Appropriate timing for surgery after neoadjuvant chemoradiation for esophageal cancer

Optimal interval between neoadjuvant chemoradiotherapy (CRT) and surgery is not elucidated for esophageal squamous carcinoma. The aim of this study is to evaluate the impact of this time interval on patient outcome. Patients treated with neoadjuvant CRT followed by surgery between 2002 and 2009 were analyzed. Patients were divided into two groups based on the median interval to surgery (64 days): A </= 64 days (n = 54) and B > 64 days (n = 53). A second analysis was performed by re-classifying patients into three interval groups: A* ≤ 40 days (n = 16); B* 41-80 days (n = 60); C* > 80 days (n = 31). Operative outcome, pathological data, and long-term survival were analyzed. One hundred and seven (n = 107) patients were analyzed. Five patients (9.4%) in group B had an anastomotic leak compared with no leakage from group A (P < 0.021). The complete pathological response was comparable in groups A and B (35% vs. 24.5%, p = 0.23). R0 was significantly lower in group A* (A*: 56.3%, B*: 90%, C*: 74.2%, P = 0.006). In patients with R0 resection, 5-year survival was significantly better in group A than B (71.7% vs. 51%, P = 0.032) and in group A* (A* 100% vs. B* 60.2% & C* 48.3%; A* vs. B*, P = 0.036; A* vs. C*, P = 0.019). Complete pathological response was an independent predictor of survival. Early surgery with R0 resection following neoadjuvant CRT may lead to a better outcome. Further prospective studies are still necessary to provide better insight into the issue. At present, timing of surgery should be individualized and performed at the earliest opportunity.

Genotype-specific regulation of oral innate immunity by T2R38 taste receptor

The bitter taste receptor T2R38 has been shown to regulate mucosal innate immune responses in the upper airway epithelium. Furthermore, SNPs in T2R38 influence the sensitivity to 6-n-propylthiouracil (PROP) and are associated with caries risk/protection. However, no study has been reported on the role of T2R38 in the innate immune responses to oral bacteria. We hypothesize that T2R38 regulates oral innate immunity and that this regulation is genotype-specific. Primary gingival epithelial cells carrying three common genotypes, PAV/PAV (PROP super-taster), AVI/PAV (intermediate) and AVI/AVI (non-taster) were stimulated with cariogenic bacteria Streptococcus mutans, periodontal pathogen Porphyromonas gingivalis or non-pathogen Fusobacterium nucleatum. QRT-PCR analyzed T2R38 mRNA, and T2R38-specific siRNA and ELISA were utilized to evaluate induction of hBD-2 (antimicrobial peptide), IL-1α and IL-8 in various donor-lines. Experiments were set up in duplicate and repeated three times. T2R38 mRNA induction in response to S. mutans was highest in PAV/PAV (4.3-fold above the unstimulated controls; p<0.05), while lowest in AVI/AVI (1.2-fold). In PAV/PAV, hBD-2 secretion in response to S. mutans was decreased by 77% when T2R38 was silenced. IL-1α secretion was higher in PAV/PAV compared to AVI/PAV or AVI/AVI with S. mutans stimulation, but it was reduced by half when T2R38 was silenced (p<0.05). In response to P. gingivalis, AVI/AVI showed 4.4-fold increase (p<0.05) in T2R38 expression, whereas the levels in PAV/PAV and AVI/PAV remained close to that of the controls. Secretion levels of IL-1α and IL-8 decreased in AVI/AVI in response to P. gingivalis when T2R38 was silenced (p<0.05), while the changes were not significant in PAV/PAV. Our data suggest that the regulation of gingival innate immunity by T2R38 is genotype-dependent and that the ability to induce a high level of hBD-2 by PAV/PAV carriers may be a reason for protection against caries in this group.

