Combined Pan-HER and ALK/ROS1/MET Inhibition with Dacomitinib and Crizotinib in Advanced Non-Small Cell Lung Cancer: Results of a Phase I Study.

INTRODUCTION: This phase I study investigated the activity of the irreversible pan-human epidermal growth factor receptor inhibitor dacomitinib in combination with the mesenchymal-epithelial transition factor/anaplastic lymphoma kinase/ROS proto-oncogene 1, receptor tyrosine kinase inhibitor crizotinib in advanced non-small cell lung cancer. METHODS: Patients with progression after at least one line of chemotherapy or targeted therapy received dacomitinib once daily and crizotinib once daily or twice daily, with doses escalated until intolerable toxicity; the expansion cohorts received the maximum tolerated dose of the combination. The primary objective was to define the recommended phase II dose; secondary objectives included assessment of safety and activity of the combination in epidermal growth factor receptor inhibitor-resistant patients and correlation with tumor biomarkers. RESULTS: Seventy patients were treated in the dose-escalation (n = 33) and expansion phases (n = 37), with the maximum tolerated dose defined as dacomitinib, 30 mg once daily, plus crizotinib, 200 mg twice daily. Grade 3 or 4 treatment-related adverse events were reported in 43% of patients: the most common were diarrhea (16%), rash (7%), and fatigue (6%). There were 16 deaths; none were considered treatment related. One patient (1%) had a partial response; 46% had stable disease. Most of the tumor samples analyzed had activating epidermal growth factor receptor gene (EGFR) mutations (18 of 20 [90%]); 50% (10 of 20) had a concurrent resistance mutation. Only one sample showed MMNG HOS Transforming gene (MET) amplification (the patient had progressive disease), whereas 59% (13 of 22) and 47% (14 of 30) had high levels of expression of epidermal growth factor receptor and mesenchymal-epithelial transition factor on the basis of H-scores, respectively. There was no apparent association between biomarker expression and antitumor activity. CONCLUSION: The combination of dacomitinib and crizotinib showed limited antitumor activity in patients with advanced non-small cell lung cancer and was associated with substantial toxicity.

Effect of food or proton pump inhibitor treatment on the bioavailability of dacomitinib in healthy volunteers.

This phase 1, open-label crossover study evaluated the relative bioavailability of dacomitinib in healthy volunteers under fed and fasted conditions and following coadministration with rabeprazole, a potent acid-reducing proton pump inhibitor (PPI). Twenty-four male subjects received a single dacomitinib 45-mg dose under 3 different conditions separated by washout periods of ≥ 16 days: coadministered with rabeprazole 40 mg under fasting conditions; alone under fasting conditions; and alone after a high-fat, high-calorie meal. Increased peak exposure of 23.7% (90% confidence interval [CI], 5.3%-45.2%) was detected with dacomitinib taken after food versus fasting. The adjusted geometric mean ratio (fed/fasted) for area under the plasma concentration-time curve from time zero to infinity (AUCinf ) was 114.2% (90%CI, 104.7%-124.5%) and not considered clinically meaningful. In the fasted state, a decrease in dacomitinib AUCinf was observed following rabeprazole versus dacomitinib alone (PPI+fasted/fasted alone): 71.1% (90%CI, 61.7%-81.8%). Dacomitinib was generally well tolerated. Dacomitinib may be taken with or without food. Use of long-acting acid-reducing agents, such as PPIs with dacomitinib should be avoided if possible. Shorter-acting agents such as antacids and H2-receptor antagonists may have lesser impact on dacomitinib exposure and may be preferable to PPIs if acid reduction is clinically required.

Dacomitinib versus erlotinib in patients with advanced-stage, previously treated non-small-cell lung cancer (ARCHER 1009): a randomised, double-blind, phase 3 trial.

