Clinical trial designs for evaluating and exploiting cancer evolution

The evolution of drug-resistant cell subpopulations causes cancer treatment failure. Current preclinical evidence shows that it is possible to model herding of clonal evolution and collateral sensitivity where an initial treatment could favourably influence the response to a subsequent one. Novel therapy strategies exploiting this understanding are being considered, and clinical trial designs for steering cancer evolution are needed. Furthermore, preclinical evidence suggests that different subsets of drug-sensitive and resistant clones could compete between themselves for nutrients/blood supply, and clones that populate a tumour do so at the expense of other clones. Treatment paradigms based on this clinical application of exploiting cell-cell competition include intermittent dosing regimens or cycling different treatments before progression. This will require clinical trial designs different from the conventional practice of evaluating responses to individual therapy regimens. Next-generation sequencing to assess clonal dynamics longitudinally will improve current radiological assessment of clinical response/resistance and be incorporated into trials exploiting evolution. Furthermore, if understood, clonal evolution can be used to therapeutic advantage, improving patient outcomes based on a new generation of clinical trials.

State-of-the-art combination treatment strategies for advanced stage non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most abundant type of epithelial lung cancer being diagnosed after 40% of invasions of excrescence in pulmonary tissues. According to WHO, 30% of NSCLC patients can be cured if diagnosed and treated early. Mutations play an important role in advanced stage NSCLC treatment, which includes critical proteins necessary for cellular growth and replication. Restricting such mutations may improve survival in lung cancer patients. Newer technologies include endoscopic bronchial ultrasonography and esophageal ultrasonography. Currently, policymaking or decision-making for treatment regimens merely depends on the genomic alterations and mutations. DNA sequencing, methylation, protein, and fragmented DNA analysis do NSCLC screening. Achievement of these goals requires consideration of available therapeutics in current anticancer approaches for improving quality of life and treatment outcomes for NSCLC patient. The specific goals of this review are to discuss first-line and second-line therapies for advanced-stage NSCLC and molecularly targeted therapy including thoughtful discussion on precise role of treatment strategies in specific tumors. Also, concerned diagnostics, new clinical trial designs, and pursuing appropriate combinations of radiotherapy and/or chemotherapy with biological therapy for exceptional cases considering resistance mechanisms and palliative care will be discussed.

Epidermal Growth Factor Receptor Inhibition in the Management of Squamous Cell Carcinoma of the Lung

Molecular therapies targeting epidermal growth factor receptor (EGFR) have had a profound impact on the management of advanced non-small cell lung cancer (NSCLC). EGFR inhibition with EGFR tyrosine kinase inhibitors (EGFR-TKIs) and anti-EGFR monoclonal antibodies (mAbs) in squamous NSCLC (sqNSCLC) remains controversial in patients whose tumors are not known to harbor EGFR mutations. Recent meta-analyses of EGFR-inhibition randomized trials that are adequately powered for histological subgroup analysis and anti-EGFR trials limited to patients with squamous histology afford the opportunity to revisit EGFR treatment in sqNSCLC. In unselected patients with sqNSCLC who are not eligible for chemotherapy, EGFR-TKI therapy is a valid treatment option over placebo or best supportive care, with improved progression-free survival noted in randomized controlled trials in both the first- and second-line setting and improved overall survival (OS) in the second-line setting. In patients eligible for chemotherapy, first-line combination regimens with anti-EGFR mAbs have been shown to improve OS over chemotherapy alone in patients with squamous histology in meta-analysis and more recently in the SQUIRE sqNSCLC trial (chemotherapy with and without necitumumab). In sqNSCLC patients who respond to induction chemotherapy, maintenance therapy with erlotinib delays disease progression and may improve the survival of patients with stable disease. In the second-line setting, survival outcomes are comparable between chemotherapy and EGFR-TKIs in meta-analysis, with the latter being more tolerable as a second-line therapy. Newer-generation EGFR-TKI therapies may further benefit patients with sqNSCLC who have failed first-line chemotherapy, given the positive trial results from LUX-Lung 8 (afatinib vs. erlotinib). EGFR is a valid therapeutic target in unselected/EGFR wild-type patients with squamous cell carcinoma of the lung. With the recent approval of immune checkpoint inhibitors in the second-line management of advanced sqNSCLC and their adoption as a new standard of care, there exists an opportunity for novel combination therapies to increase therapeutic efficacy and durable tumor control. As more targeted agents are approved, combination regimens that include an anti-EGFR agent should be evaluated, and the optimal sequencing of targeted therapies should be defined.

