Does adjuvant systemic therapy with interferon-alpha for stage II-III melanoma prolong survival?

(Neo)adjuvant systemic therapy for melanoma

Surgery still is the cornerstone of treatment for patients with stage II and III melanoma, but despite great efforts to gain or preserve locoregional control with excision of the primary tumour, satellites, intransits, sentinel node biopsy and lymphadenectomy, surgery alone does not seem to improve survival any further. Prognosis for patients with high risk melanoma remains poor with 5-year survival rates of 40 to 80%. Only interferon-2b has been approved as adjuvant therapy since 1995, but clinical integration is low considering the high risk-benefit ratio. In recent years systemic targeted- and immunotherapy have proven to be beneficial in advanced melanoma and could be a promising strategy for (neo)adjuvant treatment of patients with resectable high risk melanomas as well. Randomised, placebo- controlled phase III trials on adjuvant systemic targeted- and immunotherapy are currently being performed using new agents like ipilimumab, pembrolizumab, nivolumab, vemurafenib and dabrafenib plus trametinib. In this article we review the literature on currently known adjuvant therapies and currently ongoing trials of (neo)adjuvant therapies in high risk melanomas.

Long-term survival benefit after adjuvant treatment of cutaneous melanoma with dacarbazine and low dose natural interferon alpha: A controlled, randomised multicentre trial

In a prospective, controlled, randomised, multicentre study 252 patients with totally resected cutaneous melanoma (248 in stage II-III and 4 in stage IV) were either treated with two doses of dacarbazine (DTIC) followed by a 6-month treatment with 3 MU thrice weekly of highly purified natural interferon-alpha (n = 128; arm A) or received no adjuvant treatment (n = 124; arm B). Treatment was well tolerated. After a median follow-up of 8.5 years ITT analysis showed that the difference in survival was statistically significant with respect to melanoma-related deaths (HR = 0.65, CI = 0.46-0.97, p = 0.022) and close to significance with respect to overall survival (HR 0.71, CI 0.49-1.00, p = 0.052). The risk reduction of melanoma-associated death, calculated by Cox proportional hazards modelling, after adjusting for identified predictive variables, was almost 50% (p = 0.002). The overall efficacy of the treatment appeared to be mainly attributable to effects observed in patients with deep and/or metastasizing tumours (HR 0.60, CI 0.40-0.90, p = 0.013).

CTLA-4: negative regulator of the immune response and a target for cancer therapy

A novel approach for cancer immunotherapy is to augment T-cell-mediated immunity by blocking inhibitory signals that suppress T-cell function. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) is a key negative regulator of T-cell activation. CTLA-4 blockade using anti-CTLA-4 monoclonal antibodies (mAbs) potentiates the T-cell response against tumors, and preliminary data on these agents demonstrate good efficacy and tolerability in the treatment of patients with metastatic melanoma and other cancers. This paper will review data from studies with anti-CTLA-4 mAbs to date, discuss some of the key clinical considerations emerging from early clinical trials with this therapeutic strategy, and provide an overview of ongoing and planned clinical trials for anti-CTLA-4 mAb therapy in metastatic melanoma and other cancers.

Adjuvant therapy of melanoma with interferon: lessons of the past decade

The effect of interferon alpha (IFNalpha2) given alone or in combination has been widely explored in clinical trials over the past 30 years. Despite the number of adjuvant studies that have been conducted, controversy remains in the oncology community regarding the role of this treatment. Recently an individual patient data (IPD) meta-analysis at longer follow-up was reported, showing a statistically significant benefit for IFN in relation to relapse-free survival, without any difference according to dosage (p = 0.2) or duration of IFN therapy (p = 0.5). Most interestingly, there was a statistically significant benefit of IFN upon overall survival (OS) that translates into an absolute benefit of at least 3% (CI 1-5%) at 5 years. Thus, both the individual trials and this meta-analysis provide evidence that adjuvant IFNalpha2 significantly reduces the risk of relapse and mortality of high-risk melanoma, albeit with a relatively small absolute improvement in survival in the overall population. We have surveyed the international literature from the meta-analysis (2006) to summarize and assimilate current biological evidence that indicates a potent impact of this molecule upon the tumor microenvironment and STAT signaling, as well as the immunological polarization of the tumor tissue in vivo. In conclusion, we argue that there is a compelling rationale for new research upon IFN, especially in the adjuvant setting where the most pronounced effects of this agent have been discovered. These efforts have already shed light upon the immunological and proinflammatory predictors of therapeutic benefit from this agent--that may allow practitioners to determine which patients may benefit from IFN therapy, and approaches that may enable us to overcome resistance or enhance the efficacy of IFN. Future efforts may well build toward patient-oriented therapy based upon the knowledge of the unique molecular features of this disease and the immune system of each melanoma patient.

