Predictive biomarkers for response to EGFR-directed monoclonal antibodies for advanced squamous cell lung cancer.

Background: Upregulated expression and aberrant activation of the epidermal growth-factor receptor (EGFR) are found in lung cancer, making EGFR a relevant target for non-small-cell lung cancer (NSCLC). Treatment with anti-EGFR monoclonal antibodies (mAbs) is associated with modest improvement in overall survival in patients with squamous cell lung cancer (SqCLC) who have a significant unmet need for effective treatment options. While there is evidence that using EGFR gene copy number, EGFR mutation, and EGFR protein expression as biomarkers can help select patients who respond to treatment, it is important to consider biomarkers for response in patients treated with combination therapies that include EGFR mAbs. Design: Randomized trials of EGFR-directed mAbs cetuximab and necitumumab in combination with chemotherapy, immunotherapy, or antiangiogenic therapy in patients with advanced NSCLC, including SqCLC, were searched in the literature. Results of associations of potential biomarkers and outcomes were summarized. Results: Data from phase III clinical trials indicate that patients with NSCLC, including SqCLC, whose tumors express high levels of EGFR protein (H-score of ≥200) and/or gene copy numbers of EGFR (e.g. ≥40% cells with ≥4 EGFR copies as detected by fluorescence in situ hybridization; gene amplification in ≥10% of analyzed cells) derive greater therapeutic benefits from EGFR-directed mAbs. Biomarker data are limited for EGFR mAbs used in combination with immunotherapy and are absent when used in combination with antiangiogenic agents. Conclusions: Therapy with EGFR-directed mAbs in combination with chemotherapy is associated with greater clinical benefits in patients with NSCLC, including SqCLC, whose tumors express high levels of EGFR protein and/or have increased EGFR gene copy number. These data support validating the role of these as biomarkers to identify those patients who derive the greatest clinical benefit from EGFR mAb therapy. However, data on biomarkers for EGFR-directed mAbs combined with immunotherapy or antiangiogenic agents remain limited.

18F-fluoro-2-deoxy-D-glucose positron emission tomography and positron emission tomography/computed tomography imaging of malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is the most common primary pleural tumor and its incidence is rising. Its diagnosis, staging and response assessment are challenging for imaging. Integrated positron emission tomography (PET)/CT increases the accuracy of overall staging in patients with mesothelioma and improves the selection of patients for curative surgical resection. It is particularly useful in identifying occult distant metastases. It may be used to predict prognosis and to assess the metabolic response to therapy.

A phase II trial of imatinib (ST1571) in patients with c-kit expressing relapsed small-cell lung cancer: a CALGB and NCCTG study.

BACKGROUND: The aim of the present study was to evaluate the clinical activity of imatinib mesylate in patients with recurrent and refractory c-kit-expressing small-cell lung cancer. PATIENTS AND METHODS: Patients with c-kit-expressing SCLC (> or =1+ by immunohistochemistry) were enrolled in two groups. Arm A included patients with disease progression <3 months and arm B included patients with disease progression > or =3 months after previous treatment. Imatinib was administered at a dose of 400 mg b.i.d. continuously, with a cycle length of 28 days. A single stage Simon design with a planned interim analysis was used to evaluate the 16-week progression free rate in each arm. RESULTS: A total of 29 evaluable patients were entered into the study (seven in arm A, median age 68; 22 in arm B, median age 64.5). Median number of treatment cycles was one in both arms. Grade 3+ non-hematologic adverse events were seen in 15 (52%) patients, with nausea, vomiting, dyspnea, fatigue, anorexia and dehydration each occurring in at least 10% of patients. Median survival was 3.9 and 5.3 months and median time to progression was 1 and 1.1 months for arms A and B, respectively. Enrollment to arm A was temporarily suspended prior to reaching interim analysis due to striking early disease progression (29%), early deaths (29%) and patient refusal (42%). No objective responses and no confirmed stable disease > or =6 weeks were seen in either arm. Accrual was permanently terminated to both arms as only one patient was progression-free at 16 weeks. CONCLUSION: Imatinib failed to demonstrate any clinical activity in spite of patient selection for c-kit-expressing SCLC. Our results strengthen the collective evidence that prediction of efficacy of novel therapeutic agents based on target expression, rather than pathway activation (for example, through activating mutations), may not be a valid paradigm for drug development.

