Effect of temozolomide on central nervous system relapse in patients with advanced melanoma

Decoding the synergistic potential of MAZ-51 and zingerone as therapy for melanoma treatment in alignment with sustainable development goals

Melanoma, an invasive class of skin cancer, originates from mutations in melanocytes, the pigment-producing cells. Globally, approximately 132,000 new cases are reported each year, and in South Africa, the incidence stands at 2.7 per 100,000 people, signifying a worrisome surge in melanoma rates. Therefore, there is a need to explore treatment modalities that will target melanoma's signalling pathways. Melanoma metastasis is aided by ligand activity of transforming growth factor-beta 1 (TGF-β1), vascular endothelial growth factor-C (VEGF-C) and C-X-C chemokine ligand 12 (CXCL12) which bind to their receptors and promote tumour cell survival, lymphangiogenesis and chemotaxis. (3-(4-dimethylaminonaphthelen-1-ylmethylene)-1,3-dihydroindol-2-one) MAZ-51 is an indolinone-based molecule that inhibits VEGF-C induced phosphorylation of vascular endothelial growth factor receptor 3 (VEGFR-3). Despite the successful use of conventional cancer therapies, patients endure adverse side effects and cancer drug resistance. Moreover, conventional therapies are toxic to the environment and caregivers. The use of medicinal plants and their phytochemical constituents in cancer treatment strategies has become more widespread because of the rise in drug resistance and the development of unfavourable side effects. Zingerone, a phytochemical derived from ginger exhibits various pharmacological properties positioning it as a promising candidate for cancer treatment. This review provides an overview of melanoma biology and the intracellular signalling pathways promoting cell survival, proliferation and adhesion. There is a need to align health and environmental objectives within sustainable development goals 3 (good health and well-being), 13 (climate action) and 15 (life on land) to promote early detection of skin cancer, enhance sun-safe practices, mitigation of environmental factors and advancing the preservation of biodiversity, including medicinal plants. Thus, this review discusses the impact of cytostatic cancer drugs on patients and the environment and examines the potential use of phytochemicals as adjuvant therapy.

Is There a Current Role for Combination Chemotherapy or High-Dose Interleukin 2 in Melanoma?

ABSTRACT

Immune checkpoint inhibition and targeted therapies have revolutionized the treatment of melanoma. However, chemotherapy and interleukin 2 (IL-2) therapy may still have a role in the later-line treatment of patients who do not have durable responses to other treatments. Chemotherapy can work transiently in patients whose disease has progressed on immune checkpoint inhibitors and for whom there are no appropriate targeted therapy options. High-dose IL-2 therapy can still be effective for a very small number of patients following progression on other therapies. In addition, modified IL-2 agents and IL-2 in combination with tumor-infiltrating lymphocyte therapy may play a role in future treatments for melanoma.

Chemotherapy in Cutaneous Melanoma: Is There Still a Role?

Purpose of Review

In the preceding decade, the management of metastatic cutaneous melanoma has been revolutionised with the development of highly effective therapies including immune checkpoint inhibitors (specifically CTLA-4 and PD-1 inhibitors) and targeted therapies (BRAF and MEK inhibitors). The role of chemotherapy in the contemporary management of melanoma is undefined.

Recent Findings

Extended analyses highlight substantially improved 5-year survival rates of approximately 50% in patients with metastatic melanoma treated with first-line therapies. However, most patients will progress on these first-line treatments. Sequencing of chemotherapy following failure of targeted and immunotherapies is associated with low objective response rates and short progression-free survival, and thus, meaningful benefits to patients are minimal.

Summary

Chemotherapy has limited utility in the contemporary management of cutaneous melanoma (with a few exceptions, discussed herein) and should not be the standard treatment sequence following failure of first-line therapies. Instead, enrolment onto clinical trials should be standard-of-care in these patients.

Adjuvant systemic treatment for high-risk resected non-cutaneous melanomas: What is the evidence?

Non-cutaneous melanomas (mucosal, uveal, leptomeningeal, unknown primaries) represent around 5-10 % of all melanoma diagnoses. Non-cutaneous melanomas demonstrate differences in tumour biology, generally present with more advanced stages and have an overall poorer prognosis compared to skin melanomas. The cornerstone of their treatment is surgery followed by radiotherapy in some cases. Unfortunately, in many of these patients their melanoma will recur. Adjuvant therapy for non-cutaneous melanomas remains controversial. To date, almost all of the tested adjuvant agents have failed to demonstrate any benefit; the two randomised positive trials were criticized for methodological reasons, small sample size and conflicting results. The aim of this review is to assess the current evidence on systemic adjuvant treatments for high-risk resected non-cutaneous melanomas. We also provide a summary table with the currently recruiting clinical trials in these settings and we discuss some strategies to improve trial design in this particularly niche area of oncology.

Neurocutaneous Melanosis with Leptomeningeal Melanoma Involving Supratentorium and Infratentorium

Neurocutaneous melanoma is a rare congenital syndrome associated with congenital melanocytic nevi with meningeal melanosis or melanoma. The disease is aggressive and has a high propensity for leptomeningeal metastases. We present the case history of a man with neurocutaneous melanoma managed with radical excision followed by hypofractionated adjuvant radiotherapy. One year, eight months later, he had a recurrence of the condition with leptomeningeal spread and was managed with re-excision of the recurrent lesion. Although our patient was disease-free for 20 months after the initial surgery, he survived only approximately five months after the second surgery, which reflects the associated poor prognosis of the disease.

Immunological effects of chemotherapy and radiotherapy against brain tumors

INTRODUCTION

The mainstays of brain tumor therapy are surgery, radiotherapy and chemotherapy. Cancer immunotherapy is explored as an additional treatment modality. However, emerging evidence indicates that also radio- and chemotherapy have immunological effects in addition to their cytotoxic and cytostatic activities.

