Systematic Literature Review of the Prevalence and Prognostic Value of Delta-Like Ligand 3 Protein Expression in Small Cell Lung Cancer.

BACKGROUND: Delta-like ligand 3 (DLL3), a member of the Notch pathway, has been identified as a potential therapeutic target as it is highly expressed in small cell lung cancer (SCLC), a subtype accounting for 15% of lung cancer cases. OBJECTIVE: A systematic literature review (SLR) was conducted to understand the prevalence and prognostic impact of DLL3 expression on survival of patients with SCLC and treatment response. PATIENTS AND METHODS: Systematic literature searches were conducted across multiple databases to capture studies of any SCLC population that evaluated DLL3 expression. Specific outcomes of interest included prevalence of DLL3 expression, method of expression analysis, and impact on outcome, including treatment response and survival (overall, progression-free, disease-free) according to varying levels of DLL3 expression/positivity. Standard risk of bias tools were used to evaluate study quality. RESULTS: Among the 30 included studies, the most common DLL3 testing method was immunohistochemistry (N = 26, 86.7%). For comparability, results focused on the 13 (22.3%) studies that used the Ventana DLL3 (SP347) immunohistochemistry assay. The prevalence of DLL3 positivity ranged from 80.0-93.5% for studies using a threshold of ≥ 1% of tumor cells (N = 4) and 58.3-91.1% for studies with a ≥ 25% threshold (N = 4). DLL3 expression was generally categorized as high using cutoffs of ≥ 50% (prevalence range: 45.8-79.5%; N = 6) or ≥ 75% (prevalence range: 47.3-75.6%; N = 5) of cells with positivity. Two studies used an H-score of ≥ 150 to define high DLL3 expression with prevalence ranging from 33.3-53.1%. No consistent associations were seen between DLL3 expression level and patient age, sex, smoking history, or disease stage. Two studies reported change in DLL3 expression category (high versus low) before and after chemotherapy. No statistically significant differences were reported between DLL3 expression groups and survival (overall, progression-free, or disease-free) or treatment response. CONCLUSIONS: There is a high prevalence of DLL3 expression in SCLC. Further research and analytical methods may help to characterize different populations of patients with SCLC based on DLL3 expression. While no significant prognostic factor in the included studies was identified, additional cohort studies using standardized methodology, with longer follow-up, are needed to better characterize any potential differences in patient survival or response by DLL3 expression level in SCLC.

Genome-wide Detection of Chimeric Transcripts in Early-stage Non-small Cell Lung Cancer.

BACKGROUND/AIM: Lung cancer remains the main culprit in cancer-related mortality worldwide. Transcript fusions play a critical role in the initiation and progression of multiple cancers. Treatment approaches based on specific targeting of discovered driver events, such as mutations in EGFR, and fusions in NTRK, ROS1, and ALK genes led to profound improvements in clinical outcomes. The formation of chimeric proteins due to genomic rearrangements or at the post-transcriptional level is widespread and plays a critical role in tumor initiation and progression. Yet, the fusion landscape of lung cancer remains underexplored. MATERIALS AND METHODS: We used the JAFFA pipeline to discover transcript fusions in early-stage non-small cell lung cancer (NSCLC). The set of detected fusions was further analyzed to identify recurrent events, genes with multiple partners and fusions with high predicted oncogenic potential. Finally, we used a generalized linear model (GLM) to establish statistical associations between fusion occurrences and clinicopathological variables. RNA sequencing was used to discover and characterize transcript fusions in 270 NSCLC samples selected from the Glans-Look specimen repository. The samples were obtained during the early stages of disease prior to the initiation of chemo- or radiotherapy. RESULTS: We identified a set of 792 fusions where 751 were novel, and 33 were recurrent. Four of the 33 recurrent fusions were significantly associated with clinicopathological variables. Several of the fusion partners were represented by well-established oncogenes ERBB4, BRAF, FGFR2, and MET. CONCLUSION: The data presented in this study allow researchers to identify, select, and validate promising candidates for targeted clinical interventions.