Randomized Trial of an Allogeneic Melanoma Lysate Vaccine With Low-Dose Interferon Alfa-2b Compared With High-Dose Interferon Alfa-2b for Resected Stage III Cutaneous Melanoma

Purpose

To compare the overall survival (OS) of patients with resected stage III melanoma administered active specific immunotherapy and low-dose interferon alfa-2b (IFN-α-2b) with the OS achieved using high-dose IFN-α-2b.

Patients and Methods

An Ad Hoc Melanoma Working Group of 25 investigators treated 604 patients from April 1997 to January 2003. Patients were stratified by sex and number of nodes and were randomly assigned to receive either 2 years of treatment with active specific immunotherapy with allogeneic melanoma lysates and low-dose IFN-α-2b (arm 1) or high-dose IFN-α-2b alone for 1 year (arm 2). Active specific immunotherapy was injected subcutaneously (SC) weekly for 4 weeks, at week 8, and bimonthly thereafter. IFN-α-2b SC was begun on week 4 and continued thrice weekly at 5 MU/m2 for 2 years. IFN-α-2b in arm 2 was administered according to the Eastern Cooperative Oncology Group 1684 study regimen.

Results

Median follow-up time was 32 months for all patients and 42 months for surviving patients. Median OS time exceeds 84 months in arm 1 and is 83 months in arm 2 (P = .56). Five-year OS rate is 61% in arm 1 and 57% in arm 2. Estimated 5-year relapse-free survival (RFS) rate is 50% in arm 1 and 48% in arm 2, with median RFS times of 58 and 50 months, respectively. The incidence of serious adverse events as a result of treatment was the same in both arms, but more severe neuropsychiatric toxicity was seen in arm 2.

Conclusion

OS and RFS achieved by active specific immunotherapy and low-dose IFN-α-2b were indistinguishable from those achieved by high-dose IFN-α-2b. Long RFS and OS times were observed in both treatment arms.

Cutaneous melanoma: interferon alpha adjuvant therapy for patients at high risk for recurrent disease

Systemic adjuvant therapy in melanoma patients is the systemic treatment that is administered with the goal of eradicating micrometastatic deposits in patients who are clinically free of disease after surgical removal of the primary melanoma, but with a high risk of systemic recurrence. Interferon-alpha (IFN-alpha) is one of the most frequently used adjuvant therapies. Several randomized trials evaluated the efficacy of IFN-alpha in melanoma patients. However, results from conducted trials are controversial. Twelve randomized IFN-alpha trials are discussed in detail. All trials, including meta-analysis, failed to demonstrate a clear impact of IFN-alpha therapy on overall survival in melanoma patients. Based on currently available evidence, IFN-alpha therapy in the adjuvant setting should not be considered standard of care for patients who have melanoma. Results from ongoing studies are awaited. Further research for this therapy is required.

[Sentinel lymph node biopsy in malignant melanoma--an update]

Ten years after the introduction of the sentinel lymph node biopsy technique in the management of malignant melanoma, it is time to take stock. The complex method has proved itself sufficiently sensitive, although a certain percentage of false-negative histological results have to be taken into account. Presently, it is still a point at issue whether sentinel lymph node biopsy should be regarded as the standard of care in high-risk patients. Three prospective multicentre trials have failed to demonstrate a survival benefit resulting from elective lymph node dissection. In contrast, a retrospective multicentre study has recently shown that patients with node metastases diagnosed by the sentinel procedure benefit from early excision of their nodal disease in terms of overall survival, as compared to patients with delayed dissection of palpable nodes. Studies worldwide have established the pathologic status of the sentinel lymph node biopsy as the most important prognostic factor for recurrence and survival after the excision of primary melanoma. As with any invasive staging procedure, sentinel lymph node biopsy should have demonstrated therapeutic consequences. Unfortunately, an unequivocally acknowledged adjuvant therapy is lacking. Moreover, the impact of complete lymph node dissection after positive sentinel biopsy on survival or local disease control has not yet been clarified.

Review: Milstein Award lecture: interferons and cancer: where from here?

Interferons (IFNs) remain the most broadly active cytokines for cancer treatment, yet ones for which the full potential is not reached. IFNs have impacted positively on both quality and quantity of life for hundreds of thousands of cancer patients with chronic leukemia, lymphoma, bladder carcinoma, melanoma, and renal carcinoma. The role of the IFN system in malignant pathogenesis continues to enhance understanding of how the IFN system may be modulated for therapeutic advantage. Reaching the full potential of IFNs as therapeutics for cancer will also result from additional understanding of the genes underlying apoptosis induction, angiogenesis inhibition, and influence on immunologic function. Food and Drug Administration (FDA) approval of IFNs occurred less than 20 years ago; after 40 years, third-generation products of early cytotoxics, such as 5- fluorouracil (5FU), are beginning to reach clinical approval. Thus, substantial potential exists for additional application of IFNs and IFN inducers as anticancer therapeutics, particularly when one considers that their pleiotropic cellular and molecular effects have yet to be fully defined.