BACKGROUND: Dacomitinib is an irreversible pan-EGFR family tyrosine kinase inhibitor. Findings from a phase 2 study in non-small cell lung cancer showed favourable efficacy for dacomitinib compared with erlotinib. We aimed to compare dacomitinib with erlotinib in a phase 3 study. METHODS: In a randomised, multicentre, double-blind phase 3 trial in 134 centres in 23 countries, we enrolled patients who had locally advanced or metastatic non-small-cell lung cancer, progression after one or two previous regimens of chemotherapy, Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, and presence of measurable disease. We randomly assigned patients in a 1:1 ratio to dacomitinib (45 mg/day) or erlotinib (150 mg/day) with matching placebo. Treatment allocation was masked to the investigator, patient, and study funder. Randomisation was stratified by histology (adenocarcinoma vs non-adenocarcinoma), ethnic origin (Asian vs non-Asian and Indian sub-continent), performance status (0-1 vs 2), and smoking status (never-smoker vs ever-smoker). The coprimary endpoints were progression-free survival per independent review for all randomly assigned patients, and for all randomly assigned patients with KRAS wild-type tumours. The study has completed accrual and is registered with ClinicalTrials.gov, number NCT01360554. FINDINGS: Between June 22, 2011, and March 12, 2013, we enrolled 878 patients and randomly assigned 439 to dacomitinib (256 KRAS wild type) and 439 (263 KRAS wild type) to erlotinib. Median progression-free survival was 2·6 months (95% CI 1·9-2·8) in both the dacomitinib group and the erlotinib group (stratified hazard ratio [HR] 0·941, 95% CI 0·802-1·104, one-sided log-rank p=0·229). For patients with wild-type KRAS, median progression-free survival was 2·6 months for dacomitinib (95% CI 1·9-2·9) and erlotinib (95% CI 1·9-3·0; stratified HR 1·022, 95% CI 0·834-1·253, one-sided p=0·587). In patients who received at least one dose of study drug, the most frequent grade 3-4 adverse events were diarrhoea (47 [11%] patients in the dacomitinib group vs ten [2%] patients in the erlotinib group), rash (29 [7%] vs 12 [3%]), and stomatitis (15 [3%] vs two [<1%]). Serious adverse events were reported in 52 (12%) patients receiving dacomitinib and 40 (9%) patients receiving erlotinib. INTERPRETATION: Irreversible EGFR inhibition with dacomitinib was not superior to erlotinib in an unselected patient population with advanced non-small-cell lung cancer or in patients with KRAS wild-type tumours. Further study of irreversible EGFR inhibitors should be restricted to patients with activating EGFR mutations. FUNDING: Pfizer.

Dacomitinib compared with placebo in pretreated patients with advanced or metastatic non-small-cell lung cancer (NCIC CTG BR.26): a double-blind, randomised, phase 3 trial.