IMPLICATIONS FOR PRACTICE

Anti-epidermal growth factor receptor (EGFR) therapies remain controversial in unselected/wild-type EGFR squamous non-small cell lung cancer (NSCLC). Recent meta-analyses and squamous-only NSCLC EGFR-inhibition trials have overcome the power limitations of early trials and can now inform the management of squamous NSCLC with anti-EGFR therapies. With the approval of immunotherapeutics in the second-line management of squamous NSCLC, there exists an opportunity for novel combination therapies to improve efficacy and durable tumor control. The optimal timing and sequencing of available second-line targeted therapies, however, have yet to be defined. This review analyzes randomized clinical trials of EGFR inhibition in NSCLC and meta-analyses of these trials, with a focus on patients with squamous histology.

50 Years of progress in the systemic therapy of non-small cell lung cancer

Non-small cell lung cancer constitutes 85% to 90% of lung cancer and is the most common cause of cancer death. Over the past 50 years, substantial progress has been made in all aspects of lung cancer including screening, diagnostic evaluation, surgery, radiation therapy, and chemotherapy. This review focuses on the advances in systemic therapy during this half century.

Treatment of stage IV non-small cell lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Stage IV non-small cell lung cancer (NSCLC) is a treatable, but not curable, clinical entity in patients given the diagnosis at a time when their performance status (PS) remains good.

METHODS

A systematic literature review was performed to update the previous edition of the American College of Chest Physicians Lung Cancer Guidelines.

RESULTS

The use of pemetrexed should be restricted to patients with nonsquamous histology. Similarly, bevacizumab in combination with chemotherapy (and as continuation maintenance) should be restricted to patients with nonsquamous histology and an Eastern Cooperative Oncology Group (ECOG) PS of 0 to 1; however, the data now suggest it is safe to use in those patients with treated and controlled brain metastases. Data at this time are insufficient regarding the safety of bevacizumab in patients receiving therapeutic anticoagulation who have an ECOG PS of 2. The role of cetuximab added to chemotherapy remains uncertain and its routine use cannot be recommended. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors as first-line therapy are the recommended treatment of those patients identified as having an EGFR mutation. The use of maintenance therapy with either pemetrexed or erlotinib should be considered after four cycles of first-line therapy in those patients without evidence of disease progression. The use of second- and third-line therapy in stage IV NSCLC is recommended in those patients retaining a good PS; however, the benefit of therapy beyond the third-line setting has not been demonstrated. In the elderly and in patients with a poor PS, the use of two-drug, platinum-based regimens is preferred. Palliative care should be initiated early in the course of therapy for stage IV NSCLC.

CONCLUSIONS

Significant advances continue to be made, and the treatment of stage IV NSCLC has become nuanced and specific for particular histologic subtypes and clinical patient characteristics and according to the presence of specific genetic mutations.

Impact of EGFR inhibitor in non-small cell lung cancer on progression-free and overall survival: a meta-analysis

BACKGROUND

The epidermal growth factor receptor (EGFR) signaling pathway is crucial for regulating tumorigenesis and cell survival and may be important in the development and progression of non-small cell lung cancer (NSCLC). We examined the impact of EGFR-tyrosine kinase inhibitors (TKIs) on progression-free survival (PFS) and overall survival (OS) in advanced NSCLC patients with and without EGFR mutations.

METHODS

Randomized trials that compared EGFR-TKIs monotherapy or combination EGFR-TKIs-chemotherapy with chemotherapy or placebo were included. We used published hazard ratios (HRs), if available, or derived treatment estimates from other survival data. Pooled estimates of treatment efficacy of EGFR-TKIs for the EGFR mutation-positive (EGFRmut(+)) and EGFR mutation-negative (EGFRmut(-)) subgroups were calculated with the fixed-effects inverse variance weighted method. All statistical tests were two-sided.

RESULTS

We included 23 eligible trials (13 front-line, 7 second-line, 3 maintenance; n = 14570). EGFR mutation status was known in 31% of patients. EGFR-TKIs treatment prolonged PFS in EGFRmut(+) patients, and EGFR mutation was predictive of PFS in all settings: The front-line hazard ratio for EGFRmut(+) was 0.43 (95% confidence interval [CI] = 0.38 to 0.49; P < .001), and the front-line hazard ratio for EGFRmut(-) was 1.06 (95% CI = 0.94 to 1.19; P = .35; P interaction < .001). The second-line hazard ratio for EGFRmut(+) was 0.34 (95% CI = 0.20 to 0.60; P < .001), and the second-line hazard ratio for EGFRmut(-) was 1.23 (95% CI = 1.05 to 1.46; P = .01; P interaction < .001). The maintenance hazard ratio for EGFRmut(+) was 0.15 (95% CI = 0.08 to 0.27; P < .001), and the maintenance hazard ratio for EGFRmut(-) was 0.81 (95% CI = 0.68 to 0.97; P = .02; P interaction < .001). EGFR-TKIs treatment had no impact on OS for EGFRmut(+) and EGFRmut(-) patients.