Phase II study of topotecan and paclitaxel for patients with previously untreated extensive stage small-cell lung cancer.

BACKGROUND: This phase II study was conducted to evaluate the safety and efficacy of the combination of paclitaxel and topotecan for patients with extensive stage small-cell lung cancer (ED-SCLC). PATIENTS AND METHODS: Previously untreated ED-SCLC patients with Eastern Coperative Oncology Group performance status <2 were eligible. Treatment consisted of topotecan 1 mg/m2 (first three patients received 1.25 mg/m2), on days 1-5, and paclitaxel 135 mg/m2 over 24 h on day 5, every 4 weeks. Prophylactic granulocyte colony-stimulating factor was administered to all patients. RESULTS: Thirty-two patients received a median of four cycles of chemotherapy. Grade 4 anemia, neutropenia and thrombocytopenia occurred in 13, 31 and 18 patients, respectively. Thirty episodes of febrile neutropenia occurred in 22 patients. Grade 3 fatigue, esophagitis, stomatitis and hypotension occurred in one patient each. Of 26 patients eligible for response evaluation, there were six complete and 12 partial responses (overall response rate 69%). The median survival was 54 weeks. The 1-, 2- and 3-year survival rates were 50%, 10% and 3%, respectively. CONCLUSIONS: The combination of topotecan and paclitaxel is active as initial therapy in SCLC, but the efficacy is similar to 'standard therapy'. This combination was associated with a high incidence of myelosuppression and febrile neutropenia, at the doses evaluated.

Molecular cytometry.

The first flow cytometric analyses were of total cellular DNA or protein content. The advent of labeled antibodies, first polyclonal and then monoclonal, led to the analysis of cellular content of specific antigen molecules and a myriad of immunological applications. Although, strictly speaking, it is incorrect to use the word "cytometry" for anything that does not refer to cellular measurements, the term has been used for a variety of non-cellular measurements such as chromosome analysis and solution molecular measurements. In recent years, there has been an increase in the development of methods to analyze molecules and their properties in solution. These analyses have ranged from ensemble measurements, primarily fluorescence-based immunoassays, to single molecule detection with applications in DNA analysis.

The correlation of emphysema or airway obstruction with the risk of lung cancer: a matched case-controlled study.

A matched case-controlled study was conducted to determine if airway obstruction or emphysema were associated with an increased risk of lung cancer. Lung cancer cases (n=24) were identified through a low-dose spiral computed tomography (CT) screening trial from 1,520 participants. Four controls without lung cancer were selected for each case from the participants and matched by sex, age and smoking history. Emphysema was assessed by quantitative CT analysis. Conditional logistic regression was employed to assess results of spirometry and CT quantitative analysis as potential risk factors for lung cancer. The likelihood of lung cancer was found to be significantly increased for those with forced expiratory volume in one second (FEV1) < or = 40% of predicted. The results suggested that a lower percentage of predicted FEV1 was indicative of lung cancer. No compelling evidence was found to suggest that the percentage of emphysema was associated with lung cancer. These results suggest an increased risk of lung cancer associated with airway obstruction. However, percentage of emphysema as determined by computed tomography was not associated with an increased risk of lung cancer.

Alterations of p14ARF, p53, and p73 genes involved in the E2F-1-mediated apoptotic pathways in non-small cell lung carcinoma.

Overexpression of E2F-1 induces apoptosis by both a p14ARF-p53- and a p73-mediated pathway. p14ARF is the alternate tumor suppressor product of the INK4a/ARF locus that is inactivated frequently in lung carcinogenesis. Because p14ARF stabilizes p53, it has been proposed that the loss of p14ARF is functionally equivalent to a p53 mutation. We have tested this hypothesis by examining the genomic status of the unique exon 1beta of p14ARF in 53 human cell lines and 86 primary non-small cell lung carcinomas and correlated this with previously characterized alterations of p53. Homozygous deletions of p14ARF were detected in 12 of 53 (23%) cell lines and 16 of 86 (19%) primary tumors. A single cell line, but no primary tumors, harbored an intragenic mutation. The deletion of p14ARF was inversely correlated with the loss of p53 in the majority of cell lines (P = 0.02), but this relationship was not maintained among primary tumors (P = 0.5). E2F-1 can also induce p73 via a p53-independent apoptotic pathway. Although we did not observe inactivation of p73 by either mutation or DNA methylation, haploinsufficiency of p73 correlated positively with either p14ARF or p53 mutation or both (P = 0.01) in primary non-small cell lung carcinomas. These data are consistent with the current model of p14ARF and p53 interaction as a complex network rather than a simple linear pathway and indicate a possible role for an E2F-1-mediated failsafe, p53-independent, apoptotic pathway involving p73 in human lung carcinogenesis.