BACKGROUND: Dacomitinib is an irreversible pan-HER tyrosine-kinase inhibitor with preclinical and clinical evidence of activity in non-small-cell lung cancer. We designed BR.26 to assess whether dacomitinib improved overall survival in heavily pretreated patients with this disease. METHODS: In this double-blind, randomised, placebo-controlled, phase 3 trial, we enrolled adults (aged ≥18 years) with advanced or metastatic non-small-cell lung cancer from 75 centres in 12 countries. Eligible patients had received up to three previous lines of chemotherapy and either gefitinib or erlotinib, and had assessable disease (RECIST 1.1) and tumour tissue samples for translational studies. Patients were stratified according to centre, performance status, tobacco use, best response to previous EGFR tyrosine-kinase inhibitor, weight loss within the previous 3 months, and ethnicity, and were then randomly allocated 2:1 to oral dacomitinib 45 mg once-daily or matched placebo centrally via a web-based system. Treatment continued until disease progression or unacceptable toxicity. The primary outcome was overall survival in the intention-to-treat population; secondary outcomes included overall survival in predefined molecular subgroups, progression-free survival, the proportion of patients who achieved an objective response, safety, and quality of life. This study is completed, although follow-up is ongoing for patients on treatment. This study is registered with ClinicalTrials.gov, number NCT01000025. FINDINGS: Between Dec 23, 2009, and June 11, 2013, we randomly assigned 480 patients to dacomitinib and 240 patients to placebo. At the final analysis (January, 2014), median follow-up was 23·4 months (IQR 15·6-29·6) for patients in the dacomitinib group and 24·4 months (11·5-38·9) for those in the placebo group. Dacomitinib did not improve overall survival compared with placebo (median 6·83 months [95% CI 6·08-7·49] for dacomitinib vs 6·31 months [5·32-7·52] for placebo; hazard ratio [HR] 1·00 [95% CI 0·83-1·21]; p=0·506). However, patients in the dacomitinib group had longer progression-free survival than those in the placebo group (median 2·66 months [1·91-3·32] vs 1·38 months [0·99-1·74], respectively; HR 0·66 [95% CI 0·55-0·79]; p<0·0001), and a significantly greater proportion of patients in the dacomitinb group achieved an objective response than in the placebo group (34 [7%] of 480 patients vs three [1%] of 240 patients, respectively; p=0·001). Compared with placebo, the effect of dacomitinib on overall survival seemed similar in patients with EGFR-mutation-positive tumours (HR 0·98, 95% CI 0·67-1·44) and EGFR wild-type tumours (0·93, 0·71-1·21; pinteraction=0·69). However, we noted qualitative differences in the effect of dacomitinib on overall survival for patients with KRAS-mutation-positive tumours (2·10, 1·05-4·22) and patients with KRAS wild-type tumours (0·79, 0·61-1·03; pinteraction=0·08). Compared with placebo, patients allocated dacomitinib had significantly longer time to deterioration of cough (p<0·0001), dyspnoea (p=0·049), and pain (p=0·041). 185 (39%) of 477 patients who received dacomitinib and 86 (36%) of 239 patients who received placebo had serious adverse events. The most common grade 3-4 adverse events were diarrhoea (59 [12%] patients on dacomitinib vs no controls), acneiform rash (48 [10%] vs one [<1%]), oral mucositis (16 [3%] vs none), and fatigue (13 [3%] vs four [2%]). INTERPRETATION: Dacomitinib did not increase overall survival and cannot be recommended for treatment of patients with advanced non-small-cell lung cancer previously treated with chemotherapy and an EGFR tyrosine-kinase inhibitor. FUNDING: Canadian Cancer Society Research Institute and Pfizer.

Dacomitinib as first-line treatment in patients with clinically or molecularly selected advanced non-small-cell lung cancer: a multicentre, open-label, phase 2 trial.

BACKGROUND: Patients with EGFR-mutant non-small-cell lung cancer generally have a progression-free survival of 9-13 months while being treated with the EGFR tyrosine-kinase inhibitors gefitinib or erlotinib. However, resistance inevitably develops, and more effective EGFR inhibitors are needed. Dacomitinib is a covalent pan-HER inhibitor that has shown clinical activity in patients previously treated with gefitinib or erlotinib. We did a trial of dacomitinib as initial systemic therapy in clinically and molecularly selected patients with advanced non-small-cell lung cancer. METHODS: In this open-label, multicentre, phase 2 trial, we enrolled treatment-naive patients with advanced lung cancer who had clinical (never-smokers [<100 cigarettes per lifetime] or former light smokers [<10 pack-years per lifetime] and ≥15 years since last cigarette) or molecular (EGFR mutation, regardless of smoking status) characteristics associated with response to EGFR inhibitors. We gave dacomitinib orally once daily (45 mg or 30 mg) until progressive disease, unacceptable toxicity, or patient withdrawal. We used Response Evaluation Criteria in Solid Tumors criteria (version 1.0) to investigate the activity of dacomitinib in all patients with a baseline scan and at least one post-treatment scan, with investigator assessment of response and progression. The primary endpoint was progression-free survival at 4 months in the as-enrolled population, with a null hypothesis of progression-free survival at 4 months of 50% or less. The study is registered with ClinicalTrials.gov, number NCT00818441, and is no longer accruing patients. FINDINGS: Between March 11, 2009, and April 1, 2011, we enrolled 89 patients from 25 centres, including 45 (51%) with EGFR-activating mutations in exon 19 (n=25) or exon 21 (n=20). Progression-free survival at 4 months was 76·8% (95% CI 66·4-84·4) in the as-enrolled population, and was 95·5% (95% CI 83·2-98·9) in the EGFR-mutant population. The most common all-grade treatment-related adverse events were diarrhoea in 83 (93%) patients, dermatitis acneiform in 69 (78%) patients, dry skin in 39 (44%) patients, and stomatitis in 36 (40%) patients. Two patients (2%) had grade 4 treatment-related events (one with hypokalaemia and one with dyspnoea). No grade 5 toxicities were recorded. INTERPRETATION: Dacomitinib had encouraging clinical activity as initial systemic treatment in clinically or molecularly selected patients with advanced non-small-cell lung cancer. FUNDING: Pfizer.

