Autophagy in cancer immunotherapy: Perspective on immune evasion and cell death interactions

Both the innate and adaptive immune systems work together to produce immunity. Cancer immunotherapy is a novel approach to tumor suppression that has arisen in response to the ineffectiveness of traditional treatments like radiation and chemotherapy. On the other hand, immune evasion can diminish immunotherapy's efficacy. There has been a lot of focus in recent years on autophagy and other underlying mechanisms that impact the possibility of cancer immunotherapy. The primary feature of autophagy is the synthesis of autophagosomes, which engulf cytoplasmic components and destroy them by lysosomal degradation. The planned cell death mechanism known as autophagy can have opposite effects on carcinogenesis, either increasing or decreasing it. It is autophagy's job to maintain the balance and proper functioning of immune cells like B cells, T cells, and others. In addition, autophagy controls whether macrophages adopt the immunomodulatory M1 or M2 phenotype. The ability of autophagy to control the innate and adaptive immune systems is noteworthy. Interleukins and chemokines are immunological checkpoint chemicals that autophagy regulates. Reducing antigen presentation to induce immunological tolerance is another mechanism by which autophagy promotes cancer survival. Therefore, targeting autophagy is of importance for enhancing potential of cancer immunotherapy.

Circulating and disseminated tumor cells: harbingers or initiators of metastasis?

Tumor cells leave the primary tumor and enter the circulation. Once there, they are called circulating tumor cells (CTCs). A fraction of CTCs are capable of entering distant sites and persisting as disseminated tumor cells (DTCs). An even smaller fraction of DTCs are capable of progressing toward metastases. It is known that the DTC microenvironment plays an important role in sustaining their survival, regulating their growth, and conferring resistance to therapy. But we still have much to learn about the nature of these rare cell populations to predict which will progress and what exactly should cause concern for future relapse. Although recent technological advances in our ability to detect and molecularly and functionally characterize CTCs and DTCs promise to unravel this ambiguity, the timing of dissemination and the precise source of CTCs and DTCs profiled will impact the conclusions that can be made from these endeavors. In this review, we discuss the biology of CTCs and DTCs; the technologies to detect, isolate, and profile these cells; and the exceptions we must apply to our understanding of what role these cells play in the metastatic process. We conclude that a greater effort to understand the unique biology of these cells in context will positively impact our ability to use these cells to predict outcome, monitor treatment efficacy, and reveal therapeutically relevant targets to deplete these populations and ultimately prevent metastasis.

Adjuvant therapy for a 3.9-cm adenocarcinoma of the lung

After routine staging tests, including a FDG-PET scan and MRI of the brain, a 59-year-old mother of four, never smoker, undergoes uncomplicated right lower lobectomy of the lung to remove a 3.9 cm adenocarcinoma with visceral pleural invasion (pIB,T2N0M0). Should she receive adjuvant chemotherapy? If so, what drug, dose, and schedule?

Selection and adaptation during metastatic cancer progression

Cancer is often regarded as a process of asexual evolution driven by genomic and genetic instability. Mutation, selection and adaptation are by convention thought to occur primarily within, and to a lesser degree outside, the primary tumour. However, disseminated cancer cells that remain after 'curative' surgery exhibit extreme genomic heterogeneity before the manifestation of metastasis. This heterogeneity is later reduced by selected clonal expansion, suggesting that the disseminated cells had yet to acquire key traits of fully malignant cells. Abrogation of the cells' progression outside the primary tumour implies new challenges and opportunities for diagnosis and adjuvant therapies.

Adjuvant treatment in resected non-small cell lung cancer: current and future issues

The cornerstone of treatment for early-stage non-small cell lung cancer (NSCLC) has been surgical resection. In the last five years two phase III trials have provided evidence of adjuvant platinum-based chemotherapy for completely resected stage II-IIIA patients. We review the evidence supporting adjuvant therapy in early-stage NSCLC; we discuss new issues surrounding adjuvant therapy such as treatment in the elderly-unfit population, treatment toxicity and its influence on outcomes, the importance of histology and gender in adjuvant treatment; and we discuss the future landscape of early-stage NSCLC research, namely, therapeutic strategies exploiting pharmacogenomic and gene-expression profiling, in an attempt to customize the treatment.