Typical and atypical pulmonary carcinoids : outcome in patients presenting with regional lymph node involvement.

STUDY OBJECTIVE: Typical pulmonary carcinoid tumors are well-differentiated neuroendocrine tumors that are associated with good patient survival rates, while atypical carcinoid tumors are more aggressive and have worse patient survival rates. Because these tumors rarely involve the thoracic lymph nodes at presentation, it is currently unknown to what extent the presence of thoracic lymph node metastases at the time of diagnosis influences patient survival. METHODS: A computerized search of the medical records for pulmonary carcinoid tumor at the Mayo Clinic from 1976 to 1997 revealed 517 patients, from which we identified 36 patients with pulmonary carcinoid tumors involving regional thoracic lymph nodes but without distant disease. For each patient, we reviewed the tumor histology, stage, and outcome. In addition, because the histologic criteria for the diagnosis of carcinoid tumors had changed significantly during the time of the study, we reexamined all of the histologic specimens using the current World Health Organization (WHO) criteria for classifying pulmonary neuroendocrine tumors. RESULTS: After reclassification with the WHO criteria for neuroendocrine tumors, 23 patients had typical carcinoid tumors with thoracic lymph node involvement. At the last follow-up, 19 patients had no evidence of disease (NED), 2 patients had developed systemic metastases (SM) and are still alive, and 2 patients had died. Eleven patients had atypical carcinoid tumors with thoracic lymph node involvement. At the last follow-up, four patients had NED, seven patients had developed SM within a median time of 17 months, and six patients with SM died shortly thereafter (median survival time, 25.5 months), while one is still alive. Two patients had been reclassified with large cell neuroendocrine carcinoma at the time of this review; both of these patients had developed SM (at 4 months and 21 months after diagnosis) and had died (at 15 months and 21 months after diagnosis, respectively). CONCLUSIONS: These data suggest that patients with atypical pulmonary carcinoid tumors with regional lymph node metastases have a high likelihood of developing recurrent disease if treated with surgical resection alone and have significantly worse outcome (p < 0.001) compared to those patients with typical carcinoid tumors with thoracic lymph node involvement.

Stage II (T3) lung cancer.

The tumors classified under T3 are diverse and usually present a difficult problem; however, with the improvements in surgery, radiation, and systemic therapies described above, a significant improvement in survival and quality of life can be anticipated for the future.

Lack of prognostic significance of p53 and K-ras mutations in primary resected non-small-cell lung cancer on E4592: a Laboratory Ancillary Study on an Eastern Cooperative Oncology Group Prospective Randomized Trial of Postoperative Adjuvant Therapy.

PURPOSE: To determine the prognostic and predictive significance of p53 and K-ras mutations in patients with completely resected non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Patients were randomized preoperatively to receive adjuvant postoperative radiotherapy (Arm A) or radiotherapy plus concurrent chemotherapy (Arm B). p53 protein expression was studied by immunohistochemistry (IHC) and p53 mutations in exons 5 to 8 were evaluated by single-strand conformational analysis. K-ras mutations in codons 12, 13, and 61 were determined using engineered restriction fragment length polymorphisms. RESULTS: Four hundred eighty-eight patients were entered onto E3590; 197 tumors were assessable for analysis. Neither presence nor absence of p53 mutations, p53 protein expression, or K-ras mutations correlated with survival or progression-free survival. There was a trend toward improved survival for patients with wildtype K-ras (median, 42 months) compared with survival of patients with mutant K-ras who were randomized to chemotherapy plus radiotherapy (median, 25 months; P = .09). Multivariate analysis revealed only age and tumor stage to be significant prognostic factors, although there was a trend bordering on statistical significance for K-ras (P = .066). Analysis of survival difference by p53 by single-stranded conformational polymorphism and IHC, interaction of p53 and K-ras, interaction of p53 and treatment arm, nodal station, extent of surgery, weight loss, and histology did not reach statistical significance. CONCLUSION: p53 mutations and protein overexpression are not significant prognostic or predictive factors in resected stage II or IIIA NSCLC. K-ras mutations may be a weak prognostic marker. p53 or K-ras should not be routinely used in the clinical management of these patients.

