Treatment-by-histology interaction analyses in three phase III trials show superiority of pemetrexed in nonsquamous non-small cell lung cancer

Real-world effectiveness of systemic agents approved for advanced non-small cell lung cancer: a SEER-Medicare analysis

OBJECTIVES

Disparity exists between patients with lung cancer enrolled in clinical trials and patients treated in the community setting. This study assessed the real-world effectiveness of cytotoxic agents that became available for the treatment of non-small cell lung cancer (NSCLC) in the last 2 decades.

METHODS

We employed the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database for patients diagnosed with stage IIIB/IV NSCLC between 1988 and 2005 to assess the effectiveness of newly approved agents. Effectiveness of specific agents was assessed at time periods immediately following the approval of the agent for NSCLC: baseline, 1988-1994; platinum, 1995-1999; docetaxel, 1999-2003; pemetrexed and bevacizumab, 2004-2005. Significant associations between specific drug treatment and survival improvement were determined using the Kaplan-Meier method, Cox proportional hazard model, and propensity score analyses. Significant differences were established by log-rank test.

RESULTS

This analysis employed data from 143,548 patients by sex (58% male, 42% female), cancer stage (35% stage IIIB, 65% stage IV), and age (12% 20-64 years, 22% 65-69 years, 45% 70-79 years, 22% 80 years and older). There was temporal improvement in survival for patients treated with newly approved chemotherapy (1-year survival rates: 32.41% in 1988-1994, 32.95% in 1995-1998, 37.40% in 1999-2003, and 39.55% in 2004-2005). Patients treated with a newly approved drug during the relevant treatment era had a significant reduction in the risk of death when compared with patients treated with chemotherapy other than the newly approved agent (hazard ratios [95% confidence interval] were 0.76 [0.71-0.81] for platinum, 0.73 [0.70-0.75] for docetaxel, 0.40 [0.37-0.44] for pemetrexed, and 0.33 [0.27-0.40] for bevacizumab; p < .001). Propensity score adjustment did not significantly alter these results.

CONCLUSIONS

Currently approved drugs for the treatment of advanced NSCLC are associated with improved survival in the U.S. Medicare patient population. Our findings support the effectiveness of these agents in the real-world oncology practice.

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.

Molecular biology of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

Based on recent bench and clinical research, the treatment of lung cancer has been refined, with treatments allocated according to histology and specific molecular features. For example, targeting mutations such as epidermal growth factor receptor (EGFR) with tyrosine kinase inhibitors has been particularly successful as a treatment modality, demonstrating response rates in selected patients with adenocarcinoma tumors harboring EGFR mutations that are significantly higher than those for conventional chemotherapy. However, the development of new targeted therapies is, in part, highly dependent on an improved understanding of the molecular underpinnings of tumor initiation and progression, knowledge of the role of molecular aberrations in disease progression, and the development of highly reproducible platforms for high-throughput biomarker discovery and testing. In this article, we review clinically relevant research directed toward understanding the biology of lung cancer. The clinical purposes of this research are (1) to identify susceptibility variants and field molecular alterations that will promote the early detection of tumors and (2) to identify tumor molecular alterations that serve as therapeutic targets, prognostic biomarkers, or predictors of tumor response. We focus on research developments in the understanding of lung cancer somatic DNA mutations, chromosomal aberrations, epigenetics, and the tumor microenvironment, and how they can advance diagnostics and therapeutics.

Targeted agents in non-small cell lung cancer therapy: What is there on the horizon?

Lung cancer is a heterogeneous group of diseases. There has been much research in lung cancer over the past decade which has advanced our ability to treat these patients with a more personalized approach. The scope of this paper is to review the literature and give a broad understanding of the current molecular targets for which we currently have therapies as well as other targets for which we may soon have therapies. Additionally, we will cover some of the issues of resistance with these targeted therapies. The molecular targets we intend to discuss are epidermal growth factor receptor (EGFR), Vascular endothelial growth factor (VEGF), anaplastic large-cell lymphoma kinase (ALK), KRAS, C-MET/RON, PIK3CA. ROS-1, RET Fibroblast growth factor receptor (FGFR). Ephrins and their receptors, BRAF, and immunotherapies/vaccines. This manuscript only summarizes the work which has been done to date and in no way is meant to be comprehensive.

A trial-based cost-effectiveness analysis of erlotinib alone versus platinum-based doublet chemotherapy as first-line therapy for Eastern Asian nonsquamous non-small-cell lung cancer

INTRODUCTION

Lung cancer, the most prevalent malignant cancer in the world, remains a serious threat to public health. Recently, a large number of studies have shown that an epidermoid growth factor receptor-tyrosine kinase inhibitor (EGFR TKI), Erlotinib, has significantly better efficacy and is better tolerated in advanced non-small cell lung cancer (NSCLC) patients with a positive EGFR gene mutation. However, access to this drug is severely limited in China due to its high acquisition cost. Therefore, we decided to conduct a study to compare cost-effectiveness between erlotinib monotherapy and carboplatin-gemcitabine (CG) combination therapy in patients with advanced EGFR mutation-positive NSCLC.

METHODS

A Markov model was developed from the perspective of the Chinese health care system to evaluate the cost-effectiveness of the two treatment strategies; this model was based on data from the OPTIMAL trial, which was undertaken at 22 centres in China. The 10-year quality-adjusted life years (QALYs), direct costs, and incremental cost-effectiveness ratio (ICER) were estimated. To allow for uncertainties within the parameters and to estimate the model robustness, one-way sensitivity analysis and probabilistic sensitivity analysis were performed.

RESULTS

The median progression-free survival (PFS) obtained from Markov model was 13.2 months (13.1 months was reported in the trial) in the erlotinib group while and 4.64 months (4.6 months was reported in the trial) in the CG group. The QALYs were 1.4 years in the erlotinib group and 1.96 years in the CG group, indicating difference of 0.56 years. The ICER was most sensitive to the health utility of DP ranged from $58,584.57 to $336,404.2. At a threshold of $96,884, erlotinib had a 50% probability of being cost-effective.

CONCLUSIONS

Erlotinib monotherapy is more cost-effective compared with platinum-based doublets chemotherapy as a first-line therapy for advanced EGFR mutation- positive NSCLC patients from within the Chinese health care system.