CONCLUSIONS

EGFR-TKIs therapy statistically significantly delays disease progression in EGFRmut(+) patients but has no demonstrable impact on OS. EGFR mutation is a predictive biomarker of PFS benefit with EGFR-TKIs treatment in all settings. These findings support EGFR mutation assessment before initiation of treatment. EGFR-TKIs should be considered as front-line therapy in EGFRmut(+) advanced NSCLC patients.

Identifying the target NSCLC patient for maintenance therapy: an analysis from a placebo-controlled, phase III trial of maintenance pemetrexed (H3E-MC-JMEN)

Background

This was a post hoc analysis of patients with non-squamous histology from a phase III maintenance pemetrexed study in advanced non-small cell lung cancer (NSCLC).

Patients and methods

The six symptom items' [average symptom burden index (ASBI)] mean at baseline was calculated using the lung cancer symptom scale (LCSS). Low and high symptom burden (LSB, ASBI < 25; HSB, ASBI ≥ 25) and performance status (PS: 0, 1) subgroups were analyzed for treatment effect on progression-free survival (PFS) and overall survival (OS) using the Cox proportional hazard models adjusted for demographic/clinical factors.

Results

Significantly longer PFS and OS for pemetrexed versus placebo occurred in LSB patients [PFS: median 5.1 versus 2.4 months, hazard ratio (HR) 0.49, P < 0.0001; OS: median 17.5 versus 11.0 months, HR 0.63, P = 0.0012] and PS 0 patients (PFS: median 5.5 versus 1.7 months, HR 0.36, P < 0.0001; OS: median 17.7 versus 10.3 months, HR 0.54, P = 0.0019). Significantly longer PFS, but not OS, occurred in HSB patients (median 3.7 versus 2.8 months, HR 0.50, P = 0.0033) and PS 1 patients (median 4.4 versus 2.8 months, HR 0.60, P = 0.0002).

Conclusions

ASBI and PS are associated with survival for non-squamous NSCLC patients, suggesting that maintenance pemetrexed is useful for LSB or PS 0 patients following induction.

Clinical meta-analyses of targeted therapies in adenocarcinoma

Although the interpretation of the data reported in meta-analyses may hide several issues, it is undoubtable that this methodological approach may significantly contribute to implement the results of clinical trials, and represent a useful and practical tool for the evidence-based medicine process. Indeed, level-one recommendations should consider well-conducted meta-analyses as well as large and adequately powered randomized trials as the main contributors for the definition of guidelines for clinical practice. In addition, the role of meta-analyses for issues whereas conflicting data (and/or unpowered results) are provided, is well established. In the field of lung cancer, meta-analyses already participated to change the current standard, and are now facing the challenging issues of predictive biomarkers of prognosis and/or efficacy of targeted agents. With this aim, the meta-analytic approach helped in the recent years to implement the quantification of the magnitude of the benefit of targeted agents, and added new insights by interpreting the data coming from clinical trials by integrating them with biomarkers. The treatment-interaction analyses according to putative predictive factors of efficacy may clarify unknown issues and generate new hypotheses for future perspectives. The current review attempts to put in the context of the clinical data of targeted agents for lung cancer all the pros and cons of the meta-analytic process published to date, and critically analyze all the potential perspectives which this methodology may add for both current practice and forthcoming research.

Maintenance erlotinib improves clinical outcomes of unresectable advanced non-small cell lung cancer: A meta-analysis of randomized controlled trials

The aim of this study was to evaluate the efficacy and safety of erlotinib as maintenance therapy in patients with unresectable non-small cell lung cancer (NSCLC) by evidence-based methodology. Six eligible studies including 4,372 patients were analyzed. Erlotinib was administered to 2,191 patients as maintenance treatment, while the remaining patients received a placebo or observation only. The meta-analysis was performed using Reviewer Manager Version 5.12 software. Compared with the control group, maintenance erlotinib improved progression-free survival (PFS) and overall survival (OS) with moderate heterogeneity. Results from the random effects model analysis for OS were not in concordance with the difference observed in the fixed effects model analysis. Administration of erlotinib only after chemotherapy obtained a higher objective response rate (ORR). Safety analyses indicated a slight increase in side-effects. The most common adverse events (AEs) were diarrhea and rash, which were usually manageable. There was no significant difference in treatment-related deaths. Erlotinib produced significant clinical benefits with acceptable toxicity as a maintenance strategy in patients with unresectable NSCLC, particularly when sequentially administered with chemotherapy. However, more well-designed randomized control trials (RCTs) are required to identify patients that may derive greater benefits from maintenance with erlotinib, and whether the use of erlotinib as maintenance therapy is more efficient than second-line treatment should also be investigated.