Phase II study of tirapazamine, cisplatin, and etoposide and concurrent thoracic radiotherapy for limited-stage small-cell lung cancer: SWOG 0222.

PURPOSE: A SWOG pilot study (S0004) showed that tirapazamine (TPZ) when combined with concurrent chemoradiotherapy yielded a promising median survival of 22 months in limited-stage small-cell lung cancer (LSCLC). We report results of the phase II study designed to confirm this result. PATIENTS AND METHODS: The concurrent phase consisted of two cycles of cisplatin, etoposide, and once-daily radiation to 61 Gy. TPZ was given at 260 mg/m(2) on days 1, 29, and at 160 mg/m(2) on days 8, 10, 12, 36, 38, and 40. Consolidation consisted of two cycles of cisplatin and etoposide. Complete responders received prophylactic cranial irradiation. Results were considered promising if the median survival time was at least 21 months and of no further interest if < or = 14 months. RESULTS: S0222 was closed early due to a report of excess toxicity for TPZ in a head and neck cancer trial elsewhere. Of planned 85 patients, 69 were accrued. In 68 assessable patients, 17 (25%) had grade 3 to 4 esophagitis and eight (12%) had grade 3 febrile neutropenia during the concurrent phase. There were three possible treatment-related deaths, two in concurrent phase (one progressive disease not otherwise specified within 30 days, one pericardial effusion) and one in consolidation phase (esophageal hemorrhage). At a median follow-up of 35 months, median progression-free survival was 11 months (95% CI, 10 to 13 months) and median overall survival was 21 months (95% CI, 17 to 33 months). CONCLUSION: S0222 showed acceptable levels of toxicity and similar promising median survival as S0004. Further study of hypoxia-targeted therapy is warranted in LSCLC.

Proteomic analysis of low dose arsenic and ionizing radiation exposure on keratinocytes.

Human exposure to arsenic and ionizing radiation (IR) occur environmentally at low levels. While the human health effects of arsenic and IR have been examined separately, there is little information regarding their combined effects at doses approaching environmental levels. Arsenic toxicity may be affected by concurrent IR especially given their known individual carcinogenic actions at higher doses. We found that keratinocytes responded to either low dose arsenic and/or low dose IR exposure, resulting in differential proteomic expression based on 2-DE, immunoblotting and statistical analysis. Seven proteins were identified that passed a rigorous statistical screen for differential expression in 2-DE and also passed a strict statistical screen for follow-up immunoblotting. These included: alpha-enolase, epidermal-fatty acid binding protein, heat shock protein 27, histidine triad nucleotide-binding protein 1, lactate dehydrogenase A, protein disulfide isomerase precursor, and S100A9. Four proteins had combined effects that were different than would be expected based on the response to either individual toxicant. These data demonstrate a possible reaction to the combined insult that is substantially different from that of either separate treatment. Several proteins had different responses than what has been seen from high dose exposures, adding to the growing literature suggesting that the cellular responses to low dose exposures are distinct.

Assessing probe-specific dye and slide biases in two-color microarray data.

BACKGROUND: A primary reason for using two-color microarrays is that the use of two samples labeled with different dyes on the same slide, that bind to probes on the same spot, is supposed to adjust for many factors that introduce noise and errors into the analysis. Most users assume that any differences between the dyes can be adjusted out by standard methods of normalization, so that measures such as log ratios on the same slide are reliable measures of comparative expression. However, even after the normalization, there are still probe specific dye and slide variation among the data. We define a method to quantify the amount of the dye-by-probe and slide-by-probe interaction. This serves as a diagnostic, both visual and numeric, of the existence of probe-specific dye bias. We show how this improved the performance of two-color array analysis for arrays for genomic analysis of biological samples ranging from rice to human tissue. RESULTS: We develop a procedure for quantifying the extent of probe-specific dye and slide bias in two-color microarrays. The primary output is a graphical diagnostic of the extent of the bias which called ECDF (Empirical Cumulative Distribution Function), though numerical results are also obtained. CONCLUSION: We show that the dye and slide biases were high for human and rice genomic arrays in two gene expression facilities, even after the standard intensity-based normalization, and describe how this diagnostic allowed the problems causing the probe-specific bias to be addressed, and resulted in important improvements in performance. The R package LMGene which contains the method described in this paper has been available to download from Bioconductor.