A randomized phase II study of pemetrexed in combination with cisplatin or carboplatin as first-line therapy for patients with locally advanced or metastatic non-small-cell lung cancer

BACKGROUND

Pemetrexed plus cisplatin was approved for first-line treatment of non-small-cell lung cancer (NSCLC) in patients with nonsquamous histology after initiation of this study. This phase II study evaluated pemetrexed plus cisplatin and pemetrexed plus carboplatin as first-line treatments for stage IIIB/IV NSCLC.

PATIENTS AND METHODS

The patients were randomized (1:1) to 2 parallel arms: pemetrexed (500 mg/m(2)) plus cisplatin (75 mg/m(2)) or pemetrexed (500 mg/m(2)) plus carboplatin (area under the curve 6) day 1 every 3 weeks (maximum, 6 cycles). Progression-free survival (PFS) was the primary objective; secondary objectives included overall survival (OS), 1-year survival, and safety.

RESULTS

Sixty-five patients were randomized to each treatment arm. The patients treated with pemetrexed plus cisplatin had a median age of 64 years and were predominantly men (42 [64.6%]) with nonsquamous histology (53 [81.5%]), stage IV (61 [92.4%]) disease, and a performance status of 0 (40 [61.5%]). Median PFS was 6.0 months, 6-month PFS rate was 50.5%, median OS was 11.7 months, and 1-year survival rate was 47.5%. Drug-related grade 3/4 toxicities included neutropenia (11 [16.9%]), anemia (5 [7.7%]), thrombocytopenia (2 [3.1%]), and nausea (3 [4.6%]). Patients treated with pemetrexed plus carboplatin had a median age of 63 years, were predominantly men (46 [70.8%]) with nonsquamous histology (52 [80.0%]), stage IV (58 [86.6%]) disease, and a performance status of 0 (45 [69.2%]). The median PFS was 4.7 months, the 6-month PFS rate was 34.9%, median OS was 8.9 months, and 1-year survival rate was 39.2%. Drug-related grade 3/4 toxicities included neutropenia (17 [26.2%]), thrombocytopenia (11 [16.9%]), anemia (7 [10.8%]), and nausea (5 [7.7%]).

CONCLUSIONS

Both the pemetrexed plus cisplatin and pemetrexed plus carboplatin arms met their primary endpoints and demonstrated efficacy and tolerability as first-line therapy in patients with advanced NSCLC. http://ClinicalTrials.gov: NCT00402051.

Current state-of-the-art therapy for advanced squamous cell lung cancer

Squamous cell carcinoma (SCC) represents the second most common histologic subtype of lung cancer (preceded only by adenocarcinoma). SSC of the lung is prevalently diagnosed in smokers and has been described as a preferentially centrally located tumor in which the main airways are commonly involved. Clinically, it presents with predominant locoregional signs and symptoms, but in recent years an increasing frequency of peripheral SCC of the lung has been reported. Pathologic diagnosis can be easily made through light microscopy and immunohistochemistry. The treatment approach for early-stage disease does not differ from that of other histologic subtypes of non-small cell lung cancer; in locally advanced unresectable or metastatic disease, doublet chemotherapy regimens (including cisplatin or carboplatin and a third-generation agent such as gemcitabine, taxanes, or vinorelbine) remain the cornerstone of front-line systemic treatment. Conversely, a single agent, mainly docetaxel, is the preferred treatment in second-line treatment. In unselected patient populations, targeted therapies have been extensively tested in combination with cytotoxic chemotherapy with disappointing results because of increased toxicity or lack of improvement in efficacy outcomes. Genomic alterations in SCC of the lung have not been comprehensively characterized, and no molecularly targeted therapies have been specifically developed for the treatment of this disease, but recently immune checkpoints have emerged as new therapeutic agent.

[Non-small cell lung cancer. Subtyping and predictive molecular marker investigations in cytology]

The diagnosis and treatment of non-small cell lung cancer (NSCLC) have been revolutionized over the last few years. Requirements for cytopathologists in lung cancer diagnosis have therefore changed. The general diagnostic category of NSLC is no longer sufficient. In addition cytological specimens need to be evaluated for adequacy regarding predictive marker analyses. Accurate NSCLC subtyping with a distinction of adenocarcinoma from squamous cell carcinoma is crucial for treatment decisions as the subtype will decide on the chemotherapy regimen and the choice of predictive marker analyses for targeted treatment. In the majority of cases, the subtype can be diagnosed by morphology alone. Cytology is equally well suited as biopsy specimens for the assessment of molecular predictive markers. The best results are achieved when both cytology and biopsy specimens are compared to choose the most appropriate specimen for morphological subtyping and molecular testing. In this paper, we discuss special issues of NSCLC subtyping and currently recommended predictive molecular marker analyses.

Pemetrexed Versus Pemetrexed and Carboplatin As Second-Line Chemotherapy in Advanced Non–Small-Cell Lung Cancer: Results of the GOIRC 02-2006 Randomized Phase II Study and Pooled Analysis With the NVALT7 Trial

Purpose

To compare efficacy of pemetrexed versus pemetrexed plus carboplatin in pretreated patients with advanced non–small-cell lung cancer (NSCLC).

Patients and Methods

Patients with advanced NSCLC, in progression during or after first-line platinum-based chemotherapy, were randomly assigned to receive pemetrexed (arm A) or pemetrexed plus carboplatin (arm B). Primary end point was progression-free survival (PFS). A preplanned pooled analysis of the results of this study with those of the NVALT7 study was carried out to assess the impact of carboplatin added to pemetrexed in terms of overall survival (OS).

Results

From July 2007 to October 2009, 239 patients (arm A, n = 120; arm B, n = 119) were enrolled. Median PFS was 3.6 months for arm A versus 3.5 months for arm B (hazard ratio [HR], 1.05; 95% CI, 0.81 to 1.36; P = .706). No statistically significant differences in response rate, OS, or toxicity were observed. A total of 479 patients were included in the pooled analysis. OS was not improved by the addition of carboplatin to pemetrexed (HR, 90; 95% CI, 0.74 to 1.10; P = .316; P heterogeneity = .495). In the subgroup analyses, the addition of carboplatin to pemetrexed in patients with squamous tumors led to a statistically significant improvement in OS from 5.4 to 9 months (adjusted HR, 0.58; 95% CI, 0.37 to 0.91; P interaction test = .039).