Patient comprehension and attitudes toward maintenance chemotherapy for lung cancer

OBJECTIVE

Maintenance chemotherapy is a recently approved approach to the treatment of advanced non-small cell lung cancer (NSCLC). We sought to gain insight into patients' perceptions of maintenance chemotherapy using qualitative methods.

METHODS

We conducted thematic content analysis of focus groups at a freestanding cancer center and at an associated safety-net county hospital. Patients with advanced NSCLC who had started but not yet completed first-line platinum doublet chemotherapy were provided visual and written explanations of maintenance chemotherapy before being guided in group discussion.

RESULTS

Key themes to emerge for consideration of maintenance chemotherapy included: (1) survival benefits, disease control, and "buying time"; (2) the importance of "doing something"; (3) quality of life concerns; (4) the role of provider opinion/preference; and (5) the importance of logistics.

CONCLUSIONS

Patients undergoing first-line chemotherapy for advanced NSCLC were able to understand the concept of maintenance chemotherapy, distinguish it from traditional treatment paradigms, identify pros and cons of this approach, and convey reasons for considering it.

PRACTICE IMPLICATIONS

Advances in oncology care that alter therapy modalities and delivery may significantly impact patient perceptions and treatment experiences. Clinical team members may wish to elicit treatment preferences of first-line patients through clinical discussion that anticipate these considerations.

Maintenance therapy for advanced non-small-cell lung cancer: ready for clinical practice?

The treatment paradigm for advanced non-small-cell lung cancer has changed in recent years with the importance of histological subtyping for the choice of chemotherapy, and the use of molecular markers to select patients for targeted therapy. Maintenance therapy (MT) is another focus of interest. The potential benefit of MT for the patient is that it prolongs tumor control reached with first-line chemotherapy in order to improve overall survival with little added toxicity. Historical studies have never reached this goal, as the agents used for MT were too poorly tolerated. We review the data of the two types of recent MT studies, 'continuation' and 'switch' or 'consolidation' MT. We comment on how the benefits demonstrated in these studies may change clinical practice and reflect on factors that may identify subgroups of patients who derive the greatest benefit from MT in general, as this will help in a rational use of MT.

[Targeted agents in the treatment of lung cancer]

Lung cancer is in France, the leading cause of cancer death. Despite the dramatic advances that have allowed in a few years to go, for metastatic cancer, from a median survival without specific treatment of 4.5 months and now almost always more than one year, survival remains disappointing and further improvements are needed. Progress in the accumulated knowledge of the inner workings of normal and tumoral cells have paved the way for the development of targeted therapeutics called biological or simply targeted therapies. Two biological processes are already the target of marketed drugs, this is the way the receptor of epidermal growth factor (EGFR) and the path of neo-angiogenesis. It is almost assumed that, in the very near future, the inhibition of EML4-ALK will also be the subject of new drugs. In the medium term, it is conceivable that the molecular dissection of the tumors actually lead to the prescription of treatments tailored to mutations and other abnormalities that direct the growth of cancers.

The effectiveness of maintenance pharmacotherapies for non-small cell lung cancer

Although current recommendations for the treatment of advanced non-small cell lung cancer (NSCLC) include a maximum of six cycles of platinum-based combination therapy as a first-line approach, most patients experience progression within 3-4 months. Therefore, a new treatment strategy, maintenance therapy, has been proposed, and several large randomized prospective controlled trials have shown benefits with maintenance therapy. Maintenance therapy can be classified as either continuation maintenance, which is defined as a prolongation of a part of the first-line chemotherapy or molecularly targeted agent until progression, or switch-maintenance, which is defined as the administration of a different cytotoxic chemotherapy or molecularly targeted agent immediately after induction therapy. In this article, recent results from large randomized phase III trials regarding maintenance therapy are reviewed in order to evaluate the role of maintenance therapy in NSCLC.

Recent advances in lung cancer: summary of presentations from the 47 th annual meeting of the American Society of Clinical Oncology (ASCO) 2011

In the last several years, we have made slow but steady progress in developing new treatment strategies for patients with lung cancer. The use of molecularly targeted therapy has made a significant impact on the outcomes of patients with lung cancer. Further research is ongoing to identify more effective ways to target lung cancer. In the recently concluded 47 th annual meeting of the American Society of Clinical Oncology, there were several presentations on novel targeted therapies for lung cancer, in addition to the effective and optimal use of existing cytotoxic and targeted therapies for lung cancer. For this review, we have selected presentations that primarily have an impact on clinical practice, and some presentations regarding emerging therapeutic agents.