Transient genome-wide transcriptional response to low-dose ionizing radiation in vivo in humans.

PURPOSE: The in vivo effects of low-dose low linear energy transfer ionizing radiation on healthy human skin are largely unknown. Using a patient-based tissue acquisition protocol, we have performed a series of genomic analyses on the temporal dynamics over a 24-hour period to determine the radiation response after a single exposure of 10 cGy. METHODS AND MATERIALS: RNA from each patient tissue sample was hybridized to an Affymetrix Human Genome U133 Plus 2.0 array. Data analysis was performed on selected gene groups and pathways. RESULTS: Nineteen gene groups and seven gene pathways that had been shown to be radiation responsive were analyzed. Of these, nine gene groups showed significant transient transcriptional changes in the human tissue samples, which returned to baseline by 24 hours postexposure. CONCLUSIONS: Low doses of ionizing radiation on full-thickness human skin produce a definable temporal response out to 24 hours postexposure. Genes involved in DNA and tissue remodeling, cell cycle transition, and inflammation show statistically significant changes in expression, despite variability between patients. These data serve as a reference for the temporal dynamics of ionizing radiation response following low-dose exposure in healthy full-thickness human skin.

A phase II study of paclitaxel, carboplatin, and radiation with or without surgery for esophageal cancer.

BACKGROUND: Cisplatin-based chemoradiotherapy (CRT) has been a standard treatment for patients with locally advanced esophageal cancer. However, cisplatin is associated with significant toxicity. We conducted a phase II clinical trial of concurrent paclitaxel, carboplatin, and radiation with or without surgery as an alternative to the standard cisplatin-based CRT for localized and metastatic esophageal cancer. METHODS: Fifty patients with esophageal cancer were enrolled: 16 patients with stage II, eight patients with stage III, and 26 patients with stage IV disease. Two thirds (67%) of patients had adenocarcinoma and one third (33%) with squamous histology. Patients with resectable disease were treated with paclitaxel 30 mg/m, twice weekly for 10 doses, carboplatin AUC (area under the curve) 1.5 weekly for five doses; and concurrent radiation, 1.8 Gy/day, for a total of 45 Gy, followed by esophagectomy. Without surgery, patients received an additional dose each of paclitaxel and carboplatin with concurrent radiation for a total of 50.4 Gy, followed by two consolidation cycles of paclitaxel (200 mg/m) and carboplatin (AUC 6). RESULTS: During CRT, common stage III/IV toxicities included nausea/emesis (19%), esophagitis (9%), and neutropenia (4%). For consolidation chemotherapy, neutropenia (23%), neuropathy (8%) and nausea/emesis (4%) were the most common stage III/IV side effects. After CRT, 26% had a complete response, 17% had a partial response, and 41% had stable disease. Ninety-one percent of patients had clinical improvement of dysphagia. With a median follow-up of 32 months, the median survival was 12 months for patients with metastatic disease, 44 months for localized disease treated with esophagectomy, and >44 months for localized disease treated with definitive CRT. CONCLUSIONS: The regimen of paclitaxel, carboplatin, and radiation with or without surgery is well tolerated with promising efficacy for patients with esophageal cancer.

Optimized methodology for sequential extraction of RNA and protein from small human skin biopsies.

Current translational human studies are moving in the direction of concurrent genomic and proteomic analysis using small clinical samples. Skin tissue, although easily accessible, is difficult to process owing to its natural resistance to mechanical shearing and high levels of RNases and proteases. Currently, these complications result in degraded RNA samples with variable yield. We have developed a method of sequential extraction of high quality RNA and protein from a single 3 mm full thickness skin punch biopsy. This method yields 1-2 microg of RNA and 150 microg of protein, which is usable in many sensitive downstream applications including microarray, quantitative real-time PCR, two-dimensional gel electrophoresis and Western blot analysis.