Conclusion

Second-line treatment of advanced NSCLC with pemetrexed plus carboplatin does not improve survival outcomes as compared with single-agent pemetrexed. The benefit observed with carboplatin addition in squamous tumors may warrant further investigation.

Maintenance therapy for advanced non-small-cell lung cancer: a pilot study on patients' perceptions

INTRODUCTION

Several randomized trials on maintenance therapy (MT) for metastatic non-small-cell lung cancer (NSCLC) have demonstrated benefit in progression-free survival. More recently, a study with pemetrexed and one with erlotinib also showed significant gains in overall survival (OS). Yet, in this palliative treatment setting, the benefit has to be weighed against the potential burden of treatment, and thus patients' preferences should be taken into account.

METHODS

In the absence of data on this topic, we undertook a pilot survey with 10 questions covering the overall patient attitude toward MT, the benefit expected by patients, and the acceptance of side effects or modes of administration. Included patients had stage IV NSCLC and were planned to start first-line platinum-based doublet chemotherapy. The questionnaire was submitted at the start of and after two and four cycles of chemotherapy.

RESULTS

Thirty patients were included. Overall, patients had a positive attitude toward MT. At baseline, it was considered worthwhile by 83%, 67%, and 43% of patients for an OS benefit of 6, 3, or 1 month, respectively, with some decrease over time. Effects on symptom control were crucial for about 90% of the patients. There was a slight preference for oral versus intravenous administration. Side effects were accepted by most patients as long as they were mild to moderate.

CONCLUSION

Our pilot survey showed that metastatic NSCLC patients in general are in favor of MT. They expect either an OS benefit of at least several months, or better symptom control, in balance with mild-to-moderate side effects.

Pathologic complete response to preoperative chemotherapy predicts cure in early-stage non-small-cell lung cancer: combined analysis of two IFCT randomized trials

INTRODUCTION

Our study aimed to evaluate whether pathologic complete response (pCR) in early-stage non-small-cell lung cancer (NSCLC) after neoadjuvant chemotherapy resulted in improved outcome, and to determine predictive factors for pCR.

METHODS

Eligible patients with stage-IB or -II NSCLC were included in two consecutive Intergroupe Francophone de Cancérologie Thoracique phase-III trials evaluating platinum-based neoadjuvant chemotherapy, with pCR defined by the absence of viable cancer cells in the resected surgical specimen.

RESULTS

Among the 492 patients analyzed, 41 (8.3%) achieved pCR. In the pCR group, 5-year overall survival was 80.0% compared with 55.8% in the non-pCR group (p = 0.0007). In multivariate analyses, pCR was a favorable prognostic factor of overall survival (relative risk = 0.34; 95% confidence interval = 0.18-0.64) in addition to squamous-cell carcinoma, weight loss less than or equal to 5%, and stage-IB disease. Five-year disease-free survival was 80.1% in the pCR group compared to 44.8% in the non-pCR group (p < 0.0001). Two patients (4.9%) in the pCR group experienced disease recurrence compared to 193 patients (42.8%) in the non-pCR group. SCC subtype was the only independent predictor of pCR (odds ratio [OR] = 4.30; 95% confidence interval = 1.90-9.72).

CONCLUSION

Our results showed that pCR after preoperative chemotherapy was a favorable prognostic factor in stage-IB-II NSCLC. Our study is the largest published series evaluating pCRs after preoperative chemotherapy. The only factor predictive of pCR was squamous-cell carcinoma. Identifying molecular predictive markers for pCR may help in distinguishing patients likely to benefit from neoadjuvant chemotherapy and in choosing the most adequate preoperative chemotherapy regimen.

Genomic copy number alterations associated with the early brain metastasis of non-small cell lung cancer

Frequent early development of systemic metastasis leads to unfavourable clinical prognosis of non-small cell lung cancer (NSCLC). Although brain metastasis (BM) contributes significantly to morbidity and mortality of NSCLC, relevant driver mechanisms are largely unknown. To elucidate genetic alterations associated with early BM of NSCLC, we retrospectively collected 18 NSCLC cases with BM [12 adenocarcinomas (ADC) and 6 squamous cell carcinomas (SQCC)] whose surgical tissues of both primary and brain metastatic tumors were preserved as formaldehyde-fixed and paraffin-embedded (FFPE) pathological samples. When chromosomal copy number alterations (CNA) of those FFPE samples were analysed by the Molecular Inversion Probe (MIP) technology, the most frequent CNAs detected in primary lung ADCs were gains of 3q, 5p, 5q, 6p, 8q, 9p, 11p, 15q, 17q and losses of 10q and 22q whereas primary lung SQCCs revealed gains in 4q and 12q and loss in 9q. In particular, when comparative MIP was performed in primary 12 ADCs depending on the pattern of BM to uncover predetermining signatures that can predict the risk of BM, selectively amplified regions of primary lung ADCs (5q35, 10q23 and 17q23-24) were identified as significantly associated with the development of early BM within 3 months after first diagnosis of primary tumors. Those regions harbour several candidate genes including NeurL1B, ACTA2, FAS and ICAM2. Although more validation is needed, the genetic signatures elucidated in this study help to identify useful molecular markers defining an NSCLC patient subgroup at risk of early BM, guiding therapeutic decisions.

