Dual-Dewetting Process for Self-Assembled Nanoparticle Clusters in Wafer Scale

Plasmonic molecules, which are geometrically well-defined plasmonic metal nanoparticle clusters, have attracted significant attention due to their enhancement of light-matter interactions owing to a stronger electric field enhancement than that by single particles. High-resolution lithography techniques provide precise positioning of plasmonic nanoparticles, but their fabrication costs are excessively high. In this study, we propose a lithography-free, self-assembly fabrication method, termed the dual-dewetting process, which allows the control of the size and density of gold nanoparticles. This process involves depositing a gold thin film on a substrate and inducing dewetting through thermal annealing, followed by a second deposition and annealing. The method achieves a uniform distribution of particle size and density, along with increased particle density, across a 6-inch wafer. The superiority of the method is confirmed by a 30-fold increase in the signal intensity of surface-enhanced Raman scattering following the additional dewetting with an 8 nm film, compared to single dewetting alone. Our findings indicate that the dual-dewetting method provides a simple and efficient approach to enable a variety of plasmonic applications through efficient plasmonic molecule large-area fabrication.

Understanding the Role of M13 Bacteriophage Thin Films on a Metallic Nanostructure through a Standard and Dynamic Model

The dynamic and surface manipulation of the M13 bacteriophage via the meeting application demands the creation of a pathway to design efficient applications with high selectivity and responsivity rates. Here, we report the role of the M13 bacteriophage thin film layer that is deposited on an optical nanostructure involving gold nanoparticles/SiO₂/Si, as well as its influence on optical and geometrical properties. The thickness of the M13 bacteriophage layer was controlled by varying either the concentration or humidity exposure levels, and optical studies were conducted. We designed a standard and dynamic model based upon three-dimensional finite-difference time-domain (3D FDTD) simulations that distinguished the respective necessity of each model under variable conditions. As seen in the experiments, the origin of respective peak wavelength positions was addressed in detail with the help of simulations. The importance of the dynamic model was noted when humidity-based experiments were conducted. Upon introducing varied humidity levels, the dynamic model predicted changes in plasmonic properties as a function of changes in NP positioning, gap size, and effective index (this approach agreed with the experiments and simulated results). We believe that this work will provide fundamental insight into understanding and interpreting the geometrical and optical properties of the nanostructures that involve the M13 bacteriophage. By combining such significant plasmonic properties with the numerous benefits of M13 bacteriophage (like low-cost fabrication, multi-wavelength optical characteristics devised from a single structure, reproducibility, reversible characteristics, and surface modification to suit application requirements), it is possible to develop highly efficient integrated plasmonic biomaterial-based sensor nanostructures.

Single Nucleotide Polymorphism (SNP) in RASSF1 and Clinical Outcomes of Breast Cancer Patients Treated with Neoadjuvant Docetaxel/Doxorubicin Chemotherapy

PurposeThe tumor suppressor gene RASSF1 (Ras association domain family member 1) regulates cell cycle, progression, apoptosis, and microtubule stability, and is inactivated by promoter hypermethylation in breast cancer. We analyzed the SNPs in RASSF1 and their predictive and prognostic value in stage II or III breast cancer patients who received neoadjuvant docetaxel/doxorubicin chemotherapyMethodsA total of 139 stage II or III breast cancer patients who received neoadjuvant docetaxel/doxorubicin chemotherapy were enrolled in this study. The patients received three cycles of neoadjuvant chemotherapy followed by curative surgery, and received additional three cycles of docetaxel/doxorubicin chemotherapy as an adjuvant. Germline DNA from peripheral blood mononuclear cells was extracted. The genotypes were performed using Illumina GoldenGate® Assay. We analyzed 3 SNPs in RASSF1 genes: rs3213621 T>C in 3'UTR, rs2073499 G>A in intron, and rs2073498 C>A in exon 3 Ala133Ser.ResultsThe overall radiologic response rate (RR) for neoadjuvant chemotherapy was 79.8% and 10 patients (7.2%) achieved a pathologic complete remission (pCR). None of the SNPs were correlated with radiologic RR or pCR rate. SNP in intron of RASSF1 (rs2073499) was associated with relapse free survival (RFS). RFS was longer in GA/AA genotype than GG genotype (Hazard ratio [HR]=0.374, p=0.034) After adjusting age and hormone status, prognostic value of RASSF1 SNP remained significant (HR=0.393, p=0.050). Other two SNPs were not significantly associated with RFS.ConclusionsThe GA/AA genotype in SNP of RASSF1 (rs2073499) is associated with significantly longer RFS than the GG genotype. Further research is warranted to identify the biologic characteristics of RASSF1.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6061.