Erlotinib and pemetrexed as maintenance therapy for advanced non-small-cell lung cancer: a systematic review and indirect comparison

BACKGROUND

Two new agents have recently been licensed as maintenance therapy for advanced non-small-cell lung cancer (NSCLC) by the US Food and Drug Administration. This paper aims to systematically review the evidence from all available clinical trials of erlotinib and pemetrexed as maintenance therapy for advanced NSCLC.

METHODS

Systematic literature searches were performed in PUBMED, EMBASE and Cochrane databases. Abstracts presented at two conferences were also researched. The effects of erlotinib and pemetrexed on overall survival and progression-free survival were compared using an indirect treatment comparison method with placebo or observation as a common comparator.

RESULTS

Five randomized controlled studies were included. Both interventions offered significant advantages for overall survival (OS) and progression-free survival (PFS) compared with placebo or observation. Using indirect comparison meta-analysis, the relative hazards ratio of pemetrexed compared with erlotinib for PFS was 0.71 (95% CI 0.60-0.85; p = 0.0001), suggested that pemetrexed was superior to erlotinib in terms of progression-free survival. Although relative hazards ratio for OS showed no significant difference between the two agents (HR 0.88; 95% CI 0.71-1.08, p = 0.22).

CONCLUSIONS

There is evidence to suggest that maintenance treatment with erlotinib or pemetrexed has clinically relevant and statistically significant advantages over treatment with placebo or observation in patients with advanced NSCLC.

Maintenance therapy for advanced non-small-cell lung cancer: switch versus continuation

INTRODUCTION

The concept of maintenance therapy in lung cancer has stirred a great deal of interest over the last decade. Several randomized studies have been conducted to find out the usefulness of maintenance therapies for advanced non-small-cell lung cancer (NSCLC).

AREAS COVERED

This article reviews the major benchmark clinical trials and strategies in the field of maintenance chemotherapy in advanced NSCLC. The two strategies used in maintenance therapy are: i) continuation maintenance - continuation of one of the initial treatments; and ii) switch maintenance - switching to a different agent not administered as initial treatment. Both chemotherapeutic and molecular targeted agents have been studied in the maintenance setting. These include docetaxel, gemcitabine, pemetrexed, bevacizumab, erlotinib and gefitinib. This paper discusses the relevant clinical trials using these agents and the two different strategies in the maintenance therapy in advanced NSCLC.

EXPERT OPINION

Despite some controversy regarding the choice or the timing of the maintenance therapy, most of the clinical trials have demonstrated a significant improvement of progression-free survival, translating to a survival benefit with pemetrexed and erlotinib. The approval of pemetrexed and erlotinib by the FDA has certainly shifted the pendulum towards maintenance therapy.

Maintenance Therapy for NSCLC: Consensus and Controversy

Nowadays, advanced non-small cell lung cancer (NSCLC) is still an incurable disease. However, recent researches on maintenance therapy have led to considerable progress. Recently, pemetrexed and erlotinib have been approved for maintenance chemotherapy by both the U.S. Food and Drug Administration and European Medicines Agency. However, there are not adequate data to support the maintenance therapy as the standard treatment for advanced NSCLC and there has been no conclusive predictor of who will get benefit from maintenance chemotherapy and what type of maintenance, continuation or switch, is preferred. This article reviews the main studies on maintenance therapy of advanced NSCLC and discusses the results available to date.

Efficacy of EGFR tyrosine kinase inhibitors in patients with EGFR-mutated non-small-cell lung cancer: a meta-analysis of 13 randomized trials

Advanced non-small-cell lung cancer (NSCLC) harboring activating mutations of epidermal growth factor receptor (EGFR) are particularly sensitive to tyrosine kinase inhibitors (TKIs), namely erlotinib and gefitinib. The purpose of this meta-analysis was to evaluate the benefit of EGFR TKIs in EGFR-mutated NSCLCs. Eligible studies included published randomized controlled trials in which erlotinib or gefitinib (alone or with chemotherapy) were compared with standard therapy in 1260 patients with EGFR-mutated NSCLCs who were included in 13 trials. The mutational status was obtained through a retrospective or prospective analysis. Relative risk (RR) was calculated for response rate, and hazard ratios (HRs) were calculated for progression-free and overall survival. EGFR TKIs increase the chance of obtaining an objective response almost 2-fold when compared with chemotherapy (RR, 2.06; 2p < .00001). The response rate was 70% vs. 33.2% in first-line trials. In 3 second-line trials, response rates were 47.4% vs. 28.5%, with a benefit similar to first-line trials (RR, 1.79; 2p = .04). EGFR TKIs reduced the hazard of progression by 70% in all trials (HR, 0.30; 2p < .00001) and by 65% in first-line trials only (HR, 0.35; 2p < .00001). Overall, however, they do not improve survival (HR, 0.96; 2p = .71). NSCLCs harboring EGFR mutations derive greater benefit from erlotinib or gefitinib than from chemotherapy. All patients affected by NSCLC with an EGFR-positive mutation test result must be offered the opportunity to be treated with an EGFR TKI upfront or during the natural course of the disease if not previously exposed.