Correlation between thymidylate synthase gene polymorphisms and efficacy of pemetrexed in advanced non-small cell lung cancer

One of the target genes of pemetrexed (PEM), thymidylate synthase (TS), has been shown to have a close association with its efficacy. TS gene polymorphisms have been shown to be associated with the efficacy of antifolate treatment in enteron tumors. The purpose of this study was to investigate the clinical significance of TS gene polymorphisms in patients with advanced NSCLC receiving PEM-based treatment. The variable nucleoid tandem repeat in the 5′-UTR region was amplified and detected using fluorescently labeled multiplex short tandem repeat polymerase chain reaction. The polymorphism in the 3′-UTR region of the TS gene was detected using the Taqman probe. Efficacy of PEM was assessed according to the Response Evaluation Criteria in Solid Tumors, version 1.1. None of the genotypes were associated with gender, smoking status and age. Disease control rate (DCR), objective response rate (ORR) and progression-free survival (PFS) were similar between patients harboring 2R and 3R alleles (PFS, p=0.518; DCR, p=0.631; ORR, p=0.541), as well as those with a 6-bp insertion and 6-bp deletion (PFS, p=0.776; DCR, p=0.626; ORR, p=0.330). To study the combined effect of TS polymorphisms, the study population was divided into three groups: 2R&6 del, 2R&6 ins and 3R&6 del. No significant differences were observed among the different groups according to DCR (p=0.517), ORR (p=0.611) and PFS (p=0.938). In conclusion, polymorphisms of the TS gene do not appear to be a prognostic marker for advanced NSCLC patients receiving PEM-based treatment.

A randomized, phase 2 study comparing pemetrexed plus best supportive care versus best supportive care as maintenance therapy after first-line treatment with pemetrexed and cisplatin for advanced, non-squamous, non-small cell lung cancer

BACKGROUND

Maintenance therapy for non-small cell lung cancer (NSCLC) aims to extend disease control after first-line chemotherapy with active and well-tolerated agents. The utility of continuation maintenance therapy requires further research.

METHODS

This multicenter, randomized, phase 2 study compared continuation maintenance therapy with pemetrexed (500 mg/m2 every 21 days) and best supportive care (BSC) versus BSC alone in patients with advanced, non-squamous NSCLC who had not progressed after 4 cycles of induction chemotherapy with pemetrexed (500 mg/m2) and cisplatin (75 mg/m2). The primary endpoint was progression-free survival (PFS) from randomization, was analyzed using a Cox model, stratified for the tumor response at the end of induction therapy, at a one-sided alpha of 0.2. Secondary endpoints: response and disease control rates, overall survival (OS), one year survival rates, and treatment-emergent adverse events (TEAEs).

RESULTS

A total of 106 patients commenced induction therapy, of whom 55 patients were randomized to maintenance pemetrexed/BSC (n = 28) or BSC (n = 27). Although the median PFS time for maintenance phase for both arms was 3.2 months, the one-sided p-value for the PFS HR comparison was less than the prespecified limit of 0.2 (HR = 0.76, two-sided 95% confidence interval [CI]: 0.42 to 1.37; one-sided p-value = 0.1815), indicating that PFS was sufficiently long in the pemetrexed/BSC arm to warrant further investigation. Similar PFS results were observed for the overall study period (induction plus maintenance) and when the PFS analysis was adjusted for sex, baseline disease stage, and the ECOG PS prior to randomization. The median OS for the maintenance phase was 12.2 months (95%CI: 5.6 to 20.6) for the pemetrexed/BSC arm and 11.8 months (95% CI: 6.3 to 25.6) for BSC arm. The one-year survival probabilities were similar for both arms for the maintenance phase and the overall study period. Both the induction and continuation maintenance therapies were generally well-tolerated, and similar proportion of patients in each arm experienced at least 1 grade 3/4 TEAE (pemetrexed/BSC, 17.9%; BSC, 18.5%).

CONCLUSIONS

Continuation pemetrexed maintenance therapy resulted in promising PFS with an acceptable safety profile in a Middle Eastern population with advanced non-squamous NSCLC and is worthy of further investigation.

TRIAL REGISTRATION

NCT00606021.

Toxic epidermal necrolysis related to Cisplatin and pemetrexed for metastatic non-small cell lung cancer

BACKGROUND

Toxic epidermal necrolysis (TEN) is an uncommon but life-threatening adverse drug reaction. Pemetrexed is a multitargeted antifolate. It was first used in combination with cisplatin as a front-line treatment for malignant pleural mesothelioma. The same combination is nowadays approved in the first-line setting for locally advanced or metastatic nonsquamous non-small cell lung cancer (NSCLC).

PATIENT AND METHODS

We report the case of a 50-year-old man treated for metastatic NSCLC. Within 5 days after administration of the second cycle of cisplatin and pemetrexed, he developed large blisters, which secondarily became hemorrhagic, and mucosal lesions. The characteristic clinical appearance, the histopathological findings, and the clinical course were decisive for the diagnosis of TEN. Treatment with systemic steroids and intravenous antibiotics as well as topical wound treatment led to resolution and improvement of his general condition.

CONCLUSIONS

To the best of our knowledge, this is the third case of TEN due to pemetrexed in a patient with NSCLC. Clinicians should be aware of TEN as a rare but potentially fatal disorder requiring hospitalization and multidisciplinary management.

Fine needle aspiration of non-small cell lung cancer: current state and future perspective

AThe emerging treatment revolution determined by the advent of new targeted therapies requires accurate tumour subtyping as a mandatory step in the clinical workup of patients with non-small cell lung carcinoma (NSCLC). As a result of advanced and inoperable disease or poor performance status, in many patients, minimally invasive procedures must be employed to obtain diagnostic material. Fine needle aspiration (FNA) is a valid and widely employed alternative to either tru-cut or open-sky biopsy. Indeed, cytological specimens are suitable for techniques such as immunocytochemistry, mutation and microRNA analysis, and may present advantages over small biopsies especially if cell blocks are prepared and attention is paid to cytomorphology and pre-analytic management of specimens at the time they are collected. These will allow the adequate stratification of patients into different diagnostic and prognostic classes.

Phase II study of carboplatin and pemetrexed in advanced non-squamous, non-small-cell lung cancer: Kyoto Thoracic Oncology Research Group Trial 0902

BACKGROUND

Subgroup analyses of randomized studies have consistently shown that pemetrexed is exclusively effective in non-small-cell lung cancer (NSCLC) other than squamous cell carcinoma and the combination of pemetrexed and platinum agents is recommended for first-line chemotherapy in advanced non-squamous NSCLC; however, there have been few prospective studies of a selected population.

PATIENTS AND METHODS

This was a single-arm phase II study of carboplatin and pemetrexed in Japanese patients with chemo-naive advanced non-squamous NSCLC. Patients received six cycles of pemetrexed (500 mg/m(2)) combined with carboplatin (area under the curve: AUC 6) every 3 weeks. Maintenance chemotherapy with pemetrexed was permitted in patients whose disease did not progress after combination chemotherapy. The primary endpoint was the response rate, and secondary endpoints were safety and survival.