Anti-angiogenic pathway associations of the 3p21.3 mapped BLU gene in nasopharyngeal carcinoma

Zinc-finger, MYND-type containing 10 (ZMYND10), or more commonly called BLU, expression is frequently downregulated in nasopharyngeal carcinoma (NPC) and many other tumors due to promoter hypermethylation. Functional evidence shows that the BLU gene inhibits tumor growth in animal assays, but the detailed molecular mechanism responsible for this is still not well understood. In current studies, we find that 93.5% of early-stage primary NPC tumors show downregulated BLU expression. Using a PCR array, overexpression of the BLU gene was correlated to the angiogenesis network in NPC cells. Moreover, expression changes of the MMP family, VEGF and TSP1, were often detected in different stages of NPC, suggesting the possibility that BLU may be directly involved in the microenvironment and anti-angiogenic activity in NPC development. Compared with vector-alone control cells, BLU stable transfectants, derived from poorly-differentiated NPC HONE1 cells, suppress VEGF165, VEGF189 and TSP1 expression at both the RNA and protein levels, and significantly reduce the secreted VEGF protein in these cells, reflecting an unknown regulatory mechanism mediated by the BLU gene in NPC. Cells expressing BLU inhibited cellular invasion, migration and tube formation. These in vitro results were further confirmed by in vivo tumor suppression and a matrigel plug angiogenesis assay in nude mice. Tube-forming ability was clearly inhibited, when the BLU gene is expressed in these cells. Up to 70-90% of injected tumor cells expressing increased exogenous BLU underwent cell death in animal assays. Overexpressed BLU only inhibited VEGF165 expression in differentiated squamous NPC HK1 cells, but also showed an anti-angiogenic effect in the animal assay, revealing a complicated mechanism regulating angiogenesis and the microenvironment in different NPC cell lines. Results of these studies indicate that alteration of BLU gene expression influences anti-angiogenesis pathways and is important for the development of NPC.

Ultracompact and fabrication-tolerant integrated polarization splitter

Design and fabrication of a 2×2 two-mode interference (TMI) coupler based on-chip polarization splitter is presented. By changing the angle between the access waveguides, one can tune the effective TMI length for the mode with less optical confinement (transverse magnetic, TM) to coincide with the target TMI length for a desired transmission of the mode with higher optical confinement (transverse electric, TE). The fabricated 0.94 μm long 2×2 TMI splits the input power into TM (bar) and TE (cross) outputs with splitting ratio over 15 dB over 50 nm bandwidth. Fabrication tolerance analysis shows that the device is tolerant to fabrication errors as large as 60 nm.

Comparative genomic hybridization: comparison between esophageal squamous cell carcinoma and gastric cardia adenocarcinoma from a high-incidence area for both cancers in Henan, northern China

Esophageal squamous cell carcinoma (SCC) remains the leading cause of cancer related deaths in Linzhou (formerly Linxian), the highest incidence area for esophageal cancer (EC) in Henan, northern China. In China, gastric cardia adenocarcinoma (GCA) shares very similar geographic distribution with SCC, suggesting the possibility of similar risk factors involved in SCC and GCA carcinogenesis in these areas. However, the underlying genetic alterations for esophageal and gastric cardia carcinogenesis, especially for the molecular difference between SCC and GCA, are largely unknown. The present study was thus undertaken to determine the difference in chromosomal aberrations in SCC (n = 37) and GCA (n = 31) using the comparative genomic hybridization method (CGH). All the patients were from Linzhou, Henan, a high-risk geographic region for both SCC and GCA. CGH results showed that chromosomal aberrations with different degrees were identified both in SCC and GCA. In SCC, chromosomal profile of DNA copy number was characterized by most frequently detected gains at 8q (29/37, 78%), 3q (24/37, 65%) and 5p (19/37, 51%); and frequently detected losses at 3p (21/37, 57%), 8p and 9q (14/37, 38%). In GCA, the frequently detected gains were identified at 20q (13/31, 42%), 6q (12/31, 39%) and 8q (11/31, 35%); the DNA copy number losses in GCA occurred frequently at 17p (17/31, 55%), 19p (15/31, 48%) and 1p (14/31, 45%). Statistically, there were evident differences between SCC and GCA in DNA copy number gains at 8q, 3q, 5p and 20q (P < 0.05) and in losses at 3p, 8p, 5q, 17p and 18q (P < 0.05). Gains at 8q were frequently observed in both SCC and GCA. Gains at 3q and 8p were frequently observed in TNM stage III of both SCC and GCA. The present CGH results provide candidate regions that may contain specific related genes involved in SCC and GCA in the Linzhou population. Gains at 8q, 3q and 5p and losses at 3p, 8p and 9q were specifically implicated in SCC; gains at 20q, 6q and 8q and losses at 17p, 19p and 1p were specifically implicated in GCA; gains at 8q were implicated in both SCC and GCA.