2011 Focused Update of 2009 American Society of Clinical Oncology Clinical Practice Guideline Update on Chemotherapy for Stage IV Non-Small-Cell Lung Cancer

PURPOSE

An American Society of Clinical Oncology (ASCO) focused update updates a single recommendation (or subset of recommendations) in advance of a regularly scheduled guideline update. This document updates one recommendation of the ASCO Guideline Update on Chemotherapy for Stage IV Non-Small-Cell Lung Cancer (NSCLC) regarding switch maintenance chemotherapy.

CLINICAL CONTEXT

Recent results from phase III clinical trials have demonstrated that in patients with stage IV NSCLC who have received four cycles of first-line chemotherapy and whose disease has not progressed, an immediate switch to alternative, single-agent chemotherapy can extend progression-free survival and, in some cases, overall survival. Because of limitations in the data, delayed treatment with a second-line agent after disease progression is also acceptable.

RECENT DATA

Seven randomized controlled trials of carboxyaminoimidazole, docetaxel, erlotinib, gefitinib, gemcitabine, and pemetrexed have evaluated outcomes in patients who received an immediate, non-cross resistant alternative therapy (switch maintenance) after first-line therapy.

RECOMMENDATION

In patients with stage IV NSCLC, first-line cytotoxic chemotherapy should be stopped at disease progression or after four cycles in patients whose disease is stable but not responding to treatment. Two-drug cytotoxic combinations should be administered for no more than six cycles. For those with stable disease or response after four cycles, immediate treatment with an alternative, single-agent chemotherapy such as pemetrexed in patients with nonsquamous histology, docetaxel in unselected patients, or erlotinib in unselected patients may be considered. Limitations of this data are such that a break from cytotoxic chemotherapy after a fixed course is also acceptable, with initiation of second-line chemotherapy at disease progression.

Maintenance therapy in NSCLC: why? To whom? Which agent?

Maintenance therapy is emerging as a treatment strategy in the management of advanced non small cell lung cancer (NSCLC). Initial trials addressing the question of duration of combination chemotherapy failed to show any overall survival benefit for the prolonged administration over a fixed number of cycles with an increased risk for cumulative toxicity. Nowadays several agents with different ways of administration and a different pattern of toxicity have been formally investigated in the maintenance setting. Maintenance strategies include continuing with an agent already present in the induction regimen or switching to a different one. Taking into consideration that no comparative trials of maintenance with different chemotherapy drugs or targeted agents have been conducted, the choice and the duration of maintenance agents is largely empirical. Furthermore, it is still unknown and it remains an open question if this approach needs to be proposed to every patient in the case of partial/complete response or stable disease after the induction therapy. Here, we critically review available data on maintenance treatment, discussing the possibility to tailor the right treatment to the right patient, in an attempt to optimize costs and benefits of an ever-growing panel of different treatment options.

Maintenance therapy in advanced non-small cell lung cancer: evolution, tolerability and outcomes

Non-small cell lung cancer (NSCLC) is the leading cause of cancer death in the industrialized world. Despite significant progress in early stage disease, survival rates for advanced disease remain low. Maintenance therapy is a treatment strategy that has been investigated extensively in NSCLC and has been the subject of considerable recent debate. Options for maintenance include continuing the initial combination chemotherapy regimen, continuing only single agent chemotherapy ('continuation maintenance') or introducing a new agent ('switch' maintenance therapy). Therapies that have been studied in this setting in randomized trials to date include chemotherapy, molecularly targeted agents and immunotherapy approaches. Following the development of multiple new agents that show activity in NSCLC, and have a tolerable side-effect profile, there has been increasing interest in utilizing them to maintain response to initial therapy after treatment with platinum-based doublets. Despite considerable controversy, it has become an acceptable treatment paradigm. Here, we briefly outline the evolution of this treatment paradigm and examine which subgroups of patients are most likely to benefit.

The search for improved systemic therapy of non-small cell lung cancer--what are today's options?