RESULTS

Fifty-one patients were enrolled between November 2009 and March 2011, and 49 patients were evaluable for both safety and efficacy. All but one patient had adenocarcinoma histology. Forty-four (90 %) patients completed four cycles, and 33 (67 %) completed six cycles of chemotherapy. Partial response was achieved in 25 patients (response rate: 51 %) and stable disease in 18 patients (37 %). Median progression-free survival (PFS) and overall survival (OS) were 6.3 months and 24.3 months, respectively. The median PFS and OS were 7.9 months and 24.3 months in patients with epidermal growth factor receptor (EGFR) mutation, and 6.3 months and 21.0 months in patients with EGFR wild type or unknown. There were no statistical differences between EGFR mutants and non-mutants for both PFS (p = 0.09) and OS (p = 0.23). Grade 3/4 neutropenia and thrombocytopenia were observed in 16 (33 %) and 9 (18 %) patients, respectively. Non-hematologic toxicities were generally mild, and there were no treatment-related deaths.

CONCLUSIONS

The combination of carboplatin and pemetrexed was safe and effective in advanced non-squamous NSCLC. Although the sample size was small, our results indicate that pemetrexed is a key drug for advanced non-squamous NSCLC, irrespective of the EGFR mutation status (UMIN-CTR number 000002451).

Safety, activity, and immune correlates of anti-PD-1 antibody in cancer

BACKGROUND

Blockade of programmed death 1 (PD-1), an inhibitory receptor expressed by T cells, can overcome immune resistance. We assessed the antitumor activity and safety of BMS-936558, an antibody that specifically blocks PD-1.

METHODS

We enrolled patients with advanced melanoma, non-small-cell lung cancer, castration-resistant prostate cancer, or renal-cell or colorectal cancer to receive anti-PD-1 antibody at a dose of 0.1 to 10.0 mg per kilogram of body weight every 2 weeks. Response was assessed after each 8-week treatment cycle. Patients received up to 12 cycles until disease progression or a complete response occurred.

RESULTS

A total of 296 patients received treatment through February 24, 2012. Grade 3 or 4 drug-related adverse events occurred in 14% of patients; there were three deaths from pulmonary toxicity. No maximum tolerated dose was defined. Adverse events consistent with immune-related causes were observed. Among 236 patients in whom response could be evaluated, objective responses (complete or partial responses) were observed in those with non-small-cell lung cancer, melanoma, or renal-cell cancer. Cumulative response rates (all doses) were 18% among patients with non-small-cell lung cancer (14 of 76 patients), 28% among patients with melanoma (26 of 94 patients), and 27% among patients with renal-cell cancer (9 of 33 patients). Responses were durable; 20 of 31 responses lasted 1 year or more in patients with 1 year or more of follow-up. To assess the role of intratumoral PD-1 ligand (PD-L1) expression in the modulation of the PD-1-PD-L1 pathway, immunohistochemical analysis was performed on pretreatment tumor specimens obtained from 42 patients. Of 17 patients with PD-L1-negative tumors, none had an objective response; 9 of 25 patients (36%) with PD-L1-positive tumors had an objective response (P=0.006).

CONCLUSIONS

Anti-PD-1 antibody produced objective responses in approximately one in four to one in five patients with non-small-cell lung cancer, melanoma, or renal-cell cancer; the adverse-event profile does not appear to preclude its use. Preliminary data suggest a relationship between PD-L1 expression on tumor cells and objective response. (Funded by Bristol-Myers Squibb and others; ClinicalTrials.gov number, NCT00730639.).

Treatment paradigms for patients with metastatic non-small-cell lung cancer: first-, second-, and third-line

Metastatic non-small-cell lung cancer (nsclc) is the leading cause of cancer mortality in Canada. Although treatment outcomes in advanced disease remain modest, with paradigm shifts in the approach to treatment, they are steadily improving. Customizing treatment based on histology and molecular typing has become the standard of care. EGFR genotyping and pathology subtyping should be considered routine in new diagnoses of metastatic nsclc. Treatment options for those with somatic EGFR activating mutations include gefitinib until progression, followed by standard chemotherapy. For patients with wild-type EGFR, or in patients whose EGFR genotype is unknown, platinum-based chemotherapy remains the first-line standard, with single-agent chemotherapy as an option for older patients and those who are unfit for platinum-doublet therapy. Patients with nonsquamous histology may receive treatment regimens incorporating pemetrexed or bevacizumab. In patients with squamous cell carcinoma, the latter agents should be avoided because of concerns about enhanced toxicity or decreased efficacy. Second-line chemotherapy is offered to a selected subgroup of patients upon progression and may include pemetrexed in non-squamous histology and docetaxel or erlotinib (or both) in all histologies. Currently, only erlotinib is offered as a third-line option in unselected nsclc patients after failure of first- and second-line chemotherapy. Maintenance therapy is emerging as a new option for patients, as are targeted therapies for particular molecular subtypes of nsclc, such as crizotinib in tumours harbouring the EML4-ALK gene rearrangement.

Prognostic evaluation and choice of second-line treatment for patients with advanced non-small-cell lung cancer

SUMMARY Patients with progressive disease after first-line treatment for advanced non-small-cell lung cancer have a limited life expectancy. In the second-line setting, a better understanding of prognostic factors and the availability of a prognostic score can contribute to a sensible evaluation of the risks and benefits associated with treatment. We previously showed that the prognosis of patients receiving second-line treatment is significantly conditioned by gender, performance status, histology, stage, previous platinum use and response to first-line treatment. A prognostic score based on these factors allows for the classification of patients into three categories. The score is simple to calculate because all of the variables considered are routinely collected as part of the baseline clinical evaluation of patients. For the majority of non-small-cell lung cancer patients, in the absence of known molecular predictive factors, the choice of second-line treatment among drugs with demonstrated efficacy should necessarily take into account prognosis and the risk:benefit ratio of patients.

