Carrie B. Lee

A murine lung cancer co-clinical trial identifies genetic modifiers of therapeutic response

Targeted therapies have demonstrated efficacy against specific subsets of molecularly defined cancers. Although most patients with lung cancer are stratified according to a single oncogenic driver, cancers harbouring identical activating genetic mutations show large variations in their responses to the same targeted therapy. The biology underlying this heterogeneity is not well understood, and the impact of co-existing genetic mutations, especially the loss of tumour suppressors, has not been fully explored. Here we use genetically engineered mouse models to conduct a ‘co-clinical’ trial that mirrors an ongoing human clinical trial in patients with KRAS-mutant lung cancers. This trial aims to determine if the MEK inhibitor selumetinib (AZD6244) increases the efficacy of docetaxel, a standard of care chemotherapy. Our studies demonstrate that concomitant loss of either p53 (also known as Tp53) or Lkb1 (also known as Stk11), two clinically relevant tumour suppressors, markedly impaired the response of Kras-mutant cancers to docetaxel monotherapy. We observed that the addition of selumetinib provided substantial benefit for mice with lung cancer caused by Kras and Kras and p53 mutations, but mice with Kras and Lkb1 mutations had primary resistance to this combination therapy. Pharmacodynamic studies, including positron-emission tomography (PET) and computed tomography (CT), identified biological markers in mice and patients that provide a rationale for the differential efficacy of these therapies in the different genotypes. These co-clinical results identify predictive genetic biomarkers that should be validated by interrogating samples from patients enrolled on the concurrent clinical trial. These studies also highlight the rationale for synchronous co-clinical trials, not only to anticipate the results of ongoing human clinical trials, but also to generate clinically relevant hypotheses that can inform the analysis and design of human studies.

Activation of MET via Diverse Exon 14 Splicing Alterations Occurs in Multiple Tumor Types and Confers Clinical Sensitivity to MET Inhibitors

UNLABELLED Focal amplification and activating point mutation of the MET gene are well-characterized oncogenic drivers that confer susceptibility to targeted MET inhibitors. Recurrent somatic splice site alterations at MET exon 14 (METex14) that result in exon skipping and MET activation have been characterized, but their full diversity and prevalence across tumor types are unknown. Here, we report analysis of tumor genomic profiles from 38,028 patients to identify 221 cases with METex14 mutations (0.6%), including 126 distinct sequence variants. METex14 mutations are detected most frequently in lung adenocarcinoma (3%), but also frequently in other lung neoplasms (2.3%), brain glioma (0.4%), and tumors of unknown primary origin (0.4%). Further in vitro studies demonstrate sensitivity to MET inhibitors in cells harboring METex14 alterations. We also report three new patient cases with METex14 alterations in lung or histiocytic sarcoma tumors that showed durable response to two different MET-targeted therapies. The diversity of METex14 mutations indicates that diagnostic testing via comprehensive genomic profiling is necessary for detection in a clinical setting. SIGNIFICANCE Here we report the identification of diverse exon 14 splice site alterations in MET that result in constitutive activity of this receptor and oncogenic transformation in vitro. Patients whose tumors harbored these alterations derived meaningful clinical benefit from MET inhibitors. Collectively, these data support the role of METex14 alterations as drivers of tumorigenesis, and identify a unique subset of patients likely to derive benefit from MET inhibitors.

Lung squamous cell carcinoma mRNA expression subtypes are reproducible, clinically important, and correspond to normal cell types.

Purpose: Lung squamous cell carcinoma (SCC) is clinically and genetically heterogeneous, and current diagnostic practices do not adequately substratify this heterogeneity. A robust, biologically based SCC subclassification may describe this variability and lead to more precise patient prognosis and management. We sought to determine if SCC mRNA expression subtypes exist, are reproducible across multiple patient cohorts, and are clinically relevant. Experimental Design: Subtypes were detected by unsupervised consensus clustering in five published discovery cohorts of mRNA microarrays, totaling 382 SCC patients. An independent validation cohort of 56 SCC patients was collected and assayed by microarrays. A nearest-centroid subtype predictor was built using discovery cohorts. Validation cohort subtypes were predicted and evaluated for confirmation. Subtype survival outcome, clinical covariates, and biological processes were compared by statistical and bioinformatic methods. Results: Four lung SCC mRNA expression subtypes, named primitive, classical, secretory, and basal, were detected and independently validated (P < 0.001). The primitive subtype had the worst survival outcome (P < 0.05) and is an independent predictor of survival (P < 0.05). Tumor differentiation and patient sex were associated with subtype. The expression profiles of the subtypes contained distinct biological processes (primitive: proliferation; classical: xenobiotic metabolism; secretory: immune response; basal: cell adhesion) and suggested distinct pharmacologic interventions. Comparison with lung model systems revealed distinct subtype to cell type correspondence. Conclusions: Lung SCC consists of four mRNA expression subtypes that have different survival outcomes, patient populations, and biological processes. The subtypes stratify patients for more precise prognosis and targeted research. Clin Cancer Res; 16(19); 4864–75. ©2010 AACR.