Adjuvant chemotherapy after pulmonary resection for lung cancer

Adjuvant chemotherapy using a cisplatin-based regimen is currently recommended for patients with stage II and III non-small cell lung cancer (NSCLC) after complete tumor resection and may be considered for patients with stage IB NSCLC. Although adjuvant chemotherapy after complete resection of localized NSCLC is associated with an absolute survival advantage of approximately 5% at 5 years, there is still a relatively high risk of relapse even for early-stage NSCLC. Efforts are ongoing to identify new treatments in the adjuvant setting and to select patients for individualized treatment based on biomarkers.

Distinct clinical course of EGFR-mutant resected lung cancers: results of testing of 1118 surgical specimens and effects of adjuvant gefitinib and erlotinib

BACKGROUND

EGFR and KRAS mutations are mutually exclusive and predict outcomes with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) treatment in patients with stage IV lung cancers. The clinical significance of these mutations in patients with resected stage I-III lung cancers is unclear.

METHODS

At our institution, resection specimens from patients with stage I-III lung adenocarcinomas are tested for the presence of EGFR or KRAS mutations during routine pathology analysis such that the results are available before consideration of adjuvant therapy. In a cohort of 1118 patients tested over 8 years, overall survival was analyzed using multivariate analysis to control for potential confounders, including age, sex, stage, and smoking history. The impact of adjuvant erlotinib or gefitinib was examined in an independent data set of patients exclusively with EGFR mutation, in which date of recurrence was recorded.

RESULTS

In the overall population, we identified 227 KRAS (25%) and 222 EGFR (20%) mutations. Patients with EGFR-mutant lung cancers had a lower risk of death compared with those without EGFR mutations, overall survival (OS) HR 0.51 (95% confidence interval [CI]: 0.34-0.76, p < 0.001). Patients with KRAS-mutant lung cancers had similar outcomes compared with individuals with KRAS wild-type tumors, OS HR 1.17 (95% CI: 0.87-1.57, p = 0.30). A separate data set includes only patients with EGFR-mutant lung cancers identified over 10 years (n = 286). In patients with resected lung cancers and EGFR mutation, treatment with adjuvant erlotinib or gefitinib was associated with a lower risk of recurrence or death, disease-free survival HR 0.43 (95% CI: 0.26-0.72, p = 0.001), and a trend toward improved OS.

CONCLUSIONS

Patients with resected stage I-III lung cancers and EGFR mutation have a lower risk of death compared with patients without EGFR mutation. This may be because of treatment with EGFR TKIs. Patients with, and without KRAS mutation have similar OS. These data support reflex testing of resected lung adenocarcinomas for EGFR mutation to provide prognostic information and identify patients for enrollment on prospective clinical trials of adjuvant EGFR TKIs.

Epidermal growth factor receptor (EGFR) inhibitors and derived treatments

Epidermal growth factor receptor inhibitors are used to treat advanced lung cancer patients for almost a decade. Current knowledge on their role in the first or subsequent lines of therapy serves as a model for other targeted therapies in development. Several molecular predictors of outcomes were successfully identified in preclinical and clinical studies. Evaluation of EGFR-activating mutations is currently used to define biologically distinct patient subsets with important consequences for prognosis and therapy. Ongoing translational and clinical research exploring EGFR inhibition in lung cancer focuses on better understanding of biology of EGFR-driven disease, efficacy of novel irreversible EGFR inhibitors and monoclonal antibodies, efficacy of combination strategies, and attempts to move EGFR inhibitors into therapy portfolio for early-stage disease.