Emerging therapies targeting the delta-like ligand 3 (DLL3) in small cell lung cancer.

Small cell lung cancer (SCLC) is an aggressive neuroendocrine carcinoma with a poor prognosis. Initial responses to standard-of-care chemo-immunotherapy are, unfortunately, followed by rapid disease recurrence in most patients. Current treatment options are limited, with no therapies specifically approved as third-line or beyond. Delta-like ligand 3 (DLL3), a Notch inhibitory ligand, is an attractive therapeutic target because it is overexpressed on the surface of SCLC cells with minimal to no expression on normal cells. Several DLL3-targeted therapies are being developed for the treatment of SCLC and other neuroendocrine carcinomas, including antibody-drug conjugates (ADCs), T-cell engager (TCE) molecules, and chimeric antigen receptor (CAR) therapies. First, we discuss the clinical experience with rovalpituzumab tesirine (Rova-T), a DLL3-targeting ADC, the development of which was halted due to a lack of efficacy in phase 3 studies, with a view to understanding the lessons that can be garnered for the rapidly evolving therapeutic landscape in SCLC. We then review preclinical and clinical data for several DLL3-targeting agents that are currently in development, including the TCE molecules-tarlatamab (formerly known as AMG 757), BI 764532, and HPN328-and the CAR T-cell therapy AMG 119. We conclude with a discussion of the future challenges and opportunities for DLL3-targeting therapies, including the utility of DLL3 as a biomarker for patient selection and disease progression, and the potential of rational combinatorial approaches that can enhance efficacy.

A Comparison of Patients' and Physicians' Knowledge and Expectations Regarding Precision Oncology Tests.

(1) Background: As genomic testing is becoming a part of the mainstream oncology practice, it is vital to ensure that our patients fully understand the implications of these tests. This study aimed to compare the attitudes and expectations of cancer patients with those of their physicians regarding the role of biomarker testing in clinical decision making. (2) Methods: Two separate, complimentary, self-administered questionnaires for patients with cancer and their physicians, respectively, were collected in Calgary, Alberta, Canada. Out of 117, 113 completed patient surveys were included in the statistical analysis, constituting a 96.4% response rate. These surveys were subsequently matched with those of their corresponding oncologists to determine the concordance rates. (3) Results: Overall, patients demonstrated a good understanding of general cancer biology (80.0%) and diagnostic processes (90.0%) associated with precision oncology. Most patients wanted their tumours to be tested to guide treatment, and the oncologists broadly shared these views (concordance 65.1%). However, there were discrepancies between the knowledge and expectations regarding the applications of test results on actual diagnosis and prognosis between patients and their oncologists (concordance 26.1% and 36.0%, respectively). While only 28.0% of patients thought they had enough knowledge to make informed decisions, the majority (68.0%) said they needed more information. (4) Conclusion: Our study shows that patients and cancer physicians do not always agree with the roles and applications of genomic tests, which could lead to misplaced expectations and poor health outcomes. More research is needed to devise strategies to improve education and communication to align these expectations and improve the quality of clinical decision making.

Estimating the Impact of Delayed Access to Oncology Drugs on Patient Outcomes in Canada.

INTRODUCTION: New requirements in Canada's pricing processes for patented drugs may exacerbate delays in regulatory and reimbursement reviews. This study seeks to better understand the impact of any additional delays on non-small cell lung cancer (NSCLC) patients by measuring the following: (a) durations and outcomes of regulatory and reimbursement reviews of NSCLC drugs in Canada and reference countries; (b) delays in Canada's reviews of three NSCLC drugs (nivolumab, afatinib, and pemetrexed [NAP]); and (c) estimating clinical, patient, and economic impacts of delays in Canada's reviews on access to NAP. METHODS: Information from the Context Matters database and the literature (2005-2020) was used to evaluate the durations and outcomes of reimbursement reviews of NSCLC drugs in Canada and comparator countries. Public information was used to assess delays in Canada's reviews of NAP. Empirical modeling with data from the literature and the Southern Alberta Lung Cancer database was used to estimate the impact of delays in Canada's NAP reviews on patients (i.e., as losses in person-years of life and quality-adjusted life-years [QALYs]). RESULTS: Regulatory and reimbursement reviews in countries of interest take 12-18 months. In Canada, reviews of NSCLC drugs took 216 days (median), with a 24% rejection rate (mean = 19%). Delays in NAP reviews ranged from 5 to 94 days at Health Canada, 0-80 days at CADTH/pCODR, and 12-797 days in Canadian provinces. These delays may have affected 6400 patients, who lost up to 1740 person-years of life and 1122 QALYs (valued at CA$112 million). CONCLUSION: Changes to Canada's prescription drug pricing processes may prolong reviews.