Use of benchmark dose-volume histograms for selection of the optimal technique between three-dimensional conformal radiation therapy and intensity-modulated radiation therapy in prostate cancer.

PURPOSE: The aim of this study was to develop and validate our own benchmark dose-volume histograms (DVHs) of bladder and rectum for both conventional three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT), and to evaluate quantitatively the benefits of using IMRT vs. 3D-CRT in treating localized prostate cancer. METHODS AND MATERIALS: During the implementation of IMRT for prostate cancer, our policy was to plan each patient with both 3D-CRT and IMRT. This study included 31 patients with T1b to T2c localized prostate cancer, for whom we completed double-planning using both 3D-CRT and IMRT techniques. The target volumes included prostate, either with or without proximal seminal vesicles. Bladder and rectum DVH data were summarized to obtain an average DVH for each technique and then compared using two-tailed paired t test analysis. RESULTS: For 3D-CRT our bladder doses were as follows: mean 28.8 Gy, v60 16.4%, v70 10.9%; rectal doses were: mean 39.3 Gy, v60 21.8%, v70 13.6%. IMRT plans resulted in similar mean dose values: bladder 26.4 Gy, rectum 34.9 Gy, but lower values of v70 for the bladder (7.8%) and rectum (9.3%). These benchmark DVHs have resulted in a critical evaluation of our 3D-CRT techniques over time. CONCLUSION: Our institution has developed benchmark DVHs for bladder and rectum based on our clinical experience with 3D-CRT and IMRT. We use these standards as well as differences in individual cases to make decisions on whether patients may benefit from IMRT treatment rather than 3D-CRT.

Human in vivo dose-response to controlled, low-dose low linear energy transfer ionizing radiation exposure.

PURPOSE: The effect of low doses of low-linear energy transfer (photon) ionizing radiation (LDIR, <10 cGy) on human tissue when exposure is under normal physiologic conditions is of significant interest to the medical and scientific community in therapeutic and other contexts. Although, to date, there has been no direct assessment of the response of human tissue to LDIR when exposure is under normal physiologic conditions of intact three-dimensional architecture, vasculature, and cell-cell contacts (between epithelial cells and between epithelial and stromal cells). EXPERIMENTAL DESIGN: In this article, we present the first data on the response of human tissue exposed in vivo to LDIR with precisely controlled and calibrated doses. We evaluated transcriptomic responses to a single exposure of LDIR in the normal skin of men undergoing therapeutic radiation for prostate cancer (research protocol, Health Insurance Portability and Accountability Act-compliant, Institutional Review Board-approved). Using newly developed biostatistical tools that account for individual splice variants and the expected variability of temporal response between humans even when the outcome is measured at a single time, we show a dose-response pattern in gene expression in a number of pathways and gene groups that are biologically plausible responses to LDIR. RESULTS: Examining genes and pathways identified as radiation-responsive in cell culture models, we found seven gene groups and five pathways that were altered in men in this experiment. These included the Akt/phosphoinositide-3-kinase pathway, the growth factor pathway, the stress/apoptosis pathway, and the pathway initiated by transforming growth factor-beta signaling, whereas gene groups with altered expression included the keratins, the zinc finger proteins and signaling molecules in the mitogen-activated protein kinase gene group. We show that there is considerable individual variability in radiation response that makes the detection of effects difficult, but still feasible when analyzed according to gene group and pathway. CONCLUSIONS: These results show for the first time that low doses of radiation have an identifiable biosignature in human tissue, irradiated in vivo with normal intact three-dimensional architecture, vascular supply, and innervation. The genes and pathways show that the tissue (a) does detect the injury, (b) initiates a stress/inflammatory response, (c) undergoes DNA remodeling, as suggested by the significant increase in zinc finger protein gene expression, and (d) initiates a "pro-survival" response. The ability to detect a distinct radiation response pattern following LDIR exposure has important implications for risk assessment in both therapeutic and national defense contexts.

Dosimetry for quantitative analysis of the effects of low-dose ionizing radiation in radiation therapy patients.