Developments in the treatment of early NSCLC: when to use chemotherapy

approximately 30% of lung carcinomas are resected and these cases are candidates for adjuvant treatments. The PORT meta-analysis reported in 1999 that postoperative radiotherapy had a detrimental effect for pathological N0 and N1 patients, and a debatable effect for N2 patients. Following the results of the 1995 meta-analysis on the role of chemotherapy (CT) in non-small-cell lung cancer (NSCLC), many randomized, controlled trials were launched to evaluate the effect of adjuvant cisplatin-based CT after the complete resection of NSCLC. The Lung adjuvant Ciplatin Evaluation pooled analysis included a total of 4584 patients recruited in five recent cisplatin-based adjuvant trials. It confirmed that adjuvant CT was associated with an absolute 5-year survival benefit of 5.3% (P = 0.0043). In addition, it showed that adjuvant cisplatin-based CT is detrimental in cases of stage Ia resected NSCLC; it also suggested that the combination of vinorelbine and cisplatin was of more benefit than older two and three drug combinations. The individual data-based meta-analysis was also updated with a total of over 10 000 patients. It confirmed the substantial effect of postoperative CT, with or without postoperative radiotherapy, with a substantial overall benefit of 4% at 5 years. Recent results of biological programs suggest that evaluating the expression of various tumor markers, including excision repair cross-complementation group 1, may allow the identification of patients most likely to benefit from CT. If these results are confirmed, tailored therapy might be the next step forward for resected NSCLC.

Prognostic and predictive role of the VeriStrat plasma test in patients with advanced non-small-cell lung cancer treated with erlotinib or placebo in the NCIC Clinical Trials Group BR.21 trial

INTRODUCTION

We investigated the predictive and prognostic effects of VeriStrat, a serum or plasma-based assay, on response and survival in a subset of patients enrolled on the NCIC Clinical Trials Group, BR.21 phase III trial of erlotinib versus placebo in previously treated advanced non-small-cell lung cancer patients.

METHODS

Pretreatment plasma samples were available for 441 of 731 enrolled patients and were provided as anonymized aliquots to Biodesix. The VeriStrat test was performed in a Clinical Laboratory Improvement Act-accredited laboratory at Biodesix, Inc. (Boulder, CO). The results (Good, Poor) were returned to NCIC Clinical Trials Group, which performed all the statistical analyses.

RESULTS

VeriStrat testing was successful in 436 samples (98.9%), with 61% classified as Good. VeriStrat was prognostic for overall survival in both erlotinib-treated patients and those on placebo, independent of clinical covariates. For VeriStrat Good patients, the median survival was 10.5 months on erlotinib versus 6.6 months for placebo (hazard ratio 0.63, 95% confidence interval 0.47-0.85, p = 0.002). For VeriStrat Poor patients, the median survival was 4 months for patients receiving erlotinib, and 3.1 months for placebo (hazard ratio: 0.77, 95% confidence interval 0.55-1.06, p = 0.11). VeriStrat was predictive for objective response (p = 0.002), but was not able to predict for differential survival benefit from erlotinib (interaction p = 0.48). Similar results were found for progression-free survival.

CONCLUSION

We were able to confirm that VeriStrat is predictive of objective response to erlotinib. VeriStrat is prognostic for both OS and progression-free survival, independent of clinical features, but is not predictive of differential survival benefit versus placebo.