Although stage IV non small cell lung cancer (NSCLC) remains an incurable disease and drug resistance ultimately develops, important steps forward have been made within the last few years. The number of new active agents is rapidly increasing and the area of personalized medicine has definitively arrived. Treatment choices are starting to be made upon tumour characteristics, and more effective and better tolerated agents are now available. In the molecular era we are facing many new challenges: The availability of sufficient tissue, which is often not easily accessible in a tumour arising from an internal organ, sensitivity and specificity of biomarker testing, heterogeneity of marker profiles between primary tumour and metastases or even within a single tumour mass, application and reproducibility of the correct biomarker test method and the differentiation of the predictive vs. the prognostic value of biomarkers. Unfortunately, the development of new targeted agents frequently continues to be performed in unselected patient populations, lacking the early identification of relevant predictive molecular biomarkers. Consequently, thousands of patients are enrolled into clinical trials with a low probability of success. This overview will focus on the most recent new systemic treatment options in NSCLC, including the role of pemetrexed, bevacizumab, cetuximab, maintenance therapy and tyrosine kinase inhibitors in patients with an activating epidermal growth factor receptor mutation. In addition, emerging treatment strategies will be described.

The SATURN trial: the value of maintenance erlotinib in patients with non-small-cell lung cancer

The first-line treatment of advanced non-small-cell lung cancer (NSCLC) generally consists of a maximum of six cycles of platinum-based doublet chemotherapy followed by surveillance for disease progression. Recently, the strategy of starting second-line treatment immediately following the completion of chemotherapy, known as 'maintenance' chemotherapy, has been investigated. The use of maintenance pemetrexed improves both progression-free and overall survival, while the use of maintenance docetaxel did not significantly improve overall survival. The Sequential Tarceva in Unresectable NSCLC (SATURN) study investigated the use of maintenance erlotinib following the completion of first-line chemotherapy. It demonstrated a significant improvement in overall survival from 11.1 months in the placebo group to 12.3 months in patients receiving maintenance erlotinib, with the important caveat that only 21% of patients in the placebo group ever received erlotinib. A subset of patients whose tumors had EGF receptor mutations had a higher magnitude of benefit from maintenance treatment. Therefore, maintenance erlotinib should be considered in the treatment of patients with NSCLC.

Lung cancer: New biological insights and recent therapeutic advances

Approximately 1.6 million new cases of lung cancer are diagnosed each year throughout the world. In many countries, the mortality related to lung cancer continues to rise. The outcomes for patients with all stages of lung cancer have improved in recent years. The use of systemic therapy in conjunction with local therapy has led to improved cure rates in both resectable and unresectable patient groups. For patients with advanced stage disease, modest but real improvements in overall survival and quality of life have been achieved with systemic chemotherapy. A major focus of research has been the development of molecularly targeted agents and the identification of biomarkers for patient selection. Patients with non-small cell lung cancer with mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase domain achieve response rates of greater than 70% and superior progression-free survival when treated with an EGFR tyrosine kinase inhibitor compared with standard chemotherapy. This has now emerged as the preferred therapeutic approach for the subset of patients with a mutation in exons 19 or 21 of the EGFR. Another promising targeted approach involves the use of an anaplastic lymphoma kinase (ALK) inhibitor in patients with a translocation involving the echinoderm microtubule-associated protein-like 4 (EML4) and -ALK genes. Finally, a paradigm shift in favor of maintenance therapy for patients with advanced stage disease has gained strength from recent data. All of these advances have been made possible by developing a greater understanding of the biology, the discovery of novel anticancer agents, and improved supportive care measures. This article reviews the major strides made in the treatment of lung cancer in the recent past.

[Maintenance therapy in advanced non-small cell lung cancer: A new paradigm?]

Standard treatment of advanced non-small cell lung cancer is based on several lines of therapy separated by treatment-free intervals in which each new line is started when tumour progression is detected. The maintenance strategy consists of pursuing an appropriate, well-tolerated treatment after the end of first-line chemotherapy in order to maintain the initial therapeutic benefit and to avoid rapid clinical deterioration that would rule out further treatment. Two kinds of maintenance therapy have been investigated: continuation maintenance which consists in continuing a targeted agent or a chemotherapy agent that was part of initial induction therapy and switch maintenance defined by initiating a new agent immediately after the end of induction chemotherapy. Clinical trials show that maintenance strategy provides a significant benefit in terms of disease control and improves overall survival for switch maintenance with pemetrexed or erlotinib. Survival benefit appears to be due mainly to the progression-free survival gain and to the increase in the proportion of patients who can receive several lines of treatment. Maintenance therapy is an important option for patients receiving first-line treatment, particularly for those with rapid disease progression. The choice of continuation or switch maintenance will depend on drug used in combination to platinum for induction treatment, response to first-line, histology and patient's preference.