Techniques for flow cytometer alignment.

This unit provides essential knowledge for correctly using any flow cytometer to ensure that data collected are accurate and reliable. Two levels of system alignment are described: routine alignment checks and complete alignment, both of which can be applied to a variety of instrument configurations.

A phase II trial of edatrexate, vinblastine, adriamycin, cisplastin, and filgrastim (EVAC/G-CSF) in patients with non-small-cell carcinoma of the lungs: a North Central Cancer Treatment Group Trial.

Edatrexate is an antifolate agent with improved in vitro antineoplastic activity as compared with methotrexate. A Mayo phase I trial of edatrexate (E), vinblastine (V), doxorubicin (Adriamycin) (A), cisplatin (C), and filgrastim (GCSF), (EVAC-GCSF) showed promising antineoplastic activity in non-small-cell lung cancer (NSCLC) (Colon-Otero G, et al. Cancer J Sci Am 1997;3:297-302) leading to a phase II trial of this regimen, the results of which are reported here. A total of 34 patients with stage IIIB or IV measurable or evaluable NSCLC were entered in this North Central Cancer Treatment Group phase II study. Treatment consisted of edatrexate 100 mg/m2 intravenously on day 1 and cisplatin 30 mg/m2/d on day 1 and day 2 followed by vinblastine 3 mg/m2 intravenously and doxorubicin 30 mg/m2 intravenously on day 2. Filgrastim was given at 300 microg subcutaneously daily from day 4 to day 18 or until an absolute neutrophil count of 2,000/mm3 or more was obtained. Cycles were repeated every 21 days until either progression or the development of intolerable toxicity. Sixteen of 34 evaluable patients responded to therapy, for a response rate of 47.1% with a 95% CI of 30.3% to 63.8%. Median time to disease progression was 132 days, median survival time was 219 days, and the estimated 1-year survival was 41.2% (95% CI of 27.6-61.5%). The EVAC/G-CSF regimen has significant antineoplastic activity as seen by the response rates for patients with NSCLC. However, this study had significant myelosuppressive toxicity; 56% patients had grade III or higher leukopenia with three treatment-related deaths observed. In addition, Quality of Life assessments indicate that patients experienced an overall decline in quality of life during the course of treatment. These mitigating factors need to be considered regarding further evaluation of this regimen in this patient population.

Rapid DNA fingerprinting of pathogens by flow cytometry.

BACKGROUND: A new method for rapid discrimination among bacterial strains based on DNA fragment sizing by flow cytometry is presented. This revolutionary approach combines the reproducibility and reliability of restriction fragment length polymorphism (RFLP) analysis with the speed and sensitivity of flow cytometry. METHODS: Bacterial genomic DNA was isolated and digested with a rare-cutting restriction endonuclease. The resulting fragments were stained stoichiometrically with PicoGreen dye and introduced into an ultrasensitive flow cytometer. A histogram of burst sizes from the restriction fragments (linearly related to fragment length in base pairs) resulted in a DNA fingerprint that was used to distinguish among different bacterial strains. RESULTS: Five different strains of gram-negative Escherichia coli and six different strains of gram-positive Staphylococcus aureus were distinguished by analyzing their restriction fragments with DNA fragment sizing by flow cytometry. Fragment distribution analyses of extracted DNA were approximately 100 times faster and approximately 200,000 times more sensitive than pulsed-field gel electrophoresis (PFGE). When sample preparation time is included, the total DNA fragment analysis time was approximately 8 h by flow cytometry and approximately 24 h by PFGE. CONCLUSIONS: DNA fragment sizing by flow cytometry is a fast and reliable technique that can be applied to the discrimination among species and strains of human pathogens. Unlike some polymerase chain reaction (PCR)-based methods, sequence information about the bacterial strains is not required, allowing the detection of unknown, newly emerged, or unanticipated strains.

Development of a mechanism-based, DNA staining protocol using SYTOX orange nucleic acid stain and DNA fragment sizing flow cytometry.