AREA COVERED

We summarize the literature on radio- and chemotherapy-mediated immunological effects in primary and secondary brain tumors and outline open questions within the field. To this end, a literature search was performed using the terms 'brain tumor', 'immune system', 'immunogenic cell death', 'vaccination', 'checkpoint inhibition', 'radiotherapy', 'chemotherapy' and derivations thereof. Expert commentary: Immunological effects of chemo- and radiotherapy in brain tumors involve direct immunogenic modulations of tumor cells, changes of the microenvironment and functional alterations of innate and adaptive immune cells. Each treatment modality can exert various effects that comprise both immune-stimulatory and immunosuppressive mechanisms. A detailed knowledge of these mechanisms is indispensable for an optimal combination of conventional anti-tumor treatments and novel immunotherapeutic approaches.

A phase 2 study of radiosurgery and temozolomide for patients with 1 to 4 brain metastases

PURPOSE

To determine if temozolomide reduces the risk of distant brain failure (DBF, metachronous brain metastases) in patients with 1 to 4 brain metastases treated with radiosurgery without whole-brain radiation therapy (WBRT).

METHODS AND MATERIALS

Twenty-five patients with newly diagnosed brain metastases were enrolled in a single institution phase 2 trial of radiosurgery (15-24 Gy) and adjuvant temozolomide. Temozolomide was continued for a total of 12 cycles unless the patient developed DBF, unacceptable toxicity, or systemic progression requiring other therapy.

RESULTS

Twenty-five patients were enrolled between 2002 and 2005; 3 were not evaluable for determining DBF. Of the remaining 22 patients, tumor types included non-small cell lung cancer (n = 8), melanoma (n = 7), and other (n = 7). Extracranial disease was present in 10 (45%) patients. The median number of tumors at the time of radiosurgery was 3 (range, 1-6). The median overall survival was 31 weeks. The median radiographic follow-up for patients who did not develop DBF was 33 weeks. Six patients developed DBF. The 1-year actuarial risk of DBF was 37%.

CONCLUSIONS

In this study, there was a relatively low risk of distant brain failure observed in the nonmelanoma subgroup receiving temozolamide. However, patient selection factors rather than chemotherapy treatment efficacy are more likely the reason for the relatively low risk of distant brain failure observed in this study. Future trial design should account for these risk factors.

Chemotherapy for Melanoma

Prior to the recent therapeutic advances, chemotherapy was the mainstay of treatment options for advanced-stage melanoma. A number of studies have investigated various chemotherapy combinations in order to expand on the clinical responses achieved with single-agent dacarbazine, but these have not demonstrated an improvement in overall survival. Similar objective responses were observed with the combination of carboplatin and paclitaxel as were seen with single-agent dacarbazine. The combination of chemotherapy and immunotherapy, known as biochemo-therapy, has shown high clinical responses; however, biochemo-therapy has not been shown to improve overall survival and resulted in increased toxicities. In contrast, palliation and long-term responses have been observed with localized treatment with isolated limb perfusion or infusion in limb-isolated disease. Although new, improved therapeutic options exist for first-line management of advanced-stage melanoma, chemotherapy may still be important in the palliative treatment of refractory, progressive, and relapsed melanoma. We review the various chemotherapy options available for use in the treatment and palliation of advanced-stage melanoma, discuss the important clinical trials supporting the treatment recommendations, and focus on the clinical circumstances in which treatment with chemotherapy is useful.

Role of ventriculoperitoneal shunting in patients with neoplasms of the central nervous system: An analysis of 59 cases

Approximately 1-5% of patients with cerebral metastasis and ~40% of patients with primary brain tumors suffer from hydrocephalus. These patients often exhibit a poor prognosis. The aim of the present study was to reassess the validity of ventriculoperitoneal shunting (VPS) with the assistance of the general surgeon in oncological patients. A total of 59 patients underwent first-time VPS at the Beth Israel Deaconess Medical Center (Boston, USA) between 2004 and 2012; 40 patients had hydrocephalus from brain metastasis and 19 from primary tumors. The analyzed independent variables included demographics, body mass index, past medical history, clinical presentation, indication for surgery, Karnofsky performance status (KPS) score and surgical technique; the dependent variables were postoperative symptoms and occurrence, cause and time of shunt failure. The outcomes were analyzed with the t-test and Kaplan-Meier estimates for shunt survival. The mean age of the patients was 57.2 years and the mean operative time was 50.4 min. Symptomatic palliation was achieved in 93% of the cases; patients with severe symptoms, such as debilitating headaches, nausea and vomiting, benefited significantly from VPS. The mean follow-up time was 6.3 months; complications occurred in only 7 patients (11.8%) during follow-up: 2 in the proximal shunt (1 infection and 1 obstruction), both requiring revision, 1 infection in the distal catheter requiring shunt removal, 2 cases of intracerebral bleeding that were monitored with computed tomography scans, 1 wound infection treated with antibiotics and 1 valve complication that required temporary revision. The initial and 3-month KPS scores were 65±16.4 and 75±16.0, respectively. The mean overall shunt survival was 6.4 months (range, 1.0 day-76.0 months) from the placement of the VP shunt. At 3 months after VPS, 93.5% of the patients remained alive with functioning shunts and at 1 year 87% of the shunts were still functioning. In conclusion, VPS remains a valid option for cancer patients with low KPS, as it improves the quality of life in such patients, even in the setting of previous infection, hemorrhage, or leptomeningeal disease, since shunt patency outlasts the overall survival of nearly all patients.

Primary Intracranial Melanoma with Early Leptomeningeal Spread: A Case Report and Treatment Options Available

Primary CNS melanomas are rare and they constitute about 1% of all cases of melanomas and 0.07% of all brain tumors. These tumors are aggressive in nature and may metastasise to other organs. Till date less than 25 cases have been reported in the literature. The primary treatment for local intraparenchymal tumours is complete resection and/or radiotherapy and it is associated with good survival. However once there is disease spread to leptomeninges the overall median survival is around 10 weeks. In this case report we describe a primary intracranial melanoma without any dural attachment in 16-year-old boy who had radical excision of the tumor followed by radiotherapy who eventually had rapidly developed leptomeningeal disease and review the literature with a focus on the clinic pathological, radiological, and treatment options.

