Jean-Claude Cutz

Role of KRAS and EGFR As Biomarkers of Response to Erlotinib in National Cancer Institute of Canada Clinical Trials Group Study BR.21

PURPOSE To evaluate the effect of KRAS and epidermal growth factor receptor (EGFR) genotype on the response to erlotinib treatment in the BR.21, placebo-controlled trial. PATIENTS AND METHODS We analyzed 206 tumors for KRAS mutation, 204 tumors for EGFR mutation, and 159 tumors for EGFR gene copy by fluorescent in situ hybridization (FISH). We reanalyzed EGFR deletion/mutation using two highly sensitive techniques that detect abnormalities in samples with 5% to 10% tumor cellularity. KRAS mutation was analyzed by direct sequencing. RESULTS Thirty patients (15%) had KRAS mutations, 34 (17%) had EGFR exon 19 deletion or exon 21 L858R mutations, and 61 (38%) had high EGFR gene copy (FISH positive). Response rates were 10% for wild-type and 5% for mutant KRAS (P = .69), 7% for wild-type and 27% for mutant EGFR (P = .03), and 5% for EGFR FISH-negative and 21% for FISH-positive patients (P = .02). Significant survival benefit from erlotinib therapy was observed for patients with wild-type KRAS (hazard ratio [HR] = 0.69, P = .03) and EGFR FISH positivity (HR = 0.43, P = .004) but not for patients with mutant KRAS (HR = 1.67, P = .31), wild-type EGFR (HR = 0.74, P = .09), mutant EGFR (HR = 0.55, P = .12), and EGFR FISH negativity (HR = 0.80, P = .35). In multivariate analysis, only EGFR FISH-positive status was prognostic for poorer survival (P = .025) and predictive of differential survival benefit from erlotinib (P = .005). CONCLUSION EGFR mutations and high copy number are predictive of response to erlotinib. EGFR FISH is the strongest prognostic marker and a significant predictive marker of differential survival benefit from erlotinib.

Metformin inhibits growth and enhances radiation response of non-small cell lung cancer (NSCLC) through ATM and AMPK.

Background:We examined the potential of metformin (MET) to enhance non-small cell lung cancer (NSCLC) responses to ionising radiation (IR).Methods:Human NSCLC cells, mouse embryonic fibroblasts from wild-type and AMP-activated kinase (AMPK) α1/2-subunit−/− embryos (AMPKα1/2−/−-MEFs) and NSCLC tumours grafted into Balb/c-nude mice were treated with IR and MET and subjected to proliferation, clonogenic, immunoblotting, cell cycle and apoptosis assays and immunohistochemistry (IHC).Results:Metformin (2.5 μM–5 mM) inhibited proliferation and radio-sensitised NSCLC cells. Metformin (i) activated the ataxia telengiectasia-mutated (ATM)–AMPK–p53/p21cip1 and inhibited the Akt–mammalian target of rapamycin (mTOR)–eIF4E-binding protein 1 (4EBP1) pathways, (ii) induced G1 cycle arrest and (iii) enhanced apoptosis. ATM inhibition blocked MET and IR activation of AMPK. Non-small cell lung cancer cells with inhibited AMPK and AMPKα1/2−/−-MEFs were resistant to the antiproliferative effects of MET and IR. Metformin or IR inhibited xenograft growth and combined treatment enhanced it further than each treatment alone. Ionising radiation and MET induced (i) sustained activation of ATM–AMPK–p53/p21cip1 and inhibition of Akt–mTOR–4EBP1 pathways in tumours, (ii) reduced expression of angiogenesis and (iii) enhanced expression of apoptosis markers.Conclusion:Clinically achievable MET doses inhibit NSCLC cell and tumour growth and sensitise them to IR. Metformin and IR mediate their action through an ATM–AMPK-dependent pathway. Our results suggest that MET can be a clinically useful adjunct to radiotherapy in NSCLC.

Ionizing radiation activates AMP-activated kinase (AMPK): a target for radiosensitization of human cancer cells.

PURPOSE Adenosine monophosphate (AMP)-activated kinase (AMPK) is a molecular energy sensor regulated by the tumor suppressor LKB1. Starvation and growth factors activate AMPK through the DNA damage sensor ataxia-telangiectasia mutated (ATM). We explored the regulation of AMPK by ionizing radiation (IR) and its role as a target for radiosensitization of human cancer cells. METHODS AND MATERIALS Lung, prostate, and breast cancer cells were treated with IR (2-8 Gy) after incubation with either ATM or AMPK inhibitors or the AMPK activator metformin. Then, cells were subjected to either lysis and immunoblotting, immunofluorescence microscopy, clonogenic survival assays, or cell cycle analysis. RESULTS IR induced a robust phosphorylation and activation of AMPK in all tumor cells, independent of LKB1. IR activated AMPK first in the nucleus, and this extended later into cytoplasm. The ATM inhibitor KU-55933 blocked IR activation of AMPK. AMPK inhibition with Compound C or anti-AMPK alpha subunit small interfering RNA (siRNA) blocked IR induction of the cell cycle regulators p53 and p21(waf/cip) as well as the IR-induced G2/M arrest. Compound C caused resistance to IR, increasing the surviving fraction after 2 Gy, but the anti-diabetic drug metformin enhanced IR activation of AMPK and lowered the surviving fraction after 2 Gy further. CONCLUSIONS We provide evidence that IR activates AMPK in human cancer cells in an LKB1-independent manner, leading to induction of p21(waf/cip) and regulation of the cell cycle and survival. AMPK appears to (1) participate in an ATM-AMPK-p21(waf/cip) pathway, (2) be involved in regulation of the IR-induced G2/M checkpoint, and (3) may be targeted by metformin to enhance IR responses.

