicity in A-375 cells with no statistical significance (P>0.05). Higher concentrated formulation might be needed for H. diffusa to exert its cytotoxic effect against A-375 cells. No cytotoxicity was observed in A-375 cells treated with crude water extract of S. barbata and L. chinensis. Further high performance liquid chromatography-tandem mass spectroscopy analysis of the herbal extracts implicated that S. nigrum and H. diffusa might have adopted the same bioactive components for their cytotoxic effects in spite of belonging to two different plant families. We also showed that the crude water extract of S. nigrum reduced intracellular reactive oxygen species generation in A-375 cells, which may lead to a cytostatic effect. Furthermore, synergistic effect was achieved when crude water extract of S. nigrum was coadministered with temozolomide, a chemotherapy drug for skin cancer.

Results of a Randomized Controlled Multicenter Phase III Trial of Percutaneous Hepatic Perfusion Compared with Best Available Care for Patients with Melanoma Liver Metastases

PURPOSE

There is no consensus for the treatment of melanoma metastatic to the liver. Percutaneous hepatic perfusion with melphalan (PHP-Mel) is a method of delivering regional chemotherapy selectively to the liver. In this study, we report the results of a multicenter, randomized controlled trial comparing PHP-Mel with best alternative care (BAC) for patients with ocular or cutaneous melanoma metastatic to the liver.

PATIENTS AND METHODS

A total of 93 patients were randomized to PHP-Mel (n = 44) or BAC (n = 49). On the PHP-Mel arm, melphalan was delivered via the hepatic artery, and the hepatic effluent captured and filtered extracorporeally prior to return to the systemic circulation via a venovenous bypass circuit. PHP-Mel was repeatable every 4-8 weeks. The primary endpoint was hepatic progression-free survival (hPFS), and secondary endpoints included overall PFS (oPFS), overall survival (OS), hepatic objective response (hOR), and safety.

RESULTS

hPFS was 7.0 months for PHP-Mel and 1.6 months for BAC (p < 0.0001), while oPFS was 5.4 months for PHP-Mel and 1.6 months for BAC (p < 0.0001). Median OS was not significantly different (PHP-Mel 10.6 months vs. BAC 10.0 months), likely due to crossover to PHP-Mel treatment (57.1 %) from the BAC arm, and the hOR was 36.4 % for PHP-Mel and 2.0 % for BAC (p < 0.001). The majority of adverse events were related to bone marrow suppression. Four deaths were attributed to PHP-Mel, three in the primary PHP-Mel group, and one post-crossover to PHP-Mel from BAC.

CONCLUSION

This randomized, phase III study demonstrated the efficacy of the PHP-Mel procedure. hPFS, oPFS, and hOR were significantly improved with PHP-Mel. PHP with melphalan should provide a new treatment option for unresectable metastatic melanoma in the liver.

Connexin 43 Inhibition Sensitizes Chemoresistant Glioblastoma Cells to Temozolomide

Resistance of glioblastoma (GBM) to the front-line chemotherapeutic agent temozolomide (TMZ) continues to challenge GBM treatment efforts. The repair of TMZ-induced DNA damage by O-6-methylguanine-DNA methyltransferase (MGMT) confers one mechanism of TMZ resistance. Paradoxically, MGMT-deficient GBM patients survive longer despite still developing resistance to TMZ. Recent studies indicate that the gap junction protein connexin 43 (Cx43) renders GBM cells resistant to TMZ through its carboxyl terminus (CT). In this study, we report insights into how Cx43 promotes TMZ resistance. Cx43 levels were inversely correlated with TMZ sensitivity of GBM cells, including GBM stem cells. Moreover, Cx43 levels inversely correlated with patient survival, including as observed in MGMT-deficient GBM patients. Addition of the C-terminal peptide mimetic αCT1, a selective inhibitor of Cx43 channels, sensitized human MGMT-deficient and TMZ-resistant GBM cells to TMZ treatment. Moreover, combining αCT1 with TMZ-blocked AKT/mTOR signaling, induced autophagy and apoptosis in TMZ-resistant GBM cells. Our findings suggest that Cx43 may offer a biomarker to predict the survival of patients with MGMT-independent TMZ resistance and that combining a Cx43 inhibitor with TMZ could enhance therapeutic responses in GBM, and perhaps other TMZ-resistant cancers.

The Role of Regional Therapies for in-Transit Melanoma in the Era of Improved Systemic Options

The incidence of melanoma has been increasing at a rapid rate, with 4%–11% of all melanoma recurrences presenting as in-transit disease. Treatments for in-transit melanoma of the extremity are varied and include surgical excision, lesional injection, regional techniques and systemic therapies. Excision to clear margins is preferred; however, in cases of widespread disease, this may not be practical. Historically, intralesional therapies were generally not curative and were often used for palliation or as adjuncts to other therapies, but recent advances in oncolytic viruses may change this paradigm. Radiation as a regional therapy can be quite locally toxic and is typically relegated to disease control and symptom relief in patients with limited treatment options. Regional therapies such as isolated limb perfusion and isolated limb infusion are older therapies, but offer the ability to treat bulky disease for curative intent with a high response rate. These techniques have their associated toxicities and can be technically challenging. Historically, systemic therapy with chemotherapies and biochemotherapies were relatively ineffective and highly toxic. With the advent of novel immunotherapeutic and targeted small molecule agents for the treatment of metastatic melanoma, the armamentarium against in-transit disease has expanded. Given the multitude of options, many different combinations and sequences of therapies can be offered to patients with in-transit extremity melanoma in the contemporary era. Reported response and survival rates of the varied treatments may offer valuable information regarding treatment decisions for patients with in-transit melanoma and provide rationale for these decisions.

Regional therapies for in-transit disease

In-transit melanoma is an uncommon pattern of recurrence, but presents unique management challenges and opportunities for treatment. The clinical presentation usually involves from 1 to more than 100 small subcutaneous or cutaneous nodules, ranging from submillimeter to multiple centimeters in diameter. Regional chemotherapy techniques are a mainstay of treatment of patients without systemic disease spread. Future applications of regional therapy are likely to involve combination therapy with cytotoxic agents and novel immune modulators. Regional therapy provides distinct opportunities for the treatment of unresectable disease, and offers a unique platform for investigation of novel therapeutics in early-stage clinical trials.