Plasma Immersion Ion Implantation for Impurity Gettering in Silicon

We have utilized plasma immersion ion implantation (PIII) to demonstrate effective gettering of metallic impurities in silicon wafers. Metallic impurities such as Ni, Cu or Au were intentionally diffused into Si as marker impurities. The Ar or Ne atoms were ionized in an electron cyclotron resonance (ECR) plasma chamber. The ions were accelerated by a negative voltage applied to the wafer and implanted into the wafer. The as-implanted saturation dose can be as high as 5×1016cm−2. After an annealing step at 1000°C for 1 hour in a N2 ambient, the retained doses and the amount of gettered impurities were measured with Rutherford backscattering spectrometry (RBS). With a retained Ar dose in 1015cm−2 range after annealing, the gettered Ni, Cu and Au were 3.0×1014cm−2, 3.0×1014cm−2 and 4.4×1013cm−2 respectively.

Platinum-based adjuvant chemotherapy for early-stage epithelial ovarian cancer: single or combination chemotherapy?

OBJECTIVE

To evaluate the clinical benefit and toxicity of two regimens; single agent carboplatin (C) and a carboplatin/paclitaxel (CP) combination in early epithelial ovarian cancer.

DESIGN

A retrospective review.

SETTING

Single cancer centre serving a population of 2.1 million in the northwest of England.

POPULATION

All women treated with adjuvant chemotherapy for International Federation of Obstetrics and Gynecology stage Ia-IIc ovarian cancer between 2002 and 2005.

METHODS

Case and operation notes were reviewed. Details of the surgery performed, performance status (PS), tumour histology, stage, grade, intended chemotherapy, chemotherapy received, acute and late toxicity, relapse and death were all recorded.

MAIN OUTCOME MEASURES

Overall survival (OS), relapse-free survival (RFS), acute and late toxicity.

RESULTS

Sixty women received CP and 35 received C. Younger women (P < 0.0001) and those with a better performance status (P = 0.045) were more likely to receive CP. Median follow- up was 38 months (range 0-70). Five-year OS was 62% (95% CI 44-81%) for C and 73% (95% CI 61-85%) for CP P= = 0.316. For the subgroup with stage I disease and good PS (0/1) 5-year OS was 80% (59-100%) for C and 79% (63-95%) for CP; P = 1.0. For those with stage 2 disease, 5-year OS was 29% (95% CI 0-62%) for C and 63% (95% CI 44-82%) for CP; P = 0.025. Subgroup analyses by grade or histology showed no difference in OS. P was discontinued prematurely in nine (15%) women on account of toxicity, whereas C was not stopped early. P-related neuropathy (G1/2) was reported in ten (17%) women at 6 months and in two (3%) at 1 year.

CONCLUSIONS

Combination therapy is administered more often than carboplatin; especially in those with younger age, better PS and nonmucinous histology. Recurrence and death rates were similar with both treatments. Well-designed trials are needed to identify the optimum chemotherapy regimen in this group.

Growth of dielectric-embedded silicon nanocrystallites for light-emitting device application

Dielectric films with embedded silicon Si nanocrystallites (Si-Nc) have been recognized as promising light-emitting materials for future integrated photonics based on silicon technology. This work reports a novel method of making this kind of material by high-temperature annealing of Si-rich oxide or nitride films which gives rise to the phase separation reaction and the formation of crystalline silicon nanoclusters in the films. Various characteristics of these materials were studied in detail by using transmission electron microscope, X-ray photoelectron spectroscopy (XPS), Raman, and photoluminescence (PL). Strong transverse optical (TO) mode of Si-Nc at around 516 cm(-1) was found in the Raman spectra of the annealed dielectric films. XPS studies indicate that the Si 2p spectra could be transformed from a random bonding structure (as-deposited) to a random mixing of Si-Nc with stoichiometric oxide or nitride phase after the high-temperature annealing. The energy locations of PL were found to depend on the amount of rich Si and the annealing conditions. Longer and higher temperature annealing can result in the growth of the Si-Nc size and leads to a red-shift of PL. Direct correlation among the crystallite sizes with the PL peaks was found.

Can increasing the dose of radiation by HDR brachytherapy boost following pre operative chemoradiotherapy for advanced rectal cancer improve surgical outcomes?