Feasibility of a multimodal exercise, nutrition, and palliative care intervention in advanced lung cancer.

BACKGROUND: Advanced lung cancer patients face significant physical and psychological burden leading to reduced physical function and quality of life. Separately, physical activity, nutrition, and palliative symptom management interventions have been shown to improve functioning in this population, however no study has combined all three in a multimodal intervention. Therefore, we assessed the feasibility of a multimodal physical activity, nutrition, and palliative symptom management intervention in advanced lung cancer. METHODS: Participants received an individually tailored 12-week intervention featuring in-person group-based exercise classes, at-home physical activity prescription, behaviour change education, and nutrition and palliative care consultations. Patients reported symptom burden, energy, and fatigue before and after each class. At baseline and post-intervention, symptom burden, quality of life, fatigue, physical activity, dietary intake, and physical function were assessed. Post-intervention interviews examined participant perspectives. RESULTS: The multimodal program was feasible, with 44% (10/23) recruitment, 75% (75/100) class attendance, 89% (8/9) nutrition and palliative consult attendance, and 85% (17/20) assessment completion. Of ten participants, 70% (7/10) completed the post-intervention follow-up. Participants perceived the intervention as feasible and valuable. Physical activity, symptom burden, and quality of life were maintained, while tiredness decreased significantly. Exercise classes prompted acute clinically meaningful reductions in fatigue, tiredness, depression, pain, and increases in energy and well-being. CONCLUSION: A multimodal physical activity, nutrition, and palliative symptom management intervention is feasible and shows potential benefits on quality of life that warrant further investigation in a larger cohort trial. TRIAL REGISTRATION: NCT04575831 , Registered 05 October 2020 - Retrospectively registered.

A phase IB study of durvalumab with or without tremelimumab and platinum-doublet chemotherapy in advanced solid tumours: Canadian Cancer Trials Group Study IND226.

This multicenter phase Ib study aimed to establish a recommended phase II dose for durvalumab (Du) ± tremelimumab (Tr) in combination with standard platinum-doublet chemotherapy. Eligible patients were enrolled into one of six dose levels (DL) of Du ± Tr which included concomitant treatment with standard platinum-doublet regimens; (pemetrexed, gemcitabine, etoposide, (each with cisplatin or carboplatin) or nab-paclitaxel (with carboplatin)). Dose escalation was according to a Rolling Six type design. Both weight-based and fixed dosing of Du and Tr were explored. Du was continued until progression. Tr dosing was finite (up to 6 doses) with increasing dose and/or frequency by DL. 136 patients were enrolled. The majority of drug-related adverse events (AEs) were ≤ grade 2 and attributable to chemotherapy. AEs considered related to immunotherapy were mainly ≤ grade 2; the most frequent (occurring ≥10 %) were colitis/diarrhea, skin, and thyroid dysfunction. Seven patients had DLTs including pneumonitis, myocarditis, diarrhea, encephalitis, motor neuropathy, and enterocolitis. There were 2 treatment-related deaths. Tr and Du exposures did not appear affected by chemotherapy. Among the 73 non-small cell lung cancer (NSCLC) patients treated, the objective response rate was 51 % (95 %CI = 38.7-62.6 %) with a median progression-free and overall survival of 6.5 months (95 % CI = 5.5-9.4 months) and 19.8 months (95 % CI = 14.8 months - not yet reached) respectively. Anti-tumour activity was observed across PD-L1 subtypes. Du 1500 mg q3w and Tr 75 mg q3wx5 can be safely combined with platinum-doublet chemotherapy. Efficacy among NSCLC patients appears comparable to results from other immunotherapy and chemotherapy combination trials. NCT02537418.