Phase II Study of Erlotinib in Recurrent or Metastatic Endometrial Cancer: NCIC IND-148

PURPOSE Epidermal growth factor receptor (EGFR) overexpression is common in endometrial cancers and may have a major role in tumor growth and progression. Erlotinib is an orally active, selective inhibitor of EGFR tyrosine kinase activity. PATIENTS AND METHODS A multinomial design two-stage phase II study was performed to evaluate single-agent activity of erlotinib in women with advanced endometrial cancer with recurrent or metastatic disease who were chemotherapy naïve and had received up to one line of prior hormonal therapy. Erlotinib was administered at daily dose of 150 mg. Archival tumor tissue was analyzed for EGFR expression by immunohistochemistry (IHC) and gene amplification by fluorescent in situ hybridization (FISH). Mutational status of EGFR was determined in responders. RESULTS Thirty-two of 34 entered patients are assessable for response. Treatment was well tolerated and severe toxicity infrequent, with the only grade 4 toxicity being an elevation of transaminases (AST). There were four confirmed partial responses (PRs; 12.5%; 95% CI, 3.5% to 29%) lasting 2 to 36 months. Fifteen patients had stable disease (SD), with median duration of 3.7 months (range, 2 to 12 months). EGFR expression was analyzed in thirty patients; 19 were positive, nine were negative, and two were not assessable. Of the 19 patients who were EGFR positive, three had PR (16%), seven SD, and eight progressive disease, and one was not assessable. No mutations were identified in responders. FISH showed no correlation of response with gene amplification. CONCLUSION Erlotinib is well tolerated with an overall objective response rate of 12.5%. Molecular analysis did not identify EGFR mutations in responders or correlation of response with gene amplification.

An orthotopic metastatic prostate cancer model in SCID mice via grafting of a transplantable human prostate tumor line

Metastasis is the major cause of prostate cancer deaths and there is a need for clinically relevant in vivo models allowing elucidation of molecular and cellular mechanisms underlying metastatic behavior. Here we describe the development of a new in vivo model system for metastatic prostate cancer. Pieces of prostate cancer tissue from a patient were grafted in testosterone-supplemented male NOD-SCID mice at the subrenal capsule graft site permitting high tumor take rates. After five serial transplantations, the tumor tissues were grafted into mouse prostates. Resulting tumors and suspected metastatic lesions were subjected to histopathological and immunohistochemical analysis. Samples of metastatic tissue were regrafted in mouse anterior prostates and their growth and spread examined, leading to isolation from lymph nodes of a metastatic subline, PCa1-met. Orthotopic grafting of PCa1-met tissue in 47 hosts led in all cases to metastases to multiple organs (lymph nodes, lung, liver, kidney, spleen and, notably, bone). Histopathological analysis showed strong similarity between orthotopic grafts and their metastases. The latter were of human origin as indicated by immunostaining using antibodies against human mitochondria, androgen receptor, prostate-specific antigen and Ki-67. Spectral karyotyping showed few chromosomal alterations in the PCa1-met subline. This study indicates that transplantable subrenal capsule xenografts of human prostate cancer tissue in NOD-SCID mice can, as distinct from primary cancer tissue, be successfully grown in the orthotopic site. Orthotopic xenografts of the transplantable tumor lines and metastatic sublines can be used for studying various aspects of metastatic prostate cancer, including metastasis to bone.

Cost Effectiveness of EML4-ALK Fusion Testing and First-Line Crizotinib Treatment for Patients With Advanced ALK-Positive Non–Small-Cell Lung Cancer

PURPOSE ALK-targeted therapy with crizotinib offers significant improvement in clinical outcomes for the treatment of EML4-ALK fusion-positive non-small-cell lung cancer (NSCLC). We estimated the cost effectiveness of EML4-ALK fusion testing in combination with targeted first-line crizotinib treatment in Ontario. PATIENTS AND METHODS A cost-effectiveness analysis was conducted using a Markov model from the Canadian Public health (Ontario) perspective and a lifetime horizon in patients with stage IV NSCLC with nonsquamous histology. Transition probabilities and mortality rates were calculated from the Ontario Cancer Registry and Cancer Care Ontario New Drug Funding Program (CCO NDFP). Costs were obtained from the Ontario Case Costing Initiative, CCO NDFP, University Health Network, and literature. RESULTS Molecular testing with first-line targeted crizotinib treatment in the population with advanced nonsquamous NSCLC resulted in a gain of 0.011 quality-adjusted life-years (QALYs) compared with standard care. The incremental cost was Canadian

Establishment in Severe Combined Immunodeficiency Mice of Subrenal Capsule Xenografts and Transplantable Tumor Lines from a Variety of Primary Human Lung Cancers: Potential Models for Studying Tumor Progression–Related Changes

2,725 per patient, and the incremental cost-effectiveness ratio (ICER) was

Amplification of telomerase (hTERT) gene is a poor prognostic marker in non-small-cell lung cancer.

255,970 per QALY gained. Among patients with known EML4-ALK-positive advanced NSCLC, first-line crizotinib therapy provided 0.379 additional QALYs, cost an additional

Canadian Anaplastic Lymphoma Kinase Study: A Model for Multicenter Standardization and Optimization of ALK Testing in Lung Cancer

95,043 compared with standard care, and produced an ICER of

Bmi1 promotes prostate tumorigenesis via inhibiting p16INK4A and p14ARF expression

250,632 per QALY gained. The major driver of cost effectiveness was drug price. CONCLUSION EML4-ALK fusion testing in stage IV nonsquamous NSCLC with crizotinib treatment for ALK-positive patients is not cost effective in the setting of high drug costs and a low biomarker frequency in the population.