Profound prevention of experimental brain metastases of breast cancer by temozolomide in an MGMT-dependent manner

PURPOSE

Brain metastases of breast cancer cause neurocognitive damage and are incurable. We evaluated a role for temozolomide in the prevention of brain metastases of breast cancer in experimental brain metastasis models.

EXPERIMENTAL DESIGN

Temozolomide was administered in mice following earlier injection of brain-tropic HER2-positive JIMT-1-BR3 and triple-negative 231-BR-EGFP sublines, the latter with and without expression of O(6)-methylguanine-DNA methyltransferase (MGMT). In addition, the percentage of MGMT-positive tumor cells in 62 patient-matched sets of breast cancer primary tumors and resected brain metastases was determined immunohistochemically.

RESULTS

Temozolomide, when dosed at 50, 25, 10, or 5 mg/kg, 5 days per week, beginning 3 days after inoculation, completely prevented the formation of experimental brain metastases from MGMT-negative 231-BR-EGFP cells. At a 1 mg/kg dose, temozolomide prevented 68% of large brain metastases, and was ineffective at a dose of 0.5 mg/kg. When the 50 mg/kg dose was administered beginning on days 18 or 24, temozolomide efficacy was reduced or absent. Temozolomide was ineffective at preventing brain metastases in MGMT-transduced 231-BR-EGFP and MGMT-expressing JIMT-1-BR3 sublines. In 62 patient-matched sets of primary breast tumors and resected brain metastases, 43.5% of the specimens had concordant low MGMT expression, whereas in another 14.5% of sets high MGMT staining in the primary tumor corresponded with low staining in the brain metastasis.

CONCLUSIONS

Temozolomide profoundly prevented the outgrowth of experimental brain metastases of breast cancer in an MGMT-dependent manner. These data provide compelling rationale for investigating the preventive efficacy of temozolomide in a clinical setting.

Treatment of brain metastases in uncommon tumors

Melanoma spreads to the CNS with an incidence of 4 to 20%. Metastases from cancer of the colorectal and genitourinary tract, as well as sarcoma, are less frequent (1%). Surgery should be considered for single brain metastases in patients with controllable disease. Stereotactic needle biopsy may still be worthwhile to confirm diagnosis, and also in patients whose tumors are considered unresectable. Whole-brain radiotherapy is the treatment of choice for most brain metastases, since more than 70% of patients have multiple metastases at the time of diagnosis. Radiosurgery is particularly useful for patients unable to tolerate surgery and for patients with lesions inaccessible to surgery. Chemotherapy could be useful in patients with asymptomatic brain metastases and uncontrolled extracranial disease, depending on performance status and previous chemotherapy received.

Advances in therapy for melanoma brain metastases

Melanoma cells frequently metastasize to the brain, and approximately 50% of patients with metastatic melanoma develop intracranial disease. Historically, central nervous system dissemination has portended a very poor prognosis. Recent advances in systemic therapies for melanoma, supported by improved local therapy control of brain lesions, have resulted in better median survival for these patients. We review current local and systemic approaches for patients with melanoma brain metastases.

Revisiting the role of systemic therapies in patients with metastatic melanoma to the CNS

The CNS is a common site of metastasis in patients with malignant melanoma. Locoregional control either with surgery or radiotherapy is first-line treatment for patients with brain metastasis should they be suitable candidates. For those patients who are not and those who progress after previous treatment, there is an unmet clinical need for effective systemic therapies. Systemic cytotoxics, such as temozolamide and fotemustine, have only modest activity, resulting in a median progression-free survival ranging from 1-2 months, in patients with metastatic melanoma to the brain. Newer systemic treatments such as vemurafenib and ipilimumab have been approved for the treatment of melanoma, but evidence regarding their activity in brain metastases is inconclusive due to the limited access of patients to clinical trials. This is now being revised and more data are emerging supporting the inclusion of patients with brain metastasis in trials. In this review, the authors present data regarding the efficacy of systemically administered therapies in patients with metastatic melanoma to the brain.

Innovative therapeutic strategies in the treatment of brain metastases

Brain metastases (BM) are the most common intracranial tumors and their incidence is increasing. Untreated brain metastases are associated with a poor prognosis and a poor performance status. Metastasis development involves the migration of a cancer cell from the bulk tumor into the surrounding tissue, extravasation from the blood into tissue elsewhere in the body, and formation of a secondary tumor. In the recent past, important results have been obtained in the management of patients affected by BM, using surgery, radiation therapy, or both. Conventional chemotherapies have generally produced disappointing results, possibly due to their limited ability to penetrate the blood-brain barrier. The advent of new technologies has led to the discovery of novel molecules and pathways that have better depicted the metastatic process. Targeted therapies such as bevacizumab, erlotinib, gefitinib, sunitinib and sorafenib, are all licensed and have demonstrated improved survival in patients with metastatic disease. In this review, we will report current data on targeted therapies. A brief review about brain metastatic process will be also presented.

Temozolomide and unusual indications: review of literature

Temozolomide (TMZ) was first known to be useful as a radiosensitiser in both primary brain tumours like glioblastoma multiforme and oligodendroglioma. Later, TMZ proved its efficacy in the treatment of melanoma. Multiple publications have demonstrated the benefit of TMZ in terms of efficacy and tolerance (used as mono-therapy or as adjuvant chemotherapy) compared to the "gold standard" treatment of this kind of tumours. Furthermore, several recent clinical trials have shown the particular importance of TMZ in other types of cancer. This publication deals with the use of TMZ in cancers which are not formal indications for TMZ (excluding glioblastoma multiforme, oligodendroglioma and melanoma). It also includes a necessary review of recent literature about the role of TMZ in the treatment of brain metastases, lymphomas, refractory leukaemia, neuroendocrine tumours, pituitary tumours, Ewing's sarcoma, primitive neuroectodermal tumours, lung cancer and other tumours.