Accurate measurement of single DNA fragments by DNA fragment sizing flow cytometry (FSFC) depends upon precise, stoichiometric DNA staining by the intercalating dye molecules. In this study, we determined the binding characteristics of a commercially available 532 nm wavelength-excitable dye and used this information to develop a universal DNA staining protocol for DNA FSFC using a compact frequency-doubled Nd:YAG laser excitation source. Among twelve 532 nm wavelength-excitable nucleic acid staining dyes tested, SYTOX Orange stain showed the highest fluorescence intensity along with a large fluorescence enhancement upon binding to double-stranded DNA ( approximately 450-fold). Furthermore, using SYTOX Orange stain, accurate fragment-size-distribution histograms were consistently obtained without regard to the staining dye to base pair (dye/bp) ratio. A model describing two binding modes, intercalation (primary, yielding fluorescence) and external binding (secondary, involving fluorescence quenching), was proposed to interpret the performance of the dyes under different dye/bp ratios. The secondary equilibrium dissociation constant was found to be the most critical parameter in determining the sensitivity of each fluorophore to the staining dye/bp ratio. The measurements of both equilibrium dissociation constants provided us with a theoretical framework for developing a universal protocol which was successfully demonstrated over a wide range of DNA concentrations on a compact flow cytometer equipped with a frequency-doubled, diode-pumped, solid-state Nd:YAG laser for rapid and sensitive DNA fragment sizing.

Phase I and pharmacologic study of sequences of gemcitabine and the multitargeted antifolate agent in patients with advanced solid tumors.

PURPOSE: Multitargeted antifolate (MTA) is an investigational agent that, like gemcitabine, exhibits broad activity in solid tumors. A phase I trial of MTA and gemcitabine was undertaken, based on the demonstration of preclinical cytotoxic synergy. PATIENTS AND METHODS: Thirty-five patients (group I) received 164 courses (median, four; range, one to 14 courses) of treatment of gemcitabine at doses of 1,000 and 1,250 mg/m(2) on days 1 and 8 and MTA at doses of 200, 300, 400, 500, and 600 mg/m(2), given 90 minutes after gemcitabine on day 1. Courses were repeated every 3 weeks. Because the day 8 dose of gemcitabine was reduced or omitted in 57% of courses due to neutropenia, 21 patients (group II) were treated on an alternate schedule, with MTA administered on day 8 rather than day 1. This group received 85 treatment courses (median, four; range, one to 10 courses). RESULTS: The most common and dose-limiting toxicity was neutropenia. Other toxicities included nausea, fatigue, rash, and elevated hepatic transaminases. The maximum-tolerated dose was gemcitabine/MTA 1,000/500 mg/m(2) for group I and 1,250/500 mg/m(2) for group II. Thirteen objective responses were documented (colorectal cancer, n = 3; non-small-cell lung cancer, n = 3; cholangiocarcinoma, n = 2; ovarian carcinoma, n = 2; mesothelioma, n = 1; breast cancer, n = 1; and adenocarcinoma of unknown primary site, n = 1). Gemcitabine had no effect on the disposition of MTA. CONCLUSION: The gemcitabine/MTA combination is broadly active and warrants further evaluation. The sequence of gemcitabine administered on days 1 and 8 with MTA administered on day 8 is better tolerated and is recommended for further study at doses of gemcitabine/MTA 1,250/500 mg/m(2).

Multi-institutional phase I/II trial of paclitaxel, cisplatin, and etoposide with concurrent radiation for limited-stage small-cell lung carcinoma.