Radical treatment of non-small cell lung cancer during the last 5 years

The management of non-small cell lung cancer (NSCLC) has continued to improve over the last 5 years due to advances in surgery, radiological staging, combined modality therapies and advances in radiation technology. We have an updated staging classification (7th Edition American Joint Committee on Cancer staging) and now in 2011, a new histology classification introducing the concepts of adenocarcinoma in situ and minimally invasive adenocarcinoma. This classification has profound surgical implications as the role of limited resection is reconsidered for early stage lesions. Surgery is curative in early stage disease. The role of surgery in locally advanced NSCLC remains controversial. The principal aim is a complete resection as this will determine long-term prognosis. Intraoperative staging of lung cancer is extremely important to determine the extent of resection according to the tumour and nodal status. Systematic nodal dissection is generally advocated to obtain accurate intraoperative staging and to help decide on adjuvant therapy. Radiotherapy currently plays a major role in the management of lung cancer as most patients are not surgical candidates due to disease stage, fitness and co-morbidities. In the last 5 years we have seen continuing optimisation of chemo-radiotherapy combinations and technological advances including the development of image guided radiotherapy (IGRT), stereotactic ablative body radiotherapy (SABR) and intensity modulated radiotherapy (IMRT). Quality of life evaluation is becoming increasingly important and should be considered when deciding on a specific treatment, especially in a multimodality setting.

Epidermal growth factor receptor mutation and treatment outcome of mediastinoscopic N2 positive non-small cell lung cancer patients treated with neoadjuvant chemoradiotherapy followed by surgery

Epidermal growth factor receptor (EGFR) mutation in non-small cell lung cancer (NSCLC) is a strong predictive factor for a favorable response to EGFR tyrosine kinase inhibitors, however, its prognostic role in locally advanced stage is unclear. The aim of this study was to analyze the association of EGFR mutational status and clinical outcome after neoadjuvant chemoradiotherapy (CRT) followed by surgical resection in mediastinoscopically proven N2(+) NSCLC patients. We retrospectively identified 168 patients diagnosed between 1998 and 2006. EGFR mutational status was identified in 107 patients. Response and survival after neoadjuvant CRT followed by surgery were compared according to EGFR mutational status. 83 patients (77.6%) were found to have wild type EGFR, while exon 19 deletions or L858R missense mutations in the EGFR gene were detected in 19 patients. There was no significant difference in overall survival; however, the 5-year PFS rate in EGFR mutant patients (8.4%) were significantly lower than in the EGFR wild-type patients (33.6%; p=0.005). In multivariate analysis, EGFR mutation was a significant prognostic factor for a higher risk of distant recurrence/progression than the EGFR wild type (HR=7.183, p=0.005). In locally advanced mediastinoscopic N2-positive NSCLC, EGFR mutation was associated with more frequent distant relapses and worse 5-year PFS rate after neoadjuvant CRT followed by surgery, which might suggest that systemic control might be important in patients with the EGFR mutation. Therefore, the role of TKI for adjuvant EGFR TKI to decrease disease recurrence in distant sites should be further investigated.

Randomized phase 2 trial on refinement of early-stage NSCLC adjuvant chemotherapy with cisplatin and pemetrexed versus cisplatin and vinorelbine: the TREAT study

BACKGROUND

Adjuvant chemotherapy is beneficial in non-small-cell lung cancer (NSCLC). However, balancing toxicity and efficacy mandates improvement.

PATIENTS AND METHODS

Patients with completely resected stages IB-pT3N1 NSCLC were randomly assigned to either four cycles cisplatin (C: 50 mg/m(2) day (d)1 + 8) and vinorelbine (V: 25 mg/m(2) d1, 8, 15, 22) q4 weeks or four cycles cisplatin (75 mg/m(2) d1) and pemetrexed (Px: 500 mg/m(2) d1) q3 weeks. Primary objective was the clinical feasibility rate (no grade (G)4 neutropenia/thrombocytopenia or thrombocytopenia with bleeding, no G3/4 febrile neutropenia or non-hematological toxicity; no premature withdrawal/death). Secondary objectives were drug delivery and efficacy.