Microsatellite allelotyping of chinese nasopharyngeal carcinomas

BACKGROUND

Chinese nasopharyngeal carcinoma (NPC) specimens were analyzed by microsatellite allelotyping to evaluate their usefulness as biomarkers for cancer detection.

MATERIALS AND METHODS

A panel of eight microsatellite markers localized to chromosomes 3p, 6p, 9p, I1q and 14q were used to study 47 specimens.

RESULTS

A moderately low loss of heterozygosity (LOH) frequency (8% to 35%) was observed; 23 (49%) specimens showed LOH with at least one marker while microsatellite instability (MSI) was detected in 10 specimens (21%).

CONCLUSION

Poor survival was significantly associated with LOH detected by a chromosome 3 marker. Interestingly, tumors with multiple genetic alterations were significanty associated with earlier staging

Comparative genomic hybridization analysis of nasopharygeal carcinoma: consistent patterns of genetic aberrations and clinicopathological correlations

To define the patterns of genetic imbalances in nasopharyngeal carcinoma (NPC), we studied 30 primary NPC tumors with comparative genomic hybridization (CGH). The common sites of chromosomal gains were found in descending order of frequency in 12p11.2-p12 (36%), 12q14-q21 (33%), 2q24-q31 (23%), 1q31-qter (20%), 3q13 (20%), 1q13.3 (20%), 5q21 (17%), 6q14-q22 (13%), 7q21 (13%), 8q11.2-q23 (13%) and 18q12-qter (13%). The common sites of chromosomal loss were at 3p14-p21 (20%), 11q23-qter (20%), 16q21-qter (17%) and 14q24-qter (13%). Correlation with clinicopathologic features showed that 3p loss was associated with a significantly higher risk of death related to recurrence as compared with patients without 3p loss (50% vs. 9%, P=.029). The presence of 16q loss was associated with more advanced stage tumors (stages I & II: 6% vs. stages III & IV: 33%, P=.046). We conclude that consistent patterns of genetic imbalances can be observed in NPC. Deletion of 3p and 16q were associated with higher risk of tumor recurrence and advanced stage cancer.

Preliminary study of in vivo autofluorescence of nasopharyngeal carcinoma and normal tissue

BACKGROUND AND OBJECTIVE

In nasopharyngeal cancer, conventional white light endoscopy does not provide adequate information to detect the flat/small lesion and identify the margin of observable tumor. In the present study, we evaluate the potential of light-induced fluorescence spectroscopic imaging for the localization of cancerous nasopharyngeal tissue.

STUDY DESIGN/MATERIALS AND METHODS

We built a multiple channel spectrometer specifically for the investigation of fluorescence collected by a conventional endoscopic system. Nasopharyngeal fluorescence were measured in vivo from 27 subjects during the routine endoscopy. The biopsy specimens for histologic analysis were taken from the tissue sites where the fluorescence were measured.

RESULTS

Two algorithms to discriminate the nasopharyngeal carcinoma from normal tissue were created based on the good correlation between the tissue autofluorescence and histologic diagnosis. For the two-wavelength algorithm, carcinoma can be differentiated from normal tissue with a sensitivity and specificity of 93% and 92%, respectively. For the three-wavelength algorithm with compensation of variation of blood content in tissue, a sensitivity of 98% and specificity of 95% were achieved.

CONCLUSION

Fluorescence endoscopic imaging used with the algorithms developed in this report is an efficient method for detecting the nasopharyngeal carcinoma.

Mucosal changes of the free jejunal graft in response to radiotherapy

BACKGROUND

Microvascular free jejunal transfer was employed for reconstruction of pharyngeal defect resulting from circumferential resection of the hypopharynx. Postoperative radiotherapy to the neck might affect the graft, but this information was lacking. The mucosal changes of the jejunum in response to radiation were identified in this prospective study.

METHODS

Normal jejunal mucosa was obtained at operation, and endoscopic jejunal mucosal biopsies were taken during and at completion of radiotherapy. Endoscopic biopsies were repeated at 1, 3, 6, 12, and 24 months afterwards. All jejunal biopsies were subjected to histologic and scanning electron microscopic (SEM) examinations. Nine patients had a complete set of biopsy while 5 other patients who received no radiotherapy also went through a similar sequence of biopsies as controls.