Demographic and clinical correlates of accelerometer assessed physical activity and sedentary time in lung cancer survivors.

OBJECTIVE: To determine demographic and clinical correlates of accelerometer assessed physical activity and sedentary time among a population-based sample of lung cancer survivors. METHODS: Lung cancer survivors in Southern Alberta, Canada (N = 527) were invited to complete a mailed survey assessing socio-demographics and wear an Actigraph® GT3X+ accelerometer for 7 days. Average daily minutes of physical activity and sedentary time were derived from the accelerometer data. Accelerometer data were processed using standard Freedson cutpoints, and correlates of physical activity and sedentary time were determined with linear regression. RESULTS: A total of 127 lung cancer survivors participated (mean age = 71 years), for a 24% response rate. Moderate-to-vigorous physical activity was negatively associated with being >60 years of age (ß = -7.4, CI: -14.7, -0.10). Moderate-to-vigorous physical activity accumulated in 10-minute bouts was associated with receiving surgery and adjuvant chemotherapy (ß = 9.1, CI: 2.1, 16.1). Sedentary time was associated with being >60 years of age (ß = 32.4, CI: 3.1, 61.7), smoking (ß = 63.9, CI: 22.5, 105.4), and being overweight/obese (ß = 28.6, CI: 6.4, 50.1). CONCLUSION: Age, smoking history, and body mass index emerged as correlates of accelerometer assessed light, moderate, and vigorous physical activity, and sedentary time among lung cancer survivors. IMPLICATIONS FOR CANCER SURVIVORS: Identifying correlates of physical activity and sedentary time may aid in the development of targeted behavioral interventions for this population.

Low Ki67/high ATM protein expression in malignant tumors predicts favorable prognosis in a retrospective study of early stage hormone receptor positive breast cancer.

INTRODUCTION: This study was designed to investigate the combined influence of ATM and Ki67 on clinical outcome in early stage hormone receptor positive breast cancer (ES-HPBC), particularly in patients with smaller tumors (< 4 cm) and fewer than four positive lymph nodes. METHODS: 532 formalin-fixed paraffin-embedded specimens of resected primary breast tumors were used to construct a tissue microarray. Samples from 297 patients were suitable for final statistical analysis. We detected ATM and Ki67 proteins using fluorescence and brightfield immunohistochemistry respectively, and quantified their expression with digital image analysis. Data on expression levels were subsequently correlated with clinical outcome. RESULTS: Remarkably, ATM expression was useful to stratify the low Ki67 group into subgroups with better or poorer prognosis. Specifically, in the low Ki67 subgroup defined as having smaller tumors and no positive nodes, patients with high ATM expression showed better outcome than those with low ATM, with estimated survival rates of 96% and 89% respectively at 15 years follow up (p = 0.04). Similarly, low-Ki67 patients with smaller tumors, 1-3 positive nodes and high ATM also had significantly better outcomes than their low ATM counterparts, with estimated survival rates of 88% and 46% respectively (p = 0.03) at 15 years follow up. Multivariable analysis indicated that the combination of high ATM and low Ki67 is prognostic of improved survival, independent of tumor size, grade, and lymph node status (p = 0.02). CONCLUSIONS: These data suggest that the prognostic value of Ki67 can be improved by analyzing ATM expression in ES-HPBC.

ATM, THMS, and RRM1 protein expression in nasopharyngeal carcinomas treated with curative intent.