PURPOSE: To determine the feasibility of adding paclitaxel to standard cisplatin/etoposide (EP) and thoracic radiotherapy. PATIENTS AND METHODS: Thirty-one patients were enrolled onto this study. During the phase I section of this study, the dose of paclitaxel was escalated in groups of three or more patients. Cycles were repeated every 21 days. For cycles 1 and 2, paclitaxel was administered according to the dose-escalation schema at doses of 100, 135, or 170 mg/m(2) intravenously over 3 hours on day 1. Once the maximum-tolerated dose (MTD) of paclitaxel (for cycles 1 and 2, concurrent with radiation) was determined, that dose was used in all subsequent patients entered onto the phase II section of this study. For cycles 3 and 4, the paclitaxel dose was fixed at 170 mg/m(2) in all patients. On day 2, cisplatin 60 mg/m(2) was administered for all cycles. On days 1, 2, and 3, etoposide 60 mg/m(2)/d (cycles 1 and 2) or 80 mg/m(2)/d (cycles 3 and 4) was administered. Chest radiation was given at 9 Gy/wk in five fractions for 5 weeks beginning on day 1 of cycle 1. Granulocyte colony-stimulating factors were used during cycles 3 and 4 only. RESULTS: Twenty-eight patients were assessable. The MTD of paclitaxel was 135 mg/m(2), with the dose-limiting toxicity being grade 4 neutropenia. Cycles 1 and 2 were associated with grade 4 neutropenia in 32% of courses, with fever occurring in 7% of courses and grade 2/3 esophagitis in 13%. Cycles 3 and 4 were complicated by grade 4 neutropenia in 20% of courses, with fever occurring in 6% of courses and grade 2/3 esophagitis in 16%. The overall response rate was 96% (complete responses, 39%; partial responses, 57%). After a median follow-up period of 23 months (range, 9 to 40 months), the median survival time was 22.3 months (95% confidence interval, 15.1 to 34.3 months) CONCLUSION: The MTD of paclitaxel with radiation and EP treatment is 135 mg/m(2) given over 3 hours. In this schedule of administration, a high response rate and acceptable toxicity can be anticipated.

A randomized phase II trial of two schedules of topotecan for the treatment of advanced stage non-small cell lung cancer.

We conducted a randomized phase II trial of two different schedules of topotecan in patients with advanced-stage non small lung cancer (NSCLC) without prior cytotoxic chemotherapy. All patients had histologic or cytologic confirmation of stage IV (M1) or III-B NSCLC. Patients were stratified by performance status, stage and weight loss. Patients were randomized to receive topotecan at intravenous doses of 1.5 mg/m(2)/day over 30 min for 5 days every 3 weeks (Arm A) or 1.3 mg/m(2)grade 3 in both arms included leukopenia, thrombocytopenia, malaise, constipation, diarrhea, lethargy, pulmonary, vomiting, infection and myalgia. Severe (> or = grade 3) thrombocytopenia occurred in 15.8% of Arm A patients and 37.8% of Arm B patients and this difference was statistically significant (P=0.03). The median times to progression are 101 and 63 days (P=0. 75) and the median survival times are 257 and 179 days (P=0.83) for Arms A and B, respectively. These differences in time to progression and overall survival are not statistically significant. Topotecan has limited, single agent activity in advanced NSCLC when given as 1. 5 mg/m(2)/day over 30 min for 5 days every 3 weeks. We do not intend to pursue further investigations with topotecan in patients with NSCLC.

Nitric oxide synthase, cyclooxygenase 2, and vascular endothelial growth factor in the angiogenesis of non-small cell lung carcinoma.

We have investigated the hypothesis that nitric oxide synthase (NOS2), cyclooxygenase-2 (COX2), and vascular endothelial growth factor (VEGF) protein levels individually demonstrate a direct correlation with microvessel density (MVD) and clinical outcome in human non-small cell lung cancer (NSCLC). Furthermore, we hypothesized that MVD may explain the propensity of certain histological lung cancer subtypes for early metastasis via a hematological route. Immunohistochemically, we studied the protein expression levels of NOS2, COX2, and VEGF and MVD by counting CD31-reactive blood vessels (BVs) in 106 surgically resected NSCLC specimens. NOS2, COX2, and VEGF immunoreactivity were observed in 48, 48, and 58%, respectively, of the study subjects, and their levels correlated with MVD at the tumor-stromal interphase (P < or = 0.001). More adenocarcindmas and large cell carcinomas displayed overexpression of NOS2 when compared with squamous cell carcinoma (SCC; r = 0.44; P < 0.001). NOS2 and COX2 levels were found to correlate positively with VEGF status (r = 0.44; P < 0.001, 0.01, and 0.03, respectively). These results attest to the significant interaction of these factors in the angiogenesis of NSCLC. Although neither angiogenic factors nor MVD correlated with patient survival, the latter correlated with tumor clinical stage in both squamous (SCC; 73 BVs/mm2) and non-SCC (78 BVs/mm2) tumors. These results indicate that angiogenesis is a complex process that involves multiple factors including NOS2, COX2, and VEGF. Furthermore, the role of angiogenesis in the biology of various histological lung cancer types may be different. The complexity of angiogenesis may explain the modest results observed in antiangiogenesis therapy that target a single protein.