RESULTS

One hundred and thirty two patients were randomized (stages: 38% IB, 10% IIA, 47% IIB, 5% pT3pN1; histology: 43% squamous, 57% non-squamous). The feasibility rates were 95.5% (cisplatin and pemetrexed, CPx) and 75.4% (cisplatin and vinorelbine, CVb) (P = 0.001); hematological G3/4 toxic effects were 10% (CPx) and 74% (CVb) (P < 0.001), non-hematological toxic effects were comparable (33% and 31%, P = 0.798). Delivery of total mean doses was 90% of planned with CPx, but 66% (cisplatin) and 64% (vinorelbine) with CVb (P < 0.0001). The median number of cycles [treatment time (weeks)] was 4 for CPx (11.2) and 3 for CVb (9.9). Time to withdrawal from therapy differed significantly between arms favoring CPx (P < 0.001).

CONCLUSION

Adjuvant chemotherapy with CPx is safe and feasible with less toxicity and superior dose delivery compared with CVb.

First- and second-line treatment of non-small-cell lung cancer patients withEGFRmutation-positive tumors

SUMMARY EGFR is a mediator of cell proliferation and is targeted by EGFR tyrosine kinase inhibitors (TKIs) to treat non-small-cell lung cancer (NSCLC). Efficacy of EGFR TKIs (specifically erlotinib and gefitinib) is influenced by mutations in EGFR. We review the evidence for targeted use of EGFR TKIs in the first-line treatment of EGFR mutation-positive NSCLC, considering epidemiology and timing/methodology of diagnosis. First- and second-generation TKIs, and other investigational drugs, also have a role in the second-line treatment of EGFR mutation-positive NSCLC; we discuss this in the context of disease progression and drug resistance. Patients with EGFR mutation-positive tumors should be considered as a separate subpopulation within NSCLC, which is the first step towards individualized treatment of this disease.

EGFR molecular profiling in advanced NSCLC: a prospective phase II study in molecularly/clinically selected patients pretreated with chemotherapy

INTRODUCTION

The optimal use of epidermal growth factor receptor (EGFR)-related molecular markers to prospectively identify tyrosine kinase inhibitor (TKI)-sensitive patients, particularly after a previous chemotherapy treatment, is currently under debate.

METHODS

We designed a prospective phase II study to evaluate the activity of EGFR-TKI in four different patient groups, according to the combination of molecular (EGFR gene mutations, EGFR gene copy number and protein expression, and phosphorylated AKT expression, pAKT) and clinicopathological (histology and smoking habits) factors. Correlations between molecular alterations and clinical outcome were also explored retrospectively for first-line chemotherapy and EGFR-TKI treatment.

RESULTS

Patients who had progressed during or after first-line chemotherapy were prospectively assigned to EGFR-TKI treatment as follows: (G1) EGFR mutation (n = 12); (G2) highly polysomic/amplified EGFR (n = 18); (G3) EGFR and/or pAKT positive (n = 41); (G4) adenocarcinoma/bronchoalveolar carcinoma and no smoking history (n = 15). G1 and G4 had the best and second-best overall response rate (25% and 20%, respectively), whereas the worst outcome was observed in G2 (ORR, 6%; p = 0.05). Disease control was highest in G1 and G4 (>50%) and lowest in G3 (<20%) (p = 0.02). Patients selected by EGFR mutation or clinical parameters (G1 and G4) also had significantly better progression-free survival and overall survival (p = 0.02 and p = 0.01, respectively). Multivariate analysis confirmed the impact of sex, smoking history, EGFR/KRAS mutation, and pAKT on outcomes and allowed us to derive an efficient predictive model. Histology, EGFR mutations, and pAKT were independent predictors of response to first-line chemotherapy at retrospective analysis, whereas pAKT and human epidermal growth factor receptor 2 expression were the only independent predictors of progression-free survival and overall survival.

CONCLUSIONS

Selection of patients based on either EGFR mutation or clinical characteristics seems an effective approach to optimize EGFR-TKI treatment in chemotherapy-pretreated non-small-cell lung cancer patients.