Predictors and impact of second-line chemotherapy for advanced non-small cell lung cancer in the United States: real-world considerations for maintenance therapy

INTRODUCTION

: Recent clinical trials incorporating maintenance chemotherapy into the initial treatment of advanced non-small cell lung cancer (NSCLC) have highlighted the benefits of exposing patients to second-line therapies. We, therefore, determined the predictors and impact of second-line chemotherapy administration in a contemporary, diverse NSCLC population.

METHODS

: We performed a retrospective analysis of consecutive patients diagnosed with stage IV NSCLC from 2000 to 2007 at clinical facilities associated with the University of Texas Southwestern Medical Center. Demographic, disease, treatment, and outcome data were obtained from hospital tumor registries. The association between these variables was assessed using univariate analysis and multivariate logistic regression.

RESULTS

: A total of 406 patients in this cohort received first-line chemotherapy and were included in the analysis. Mean age was 59 years, 28% were women, and 59% were white. Among these patients, 197 (49%) received second-line chemotherapy. Among those patients who had not progressed after four to six cycles of first-line chemotherapy, 67% received second-line chemotherapy. Receipt of second-line chemotherapy was significantly associated with patient insurance type (p = 0.007), number of cycles of first-line chemotherapy (p < 0.001), and receipt of prechemotherapy palliative radiation therapy (p = 0.005) but was not associated with patient age, gender, race, histology, or year of diagnosis. In a multivariate model, second-line chemotherapy administration remained associated with insurance type (p = 0.003), number of cycles of first-line chemotherapy (p < 0.001), and receipt of prechemotherapy palliative radiation therapy (p = 0.008). The number of cycles of first-line chemotherapy and administration of second-line chemotherapy were associated with overall survival in both univariate and multivariate analyses.

CONCLUSIONS

: In this unselected, contemporary, and diverse cohort of patients with advanced NSCLC, 67% of individuals whose disease had not progressed after four to six cycles of first-line chemotherapy eventually received second-line chemotherapy. Markers of socioeconomic status, symptom burden, and response to and tolerance of first-line chemotherapy were associated with receipt of second-line chemotherapy. These factors may assist in the selection of patients most likely to benefit from maintenance chemotherapy.

Summary of presentations from the 46th Annual Meeting of the American Society of Clinical Oncology: focus on non-small cell lung cancer (2010)

The promising results of crizotinib in molecularly selected patients with advanced non-small cell lung cancer (NSCLC) whose tumor cells had a novel fusion protein involving anaplastic lymphoma kinase presented at the 2010 American Society of Clinical Oncology reinforce once again the importance of understanding molecular heterogeneity of lung cancer and careful patient selection. Several other important issues were the subject of presentations related to lung cancer at the recently concluded American Society of Clinical Oncology annual meeting. The articles covered a wide variety of topics including optimal staging techniques to detect mediastinal nodal involvement, the role of platinum-based doublet chemotherapy in the management of elderly patients with advanced NSCLC, use of maintenance therapy with gemcitabine, and the impact of early introduction of organized palliative care in improving the quality of life of patients with advanced NSCLC. This report provides a brief overview of the presentations related to lung cancer that are relevant to clinical practice and future research.

Strategies for prolonged therapy in patients with advanced non-small-cell lung cancer

PURPOSE

A key challenge in the treatment of advanced non-small-cell lung cancer (NSCLC) is improving outcomes for patients who have achieved at least stable disease after standard first-line therapy. Although current guidelines recommend a maximum of six cycles of first-line therapy, even in responding patients, recent trials have shown benefit with maintenance therapy.

METHODS

We reviewed the English literature for randomized controlled trials on prolonged therapy for NSCLC conducted between January 1999 and January 2010. The search was supplemented by a review of abstracts presented at the American Society of Clinical Oncology annual meetings (2004 to 2010), the World Lung Cancer Conference (2007 to 2009), and the 2009 Joint European CanCer Organisation-European Society for Medical Oncology conference.

RESULTS

Several alternative strategies for prolongation of chemotherapy have been tested: these can be broadly categorized as continuation (prolongation of the first-line regimen until disease progression, unacceptable toxicity, or administration of a predefined greater number of treatment cycles), switch-maintenance (administration of an active agent immediately after completion of the initial course of chemotherapy), and continuation-maintenance (ongoing administration of a lower intensity version of the first-line chemotherapy regimen). These approaches differ from traditional second line, which is defined as treatment administered after documented clinical progression subsequent to first-line therapy.

CONCLUSION

There are no data to support continuation chemotherapy in advanced NSCLC. Switch-maintenance trials with erlotinib and pemetrexed have demonstrated an improvement in overall survival. Thus far, continuation-maintenance has shown an improvement in progression-free survival, without an overall survival advantage.