AIM

Preoperative radiotherapy has been shown to improve local control in advanced rectal carcinoma compared with surgery alone. Several large randomized trials have confirmed that chemoradiotherapy (CRT) is better than radiotherapy alone. This pilot study was designed to increase the radiation dose using high-dose rate (HDR) brachytherapy boost following preoperative CRT to evaluate whether this strategy improves the outcome of surgery without increase in toxicity.

METHOD

Since October 2004, we have used the new rectal HDR applicator for brachytherapy boost in 68 patients following CRT. The patients had CT and MRI Scans as part of staging. All had locally advanced disease either bulky low T2 or T3 with threatened circumferential resection margin and multiple suspicious lymph nodes. They were offered preoperative CRT either by 5-FU infusion 1 g/m(2) day 1-4 (week 1 + 5) or by oral capecitabine 825 mg/m(2) Monday-Friday for 5 weeks together with CT planned external beam RT 45Gy in 25 fractions over 5 weeks (CRT). Those downstage on repeat MRI scan were offered additional HDR Boost 10Gy directly to the tumour followed by surgery 6-8 weeks later [group A]. Four patients proceeded directly to surgery but because of involved resection margin had a HDR brachytherapy boost as postoperative treatment [group B]. Thirty patients were not planned for immediate surgery after CRT and brachytherapy boost, as they were either elderly or considered high risk for anaesthesia [group C].

RESULTS

There were 34 patients (median age 67 (range 39-81) years in group A, including 24 men). The PS was 0-1. The clinical stage at presentation was cT2 in five, cT3 in 23 and T4 in six patients and cN0 in 2, cN1 in 21 and N2 in 11. Thirty-three patients had CRT, and one had radiotherapy alone. All patients completed treatment without interruption. Twenty-nine patients had surgery following CRT and brachytherapy boost including anterior resection in 10 patients, Abdominoperineal excision (APR) in 18 and Hartmann's resection in one. Five patients did not have the intended surgery. Twenty-four (83%) patients had an RO resection compared with 63% having conventional preoperative CRT using bolus 5FU regimes. Pathological complete remission (pCR) was achieved in 9 (31%) compared with 12% patients having conventional CRT. There was no increase in G 3-4 toxicity from RT and no delay in wound healing or increase in anastomotic leakage. One of the four patients in group B developed local recurrence. The thirty patients in group C who had modified radical CRT followed by brachytherapy boost as a definitive treatment will be reported in a further communication.

CONCLUSION

Increasing the dose of radiation by HDR brachytherapy boost appears to improve the RO resection and pCR rates compared with conventional CRT. The follow up is too short to judge its effect on disease-free survival. This study will be extended to compare this strategy in a randomized phase III trial with conventional CRT in patients who are not fit for more intensive CRT (HERCULES).

Preoperative chemoradiotherapy for rectal cancer: a comparison between intravenous 5-fluorouracil and oral capecitabine

INTRODUCTION

Capecitabine provides an attractive alternative to intravenous (IV) 5-flourouracil (5-FU) in chemoradiation regimes for rectal cancer by avoiding the need for intravenous access and inpatient stay. We aimed to compare retrospectively the efficacy of concurrent capecitabine with IV 5-FU in preoperative pelvic chemoradiation schedules for rectal cancer in our centre.

METHOD

Patients treated from January 2005 to June 2007 were included. Information was collected on patient characteristics; treatment details; pathological response to treatment; recurrence and survival. All statistical analyses were performed using SPSS V17.

RESULTS

All patients had pelvic radiation. Ninety-nine patients were treated with capecitabine and 97 with 5-FU. The two groups were well matched for age, sex and TNM stage. There were significantly more PS (performance status) 0 patients in the capecitabine group (51%vs 30%) (P = 0.001). Of the 99 patients in the capecitabine group, 91 (92%) were able to undergo surgery with 84 (93%) achieving R0 resection. In the 5-FU group, these proportions were 87 (90%) and 70 (80%). The difference in the rate of R0 resection was statistically significant (P = 0.024). The APR rate was 35% in the capecitabine group compared with 47% in the 5-FU group (P = 0.06). There was no significant difference in pathological complete response (pCR) rates between capecitabine (14%) and 5-FU(12%). A higher pCR rate (30%) was observed in patients who underwent a brachytherapy boost (P = 0.051). There were three local recurrences in the whole patient group, (capecitabine 1; 5-FU 2). Thirty-five patients had distant metastases, 14 in the capecitabine and 21 in the 5-FU group. There was no significant difference in the risk of recurrence between the two groups. Six patients in each group had grade 3 toxicity with diarrhoea being more common with capecitabine.