Induction chemotherapy with carboplatin, irinotecan, and paclitaxel followed by high dose three-dimension conformal thoracic radiotherapy (74 Gy) with concurrent carboplatin, paclitaxel, and gefitinib in unresectable stage IIIA and stage IIIB non-small cell lung cancer.

Introduction: Combined modality therapy is a standard therapy for patients with unresectable stage III non-small cell lung cancer (NSCLC). Gefitinib is active in advanced NSCLC, and in preclinical models, it potentiates the activity of radiation therapy. We investigate the tolerability of gefitinib in combined modality therapy in combination with three-dimensional thoracic conformal radiation therapy (3-dimensional TCRT). Methods: Stage III patients with a good performance status were treated with induction chemotherapy (carboplatin area under the curve [AUC] of 5, irinotecan 100 mg/m2, and paclitaxel 175 mg/m2 days 1 and 22) with pegfilgrastim support followed by concurrent chemotherapy (carboplatin AUC 2, and paclitaxel 45 mg/m2 weekly) and gefitinib 250 mg daily beginning on day 43 with 3-dimensional TCRT to 74 Gy. Results: Between March 2004 and January 2006, 23 patients received treatment on the trial: median age 62 years (range 44–82), 52% female, 61% stage IIIA, 61% performance status 0, 17% ≥5% weight loss, and 91% underwent positron emission tomography staging. Induction chemotherapy with pegfilgrastim support was well tolerated and active (partial response rate, 24%; stable disease, 76%; and early progression, 0%). Twenty-one patients initiated the concurrent chemoradiation, and 20 patients completed therapy to 74 Gy. The primary toxicities of concurrent chemoradiation were grade 3 esophagitis (19.5%) and cardiac arrhythmia (atrial fibrillation) (9.5%). The median progression-free survival and overall survival were 9 months (95% confidence intervals [CI]: 7–13 months) and 16 months (95% CI: 10–20 months), respectively. Conclusions: Treatment with induction chemotherapy and gefitinib concurrent with 3-dimensional TCRT has an acceptable toxicity and tolerability, but the survival results were disappointing.

Cardiac toxicity after radiotherapy for stage III non-small-cell lung cancer: Pooled analysis of dose-escalation trials delivering 70 to 90 Gy

Purpose The significance of radiotherapy (RT) -associated cardiac injury for stage III non-small-cell lung cancer (NSCLC) is unclear, but higher heart doses were associated with worse overall survival in the Radiation Therapy Oncology Group (RTOG) 0617 study. We assessed the impact of heart dose in patients treated at our institution on several prospective dose-escalation trials. Patients and Methods From 1996 to 2009, 127 patients with stage III NSCLC (Eastern Cooperative Oncology Group performance status, 0 to 1) received dose-escalated RT to 70 to 90 Gy (median, 74 Gy) in six trials. RT plans and cardiac doses were reviewed. Records were reviewed for the primary end point: symptomatic cardiac events (symptomatic pericardial effusion, acute coronary syndrome, pericarditis, significant arrhythmia, and heart failure). Cardiac risk was assessed by noting baseline coronary artery disease and calculating the WHO/International Society of Hypertension score. Competing risks analysis was used. Results In all, 112 patients were analyzed. Median follow-up for surviving patients was 8.8 years. Twenty-six patients (23%) had one or more events at a median of 26 months to first event (effusion [n = 7], myocardial infarction [n = 5], unstable angina [n = 3], pericarditis [n = 2], arrhythmia [n = 12], and heart failure [n = 1]). Heart doses (eg, heart mean dose; hazard ratio, 1.03/Gy; P = .002,), coronary artery disease ( P < .001), and WHO/International Society of Hypertension score ( P = .04) were associated with events on univariable analysis. Heart doses remained significant on multivariable analysis that accounted for baseline risk. Two-year competing risk-adjusted event rates for patients with heart mean dose < 10 Gy, 10 to 20 Gy, or ≥ 20 Gy were 4%, 7%, and 21%, respectively. Heart doses were not associated with overall survival. Conclusion Cardiac events were relatively common after high-dose thoracic RT and were independently associated with both heart dose and baseline cardiac risk. RT-associated cardiac toxicity after treatment of stage III NSCLC may occur earlier than historically understood, and heart doses should be minimized.