Central nervous system failure in melanoma patients: results of a randomised, multicentre phase 3 study of temozolomide- and dacarbazine- based regimens

Background:

This study compared the central nervous system (CNS) metastasis incidence between a temozolomide- and a dacarbazine-based regimen in untreated stage IV melanoma patients.

Methods:

A total of 150 patients were randomly assigned to receive either oral temozolomide (200 mg m⁻² per day; days 1–5) or intravenous dacarbazine (800 mg m⁻²; day 1), in combination with intravenous cisplatin (75 mg m⁻²; day 1) and subcutaneous interleukin-2 (3 MU twice daily; days 9–18), every 28 days (CTI and CDI).

Results:

A total of 149 patients were eligible for an intention-to-treat analysis (CTI: n=74, CDI: n=75). The 1-year cumulative CNS incidence failure was 20.6% for CTI and 31.1% for CDI (P=0.22). In all 24 patients in CTI (32%) and 34 (45%) in CDI developed CNS metastases; 31 patients died of early systemic progression, before CNS evaluation. Median survival time was 8.4 months in the CTI and 8.7 in the CDI arm; in patients with CNS metastases the median survival time was 13.5 months in the CTI and 11.5 in the CDI arm. No difference in toxicity was observed between the two arms.

Conclusion:

The incidence of CNS failures in metastatic melanoma was not significantly reduced and the clinical course was not modified substituting a dacarbazine-based regimen with a temozolomide–based regimen. Patients who developed CNS metastases did not have a worse prognosis than patients progressing in other sites and should not be excluded from new investigational studies.

Combining temozolomide with other antitumor drugs and target-based agents in the treatment of brain metastases: an unending quest or chasing a chimera?

INTRODUCTION

Medical treatment of brain metastases (BM) is still a controversial issue in cancer therapy being mainly limited by the existence of the BBB. Temozolomide (TMZ) can cross BBB and several clinical trials have been performed attempting to demonstrate the activity of TMZ in combination with whole brain radiotherapy (WBRT) in the treatment of BM.

AREAS COVERED

This review summarizes TMZ-WBRT combination trials highlighting the confounding factors that limit the interpretation of the achieved results and describes the main clinical trials using TMZ in combination with other cytotoxic or biological agents. The main limitations of these trials are: i) patient selection for heterogenous primitive neoplasms and for heterogeneous neuro-functional score; ii) poor penetration across BBB of the other drugs; iii) cumulative toxicity and iv) poor control of extracranial tumor sites.

EXPERT OPINION

Biotechnological, biological and biochemical advances in the management of BM could allow in short time the definition of new schedules based on the rational use of new anticancer weapons. The latter could be cytotoxic agents encapsulated in nanotechnological tools able to cross BBB, lipophilic small kinase inhibitors (lapatinib, sunitinib), mTOR inhibitors and PARP inhibitors combined with old drugs such as TMZ.

Phase I safety study of lenalidomide and dacarbazine in patients with metastatic melanoma previously untreated with systemic chemotherapy

This phase I trial assessed the maximal tolerated dose (MTD) of dacarbazine in combination with lenalidomide in metastatic melanoma. Cohorts of three to six patients with metastatic melanoma without brain metastases were enrolled at each of three dose levels of dacarbazine: 600 mg/m², 800 mg/m², and 1000 mg/m² administered intravenously every 3 weeks. Lenalidomide (25 mg/day) was administered orally for 14 days followed by a 7-day rest. Safety was assessed every 3 weeks, and tumor response was evaluated every 6 weeks. An additional 10 patients were enrolled in an expansion cohort at MTD level. Twenty-eight chemotherapy-naive patients were enrolled. The MTD was determined to be dose level 2 (800 mg/m²). Three patients experienced a grade 4 adverse reaction; two pulmonary emboli and one cerebral ischemia. Two patients had a deep venous thrombosis. Of 27 patients assessable for disease response, two experienced a complete response and four experienced a partial response. The median overall survival was 10.6 months (range 1.6-46.0+ months). One patient had a small brain lesion at the baseline; 10 additional patients developed brain metastasis at 0-10.8 months after completion of study therapy. The combination of dacarbazine and lenalidomide is safe and well tolerated in patients with metastatic melanoma. Clinical activity was seen at the MTD level. Additional measures to prevent brain metastasis are needed for patients who achieve a response.

Treatment of cutaneous melanoma: current approaches and future prospects

Melanoma is the most aggressive and deadly type of skin cancer. Surgical resection with or without lymph node sampling is the standard of care for primary cutaneous melanoma. Adjuvant therapy decisions may be informed by careful consideration of prognostic factors. High-dose adjuvant interferon alpha-2b increases disease-free survival and may modestly improve overall survival. Less toxic alternatives for adjuvant therapy are currently under study. External beam radiation therapy is an option for nodal beds where the risk of local recurrence is very high. In-transit melanoma metastases may be treated locally with surgery, immunotherapy, radiation, or heated limb perfusion. For metastatic melanoma, the options include chemotherapy or immunotherapy; targeted anti-BRAF and anti-KIT therapy is under active investigation. Standard chemotherapy yields objective tumor responses in approximately 10%-20% of patients, and sustained remissions are uncommon. Immunotherapy with high-dose interleukin-2 yields objective tumor responses in a minority of patients; however, some of these responses may be durable. Identification of activating mutations of BRAF, NRAS, c-KIT, and GNAQ in distinct clinical subtypes of melanoma suggest that these are molecularly distinct. Emerging data from clinical trials suggest that substantial improvements in the standard of care for melanoma may be possible.