CONCLUSIONS

Preoperative chemoradiotherapy with capecitabine for rectal cancer is efficacious and comparable to 5-FU (IV). It is more convenient, is well tolerated and avoids the need for inpatient admission.

Novel Stably Transplantable Xenograft Models of Human Breast Cancer for Evaluation of Experimental Therapeutics

In translational breast cancer research, our ability to evaluate clinical responses of human tumors to new therapeutic agents is severely limited experimentally. For example, it is not possible to evaluate the response of a single tumor to multiple candidate therapeutic agents. Conversely, the limited number of well-characterized in vivo preclinical human tumor models currently available precludes evaluation of multiple clinically relevant tumors with candidate therapeutic agents. These limitations severely impinge on our ability to develop and test novel therapeutic agents, particularly those that may target tumor-initiating “cancer stem cells”, which are relatively resistant to chemotherapy and radiation and may be responsible for disease recurrence and metastases.Historically, in vivo experimental therapeutic research has relied on either genetically engineered animal models, or “xenograft” transplantation models in which established human cancer cell lines are transplanted into immunocompromised host mice. However, each type of model has significant limitations. We sought to circumvent some of these limitations by propagating a cohort of human tumors as stably transplantable xenograft tissue lines grown in the absence of engineered or immortalized fibroblasts by transplanting clinical biopsies directly into the mammary fat pad of SCID/Beige immunocompromised mice (lacking B-cell, T-cell, and NK cell function) without intervening culture in vitro.Thus far, we have established 13 independent stably transplantable xenograft lines representing nine “triple-negative” (ER-PR-HER2-), two HER2+, and two ER+ breast cancers. Established xenograft lines show phenotypic similarity to the primary tumor with respect to histology and gene expression. Xenografts are being characterized genetically by whole genome sequencing as well as for the diversity of tumor-initiating cell types present. These models are proving useful for the evaluation of experimental therapeutics for their ability to inhibit tumor growth, and for their ability to target the subset cancer cells capable of regenerating tumors upon transplantation, with the goals of overcoming chemoresistance, preventing disease recurrence, and eliminating metastases.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1159.

A BRCA1-Like, 25-Gene Assay Predicts for Anthracycline-Chemosensitivity in Sporadic Triple-Negative Breast Cancer

Background Studies have shown higher chemosensitivity to anthracyclines in BRCA1-associated breast cancer (BABC) when compared to sporadic triple-negative breast cancers (TNBC), possibly due to differences in DNA repair function. We hypothesized that a subset of TNBC with acquired BRCA1 deficiency and defective DNA repair function will benefit most from DNA-damaging agents, such as anthracyclines. Methods We applied a previously published BRCA1 gene expression signature that differentiates BABC from sporadic TNBC to three datasets of sporadic TNBC from Baylor College of Medicine (BCM, n=68), GSE2034 (n=49), and the Netherlands Cancer Institute (NKI2, n=40). The signature separated the sporadic TNBC samples into those with a gene expression profile similar to BABC, or BRCA1-like, versus those with an expression pattern similar to sporadic TNBC, nonBRCA1-like. A list of 92 genes was obtained from the overlap of the most differentially expressed genes between the BRCA1-like samples and nonBRCA1-like samples in each of the three datasets. We then confirmed a subset of the 25 most differentially expressed genes by quantitative RTPCR. We validated the predictive value of this BRCA1-based, 25-gene assay in anthracycline response in three neoadjuvant studies of fluorouracil, epirubicin, and cyclophosphamide (FEC 6 cycles, n=53), doxorubicin and cyclophosphamide (AC 4 cycles, n=12), and T-FAC (paclitaxel-FAC, n=16). Results We determined gene expression of the 92 candidate genes by RT-PCR on 30 available samples of the BCM database. 25 genes were found to have the highest correlation between the microarray and RTQPCR gene expression. Gene expression profile using these 25-gene assay was obtained for three databases which included neoadjuvant anthracycline response data. The 25-gene assay predicted for anthracycline response in sporadic triple-negative breast cancers. In a neoadjuvant FEC study, this assay predicted for pathologic complete response (pCR) in 14/25 patients with BRCA1-like pattern, vs. 7/25 with sporadic-like pattern, p&lt;0.05. In the AC study, 6/9 patients in the BRCA1-like group achieved pCR, vs. 0/3 in nonBRCA1-like group, p&lt;0.05. Finally, in the T-FAC study, 5/7 patients in the BRCA1-like group achieved pCR vs. 3/9 patients in the nonBRCA1-like group, p=0.15. Analysis of the microarray data of triple negative breast cancer revealed higher PARP1 expression levels in the BRCA1-like group when compared to nonBRCA1-like group. Conclusion We present a promising BRCA1-based 25-gene assay that can be used on formalin-fixed paraffin-embedded tissue that may guide therapy in triple- negative breast cancer. The assay differentiates TNBC that are very sensitive to anthracyclines, and it should now be tested and validated prospectively in clinical trials with anthracyclines, other DNA-damaging agents, and PARP1 inhibitors.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 110.