A Retrospective Analysis of VeriStrat Status on Outcome of a Randomized Phase II Trial of First-Line Therapy with Gemcitabine, Erlotinib, or the Combination in Elderly Patients (Age 70 Years or Older) with Stage IIIB/IV Non–Small-Cell Lung Cancer

Purpose: In a multicenter randomized phase II trial of gemcitabine (arm A), erlotinib (arm B), and gemcitabine and erlotinib (arm C), similar progression-free survival (PFS) and overall survival (OS) were observed in all arms. We performed an exploratory, blinded, retrospective analysis of plasma or serum samples collected as part of the trial to investigate the ability of VeriStrat (VS) to predict treatment outcomes. Methods: Ninety-eight patients were assessable, and the majority had stage IV disease (81%), adenocarcinoma histology (63%), reported current or previous tobacco use (84%), and 26% had a performance status (PS) of 2. Results: In arm A, patients with VS Good (n = 20) compared with VS Poor status (n = 8) had similar PFS (hazard ratio [HR]: 1.21; p = 0.67) and OS (HR: 0.82; p = 0.64). In arm B, patients with VS Good (n = 26) compared with VS Poor (n = 12) had a statistically significantly superior PFS (HR: 0.33; p = 0.002) and OS (HR: 0.40; p = 0.014). In arm C, patients with VS Good (n = 17) compared with Poor (n = 1 5) had a superior PFS (HR: 0.42; p = 0.027) and a trend toward superior OS (HR: 0.48; p = 0.051). In the multivariate analysis for PFS, VS status was statistically significant (p = 0.011); for OS, VS status (p = 0.017) and PS (p = 0.005) were statistically significant. A statistically significant VS and treatment interaction (gemcitabine versus erlotinib) was observed for PFS and OS. Conclusions: Gemcitabine is the superior treatment for elderly patients with VS Poor status. First-line erlotinib for elderly patients with VS Good status may warrant further investigation.

Historical review of melanoma treatment and outcomes

The surgical and medical management of melanoma has changed dramatically since the first description of melanoma as a disease entity more than 200 years ago. Refinement of surgical techniques, including evaluation of optimal surgical margins, utility of elective lymph node dissection, and incorporation of sentinel lymph node mapping as both a prognostic tool and guide for selective lymphadenectomy have lessened surgical morbidity and improved outcomes for early-stage and locally advanced melanoma. Astute clinical observations of the integrated roles of the immune system and oncogenic mutations have more recently led to improvements in survival and quality of life for advanced melanoma. Herein, we provide an overview of the most significant surgical and medical milestones in the treatment of melanoma over the past 2 centuries.

A Randomized Phase II Trial of First-Line Treatment with Gemcitabine, Erlotinib, or Gemcitabine and Erlotinib in Elderly Patients (Age ≥70 Years) with Stage IIIB/IV Non-small Cell Lung Cancer

Introduction: Single-agent gemcitabine is a standard of care for elderly patients with advanced non-small cell lung cancer, but novel therapies are needed for this patient population. Methods: We performed a noncomparative randomized phase II trial of gemcitabine, erlotinib, or the combination in elderly patients (age ≥70 years) with stage IIIB or IV non-small cell lung cancer. Patients were randomized to arms: A (gemcitabine 1200 mg/m2 on days 1 and 8 every 21 days), B (erlotinib 150 mg daily), or C (gemcitabine 1000 mg/m2 on days 1 and 8 every 21 days and erlotinib 100 mg daily). Arms B and C were considered investigational; the primary objective was 6-month progression-free survival. Results: Between March 2006 and May 2010, 146 eligible patients received protocol therapy. The majority of the patients (82%) had stage IV disease, 64% reported adenocarcinoma histology, 90% reported current or previous tobacco use, and 28% had a performance status of 2. The 6-month progression-free survival rate observed in arms A, B, and C was 22% (95% confidence interval [CI] 11–35), 24% (95% CI 13–36), and 25% (95% CI 15–38), respectively; the median overall survival observed was 6.8 months (95% CI 4.8–8.5), 5.8 months (95% CI 3.0–8.3), and 5.6 months (95% CI 3.5–8.4), respectively. The rate of grade ≥3 hematological and nonhematological toxicity observed was similar in all three arms. The best overall health-related quality of life response did not differ between treatment arms. Conclusions: Erlotinib or erlotinib and gemcitabine do not warrant further investigation in an unselected elderly patient population.