A pilot study of a metronomic chemotherapy regimen with weekly low-dose docetaxel for previously treated non-small cell lung cancer

BACKGROUND

Low-dose metronomic (LDM) chemotherapy is a novel approach that involves frequent administration of a low dose of chemotherapeutic agent without a long interval.

PURPOSE

The aim of this clinical pilot study was to evaluate the toxicity and efficacy of LDM chemotherapy with weekly low-dose docetaxel for previously treated non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

The enrolled patients received 15 mg/m² of docetaxel intravenously on a weekly basis without any interval.

RESULTS

Twenty-seven patients were enrolled in the study; 20 were men, and seven were women. The median age was 62 years (range: 32-75). Eleven patients were stage IIIB, and 16 were stage IV. The Eastern Cooperative Oncology Group performance status was 0 or 1. There was no severe hematological adverse effect; importantly, there was no neutropenia or thrombocytopenia. The objective response rate was 7.4% and the disease control rate was 51.9%. The median survival time was 16.4 months (95% CI: 5.7-36.4).

CONCLUSION

Our preliminary results indicate that our metronomic regimen was well tolerated and active in patients with previously treated NSCLC. Thus, further investigation of this LDM regimen is warranted.

Ipilimumab in combination with paclitaxel and carboplatin as first-line treatment in stage IIIB/IV non-small-cell lung cancer: results from a randomized, double-blind, multicenter phase II study

PURPOSE

Ipilimumab, which is an anti-cytotoxic T-cell lymphocyte-4 monoclonal antibody, showed a survival benefit in melanoma with adverse events (AEs) managed by protocol-defined guidelines. A phase II study in lung cancer assessed the activity of ipilimumab plus paclitaxel and carboplatin.

PATIENTS AND METHODS

Patients (N = 204) with chemotherapy-naive non-small-cell lung cancer (NSCLC) were randomly assigned 1:1:1 to receive paclitaxel (175 mg/m(2)) and carboplatin (area under the curve, 6) with either placebo (control) or ipilimumab in one of the following two regimens: concurrent ipilimumab (four doses of ipilimumab plus paclitaxel and carboplatin followed by two doses of placebo plus paclitaxel and carboplatin) or phased ipilimumab (two doses of placebo plus paclitaxel and carboplatin followed by four doses of ipilimumab plus paclitaxel and carboplatin).Treatment was administered intravenously every 3 weeks for ≤ 18 weeks (induction). Eligible patients continued ipilimumab or placebo every 12 weeks as maintenance therapy. Response was assessed by using immune-related response criteria and modified WHO criteria. The primary end point was immune-related progression-free survival (irPFS). Other end points were progression-free survival (PFS), best overall response rate (BORR), immune-related BORR (irBORR), overall survival (OS), and safety.

RESULTS

The study met its primary end point of improved irPFS for phased ipilimumab versus the control (hazard ratio [HR], 0.72; P = .05), but not for concurrent ipilimumab (HR, 0.81; P = .13). Phased ipilimumab also improved PFS according to modified WHO criteria (HR, 0.69; P = .02). Phased ipilimumab, concurrent ipilimumab, and control treatments were associated with a median irPFS of 5.7, 5.5, and 4.6 months, respectively, a median PFS of 5.1, 4.1, and 4.2 months, respectively, an irBORR of 32%, 21% and 18%, respectively, a BORR of 32%, 21% and 14%, respectively, and a median OS of 12.2, 9.7, and 8.3 months. Overall rates of grade 3 and 4 immune-related AEs were 15%, 20%, and 6% for phased ipilimumab, concurrent ipilimumab, and the control, respectively. Two patients (concurrent, one patient; control, one patient) died from treatment-related toxicity.

CONCLUSION

Phased ipilimumab plus paclitaxel and carboplatin improved irPFS and PFS, which supports additional investigation of ipilimumab in NSCLC.

EBUS-TBNA in patients presented with superior vena cava syndrome

INTRODUCTION

Expedient pathological diagnosis is crucial in selection of appropriate treatment in patients presented with superior vena cava syndrome (SVCS). The performance and safety of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in this setting is unknown.

METHODS

Over a 4-year period, patients presented with SVCS in the presence of mediastinal mass and referred for EBUS-TBNA were enrolled for the study. The procedure was performed under local anaesthesia with conscious sedation. TBNA was performed under real-time with the curvilinear probe of EBUS. Rapid on site cytological examination (ROSE) was not available.

RESULTS

Eighteen procedures of EBUS-TBNA were performed in 17 patients. Malignancy was confirmed in 16 patients (diagnostic yield 94.1%). There was no major complication including significant bleeding or pneumothorax related to the procedures.

CONCLUSIONS

EBUS-TBNA has high diagnostic yield and is safe in patients presented with SVCS and mediastinal mass.

Personalized medicine for non-small-cell lung cancer: implications of recent advances in tissue acquisition for molecular and histologic testing

In light of recent advances in individualized therapy for non-small-cell lung cancer (NSCLC), molecular and histologic profiling is essential for guiding therapeutic decisions. Results of these analyses may have implications for both response (eg, molecular testing for EGFR [epidermal growth factor receptor] mutations) and safety (eg, contraindications for squamous histology) in NSCLC. Most patients with NSCLC present with unresectable advanced disease; therefore, greater emphasis is being placed on minimally invasive tissue acquisition techniques, such as small biopsy and cytology specimens. Due to the need for increasing histologic and molecular information and increasingly smaller tissue sample sizes, efforts must be focused on optimizing tissue acquisition and the development of more sensitive molecular assays. Recent advances in tissue acquisition techniques and specimen preservation may help to address this challenge and lead to enhanced personalized treatment in NSCLC.