Treatment of cutaneous melanoma: current approaches and future prospects

Melanoma is the most aggressive and deadly type of skin cancer. Surgical resection with or without lymph node sampling is the standard of care for primary cutaneous melanoma. Adjuvant therapy decisions may be informed by careful consideration of prognostic factors. High-dose adjuvant interferon alpha-2b increases disease-free survival and may modestly improve overall survival. Less toxic alternatives for adjuvant therapy are currently under study. External beam radiation therapy is an option for nodal beds where the risk of local recurrence is very high. In-transit melanoma metastases may be treated locally with surgery, immunotherapy, radiation, or heated limb perfusion. For metastatic melanoma, the options include chemotherapy or immunotherapy; targeted anti-BRAF and anti-KIT therapy is under active investigation. Standard chemotherapy yields objective tumor responses in approximately 10%-20% of patients, and sustained remissions are uncommon. Immunotherapy with high-dose interleukin-2 yields objective tumor responses in a minority of patients; however, some of these responses may be durable. Identification of activating mutations of BRAF, NRAS, c-KIT, and GNAQ in distinct clinical subtypes of melanoma suggest that these are molecularly distinct. Emerging data from clinical trials suggest that substantial improvements in the standard of care for melanoma may be possible.

The safety of temozolomide in the treatment of malignancies

BACKGROUND

Temozolomide (TMZ) has demonstrated clinical antitumor activity. In the US and the EU, TMZ is licensed for the treatment of glioblastoma multiforme concurrently with radiation followed by a maintenance treatment, and for refractory anaplastic astrocytoma or glioblastoma multiforme. TMZ is also approved for metastatic melanoma in > 20 countries worldwide.

OBJECTIVES

To ascertain the safety profile of TMZ.

METHODS

Synthesis of evidence from published clinical trials and the investigator's brochure of the manufacture.

CONCLUSION

For a cytotoxic cancer-treatment agent, TMZ has an acceptable safety profile. Lymphopenia is common in patients treated with all doses and schedules of TMZ. All patients receiving TMZ should be observed for lymphopenia and potential opportunistic infections, particularly when it is combined with other immune suppressive therapies.

The history and future of chemotherapy for melanoma

Melanoma is considered a chemotherapy-resistant cancer, but in reality there are several chemotherapy drugs with significant single-agent activity. Response rates to combination regimens are reproducibly higher than with standard dacarbazine, but of the randomized trials comparing combination regimens with dacarbazine, none were of sufficient size to detect a realistic effect on survival. Similarly, adjuvant chemotherapy has not had a realistic test in melanoma. Response to chemotherapy is associated reproducibly with better survival rates suggesting that regimens with higher response rates are needed. Recent observations suggest that combining antiangiogenic agents with either dacarbazine or temozolomide can double response rates. These combinations are worthy of further investigation and might serve as a foundation on which to build a combination regimen that improves overall survival in metastatic melanoma patients.

Genomic and molecular profiling predicts response to temozolomide in melanoma

PURPOSE

Despite objective response rates of only approximately 13%, temozolomide remains one of the most effective single chemotherapy agents against metastatic melanoma, second only to dacarbazine, the current standard of care for systemic treatment of melanoma. The goal of this study was to identify molecular and/or genetic markers that correlate with, and could be used to predict, response to temozolomide-based treatment regimens and that reflect the intrinsic properties of a patient's tumor.

EXPERIMENTAL DESIGN

Using a panel of 26 human melanoma-derived cell lines, we determined in vitro temozolomide sensitivity, O(6)-methylguanine-DNA methyltransferase (MGMT) activity, MGMT protein expression and promoter methylation status, and mismatch repair proficiency, as well as the expression profile of 38,000 genes using an oligonucleotide-based microarray platform.

RESULTS

The results showed a broad spectrum of temozolomide sensitivity across the panel of cell lines, with IC(50) values ranging from 100 micromol/L to 1 mmol/L. There was a significant correlation between measured temozolomide sensitivity and a gene expression signature-derived prediction of temozolomide sensitivity (P < 0.005). Notably, MGMT alone showed a significant correlation with temozolomide sensitivity (MGMT activity, P < 0.0001; MGMT expression, P <or= 0.0001). The promoter methylation status of the MGMT gene, however, was not consistent with MGMT gene expression or temozolomide sensitivity.

CONCLUSIONS

These results show that melanoma resistance to temozolomide is conferred predominantly by MGMT activity and suggest that MGMT expression could potentially be a useful tool for predicting the response of melanoma patients to temozolomide therapy.

Management of malignant melanoma: best practices

BACKGROUND

Melanoma is a commonly occurring cancer in Canada, with an estimated age-standardized incidence of 10 to 13 per 100,000. An estimated 4,300 new cases were diagnosed, and there were 800 reported deaths in 2005.

OBJECTIVE AND CONCLUSION

The Canadian Expert Panel on Malignant Melanoma has developed best practices to improve the management of malignant melanoma. Sections include recommendations on primary diagnosis, dermatopathologic assessment, and reporting; use of preoperative lymphoscintigraphy and an intraoperative gamma probe to map and biopsy the sentinel lymph node; indications for surgical resection, sentinel node biopsy, and surgery for advance disease; use of interferon-alpha adjuvant therapy and treatment options for stage IV disease; and management of central nervous system metastases.

Temozolomide associated with PEG-interferon in patients with metastatic melanoma: a multicenter prospective phase I/II study

Metastatic melanoma treatment remains disappointing, and a combined approach by chemotherapy and immunotherapy might increase the response rates through a synergistic action. Accordingly, a clinical trial using oral temozolomide (TMZ) and subcutaneous PEG-interferon alpha-2b (PEG) in patients with metastatic melanoma was designed to determine the maximal tolerated dosage of both drugs and the antitumoral response. A multicenter, prospective, phase I/II study was conducted in 31 metastatic melanoma patients, without cerebral metastasis. Dose escalation was performed according to the modified continual reassessment method scale and resulted in four cohorts of patients: TMZ 150 mg/m2 5 days/week each 4 weeks and PEG 0.5 microg/kg/week - TMZ 150 mg/m2 5 days/week and PEG 1.0 microg/kg/week - TMZ 200 mg/m2 5 days/week and PEG 0.5 microg/kg/week - TMZ 200 mg/m2 5 days/week and PEG 1.0 microg/kg/week. Patients received a maximum of six cycles. Thirty-three patients were enrolled in this study: one in the first dose level, one in the second one, 18 in the third one and 11 in the fourth one. At level 4, four of 11 patients experienced dose-limiting toxicity and four nondose-limiting toxicity; toxicity was mainly hematologic (grade IV thrombocytopenia). An objective response was observed in five patients (two complete response and three partial response) receiving level 3 or 4 of treatment. The disease remained stable in three patients, and six of 31 patients were alive 24 months after enrollment. The association of oral TMZ with subcutaneous PEG in metastatic melanoma displayed an unacceptable hematological toxicity with the dosages of 200 mg/m2 5 days/week and 1 microg/week, respectively. At a lower level, this treatment was effective and deserves further investigations to define its indications in metastatic melanoma patients.