BACKGROUND: In advanced nasopharyngeal carcinoma (NPC), biomarkers may help predict survival. METHODS: Tumoral expression of ataxia-telangiectasia mutated (ATM), thymidylate synthetase (THMS), and ribonucleotide reductase subunit M1 (RRM1), was correlated with survival in patients with nonmetastatic NPC using quantitative fluorescence immunohistochemistry with automated quantitative digital image analysis. RESULTS: Of the 146 patients included, 58 patients (40%) received concurrent chemoradiation therapy; the remainder was treated with radiation. Overall survival (OS) at 5 years was 71% (95% confidence interval [CI], 62% to 78%); disease-free survival (DFS) was 48% (95% CI, 39% to 57%). OS worsened for increasing values of ATM (hazard ratio [HR], 2.83; 95% CI, 1.01-7.94; p = .049) for values greater than the 75th percentile compared to less than the 25th percentile, but improved for tumors with higher THMS levels (HR, 0.44; 95% CI, 0.20-0.94; p = .033) for values greater than the 25th percentile compared to less than or equal to the 25th percentile. RRM1 was not associated with OS (p = .748). No biomarkers were associated with DFS. CONCLUSION: In our cohort, relative overexpression of ATM and low THMS levels were associated with worse OS. © 2015 Wiley Periodicals, Inc. Head Neck 38: E384-E391, 2016.

Low ATM protein expression in malignant tumor as well as cancer-associated stroma are independent prognostic factors in a retrospective study of early-stage hormone-negative breast cancer.

INTRODUCTION: The serine/threonine protein kinase ataxia telangiectasia mutated (ATM) is critical in maintaining genomic integrity. Upon DNA double-strand breaks, ATM phosphorylates key downstream proteins including p53 and BRCA1/2, thereby orchestrating complex signaling pathways involved in cell cycle arrest, DNA repair, senescence and apoptosis. Although sporadic mutation of ATM occurs rarely in breast cancer, the status of its protein expression and its clinical significance in breast cancer remain not well established. Our study was designed to investigate the influence of ATM protein in both tumor and cancer-associated stroma on clinical outcome in hormone-positive (HPBC) and hormone-negative (HNBC) early-stage breast cancer (EBC). METHODS: Tissue microarrays (TMAs), containing formalin-fixed, paraffin-embedded resected tumors from two cohorts of patients (HPBC cohort: n=130; HNBC cohort: n=168) diagnosed at the Tom Baker Cancer Centre, Calgary, Canada, were analyzed for ATM protein expression using fluorescence immunohistochemistry (IHC) and automated quantitative analysis (AQUA). ATM expression levels were measured within the tumor as a whole (tATM) as indicated by pan-cytokeratin expression, tumor nuclear compartment (nATM) as indicated by both DAPI and pan-cytokeratin-positive results, and cancer-associated stroma (csATM) as indicated by vimentin-positive and pan-cytokeratin-negative results. ATM expression levels within these compartments were correlated with clinical outcome. RESULTS: While tATM and nATM were significantly lower in tumors compared to normal breast epithelial tissues, csATM was significantly higher than the corresponding normal tissue compartment. In addition, the median expression level of both tATM and nATM were two- to threefold lower (P<0.001) in HNBC than in HPBC. In both HNBC and HPBC cohorts, patients with low tATM, nATM and csATM tumors had significantly poorer survival outcomes than those with a high tATM, nATM and csATM, but this effect was more pronounced in HNBC. A multivariate analysis demonstrates that these biomarkers predict survival independent of tumor size and lymph node status, but only in the HNBC cohort (P<0.001). CONCLUSIONS: Low ATM protein expression in both malignant tumor and stromal compartments likely contributes to the aggressive nature of breast cancer and is an independent prognostic factor associated with worse survival in HNBC patients.

Characterization of a murine model of metastatic human non-small cell lung cancer and effect of CXCR4 inhibition on the growth of metastases.