Late Complications of High-Dose (≥66 Gy) Thoracic Conformal Radiation Therapy in Combined Modality Trials in Unresectable Stage III Non-small Cell Lung Cancer

Background: Combined modality treatment is the standard of care for patients (pts) with unresectable stage III non-small cell lung cancer. Dose escalation of radiotherapy is one strategy used to improve locoregional control and survival, but it increases the risk of both early and late treatment related toxicities. Methods: From May 1996 to August 2004, a total of 112 stage III non-small cell lung cancer pts were treated on 4 phase I/II or phase II trials to assess the safety and feasibility of high-dose (60–90 Gy) thoracic conformal radiotherapy. Patients who received ≥66 Gy (n = 88) were included in an analysis of late complications. Late complications were defined as complications that developed or persisted ≥90 days postradiotherapy. The classic lung toxicities of radiation pneumonitis and fibrosis were not included in this analysis. Results: Of the 88 patients included in this analysis of late complications, 21 patients (24%) developed a late complication and a total of 28 late complications were observed. The late complications were: pulmonary (n = 5; bronchial stenosis [n = 3] and fatal pulmonary hemoptysis [n = 2]), esophageal (n = 6), cardiac (n = 9), osseous (n = 6), and second primary tumor (n = 2). The median survival for all patients enrolled on the 4 trials (with 95% confidence interval [CI]) was 24.7 months (18.1–30.4 months), and the 5-year overall survival (with 95% CI) was 24% (16–32%). Data to assess for radiographic evidence of local progression were available for 99 patients, and the rate of local progression was 43% (95% CI 34–53%). Conclusions: High-dose thoracic conformal radiotherapy is feasible and results in promising survival outcomes. Late complications occur in a minority of patients.

Long-Term Follow-Up of a Phase I/II Trial of Dose Escalating Three-Dimensional Conformal Thoracic Radiation Therapy with Induction and Concurrent Carboplatin and Paclitaxel in Unresectable Stage IIIA/B Non-small Cell Lung Cancer

Background: We conducted a modified phase I/II trial investigating the incorporation of three-dimensional conformal thoracic radiation therapy (TCRT) into the treatment paradigm of induction and concurrent carboplatin and paclitaxel in patients with unresectable stage IIIA/B non-small cell lung cancer. Methods: Patients received 2 cycles of induction carboplatin (area under the curve of 6) and paclitaxel (225 mg/m2) on days 1, and 22. On day 43 concurrent TCRT and weekly ×6 of carboplatin (area under the curve = 2) and paclitaxel (45 mg/m2) was initiated. The TCRT dose was escalated from 60 to 74 Gy in 4 cohorts (60, 66, 70, and 74 Gy), and the 74 Gy cohort was expanded into a phase II trial. Results: Sixty-two patients were enrolled; the median age 57 years (range, 36–82), 39 were male (63%), 61 (98%) had a performance status of 0 or 1, 28 (45%) had stage IIIA disease, 21 (34%) had >5% weight loss, and the median forced expiratory volume 1 = 2.10 liters (range, 1.02–3.75). With a median follow-up for survivors of approximately 9 years (range, 7–11 years) the median progression-free survival, time to tumor progression, and overall survival (OS) (with 95% confidence intervals) were 10 (8.5–17), 15 (9–50), and 25 months (18–37), respectively. The 5-year progression-free survival and OS rates were 21% (12–32%) and 27% (17–39%), respectively. The 10-year OS rate was 14% (7–25%). Conclusion: The long term survival rate compares favorably to other treatment approaches for stage III non-small cell lung cancer.