Pulmonary adenocarcinoma: a renewed entity in 2011

Lung cancer, of which non-small-cell lung cancer comprises the majority, is the leading cause of cancer-related deaths in the United States and worldwide. Lung adenocarcinomas are a major subtype of non-small-cell lung cancers, are increasing in incidence globally in both males and females and in smokers and non-smokers, and are the cause for almost 50% of deaths attributable to lung cancer. Lung adenocarcinoma is a tumour with complex biology that we have recently started to understand with the advent of various histological, transcriptomic, genomic and proteomic technologies. However, the histological and molecular pathogenesis of this malignancy is still largely unknown. This review will describe advances in the molecular pathology of lung adenocarcinoma with emphasis on genomics and DNA alterations of this disease. Moreover, the review will discuss recognized lung adenocarcinoma preneoplastic lesions and current concepts of the early pathogenesis and progression of the disease. We will also portray the field cancerization phenomenon and lineage-specific oncogene expression pattern in lung cancer and how both remerging concepts can be exploited to increase our understanding of lung adenocarcinoma pathogenesis for subsequent development of biomarkers for early detection of adenocarcinomas and possibly personalized prevention.

p40 (ΔNp63) is superior to p63 for the diagnosis of pulmonary squamous cell carcinoma

Immunohistochemistry has recently emerged as a powerful ancillary tool for differentiating lung adenocarcinoma and squamous cell carcinoma-a distinction with important therapeutic implications. Although the most frequently recommended squamous marker p63 is extremely sensitive, it suffers from low specificity due to its reactivity in a substantial proportion of lung adenocarcinomas and other tumor types, particularly lymphomas. p40 is a relatively unknown antibody that recognizes ΔNp63-a p63 isoform suggested to be highly specific for squamous/basal cells. Here we compared the standard p63 antibody (4A4) and p40 in a series of 470 tumors from the archives of Memorial Sloan-Kettering Cancer Center and The Johns Hopkins Hospital, which included lung squamous cell carcinomas (n=81), adenocarcinomas (n=237), and large cell lymphomas (n=152). The p63 was positive in 100% of squamous cell carcinomas, 31% of adenocarcinomas, and 54% of large cell lymphomas (sensitivity 100%, specificity 60%). In contrast, although p40 was also positive in 100% of squamous cell carcinomas, only 3% of adenocarcinomas, and none of large cell lymphomas had p40 labeling (sensitivity 100%, specificity 98%). The mean percentage of p63 versus p40-immunoreactive cells in squamous cell carcinomas was equivalent (97 vs 96%, respectively, P=0.73). Rare adenocarcinomas with p40 labeling had reactivity in no more than 5% of tumor cells, whereas the mean (range) of p63-positive cells in adenocarcinomas and lymphomas was 26% (1-90%) and 48% (2-100%), respectively. In summary, p40 is equivalent to p63 in sensitivity for squamous cell carcinoma, but it is markedly superior to p63 in specificity, which eliminates a potential pitfall of misinterpreting a p63-positive adenocarcinoma or unsuspected lymphoma as squamous cell carcinoma. These findings strongly support the routine use of p40 in place of p63 for the diagnosis of pulmonary squamous cell carcinoma.

Subtyping of non-small cell lung carcinoma: a comparison of small biopsy and cytology specimens

BACKGROUND

There is growing evidence that lung adenocarcinoma and squamous cell carcinoma (SQCC) have distinct oncogenic mutations and divergent therapeutic responses, which is driving the heightened emphasis on accurate pathologic subtyping of non-small cell lung carcinoma (NSCLC). The relative feasibility and accuracy of NSCLC subtyping by small biopsy versus cytology is not well established, particularly in current practice where immunohistochemistry (IHC) is becoming routinely used to aid in this distinction.

METHODS

Concurrent biopsy and cytology specimens obtained during a single procedure and diagnosed as NSCLC during a 2-year period (n = 101) were reviewed. Concordance of diagnoses in the two methods was assessed. Accuracy was determined based on subsequent resection or autopsy diagnosis (n = 21) or IHC for thyroid transcription factor 1 and p63 on a subset of cases (n = 43).

RESULTS

The distribution of definitive versus favored versus unclassified categories (reflecting the degree of diagnostic certainty) was similar for biopsy (71% versus 23% versus 6%, respectively) and cytology (69% versus 19% versus 12%, respectively), p = 0.29. When results from paired specimens were combined, the rate of definitive diagnoses by at least one method was increased to 84% and the unclassified rate was decreased to 4%. NSCLC subtype concordance between biopsy and cytology was 93%. Kappa coefficient (95% confidence interval) for agreement between methods was 0.88 (0.60-0.89) for adenocarcinoma and 0.76 (0.63-0.89) for SQCC. In pairs with discordant diagnoses (n = 7) the correct tumor type was identified with a similar frequency by biopsy (n = 4) and cytology (n = 3). Factors contributing to mistyping were poor differentiation, necrosis, low cellularity, and lack of supporting IHC. All concordant diagnoses for which verification was available (n = 57) were correct. IHC was used more frequently to subtype NSCLC in biopsy than cytology (32% versus 6%; p = 0.0001).

CONCLUSIONS

Small biopsy and cytology achieve comparable rates of definitive and accurate NSCLC subtyping, and the optimal results are attained when the two modalities are considered jointly. The lower requirement for IHC in cytology highlights the strength of cytomorphology in NSCLC subtyping. Whenever clinically feasible, obtaining parallel biopsy and cytology specimens is encouraged.

[Pemetrexed salvage chemotherapy for NSCLC: implementation study]

BACKGROUND

Registration trials demonstrated the activity of pemetrexed in non small cell lung carcinoma (NSCLC) either in combination with first-line agents or in monotherapy for salvage treatment. The aim of our implementation study was to verify, in an unselected population, the results obtained with pemetrexed salvage chemotherapy in clinical practice.

PATIENTS AND METHODS

The charts of all patients diagnosed with NSCLC, receiving pemetrexed for progressive disease after at least one previous course of chemotherapy, were retrospectively reviewed in two academic institutions. Response was assessed according to WHO and toxicity using the CTCAE and WHO criteria.

RESULTS

Between November 2004 and September 2009, 84 patients were given pemetrexed as second, third or greater than third line therapy (n=18/14/52). Intent-to-treat response rate was 11.9% (95% CI, 5%-18.8%). Median progression-free survival was 2.2 months and median survival time was 6.4 months. The most frequent grade 3-5 toxicity was neutropenia (23.9%).

CONCLUSION

Salvage chemotherapy with pemetrexed for progressing NSCLC confirmed, in an unselected population, who had been extensively treated previously, the level of activity observed in registration trials although a significant toxicity was noted.