Despite successful preclinical testing carried out through the use of subcutaneous xenografted tumors, many anti-cancer agents have gone on to fail in human trials. One potential factor accounting for this discrepancy may relate to the inadequacy of the commonly employed preclinical models to recapitulate the human disease, particularly when it comes to discovery of agents that are effective against advanced disease. Herein, we report the characterization of a NSCLC model and an exploration of the impact that a CXCR4 inhibitor, AMD3100, had on NCI-H1299-derived metastasis. These cells express a variety of metastasis-promoting factors, hence we selected them for a study of their metastatic colonization potential. To accomplish this, luciferase-expressing H1299 (H1299-luc2) cells were inoculated into athymic mice via the intracardiac route. This strategy produced adrenal, bone, ovarian, and pancreatic metastases, sites commonly involved in human metastatic NSCLC. Notably, micro-computed tomography and histological evaluation of the skeletal lesions revealed the presence of extensive osteolysis. To investigate the potential role of CXCR4 in mediating metastatic colonization of tissues, AMD3100 was administered to mice inoculated with H1299-luc2 cells. While this treatment did not appreciably alter the frequency of metastatic colonization, it was able to slow the growth of macrometastases. This model, recapitulating some of the events seen in late-stage human NSCLC, may prove useful in the evaluation of new therapies targeting metastatic disease.

Phase I clinical trial of the anti-EGFR monoclonal antibody nimotuzumab with concurrent external thoracic radiotherapy in Canadian patients diagnosed with stage IIb, III or IV non-small cell lung cancer unsuitable for radical therapy.

PURPOSE: Many patients with non-small cell lung cancer (NSCLC) are eligible only for palliative radiation (RT) at presentation. This study was designed to assess the feasibility of adding the anti-EGFR monoclonal antibody nimotuzumab to palliative thoracic RT. METHODS: Patients with stage IIB, III or IV NSCLC considered unsuitable for radical radiation or chemo-radiation received nimotuzumab weekly 8× (100, 200 or 400 mg) with radiation (30 or 36 Gy in 3 Gy fractions). If response or disease stability was observed, nimotuzumab was continued every other week starting from week 10 until progression or toxicity. RESULTS: Eighteen patients were enrolled: 6 at 100 mg, 7 at 200 mg, 5 at 400 mg nimotuzumab. Patient characteristics included median age 69 years, 11 males, 17 smokers, 17 Caucasians, stage IIIA/IIIB/IV 2/7/9, 5 Eastern Cooperative Oncology Group performance status (PS) 2; 9 adenocarcinoma. The most commonly reported adverse events were fatigue, anorexia, chills, pain and hypophosphatemia (grades 1 to 2 in most patients). No severe skin or allergic toxicity was noted. No dose-limiting toxicity was encountered. Objective response rate and disease control rate inside the radiation field were 66 and 94.0%, respectively. CONCLUSION: Nimotuzumab administered concurrently with palliative thoracic radiation is well tolerated at each of the three doses investigated in NSCLC patients unsuitable for radical treatment. The low toxicity and absence of rash make this combination therapeutically attractive for frail patients with other co-morbidities and poor performance status. These results support further testing of this regimen in the phase II setting.

The emerging role of nimotuzumab in the treatment of non-small cell lung cancer.

Current non-small cell lung cancer (NSCLC) chemotherapy and radiotherapy regimens, although showing definite survival benefit, still leave patients with a disappointing 15% 5-year overall survival rate. Because of the need to improve traditional outcomes, research has focused on identifying specific tumorigenic pathways that may serve as therapeutic targets. The most successful strategies to date are those aimed at the epidermal growth factor receptor (EGFR), which is found to be upregulated in 40%-80% of NSCLC. Several tyrosine kinase inhibitors and monoclonal antibodies (mAbs) have been developed that inhibit the EGFR receptor and have demonstrated clinical benefit in trials as single agents and in combination regimens. Here we discuss one such agent, the mAb nimotuzumab, the background of its development, its clinical experience in NSCLC thus far, and the rationale for expanding its use to other NSCLC treatment settings.

Susceptibility of mantle cell lymphomas to reovirus oncolysis.

Mantle cell lymphoma (MCL) an incurable B-cell, non-Hodgkin lymphoma (NHL) urgently requires new treatments. We assessed reovirus mediated oncolysis in a panel of human MCL cell lines. In vitro, we found the cytopathic effect of reovirus infection ranged from high to very limited and correlated with levels of Ras activation. In vivo, a single reovirus injection intra-tumorally resulted in complete regression of both the injected and the contra-lateral tumor in a subcutaneous bi-tumor model, in one out of three cell lines tested. Reovirus treatment of MCL seems feasible but will need to be guided by the presence of molecular determinants of reovirus susceptibility.