Brain and leptomeningeal metastases from cutaneous melanoma: survival outcomes based on clinical features

Brain metastases (BM) are among the most devastating and debilitating complications of melanoma. This retrospective study was conducted to gain a better understanding of patient and disease characteristics that have the greatest impact on overall survival in melanoma patients with BM; therapeutic interventions were also assessed. The records of all patients diagnosed with cutaneous melanoma and BM who were seen at Memorial Sloan-Kettering Cancer Center between 1991 and 2001 were retrospectively reviewed. A variety of factors, including age at diagnosis of stage IV disease, gender, race, disease stage at diagnosis, presence of BM at diagnosis of stage IV disease, neurologic symptoms, radiographic findings, number of BM, status and site(s) of extracranial metastasis, and treatment modalities, were analyzed for correlation with overall survival using univariate and multivariate Cox regression models. The records of 355 patients with BM were included in the analysis. On univariate analysis, seven patient and disease characteristics were significantly associated with poorer survival: age > 65 years, extracranial metastases, BM at stage IV diagnosis, neurologic symptoms, four or more BM, hydrocephalus, and leptomeningeal metastases. Of these, age, extracranial metastasis, neurologic symptoms, and number of BM were significantly associated with poorer survival in a multivariate analysis. Multivariate analysis of treatment modalities suggested that patients who had surgery, radiosurgery, or chemotherapy with temozolomide had improved survival outcomes, although this analysis has limitations. The prognostic factors identified in this retrospective study should be considered when making treatment decisions for patients with BM and used as stratification factors in future clinical trials.

Management of metastatic melanoma patients with brain metastases

Brain metastases seem to be an almost inevitable complication in patients with metastatic melanoma. Except for the rare patients who can undergo successful surgical resection of brain metastases, current management strategies do not appear adequate and result in a poor outcome (median survival, 2-4 months). In recent small series, stereotactic radiosurgery or gamma-knife treatment has suggested improvement in local control compared with whole brain radiation therapy. We have recently shown prolonged survival (11.1 months) using a multimodality treatment approach in 44 sequential patients with melanoma brain metastases. A subsequent study demonstrated that the outcome of biochemotherapy for metastatic melanoma is not affected by the presence or absence of brain metastases. Our results suggest that the outcome of patients with melanoma brain metastases can be improved using a multidisciplinary management strategy.

Temozolomide for the treatment of metastatic melanoma: a systematic review

BACKGROUND

This systematic review examines the role of temozolomide in patients with metastatic melanoma. Outcomes of interest include response rate, progression-free survival, overall survival, quality of life, and adverse effects.

METHODS

The MEDLINE, EMBASE, and Cochrane Library databases were searched from 1980 through to 2005 using variations on the search terms: melanoma, clinical trial, random, temozolomide, temodal, and temodar. The American Society of Clinical Oncology Annual Meeting proceedings were searched from 1996 to 2005. Relevant articles and abstracts were selected and reviewed by two reviewers, and the reference lists from these sources were searched for additional trials.

RESULTS

Two randomized phase III trials and three randomized phase II trials were located. In addition, 21 phase I or II trials investigating single-agent temozolomide, temozolomide plus interferon-alpha, and temozolomide plus thalidomide were reviewed. A direct comparison of temozolomide and dacarbazine demonstrated equal efficacy for response rates and overall survival; however, no significant difference was reported. A second phase III study comparing single-agent temozolomide with temozolomide combined with interferon-alpha indicated a significantly higher response rate for the combination treatment arm, but no difference in overall survival was noted. Further phase III studies are required to confirm whether there is a benefit associated with the combination of temozolomide and interferon-alpha or thalidomide.

CONCLUSION

Our review of the available literature suggests that temozolomide demonstrates comparable activity to the current standard treatment, dacarbazine, with the additional benefit of being a convenient oral treatment that penetrates the blood-brain barrier.

Biochemotherapy of metastatic melanoma in patients with or without recently diagnosed brain metastases

BACKGROUND

Brain metastases are an alarming complication of advanced melanoma, frequently contributing to patient demise. The authors performed a retrospective analysis to determine whether the treatment of metastatic melanoma with biochemotherapy would result in similar outcomes if brain metastases were first controlled with aggressive, central nervous system (CNS)-directed treatment.

METHODS

Seventy melanoma patients were treated with biochemotherapy for metastatic melanoma between 1999 and 2005. Of these, 20 patients had recently diagnosed brain metastases, whereas 50 did not. Brain metastases (if present) were treated with stereotactic radiosurgery >or=28 days prior to systemic therapy. All patients were treated with biochemotherapy consisting of either dacarbazine or temozolomide in combination with a 96-hour continuous intravenous infusion of interleukin-2 and subcutaneous interferon-alpha-2B. The primary endpoint was survival from the time of the initial diagnosis of metastatic disease.

RESULTS

Median survival from the time of the diagnosis of metastatic melanoma was 15.8 months for patients with brain metastases and 11.1 months for those without CNS involvement (P = .26 by the log-rank test; P = .075 by the Gehan Wilcoxon test). Dacarbazine-based and temozolomide-based regimens appeared similar with regard to their effect on overall survival and CNS disease progression. A plateau in further brain recurrences was observed in patients who survived for > 20 months.