We have developed and validated a practical approach to identifying the location on the skin surface that will receive a prespecified biopsy dose (ranging down to 1 cGy) in support of in vivo biological dosimetry in humans. This represents a significant technical challenge since the sites lie on the patient's surface outside the radiation fields. The PEREGRINE Monte Carlo simulation system was used to model radiation dose delivery, and TLDs were used for validation on phantoms and for confirmation during patient treatment. In the developmental studies, the Monte Carlo simulations consistently underestimated the dose at the biopsy site by approximately 15% (of the local dose) for a realistic treatment configuration, most likely due to lack of detail in the simulation of the linear accelerator outside the main beam line. Using a single, thickness-independent correction factor for the clinical calculations, the average of 36 measurements for the predicted 1-cGy point was 0.985 cGy (standard deviation: 0.110 cGy) despite patient breathing motion and other real-world challenges. Since the 10-cGy point is situated in the region of high-dose gradient at the edge of the field, patient motion had a greater effect, and the six measured points averaged 5.90 cGy (standard deviation: 1.01 cGy), a difference that is equivalent to approximately a 6-mm shift on the patient's surface.

A method for detection of differential gene expression in the presence of inter-individual variability in response.

MOTIVATION: Many stimuli to biological systems result in transcriptional responses that vary across the individual organism either in type or in timing. This creates substantial difficulties in detecting these responses. This is especially the case when the data for any one individual are limited and when the number of genes, probes or probe sets is large. RESULTS: We have developed a procedure that allows for sensitive detection of transcriptional responses that differ between individuals in type or in timing. This consists of four steps: one is to identify a group of genes, probes or probe sets that detect genes that belong to a molecular class or to a common pathway. The second is to conduct a statistical test of the hypothesis that the gene is differentially expressed for each individual and for each gene in the set. The third is to examine the collection of these statistics to see if there is a detectable signal in the aggregate of them. The final step is to assess the significance of this by resampling to avoid correlational bias. AVAILABILITY: Software in the form of R code to perform the required test is available from the first author or from his website http://www.idav.ucdavis.edu/~dmrocke/software; however the procedures are also easily performed using any standard statistical software.

Integration of novel therapeutics into combined modality therapy of locally advanced non-small cell lung cancer.

Novel therapeutic agents (NTA) directed against a wide array of newly described molecular targets are now entering clinical investigation, many in the treatment of non-small cell lung cancer (NSCLC). The great majority of these clinical trials have been directed toward patients with advanced stage (metastatic) disease. More recently, study of NTAs has turned toward earlier-stage disease. Locally advanced, or stage III, NSCLC represents a large and heterogeneous group of patients and several clinically distinct substages. During the last 15 years, randomized clinical trials have shown improved survival with sequential chemoradiation compared with radiation alone and, more recently, the superiority of concurrent versus sequential chemoradiation. As NTAs have increasingly shown clinical activity against NSCLC, questions of how to incorporate them into clinical trials in stage III disease, whether they should be given together with radiotherapy, substituting for chemotherapy, or whether they should be added to current chemoradiation strategies, all remain as issues. Here, we describe conceptual issues, preclinical rationale, and ongoing or planned clinical trials incorporating NTAs into current treatment paradigms for unresectable stage III NSCLC.

Enhancement of radiation cytotoxicity by UCN-01 in non-small cell lung carcinoma cells.

Thoracic ionizing radiation is a standard component of combined-modality therapy for locally advanced non-small cell lung cancer. To improve low 5-year survival rates (5- 15%), new strategies for enhancing the effectiveness of ionizing radiation are needed. The kinase inhibitor UCN-01 has multiple cell cycle effects, including abrogation of DNA damage-induced S- and G(2)-phase arrest, which may limit DNA repair prior to mitosis. To test the hypothesis that therapy-induced cell cycle effects would have an impact on the efficacy of a combination of UCN-01 plus ionizing radiation, the cell cycle responses of the non-small cell lung cancer cell lines Calu1 (TP53-null) and A549 (wild-type TP53) to 2 Gy ionizing radiation were correlated with clonogenic survival after irradiation plus UCN-01. Irradiated cells were exposed to UCN-01 simultaneously and at 3-h increments after irradiation. In Calu1 cells but not A549 cells, sequence-dependent potentiation of radiation by UCN-01 was observed, with maximal interaction occurring when UCN-01 was administered 6 h after irradiation. This coincided with the postirradiation time with the greatest depletion of cells from G(1). Abrogation of G(2) arrest was observed regardless of TP53 status. The role of TP53 was investigated using siRNA to achieve gene silencing. These studies demonstrated that radiation plus UCN-01 was more effective in cells with diminished TP53 activity, associated with a reduced G(1) checkpoint arrest. These studies indicate that simultaneous elimination of multiple DNA damage-induced checkpoints in G(1), S and G(2) may enhance the effects of radiation and that drug scheduling may have an impact on clinical efficacy.