Predictive markers in early research and companion diagnostic developments in oncology

Predictive biomarkers are discovered and used in oncology research to formulate hypotheses aimed at the identification of patients benefiting from specific therapeutic intervention(s). They pave the way to the development of companion diagnostic tests which are tools readily implemented in the clinic and serve to qualify a patient for treatment with a particular targeted drug or the continued use of a particular drug, thus maximizing the benefit to risk ratio of the medical intervention to the patient. Predictive biomarkers are defined by biological characteristics of the patient's or tumor status that can be measured objectively and correlated with clinical outcome: these can be molecular, cellular or biochemical features. Predictive markers need extensive analytical validation - specific for the tool utilized for their assessment - as well as rigorous clinical qualification in the context of the drug treatment for which they define clinical utility. The process of companion diagnostic development is a highly interdisciplinary and complex one, driven by key crucial milestones and accompanying the same and typical process of a whole drug discovery and development continuum, from marker discovery and validation, assay development, clinical qualification until test approval and commercialization.

Adjuvant chemotherapy for resected non-small-cell lung cancer: future perspectives for clinical research

Adjuvant chemotherapy for non-small-cell lung carcinoma (NSCLC) is a debated issue in clinical oncology. Although it is considered a standard for resected stage II-IIIA patients according to the available guidelines, many questions are still open. Among them, it should be acknowledged that the treatment for stage IB disease has shown so far a limited (if sizable) efficacy, the role of modern radiotherapies requires to be evaluated in large prospective randomized trials and the relative impact of age and comorbidities should be weighted to assess the reliability of the trials' evidences in the context of the everyday-practice. In addition, a conclusive evidence of the best partner for cisplatin is currently awaited as well as a deeper investigation of the fading effect of chemotherapy over time. The limited survival benefit since first studies were published and the lack of reliable prognostic and predictive factors beyond pathological stage, strongly call for the identification of bio-molecular markers and classifiers to identify which patients should be treated and which drugs should be used. Given the disappointing results of targeted therapy in this setting have obscured the initial promising perspectives, a biomarker-selection approach may represent the basis of future trials exploring adjuvant treatment for resected NSCLC.

The optimal chemotherapy for stage III non-small cell lung cancer patients

Nearly one third of non-small cell lung cancer (NSCLC) patients at diagnosis have stage III disease. Concurrent chemoradiation has emerged as the standard of care for patients with unresectable stage III NSCLC. Meta-analyses of studies comparing concurrent with sequential therapy showed that there was a relative improvement of about 20% with concurrent therapy over sequential therapy in these patients and that concurrent chemoradiation is more toxic than the sequential approach, particularly with regard to esophagitis. The incidence of pneumonitis is not significantly higher with concurrent therapy. All the phase 3 trials comparing concurrent with sequential therapy included cisplatin-based therapy. In addition, patients enrolled in these studies were required to have good performance status and some studies mandated limited weight loss. Some patients are also treated with lower doses of chemotherapy, particularly carboplatin and paclitaxel, concurrently with radiation followed by full-dose chemotherapy. Randomized studies have failed to show benefit of induction or consolidation chemotherapy. For patients who have a poor performance status or significant weight loss, a sequential approach of chemotherapy followed by radiation may be appropriate. Ongoing clinical trials are evaluating the utility of integrating some of the newer agents such as pemetrexed and cetuximab into the treatment plan for stage III patients.

The BATTLE to personalize lung cancer prevention through reverse migration

Agents can enter clinical development for cancer prevention either initially or after previous development for a different indication, such as arthritis, with both approaches consuming many years of development before an agent is fully evaluated for cancer prevention. We propose the following, third approach: reverse migration, that is, importing agents, targets, and study designs to personalize interventions and concepts developed in advanced cancer to the setting of cancer prevention. Importing these "ready-made" features from therapy will allow reverse migration to streamline preventive agent development. We recently reported the Biomarker-integrated Approaches of Targeted Therapy for Lung Cancer Elimination (BATTLE) trial of personalized lung cancer therapy and now propose the reverse migration development of personalized lung cancer prevention based on the BATTLE model.