Nimotuzumab: a novel anti-EGFR monoclonal antibody that retains anti-EGFR activity while minimizing skin toxicity.

Due to the broad importance of EGFR to tumorogenesis, targeted therapy against it has rapidly developed into a novel paradigm for cancer treatment. Two promising classes of drugs are now in use and undergoing development that target this receptor: tyrosine kinase inhibitors (TKIs) and mAbs that inhibit EGFR's extracellular domain. Nimotuzumab, a humanized murine mAb created in Cuba, has demonstrated antitumor activity similar to that of other anti-EGFR mAbs and shows promise as a single agent and as an adjunct to radiation in Phase I and II clinical trials. Surprisingly, the typical severe dermatological toxicities thus far associated with anti-EGFR therapy have not been described with nimotuzumab. Here we summarize the background, development and characteristics of this new drug while reviewing the latest preclinical and clinical trial data that underpin its gradual adoption into clinical practice.

The CXCR4/SDF-1 chemokine receptor axis: a new target therapeutic for non-small cell lung cancer.

Chemokines are proinflammatory chemoattractant cytokines that regulate cell trafficking and adhesion. The CXCR4 chemokine receptor and its ligand, stromal cell derived factor (SDF-1), constitute a chemokine/receptor axis that has attracted great interest because of an increasing understanding of its role in cancer, including lung cancer. The CXCR4/SDF-1 complex activates several pathways that mediate chemotaxis, migration and secretion of angiopoietic factors. Neutralization of SDF-1 by anti-SDF-1 or anti-CXCR4 monoclonal antibody in preclinical in vivo studies results in a significant decrease of non-small cell lung cancer metastases. Since anti-SDF-1/CXCR4 strategies have already been developed for use in combating human immunodeficiency virus infections, it is likely that these approaches will be used in clinical trials in non-small cell lung cancer in the very near future.

Correlations of EGFR mutations and increases in EGFR and HER2 copy number to gefitinib response in a retrospective analysis of lung cancer patients.

BACKGROUND: Gefitinib, a small molecule tyrosine kinase inhibitor of the Epidermal Growth Factor Receptor (EGFR), has shown limited efficacy in the treatment of lung cancer. Recognized clinical predictors of response to this drug, specifically female, non-smoker, Asian descent, and adenocarcinoma, together suggest a genetic basis for drug response. Recent studies have addressed the relationship between response and either sequence mutations or increased copy number of specific receptor tyrosine kinases. We set out to examine the relationship between response and the molecular status of two such kinases, EGFR and HER2, in 39 patients treated with gefitinib at the BC Cancer Agency. METHODS: Archival patient material was reviewed by a pathologist and malignant cells were selectively isolated by laser microdissection or manual recovery of cells from microscope slides. Genomic DNA was extracted from 37 such patient samples and exons 18-24, coding for the tyrosine kinase domain of EGFR, were amplified by PCR and sequenced. EGFR and HER2 copy number status were also assessed using FISH in 26 samples. Correlations between molecular features and drug response were assessed using the two-sided Fisher's exact test. RESULTS: Mutations previously correlated with response were detected in five tumours, four with exon 19 deletions and one with an exon 21 missense L858R point mutation. Increased gene copy number was observed in thirteen tumours, seven with EGFR amplification, three with HER2 amplification, and three with amplification of both genes. In our study cohort, a correlation was not observed between response and EGFR mutations (exon 19 deletion p = 0.0889, we observed a single exon 21 mutation in a non-responder) or increases in EGFR or HER2 copy number (p = 0.552 and 0.437, respectively). CONCLUSION: Neither mutation of EGFR nor increased copy number of EGFR or HER2 was diagnostic of response to gefitinib in this cohort. However, validation of these features in a larger sample set is appropriate. Identification of additional predictive biomarkers beyond EGFR status may be necessary to accurately predict treatment outcome.