Comparative Analysis of Breast Cancer (BrCa) Mortality Reduction among Regions of Canada between 1950 – 2004: Impact of Systemic and Diagnostic Guidelines after 1977, with Model Definition of Number of Potentially Avoided Annual Deaths (N-PAAD)

BACKGROUNDWe reported in the past the BrCa mortality trends in three Provinces of Canada with different Levels of Provincial Diagnostic and Therapy Guideline (ProvDgThGuide) implementation, reflecting access to optimum cancer care (LEVEL I, most uniform: British Columbia (B.C.); LEVEL II, medium: Ontario(ON); LEVEL III, least uniform (Atlantic Provinces AP), and have shown best outcomes in B.C. (Cancer Res 2009 69[S] 2:383).OBJECTIVETo estimate the number of BrCa deaths that potentially could have been avoided during the period 1978 – 2004 if the ProvDgThGuide Level I (i.e. of B.C.) had been implemented in Canada, Ontario and Atlantic Provinces, respectively.METHODSData were obtained from Statistics Canada.i. For each region, we calculated the average annual age-standardized mortality rate / 100,000 (aveASR) for the periods 1950-1977 (R1) and 1978-2004 (R2).ii. Subsequently, calculated was the Relative Change (RC, expressed in %) in mortality rate between the two time periods (RC = (R2-R1)/R1).iii. And for each region, the 1978 – 2004 expected rates (RE) based on RC from B.C. [i.e. calculated as "-13.8%" [(RE = 1- 0138) x R1].iv. These steps permitted estimates of Number of potentially avoided [annual] deaths (N-PAAD), based on the difference in observed mortality during the 1978-2004 period and the mortality that would have occurred if the regions had experienced the same relative change in mortality rate as observed in B.C. (R2-RE x # at risk).RESULTS R1(aveASR 1950-1977)R2(aveASR 1978-2004)RCREN-PAAD(N-AveAnnDeaths)BC30.025.8-13.8%----Ontario30.929.2-5.3%26.6137Atlantic27.528.8+4.7%23.760Canadaexcluding BC30.729.0-5.5%26.5315CONCLUSIONThis study confirms in most but not all regions of Canada a substantial mortality reduction after 1977, suggestive that implementation of optimum levels of Provincial Diagnostic and Therapy Guidelines (optimum access to cancer care) may affect mortality, and that their delay may prevent materialization of survival gains.Once the average annual rates of B.C. was applied to the rates of rest of Canada, the newly developed "Potentially Avoided Annual Deaths" model estimates over 8,000 avoided BrCa deaths in Canada (without B.C.) during the period 1978 – 2004 (26 [years] x 315).The model estimates over 3,500 (26 x 137) and 1500 (26 x 60) avoided deaths, respectively, for Ontario and Atlantic Provinces.These data are relevant to all world regions with differing access to optimum cancer care.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2063.

Results of an exercise to estimate the costs of interpersonal violence in Jamaica

This report describes the application of a draft version of the World Health Organization (WHO)/ United States Centers for Disease Control and Prevention (CDC) Manual for estimating the economic costs of injuries due to interpersonal and self-directed violence to measure costs of injuries from interpersonal violence.

METHODS

Fatal incidence data was obtained from the Jamaica Constabulary Force. The incidence of nonfatal violence-related injuries that required hospitalization was estimated using data obtained from patients treated at and/or admitted to three Type A government hospitals in 2006.

RESULTS

During 2006, direct medical cost (J$2.1 billion) of injuries due to interpersonal violence accounted for about 12% of Jamaica's total health budget while productivity losses due to violence-related injuries accounted for approximately J$27.5 billion or 160% of Jamaica's total health expenditure and 4% of Jamaica's Gross Domestic Product.