Personalized medicine in lung cancer: what we need to know

Lung cancer is a complex and often fatal disease. The recent discovery of activating mutations in EGFR and fusion genes involving ALK has set the stage for personalized medicine for lung cancer. Patients selected using biomarkers have benefited from the development of EGFR tyrosine kinase inhibitors and ALK inhibitors with considerable improvement in tumor control and survival. Four key areas of knowledge that are essential to the development of targeted therapy are discussed in this Review: knowing the target, knowing the biomarker, knowing the end point and knowing the mechanisms of resistance.

Maintained sensitivity to EGFR tyrosine kinase inhibitors in EGFR-mutant lung cancer recurring after adjuvant erlotinib or gefitinib

PURPOSE

Given the unprecedented efficacy of EGFR tyrosine kinase inhibitors (TKI) in advanced EGFR-mutant lung cancer, adjuvant TKI therapy is an appealing strategy. However, there are conflicting findings regarding the potential benefit of adjuvant EGFR-TKI in patients with lung cancer harboring EGFR mutations. To better understand these results, we studied the natural history of lung cancers which recurred despite adjuvant TKI.

EXPERIMENTAL DESIGN

Patients with recurrent EGFR-mutant lung cancer following adjuvant TKI were identified using an Institutional Review Board-approved mechanism. Recurrent cancer specimens were tested for resistance mutations. Sensitivity to retreatment with EGFR-TKI was evaluated.

RESULTS

Twenty-two patients with cancers harboring an EGFR sensitizing mutation received adjuvant erlotinib or gefitinib for a median of 17 months (range 1-37 months). T790M was more common in cancers which recurred while receiving TKI than in those which recurred after stopping TKI (67% vs. 0%, P = 0.011). Fourteen patients who developed recurrence after stopping EGFR-TKI were retreated, with a median time to progression of 10 months and radiographic response seen in 8 of 11 patients with evaluable disease (73%).

CONCLUSIONS

Recurrence of EGFR-mutant lung cancer after stopping adjuvant TKI should not preclude a trial of TKI retreatment; a phase II trial of erlotinib in this setting is underway. Studies of adjuvant EGFR-TKI will underestimate the potential survival benefit of adjuvant TKI for patients with EGFR-mutant lung cancers if retreatment at recurrence is not given.

Impact on disease-free survival of adjuvant erlotinib or gefitinib in patients with resected lung adenocarcinomas that harbor EGFR mutations

BACKGROUND

Patients with stage IV lung adenocarcinoma and epidermal growth factor receptor (EGFR) mutation derive clinical benefit from treatment with EGFR tyrosine kinase inhibitors (TKIs). Whether treatment with TKI improves outcomes in patients with resected lung adenocarcinoma and EGFR mutation is unknown.

METHODS

Data were analyzed from a surgical database of patients with resected lung adenocarcinoma harboring EGFR exon 19 or 21 mutations. In a multivariate analysis, we evaluated the impact of treatment with adjuvant TKI.

RESULTS

The cohort consists of 167 patients with completely resected stages I to III lung adenocarcinoma. Ninety-three patients (56%) had exon 19 del, 74 patients (44%) had exon 21 mutations, and 56 patients (33%) received perioperative TKI. In a multivariate analysis controlling for sex, stage, type of surgery, and adjuvant platinum chemotherapy, the 2-year disease-free survival (DFS) was 89% for patients treated with adjuvant TKI compared with 72% in control group (hazard ratio = 0.53; 95% confidence interval: 0.28-1.03; p = 0.06). The 2-year overall survival was 96% with adjuvant EGFR TKI and 90% in the group that did not receive TKI (hazard ratio: 0.62; 95% confidence interval: 0.26-1.51; p = 0.296).