Bevacizumab in non-small-cell lung cancer: a review

Current targeted strategies for cancer focus on the blockade of growth factor receptors and the inhibition of angiogenesis. The VEGF pathway has become an attractive target in multiple malignancies, including lung cancer. Bevacizumab, a monoclonal antibody against VEGF, increased survival in non-small-cell lung cancer (NSCLC) patients when added to standard carboplatin/paclitaxel chemotherapy. The pivotal Phase III study (ECOG 4599) in NSCLC showed longer overall survival: 12.3 versus 10.3 months and a higher median progression-free survival of 6.2 versus 4.5 months when chemotherapy was associated with bevacizumab. Benefits were confirmed in terms of progression-free survival in the European Phase III study (AVAiL). Subsequently, bevacizumab gained US FDA and European Medicines Agengy approval as a first-line therapy for advanced NSCLC. Bevacizumab's safety profile is well established: most adverse events are mild to moderate and can be managed using standard interventions. This article presents an overview of the current data on bevacizumab for NSCLC.

Cross-validation study of class III beta-tubulin as a predictive marker for benefit from adjuvant chemotherapy in resected non-small-cell lung cancer: analysis of four randomized trials

BACKGROUND

The IALT, JBR.10, ANITA and Cancer and Leukemia Group B 9633 trials compared adjuvant chemotherapy with observation for patients with resected non-small-cell lung cancer (R-NSCLC). Data from the metastatic setting suggest high tumor class III beta-tubulin (TUBB3) expression is a determinant of insensitivity to tubulin-targeting agents (e.g. vinorelbine, paclitaxel). In 265 patients from JBR.10 (vinorelbine-cisplatin versus observation), high TUBB3 was an adverse prognostic factor and was associated (nonsignificantly) with 'greater' survival benefit from chemotherapy. We explored this further in additional patients from JBR.10 and the other three trials.

PATIENTS AND METHODS

TUBB3 immunohistochemical staining was scored for 1149 patients on the four trials. The original JBR.10 cut-off scores were used to classify tumors as TUBB3 high or low. The prognostic and predictive value of TUBB3 on disease-free survival (DFS) and overall survival (OS) was assessed by Cox models stratified by trial and adjusted for clinical factors.

RESULTS

High TUBB3 expression was prognostic for OS [hazard ratio (HR)=1.27 (1.07-1.51), P=0.008) and DFS [HR=1.30 (1.11-1.53), P=0.001). TUBB3 was not predictive of a differential treatment effect [interaction P=0.20 (OS), P=0.23 (DFS)]. Subset analysis (n=420) on vinorelbine-cisplatin gave similar results.

CONCLUSIONS

The prognostic effect of high TUBB3 expression in patients with R-NSCLC has been validated. We were unable to confirm a predictive effect for TUBB3.

Acquisition and processing of endobronchial ultrasound-guided transbronchial needle aspiration specimens in the era of targeted lung cancer chemotherapy

Recent advances in therapy for non-small cell lung carcinoma have shown that a personalized approach to treatment has the potential to significantly reduce lung cancer mortality. Concurrently, endoscopic ultrasound transbronchial needle aspiration has emerged as an accurate and sensitive tool for the diagnosis and staging of this disease. As knowledge of the molecular mechanisms that drive lung cancer progression increases, the amount of information that must be derived from a tumor specimen will also increase. Recent clinical studies have demonstrated that small specimens acquired by endoscopic ultrasound transbronchial needle aspiration are sufficient for molecular testing if specimen acquisition and processing are done with these needs in mind. Optimum use of this procedure requires a coordinated effort between the bronchoscopist and the cytopathologist to collect and triage specimens for diagnostic testing. When feasible, rapid onsite evaluation should be performed to assess the specimen for both diagnostic quality and quantity and to allocate the specimen for cell-block and possible immunohistochemistry and molecular studies. It is necessary for pulmonologists and bronchoscopists to understand the rationale for histologic and molecular testing of lung cancer diagnostic specimens and to ensure that specimens are acquired and processed in a fashion that provides information from small cytologic specimens that is sufficient to guide treatment in this era of targeted therapy.

Immunohistochemical algorithm for differentiation of lung adenocarcinoma and squamous cell carcinoma based on large series of whole-tissue sections with validation in small specimens

Immunohistochemistry is increasingly utilized to differentiate lung adenocarcinoma and squamous cell carcinoma. However, detailed analysis of coexpression profiles of commonly used markers in large series of whole-tissue sections is lacking. Furthermore, the optimal diagnostic algorithm, particularly the minimal-marker combination, is not firmly established. We therefore studied whole-tissue sections of resected adenocarcinoma and squamous cell carcinoma (n=315) with markers commonly used to identify adenocarcinoma (TTF-1) and squamous cell carcinoma (p63, CK5/6, 34βE12), and prospectively validated the devised algorithm in morphologically unclassifiable small biopsy/cytology specimens (n=38). Analysis of whole-tissue sections showed that squamous cell carcinoma had a highly consistent immunoprofile (TTF-1-negative and p63/CK5/6/34βE12-diffuse) with only rare variation. In contrast, adenocarcinoma showed significant immunoheterogenetity for all 'squamous markers' (p63 (32%), CK5/6 (18%), 34βE12 (82%)) and TTF-1 (89%). As a single marker, only diffuse TTF-1 was specific for adenocarcinoma whereas none of the 'squamous markers,' even if diffuse, were entirely specific for squamous cell carcinoma. In contrast, coexpression profiles of TTF-1/p63 had only minimal overlap between adenocarcinoma and squamous cell carcinoma, and there was no overlap if CK5/6 was added as a third marker. An algorithm was devised in which TTF-1/p63 were used as the first-line panel, and CK5/6 was added for rare indeterminate cases. Prospective validation of this algorithm in small specimens showed 100% accuracy of adenocarcinoma vs squamous cell carcinoma prediction as determined by subsequent resection. In conclusion, although reactivity for 'squamous markers' is common in lung adenocarcinoma, a two-marker panel of TTF-1/p63 is sufficient for subtyping of the majority of tumors as adenocarcinomas vs squamous cell carcinoma, and addition of CK5/6 is needed in only a small subset of cases. This simple algorithm achieves excellent accuracy in small specimens while conserving the tissue for potential predictive marker testing, which is now an essential consideration in advanced lung cancer specimens.