CONCLUSIONS

Data from the current study suggest that the outcome of biochemotherapy is comparable in patients with and those without brain metastases, if brain metastases are controlled with multidisciplinary treatment. Prolonged survival can be achieved in approximately 15% of patients, regardless of whether or not brain metastases are present.

Dose-intensified bi-weekly temozolomide in patients with asymptomatic brain metastases from malignant melanoma: a phase II DeCOG/ADO study

BACKGROUND

Temozolomide has shown some efficacy in metastatic melanoma and recently received extended approval to treat brain tumours. The purpose of this study was to test a dose-intensified regimen of temozolomide in melanoma patients with brain metastases in a prospective, open-label, multicentre phase II trial.

PATIENTS AND METHODS

Forty-five patients with asymptomatic brain metastases from melanoma were stratified into arm A (no prior chemotherapy; n = 21) and arm B (previous chemotherapy; n = 24). Patients received oral temozolomide either 150 mg/m(2)/day (arm A) or 125 mg/m(2)/day (arm B), days 1-7 and 15-21, every 28 days. The primary study end point was objective response, and secondary end points were overall survival and safety.

RESULTS

Two patients (4.4%) achieved a partial response (PR) in brain metastases (one in each arm), one of them (2.2%) also showing a PR in extracerebral disease. An additional five patients (11.1%; two in arm A, three in arm B) showed disease stabilisation (SD) in brain and other sites. However, 82% revealed progressive disease (PD) already evident 8 weeks after therapy initiation. Median survival time from therapy onset was 3.5 months (range 0.7-8.3; arm B) and 4.3 months (range 1.6-11.8; arm A), P = 0.43. Dose modifications and prolongations of therapy cycles due to toxicity were required in 20% of patients. Grade 3/4 toxicity was observed in one patient only (2.2%).

CONCLUSIONS

Oral administration of temozolomide given bi-weekly is well-tolerated in melanoma patients with cerebral involvement. However, the efficacy is limited, with lower than 5% objective responses observed in brain and extracerebral metastases.

Chemotherapy and cerebral metastases: misperception or reality?

Cerebral metastases remain a common complication among patients with cancer. Surgery and radiotherapy remain the principal therapeutic interventions. In contrast, the benefit of chemotherapy has long been viewed with skepticism. Nonetheless, as survival in cancer patients improves and the incidence of cerebral metastases increases, so does the demand for effective therapies. It is now recognized that the blood-brain barrier within metastases is permeable and thus allows entry of otherwise excluded drugs. Limited data have suggested that cerebral metastases have modest sensitivity to chemotherapy. Furthermore, novel agents and delivery strategies have been developed to facilitate central nervous system penetration. Nonetheless, data are limited by methodological flaws, including heterogeneous inclusion criteria, small sample sizes, lack of randomization, and inconsistencies in defined end points and response assessment criteria. Well-designed clinical trials are needed to address the effect of chemotherapy. Acceptable control arms must be established to measure the effect of chemotherapies. Standardized response criteria and disease-specific studies are essential.

Temozolomide in advanced malignant melanoma with small brain metastases: can we withhold cranial irradiation?

BACKGROUND

The efficacy of radiotherapy (RT) in patients who have brain metastases from melanoma is limited. In this study, the authors evaluated the efficacy of treatment with temozolomide in patients with metastatic melanoma, including small brain metastases, who did not require immediate RT and investigated the feasibility of deferring RT.

METHODS

Patients with brain metastasis were identified from 3 prospective studies of temozolomide (with or without immunotherapy) for metastatic melanoma. Patients with brain metastasis that measured >2 cm, extensive edema, and localization in the brain stem were excluded from the study. For the current analysis, patients with leptomeningeal metastasis and patients who received previous stereotactic RT were excluded. In patients who achieved a systemic response or stabilization to temozolomide, the response of brain metastasis and the necessity for palliative cranial RT were evaluated.

RESULTS

Among 179 patients who received temozolomide for advanced melanoma, 52 patients with brain metastasis were evaluable. Stabilization of systemic metastasis was noted in 7 of 52 patients (13%), and there were 6 responses (5 partial responses and 1 complete response; 11%); thus, in those 13 patients, 6 had stabilization of brain metastasis (11%) and 5 had a response (2 partial responses and 3 complete responses; 9%). Immunotherapy did not influence the neurologic response. The median time to neurologic progression was 7 months (range 2-15, months). RT for cerebral recurrence was required in 2 patients. The median survival of patients with brain metastases was 5.6 months (95% confidence interval, 4.4-6.8 months). Intracranial hemorrhagic complications were not observed.

CONCLUSIONS

The current results indicated that it is feasible to treat patients who have advanced melanoma and small brain metastasis with temozolomide as the single treatment. The small subset of patients with systemic response usually showed durable stabilization or a response of brain metastasis. With this approach, neurologic disease can be controlled, and cranial irradiation may be deferred and even withheld in most of patients.

Motexafin gadolinium in the treatment of brain metastases

Motexafin gadolinium (MGd) is a novel, MRI-detectable, anticancer agent that enhances the cytotoxic potential of radiation therapy through several mechanisms, including depleting intracellular reducing metabolites that are necessary for repairing the oxidative damage induced by irradiation. It has tumor-specific uptake, normal tissue sparing, and tolerable and reversible toxicities in clinical trials. MGd's use in conjunction with whole-brain radiation therapy (WBRT) has demonstrated an improvement in neurocognitive decline, neurologic progression, and quality of life in patients with brain metastases from NSCLC. Its use in conjunction with radiosurgery and whole brain radiation therapy in the setting of brain metastases is currently being studied, as is MGd with radiation and temozolomide in patients with glioblastoma multiforme. MGd is also being actively investigated as a single agent or in combination with chemotherapy or radiation therapy in other tumors, including pediatric brain tumors, NSCLC, lymphoma, renal cell carcinoma, and pancreatic and biliary tumors.