Does triple-negative breast cancer (TNBC) have distinct clinicopathologic characteristics and prognostic significance?

21088

Background: Studies have suggested that TNBC, defined by estrogen receptor-negative, progesterone receptor-negative, and HER2-negative, may represent the subset of breast cancer(BC) with different biologic behavior. Here we investigated the clinicopathologic characteristics of TNBC and its prognostic significance in Korean BC patients. Methods: Patients diagnosed as invasive BC and underwent curative surgery at Seoul National University Hospital between Jan. 2000 and Jun. 2003, were reviewed, retrospectively. We excluded the patients whose immunohistochemistry for hormone receptor nor HER2 status had not been evaluated, and who had been treated with adjuvant trastuzumab or neoadjuvant chemotherapy (CT). Clinicopathologic variables (age, T and N stage, endovascular or lymphatic tumor emboli, nuclear and histologic grade, p53, bcl2, Ki67) and 3 year relapse free survival (3YRFS) rate of TNBC were compared with those of non- TNBC. Results: 1,136 patients were eligible for analysis. The median follow-up was 48.7 months. 341 patients underwent breast conserving surgery followed by adjuvant radiotherapy. 249 patients were TNBC and 62.1% of those were node negative. 86.4% of node negative TNBC, 88.3% of node positive TNBC, 53.9% of node negative non-TNBC, and 90.2% of node positive non-TNBC received adjuvant CT. Compared with non-TNBC, TNBC was correlated with younger age (age<35,14.1% vs. 8.2%, p=0.013), higher nuclear and histologic grade(62.2% vs. 23.6%, p=0.001;60.2% vs. 24.6%, p=0.001, respectively); positive staining for p53 (p=0.001) and higher positivity for Ki67 (p=0.001), suggesting the biologic aggressiveness of TNBC. During the follow-up periods, 17.3% of TNBC were relapsed. In particular, 3YRFS in node negative TNBC and non-TNBC were 86% and 96%, respectively (p<0.001). But, in node positive BC, 3YRFS was not different between TNBC and non-TNBC (80.6% vs. 83%, p=0.99). Conclusions: We confirm that TNBC shows more aggressive clinicopathologic characteristics and in particular, higher relapse in node negative BC. Thus, triple-negativity(TN) may be integrated into risk factor analysis in node negative BC. Final results of more detailed molecular analysis for TNBC would be available in the meeting.

No significant financial relationships to disclose.

ERCC1 expression by immunohistochemistry and EGFR mutations in resected non-small cell lung cancer

7646

Background: To investigate whether excision repair cross-complementation group 1 (ERCC1) expression, as determined immunohistochemically, and mutations of epidermal growth factor receptor (EGFR) are related to the prognosis of curatively resected non-small cell lung cancer (NSCLC), and whether these two markers are related. Methods: One-hundred and thirty-three consecutive patients with NSCLC who did not receive adjuvant chemotherapy after curative surgery were included in this study. Representative areas from formalin-fixed paraffin-embedded tumor samples were chosen for tissue microarray analysis. Immunohistochemistry was performed for ERCC1 and the median semiquantitative H-score was used as a cut-off. EGFR mutations (exons 18, 19, and 21) were analyzed by the direct sequencing of tumor samples. Results: ERCC1 expression was evaluable in 130 patients and ERCC1 was found to be positive in 80 patients (61.5%). Moreover, ERCC1 was expressed more frequently in smokers and in squamous cell carcinomas. Patients with positive ERCC1 expression survived longer (median overall survival 2,742 days for ERCC1-positive vs. 1,423 days for ERCC1-negative, P=.0463). EGFR mutations were found in 27 patients (20.3%) but they were not found to affect overall survival. Interestingly, EGFR mutations were more frequent in ERCC1-negative tumors (12.5% in ERCC1-positive vs. 30% in ERCC1-negative tumors, P=0.014). Conclusions: ERCC1 expression was identified as a prognostic marker of longer survival in resected NSCLCs. In addition, EGFR mutations were more frequently found in ERCC1-negative tumors, but were not found to affect survival in our patient group.