Analysis of treatment for small cell cancer of the bladder and report of three cases.

OBJECTIVES: To present our experience with 3 patients with small cell cancer (SCC) of the bladder who were treated with different modalities and review the literature for patients undergoing primary chemoradiotherapy. SCC of the bladder is a rare tumor, with patients commonly presenting with metastatic disease. Surgery, radiotherapy, and chemotherapy, either alone or as part of combined therapy, have been used. Because of the rarity of this disease, no prospective studies evaluating the most effective treatment have been done. METHODS: The medical records of 3 patients diagnosed with SCC of the bladder at our institution were reviewed. Additionally, we reviewed published reports to identify all cases of SCC of the bladder treated with primary chemoradiotherapy. RESULTS: Three patients with SCC of the bladder were identified at our institution. A total of 23 patients with SCC of the bladder who were treated with primary chemoradiotherapy were identified: 22 in published reports and 1 at our institution. Patients presented with muscle-invasive disease (17%), extravesical disease only (26%), and metastatic disease (52%). Multiagent chemotherapy was administered to most patients. The reported median radiation dose was 6000 cGy. A total of 16 patients (70%) were alive at a median follow-up of 34 months. The median survival of patients had not yet been reached in this study at the last follow-up. We did not find any reports of SCC recurrence in the bladder, and the bladder was preserved in most patients (87%). CONCLUSIONS: SCC of the bladder should be viewed as a systemic disease, because most patients present with metastatic disease. Primary chemoradiotherapy appears to be an effective treatment modality. Prospective studies are needed to evaluate the optimal treatment further.

Radiation phantom with humanoid shape and adjustable thickness (RPHAT).

A new radiation phantom with humanoid shape and adjustable thickness (RPHAT) has been developed. Unlike the RANDO phantom which is a fixed thickness, this newly designed phantom has adjustable thickness to address the range of thicknesses of real-world patients. RPHAT allows adjustment of the body thickness by being sliced in the coronal (instead of axial) direction. Centre slices are designed so that more sections can be added or removed while maintaining the anthropomorphic shape. A prototype of the new phantom has been successfully used in a study investigating peripheral dose delivery, where the amount of scatter within the patient, and therefore the patient thickness, plays a critical role in dose deposition. This newly designed phantom is an important tool to improve the quality of radiation therapy.

Survival and cell cycle kinetics of human prostate cancer cell lines after single- and multifraction exposures to ionizing radiation.

PURPOSE: Fractionated radiation therapy is frequently used to treat prostate cancer with an underlying assumption that each daily dose of ionizing radiation (IR) results in equal cell killing. We used three human prostate cancer cell lines to evaluate how survival after a single 2-Gy dose may predict responses after daily repeated 2-Gy exposures. METHODS AND MATERIALS: LNCaP, CWR22R, and PC3 cells were used in these studies. Survival after IR exposures was assessed using clonogenic assays and cell cycle responses were determined by flow cytometry. RESULTS: The experimentally determined multifraction survival differed significantly from that predicted from their single-dose SF2. LNCaP and CWR22R cells showed lower than predicted survivals; PC3 cells exhibited greater than predicted survival. Daily IR exposures resulted in changes in the cell cycle distributions beyond those caused by a single exposure to IR. CONCLUSIONS: Our results show that in these prostate cancer cells: (1) survival after a clinically relevant dose of IR does not predict survival after multifraction IR, (2) cell cycle responses after a single 2 Gy dose can differ from those that occur when cells receive daily 2 Gy doses, and (3) some cell cycle changes that result from fractionated IR may predict their ultimate survival responses from such treatment.