CONCLUSIONS

Compared with patients who did not receive adjuvant TKI, we observed a trend toward improvement in DFS among individuals with resected stages I to III lung adenocarcinomas harboring mutations in EGFR exon 19 or 21 who received these agents as adjuvant therapy. Based on these data, 320 patients are needed for a randomized trial to prospectively validate this DFS benefit.

Outcomes after combined modality therapy for EGFR-mutant and wild-type locally advanced NSCLC

BACKGROUND

Epidermal growth factor receptor (EGFR) mutations identify a unique biological subtype of non-small cell lung cancer (NSCLC). Treatment outcomes for EGFR-mutant locally advanced NSCLC patients have not been well described.

METHODS

We retrospectively examined outcomes after combined modality therapy including thoracic radiation therapy (RT) in 123 patients with locally advanced NSCLC and known EGFR mutation status. Outcomes were compared using Kaplan-Meier analysis, the log-rank test, and multivariate Cox regression models.

RESULTS

All 123 patients underwent thoracic RT; 25% had tumors with EGFR mutations and 94% had stage III disease. Overall, 81% received chemotherapy concurrent with RT and 55% underwent surgical resection. With a median follow-up of 27.5 months, the overall survival (OS) rate was significantly higher in patients with EGFR-mutant tumors than in those with wild-type EGFR tumors (2-year estimate: 92.6% versus 69.0%; p = .04). The 2-year relapse-free survival and distant recurrence rates did not differ significantly by genotype. The 2-year locoregional recurrence rate (LRR) was significantly lower in EGFR-mutant than in wild-type EGFR patients (17.8% versus 41.7%; p = .005). EGFR-mutant genotype was associated with a lower risk for LRR on multivariate analysis, but not OS, after adjusting for surgery and other potential confounders.

CONCLUSION

We observed that EGFR-mutant patients with locally advanced NSCLC treated with RT had lower rates of LRR than wild-type EGFR patients, raising the hypothesis that EGFR mutations may confer sensitivity to RT and/or chemotherapy. The association between mutation status and OS after combined modality therapy was less robust. Our data may serve as a useful baseline estimate of outcomes by EGFR genotype for future prospective studies.

Molecular characteristics predict clinical outcomes: prospective trial correlating response to the EGFR tyrosine kinase inhibitor gefitinib with the presence of sensitizing mutations in the tyrosine binding domain of the EGFR gene

PURPOSE

To determine if tumor regression following treatment with gefitinib correlates with the presence of sensitizing mutations in epidermal growth factor receptor (EGFR).

PATIENTS AND METHODS

Patients with resectable stage I and II non-small cell lung cancer (NSCLC) enriched for the likelihood of EGFR mutation (≤ 15 pack-year cigarette smoking history and/or a component of bronchioloalveolar carcinoma) received preoperative gefitinib for 21 days. Tumor specimens were analyzed for EGFR and KRAS mutations and EGFR protein expression and amplification. Patients with 25% or more reduction in tumor size measured bidimensionally at 3 weeks and/or patients with an EGFR mutation received adjuvant gefitinib for 2 years postoperatively.

RESULTS

Fifty patients with stage I/II NSCLC were treated. After 21 days of preoperative gefitinib a response of 25% or more was observed in 21 of 50 (42%) patients. Seventeen of 21 patients with a response had an EGFR mutation and 4 of 21 patients with a response did not (P = 0.0001). Twenty-five of 50 patients were eligible to receive adjuvant gefitinib. With a median follow-up of 44.1 months, 2-year disease free survival for EGFR mutant patients and for those who received adjuvant gefitinib was not statistically different than those who were EGFR wild-type and those who did not receive adjuvant gefitinib. The median disease free and overall survivals have not been reached.

CONCLUSIONS

The presence of sensitizing EGFR mutations correlates with radiographic response. A short course of preoperative treatment serves a platform for evaluating activity of new agents and assures sufficient tumor availability for correlative analyses.

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.

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.