No significant financial relationships to disclose.

Oxaliplatin, 5-fluorouracil, and folinic acid as first-line chemotherapy for elderly patients with advanced gastric cancer

14155

Background: We investigated the efficacy and safety of an oxaliplatin, 5-fluorouracil (5-FU), and folinic acid (FA) as first-line chemotherapy for elderly patients with advanced gastric cancer. Methods: Chemotherapy-naïve patients (≥65 yr of age) with histologically confirmed, locally advanced or recurrent/metastatic gastric cancer were studied. Chemotherapy consisted of oxaliplatin 100 mg/m2 and FA 100 mg/m2 (2-hour intravenous infusion), then 5-FU 2400 mg/m2 (46-hour continuous infusion) every 14 days. Results: A total of 24 patients were enrolled between September 2003 and July 2005. Of 22 evaluable patients, none achieved complete response (CR) and 11 achieved partial response (PR), resulting in an overall response rate of 50%. Median progression-free survival (PFS) was 5.4 months (95% CI: 5.1–5.8 months) and median overall survival (OS) was 7.4 months (95% CI: 4.4–10.4 months). The main toxicities were anemia and leucopenia, which were observed in 39.8% and 19.0%, respectively, of the total cycles administered. There were 2 cycles of grade 4 leucopenia and febrile neutropenia was not observed. Conclusions: This oxaliplatin/5-FU/FA regimen shows good efficacy and an acceptable toxicity profile in elderly patients with advanced gastric cancer.

No significant financial relationships to disclose.

Combination of local tumor invasiveness (LTI) and International Prognostic Index (IPI) provides better predictive value in extranodal NK/T-cell lymphoma, nasal type (NTCL)

17503

Background: In contrast to B-cell lymphomas, NK/T-cell lymphomas have unique clinical pattern (local invasiveness; Blood. 2005;106:3785). Prognostic factors were evaluated according to IPI as well as LTI and compared with the other prognostic model (Lee J, et al JCO 2006). Methods: 176 patients diagnosed with NTCL between 1992 and 2004 were analyzed. Overall survival (OS) and progression-free survival (PFS) were compared according to IPI, IPI combined with LTI, and the other model. LTI was briefly defined as follows: bony invasion or perforation or skin invasion (upper aerodigestive tract); serosal invasion or perforation (gastrointestinal tract); tumor more than 5cm or invasion of deep extradermal structures (skin); and neurovascular or bony invasion (muscle). Results: After a median follow-up period of 80 months, 5-year (y) OS and PFS were 33% and 25%, respectively. The IPI risk group was predictive of OS and PFS (5-y OS 52%, 23%, 10%, and 4%, respectively, P < .0001; 2-y PFS 47%, 31%, 5%, and 4%, respectively, P < .0001) but failed to show survival differences between the high-intermediate and high risk groups (P = .0737). However, once both IPI and LTI are combined, there were significant differences in OS and PFS between the IPI score 0–2/LTI-, IPI score 0–2/LTI+, IPI score 3–5/LTI-, and IPI score 3–5/LTI+ groups (5-y OS 60%, 14%, 7%, and 4%, respectively, P < .0001; 2-y PFS 53%, 21%, 9%, and 4%, respectively, P < .0001). OS and PFS were also affected by the other prognostic model but this model failed to show survival differences among the risk groups (P = .1382). Conclusions: Combination of local tumor invasiveness and International Prognostic Index provides better predictive value in extranodal NK/T-cell lymphoma, nasal type.

No significant financial relationships to disclose.