Adjuvant therapies in the treatment of stage II and III malignant melanoma

BACKGROUND

The incidence of cutaneous melanoma has increased during the past three decades. The development of sentinel lymph node biopsy has facilitated better staging. Despite these improvements, 5-year survival rates for American Joint Committee on Cancer stage II and III disease range from 50%-90%.

METHODS

A review of the current literature concerning adjuvant therapies in patients with stage II and III malignant melanomas was undertaken.

RESULTS

The focus of adjuvant therapies has shifted from radiotherapy, BCG and levamisole to newer biological agents. Interferon, interleukin and vaccines have been evaluated but none of these agents have demonstrated an increase in overall survival in patients with stage II and III melanoma. Interferon can prolong disease-free interval.

CONCLUSION

At present, no adjuvant therapy improves overall survival in patients with stage II and III melanoma. New staging allows more accurate stratification of patients for clinical trials.

Adjuvant treatment of malignant melanoma: where are we?

To date, no standard adjuvant therapy have increased overall survival in patients with malignant melanoma (MM). The effect of interferon alpha as a single agent or in combination has been widely explored in clinical trials. Critical reading of the major international randomised trials showed that response to interferon (IFN) in terms of improvement of overall survival (OS) may not be strictly correlated with the used dosage and that duration of therapy may impact disease-free survival (DFS) but not OS. Patients' heterogeneity could be an explanation for the discordant data of the international literature. Indeed, majority of these studies started in late 1980s or early 1990s, when accurate staging procedure were not available yet. The adequate surgical treatment should be considered as an independent variable in the analysis of MM adjuvant protocols. Considering the treatment cost, which is the main goal: DFS, OS or quality of life? Answering these questions is difficult, but some considerations must be taken to put order in this field. Putting together data from all different studies, IFN therapy seems to protect MM patients from recurrences during the entire treatment period and a prolonged IFN therapy seems to improve DFS. The only positive result on OS was demonstrated for high-dose IFN (HD-IFN) in a single study (presenting a relatively short follow-up median) and not confirmed in a subsequent study from the same authors. Considering that low-dose interferon (LD-IFN) is tolerated much better than HD-IFN (about 10% versus more than 70% of cases with grade 3-4 toxicity, respectively), a prolonged LD-IFN (more than 2 years) may represent a reasonable opportunity for MM patients, also considering its advantageous cost-effectiveness. Conversely, considering the improvement of OS as the main target of MM adjuvant therapy, the "wait and watch" attitude remains the only approach to be pursued at present. It is a physician's choice.

XAF1 expression is significantly reduced in human melanoma

Deregulation of apoptotic processes is likely one of the key factors contributing to the malignant nature of melanoma marked by strong chemoresistance. X-linked inhibitor of apoptosis protein (XIAP) suppresses apoptosis through the inhibition of various caspases. Recently, XIAP-associated factor 1 (XAF1) has been identified as a XIAP-binding protein that antagonizes the anti-apoptotic activity of XIAP. In this study, we sought to determine the role of XAF1 in melanoma progression. Analysis of XAF1 mRNA expression in melanoma cell lines revealed that XAF1 mRNA was downregulated in 15 of 16 cell lines examined. We next evaluated XAF1 protein expression on a tissue microarray representing 40 benign nevi and 70 primary melanomas. Our results showed that XAF1 expression in melanoma tissues was significantly reduced compared with benign melanocytic nevi (p<0.05). Our data also demonstrated that the substantial reduction of XAF1 expression occurred in both nucleus and cytoplasm in the tumor cells (p<0.0001 for both). Reduced XAF1 expression, however, was not significantly correlated with tumor thickness and 5-y patient survival. Further studies are required to understand the molecular mechanisms governing the selective loss of XAF1 expression in the tumor tissue.

Re-evaluating the role of dacarbazine in metastatic melanoma: what have we learned in 30 years?

Since dacarbazine was approved for treating metastatic melanoma in the 1970s, numerous studies have evaluated whether different schedules and dacarbazine-based combinations improve clinical outcomes. This evidence-based review shows that combining dacarbazine with other drugs having single-agent activity and/or hormonal or immunotherapeutic compounds fails to provide clinically meaningful improvements in survival, and may increase toxicity. In patients with metastatic melanoma, dacarbazine was previously administered in cycles of multiple consecutive daily infusions per cycle. The introduction of potent antiemetics, together with concerns relating to patient comfort and clinic utilisation time, has enabled regimens involving single-dose dacarbazine, administered at the same total dose per cycle. These appear to be as effective as multiple-dose schedules, are well tolerated, and are more straightforward to administer. Single-administration dacarbazine (850-1000 mg/m2), once every 3 weeks, is currently the standard reference therapy in patients with advanced melanoma. New effective therapies are urgently needed for this treatment-refractory disease.