CONCLUSIONS

The availability of accurate and reliable data of the highest quality from health-related information systems is critical for providing useful data on the burden of violence and injury to decision-makers. As Ministries of Health take a leading role in violence and injury prevention, data collection and information systems must have a central role. This study describes the results of one approach to examining the economic burden of interpersonal violence in developing countries where the burden of violence is heaviest. The WHO-CDC manual also tested in Thailand and Brazil is a first step towards generating a reference point for resource allocation, priority setting and prevention advocacy.

Concurrent hypofractionated chemoradiation (CRT) for head and neck squamous cancer with weekly cisplatin: A Lancashire experience

e17052

Background: Concurrent chemoradiation with intravenous cisplatin is the standard treatment for locally advanced head and neck cancer. We evaluated the use of hypofractionated radiotherapy and weekly concomitant cisplatin in our center. Methods: We retrospectively analysed 37 patients treated at our centre from August 2005 to November 2007. They received weekly concurrent chemoradiation with cisplatin 30 mg/m2 with radiotherapy 65Gy in 30 fractions. We analysed tumour sites, changes in weight as an indirect measure of nutritional status, calculated creatinine clearance to assess nephrotoxicity, sites of recurrence, progression free survival and overall survival. The minimum follow up was 6 months. Results: Our study population comprised of 61% of T4 disease while 25% of our patients had T3 disease. Nearly a third of our patients underwent radical neck dissection prior to concurrent chemoradiation. We found that 80% of our patients had completed the full course of concurrent chemoradiation. More than 50% of patients had oropharyngeal cancer while 25% hypopharyngeal cancer. Majority of patients lost weight during treatment. The mean weight loss was 3.56 kilograms, despite 90% having had prophylactic enteral feeding tubes. Eleven patients maintained their weight while on treatment. There were 11 recurrences: 5 were at the primary site, 4 had distant metastasis, 1 had combination of primary site and nodal drainage and 1 patient had only nodal relapse. Lung was the most common site of distant metastasis amongst the 4 patients. While a proportion of patients had a fall in creatinine clearance, the values did not drop below the accepted 50 mL/min.Two-year progression free survival was 68% and overall survival at 24 months was 68.7%. Conclusions: Weekly intravenous cisplatin when combined with radiotherapy 65Gy in 30 fractions was effective in treating head and neck cancer. The nephrotoxicity was within acceptable limits. Many patients lost weight with this treatment despite having prophylactic enteral feeding tubes. Our survival figures were encouraging and similar to other reports in the literature.

No significant financial relationships to disclose.

Phase I clinical experience of a targeted TCR-IL2 fusion protein in patients with metastatic malignancies

3040

Background: ALT-801 is recombinant human interleukin-2 (IL-2) genetically fused to a single-chain T-cell receptor specific to a peptide antigen of human p53 presented in the context of HLA-A2 positivity. In tumor xenografts in animal models, this fusion protein demonstrated potent and targeted antitumor activity. Methods: A phase I/IIa multicenter clinical study was initiated to assess safety and clinical response of ALT-801 in patients with various metastatic malignancies. Patients screened positively for HLA-A2 and tumors expressed p53 peptide/HLA-A2 complex. In this dose escalation trial, patients received ALT-801 as a daily intravenous infusion for 4 days followed by a 10-day rest period and 4 additional daily doses. Results: Data from three dosing cohorts (0.015, 0.04, and 0.08 mg/kg/dose) indicate that ALT-801 is well-tolerated up to 0.04 mg/kg/dose. The half-life of ALT-801 is 2.5–4 hours per pharmacokinetic analysis, depending on the dose. Even at the 0.015 mg/kg level, there were sufficient concentrations of ALT-801 in the patients’ serum to fully activate cell lytic activity in vitro. Treatment with ALT-801 also led to immune activation in patients as demonstrated by elevated serum IFN-γ levels as well as an increase in IFN-γ-producing immune cells in patients’ blood. Interestingly, serum TNF-α, a major inducer of hypotension in patients receiving high-dose IL-2 treatment, was not induced in patients receiving ALT-801. Evidence of antitumor activity (i.e., stable disease, tumor shrinkage) was observed in some patients after one or two courses of ALT-801. Conclusions: At a dose of 0.04 mg/kg, ALT-801 is a well-tolerated agent that generated a vigorous immune response and demonstrated clinical efficacy in a group of patients with various metastatic malignancies. An expansion cohort of patients is in progress at 0.04 mg/kg.

[Table: see text]