Clinical characteristics and prognostic factors in diffuse large B-cell lymphoma with bone marrow involvement

7588

Background: Although several studies have been reported about non-Hodgkin’s lymphomas (NHL) with bone marrow (BM) involvement, most of them have not performed immunophenotypic studies and contained heterogeneous NHL histologies. Until now, only a few studies with small sample sizes have been reported about clinical characteristics and prognostic factors in diffuse large B-cell lymphoma (DLBCL) with BM involvement. Methods: Between January 1993 and March 2004, 486 patients were diagnosed with DLBCL. Among 84 DLBCL patients who had BM involvement at initial diagnosis, 9 were not ineligible because of the lack of clinical data or unavailability of BM specimen. So, clinical factors and patterns of BM involvement of 75 patients were analyzed in this study. Results: At initial diagnosis, the median age was 57 years (range: 25∼79). In addition to BM, lymph nodes (76%), spleen (23%), Waldeyer’s ring (19%), gastrointestinal tract (16%), lung/pleura (15%), bone (15%), central nervous system (9%), nasal cavity (8%) and liver (7%) were also involved. Among 75 patients, 67 patients received anthracycline-containing chemotherapy; 4 patients received non-anthracycline-containing chemotherapy and 4 could not receive systemic chemotherapy because of combined medical conditions. The median survival was 32.3 months (5-year overall survival [OS]: 38%). In univariate analysis for prognostic factors, high-intermediate or high international prognostic index (IPI), B-symptoms, leucopenia, anemia, thrombocytopenia, pattern of BM involvement (interstitial or diffuse pattern), > 10% replacement of BM area by lymphoma cells, > 10% of large cell infiltration in BM-involved area by lymphoma at initial diagnosis were associated with poor OS (p < 0.05). Multivariate analysis indicated that > 10% replacement of BM area by lymphoma cells (p < 0.001), peripheral thrombocytopenia (p = 0.001) and high-intermediate or high IPI (p = 0.042) were independent predictors of poor OS. Conclusions: To our knowledge, this is the largest study about DLBCL patients with BM involvement. The BM areas involved by lymphoma cells, peripheral thrombocytopenia and IPI at initial diagnosis are independent prognostic factors in these patients.

No significant financial relationships to disclose.

Aggressiveness of cancer-care near the end of life

6103

Background: The objective of this study were to observe the markers of aggressive care in cancer patients including appropriateness of chemotherapy and to evaluate the trends in cancer-care and to assess their association with the availability of related health care resources. Methods: We designed restrospective cohort composed of patients who diagnosed as metastatic cancer and received palliative chemotherapy at Seoul National University Hospital in 2002. Hematologic malignancy and hepatocellular carcinoma with local treatment alone were excluded. Two hundreds ninety eight patients who died of cancer were finally evaluated the appropriateness of cancer-care including chemotherapy. Results: The median duration of chemotherapy was 6.02 months (mo) compared to 8.67 mo of median overall survival. Median periods between last chemotherapy and death were 2.02 mo. Among the 298 patients, 50.3% of the patients received chemotherapy in the last two months of life. Furthermore, 17 patients (5.7%) died within 2 weeks after receiving chemotherapy. It seemed that the patients had not enough time to prepare the death with dignity. The mean number of regimens and cycles the patients had received were 1.83 and 5.52, respectively. However, timing of discontinuance chemotherapy did not affect use of chemotherapy that there was no difference in numbers of regimens and cycles according to months between last chemotherapy and death. The proportion with >1 ER visit in the last months of life were 33.6% and average numbers of ER visits after cancer diagnosed were 1.72. Only 9.1% of patients referred to hospice center and 11.7% of patients agreed with written DNR. The lack of hospice centers and harmony with referring system in Korea might affect to this results. Conclusions: Among the patients who died of cancer, significant portion of patients received chemotherapy till the end of life as well as ER visiting. Relatively, hospice referral and discussions about DNR did not conducted well in end of life care. Not to interfere the dignity of life, the physicians should be concerned whether the patients dying of cancer are overtreated with chemotherapy and receiving the appropriate cancer-care.

No significant financial relationships to disclose.