Chemotherapy and targeted molecular therapies for brain metastases

As therapy for systemic cancers improves, an increasing number of patients are developing brain metastases. Although conventional therapy with surgery, radiation therapy and radiosurgery has improved the outcome of a significant number of patients, many develop multiple lesions that are not amenable to standard treatments. In this review, the current role of chemotherapy and targeted molecular agents for brain metastases is summarized and future directions are discussed.

Phase II study of temozolomide and thalidomide in patients with metastatic melanoma in the brain: high rate of thromboembolic events (CALGB 500102)

BACKGROUND

Preliminary studies suggesting that extended-dose temozolomide with thalidomide is safe and active in patients with metastatic melanoma have led to frequent use of this oral regimen. To confirm these observations the combination was tested in a multicenter Phase II trial in patients with melanoma brain metastases.

METHODS

Eligible patients had melanoma brain metastases, with or without systemic metastases. The primary endpoint was response rate in brain metastases. Patients received temozolomide at a dose of 75 mg/m2/day for 6 weeks with a 2-week rest between cycles, and thalidomide (escalated to 400 mg/day for patients age < 70 years or to 200 mg/day for patients age > or = 70 years). A 2-stage design required > or = 3 responses in the first 21 patients before enrolling 29 additional patients in the second stage.

RESULTS

Sixteen eligible patients were enrolled. No objective responses were observed. The median survival was 23.9 weeks. Seven patients withdrew because of tumor progression; 7 were removed during Cycle 1 because of adverse events, including allergic reaction (1 patient), severe fatigue (1 patient), sudden death (1 patient), and thromboembolic events (pulmonary embolism in 3 patients and deep vein thrombosis in 1 patient); 2 patients withdrew when the study was suspended and subsequently closed. No associations could be established between baseline characteristics and toxicity.

CONCLUSIONS

The proportion of patients with lethal or potentially life-threatening adverse events was high (0.31, 95% confidence interval, 0.11-0.59), and the absence of objective responses made it unlikely that further accrual would demonstrate the efficacy of the regimen. These observations provide little support for the use of this combination for melanoma brain metastases unless safe and effective methods to prevent thrombosis are developed.

Complete metastasectomy in patients with stage IV metastatic melanoma

Patients with stage IV melanoma have traditionally been managed with various systemic treatments; however, overall survival with this approach has been disappointing. Findings of many retrospective, single-institution, and multicentre studies suggest that participants treated with complete metastasectomy for stage IV metastases have enhanced overall 5-year survival. Complete surgical resection of metastatic disease to stage IV sites-including skin, soft tissue, distant lymph nodes, lungs, or other non-CNS visceral regions-offers the best chance for prolonged survival. This Review will present data lending support to the idea that if complete surgical metastasectomy is technically feasible, then surgery should be the first option for properly selected patients with stage IV melanoma.

Alternating chemo-immunotherapy with temozolomide and low-dose interleukin-2 in patients with metastatic melanoma

Temozolomide is a rapidly absorbed chemotherapeutic agent, achieving significant central nervous system penetration. Previous clinical trials suggested that temozolomide in sequence with low-dose recombinant human interleukin-2 might be an efficacious and relatively non-toxic chemo-immunotherapeutic treatment, which may synergistically eliminate tumours. The primary objective was to determine the safety and tolerance of temozolomide administered orally 200 mg/m days 1-5, in sequential combination with subcutaneous injections of 4.5x10 IU recombinant human interleukin-2 on days 8-11, 15-18 and 22-25 in patients with measurable, progressive metastatic malignant melanoma without radiological signs of central nervous system metastases. The secondary objectives were to determine tumour response and time to progression. Twenty-seven patients were included, of which four were non-evaluable for response. Twenty-three patients tolerated the regimen with side effects below grade 3 according to the World Health Organization (WHO) scale. Three patients suspended the treatment because of WHO grade 3 side effects already during the first 3 days of the first course of temozolomide. Seven patients showed no tumour progression during the first four treatment cycles. Two patients had complete responses, three partial responses and two stable disease at the end of the four cycles defined by the protocol and they continued the treatment until signs of relapse or a maximum of 21 courses. Five of these patients are still alive. Thrombocytopenia was significantly more pronounced in patients with objective response and stable disease than in non-responders to therapy. The median time to progression for all patients was 3.1 months and for responding and stable disease patients was 15 months. Five of 23 treated patients (22%) developed brain metastases during follow-up. Temozolomide in combination with recombinant human interleukin-2 is a well-tolerated regimen for outpatient treatment and the bio-chemotherapy combination induced durable clinical responses. Thrombocytopenia might be a positive predictive factor for response to therapy.

Temozolomide: a milestone in neuro-oncology and beyond?

Temozolomide (Temodal, Temodar), an imidazol derivative, is a second-generation alkylating agent. The orally available prodrug with the capacity of crossing the blood-brain barrier received accelerated US FDA approval in 1999. Three pivotal Phase II trials showed modest activity in the treatment of recurrent anaplastic astrocytoma glioblastoma. In 2005, the FDA and the European Agency for the Evaluation of Medicinal Products approved temozolomide for use in newly diagnosed glioblastoma, in conjunction with radiotherapy, based on an European Organisation for Research and Treatment of Cancer/National Cancer Institute of Canada Phase III trial. The adverse events associated with temozolomide are mild-to-moderate and generally predictable; the most serious are noncumulative and reversible myelosuppression and, in particular, thrombocytopenia, which occurs in less than 5% of patients. Continuous temozolomide administration is associated with profound CD4-selective lymphocytopenia. Molecular studies have suggested that the benefit of temozolomide chemotherapy is restricted to patients whose tumors have a methylated methylguanine methyltransferase gene promotor and are thus unable to repair some of the chemotherapy-induced DNA damage. Temozolomide is under investigation for other disease entities, in particular lower-grade glioma, brain metastases and melanoma.