RESULTS

Histologic examination showed mucosal edema and extensive blunting of jejunal villi at the completion of radiotherapy. Increased fibrosis with focal loss of glands was noticed at 3 months after radiotherapy, and this remained throughout the 2-year period. SEM revealed patchy loss of microvilli at completion and at 1 month after radiotherapy, but this feature was not apparent in biopsies taken at 3 months onwards, showing that it was only a transient event.

CONCLUSIONS

Transient responses and persistent changes of jejunal mucosa to radiotherapy were identified and characterized. The presence of these mucosal lesions was not associated with any clinically significant adverse effect in the graft up to 2 years postradiotherapy.

Results of surgical salvage of locoregional recurrence of carcinoma of the tongue after radiotherapy failure

The aim of this study was to evaluate the efficacy of surgical salvage of local and nodal recurrence of carcinoma of the oral tongue after radiotherapy failure. Of the 47 patients in this retrospective review (between 1980 and 1992), there were 25 with local recurrence alone, 11 with locoregional recurrence, and 11 with nodal recurrence alone. There was no operative mortality, and 17% of patients had one or more surgical complications, including wound infection, flap necrosis, anastomotic leakage, and chest infection. Twenty-nine (62%) patients developed recurrences in the head and neck region after the salvage operation, and 9 of them had second surgical salvage operations. At the last follow-up, 53% of patients had died of carcinoma of the tongue and the overall 5-year actuarial survival rate was 43%. The 5-year actuarial survival rates were 39% for local recurrence alone, 27% for locoregional recurrence, and 68% for nodal recurrence alone. Surgical salvage had satisfactory results for patients with oral tongue carcinoma after radiotherapy failure. Close follow-up and early surgical intervention are essential for patients primarily treated with radiotherapy.

Kinetics and locus of failure of receptor-ligand-mediated adhesion between latex spheres. II. Protein-protein bond

In an extension of the previous paper, we describe the force dependence of break-up of doublets of latex spheres cross-linked by protein G-IgG bonds via the Fc region of the antibody. The receptor, the monoclonal Bear-1 antibody, was either covalently linked to 4.75-microns aldehyde/sulfate (A/S) latex spheres in a one-step reaction, or physically adsorbed to the 4.63-microns carboxyl-modified latex spheres used in Part I of this paper. The spheres were suspended in 19% buffered Dextran 40 containing the ligand, the bivalent recombinant protein G (Gamma-Bind G), and observed in the counter-rotating cone and plate Rheoscope. Break-up of doublets, tracked individually under the microscope, as well as in populations of 50-150 particles, was studied over a range of normal force from 20 to 260 pN. In individual particle studies, the fraction of doublets of spheres with covalently linked IgG breaking up in the first 10 rotations, increased from 16% in the low-force to 63% in the high-force range. In population studies, the fraction broken up increased with duration and magnitude of the applied force, and decreased with increasing ligand concentration. Moreover, doublets of physically adsorbed IgG spheres required significantly lower force than doublets of covalently linked IgG spheres for the same degree of break-up, possibly because of surface detachment of IgG molecules rather than rupture of receptor-ligand bonds. Computer simulation, using the Bell stochastic model of break-up and a Poisson distribution for the number of bonds, described in Part I, showed that the parameters of the protein-protein bond differed significantly from those of the carbohydrate-protein bond studied in Part I of this paper, the former being much more responsive to force than the latter.

The effect of loco-regional control on distant metastatic dissemination in carcinoma of the nasopharynx: an analysis of 1301 patients

PURPOSE

This study evaluated the effect of loco-regional control on incidence of distant metastases in patients with nasopharyngeal carcinoma.

METHODS AND MATERIALS

Retrospective analysis was performed on 1301 patients with nasopharyngeal carcinoma treated from 1976-1989 in our hospital. The effect of different prognostic indicators on distant metastases free survival (DMFS) was analyzed, including T stage, N stage, sex, and loco-regional control. The significance of loco-regional control in distant metastatic dissemination was further studied with period and subgroup analysis. Cox regression was performed to identify the independent prognostic variables.

RESULTS

Patients with loco-regional relapse had significantly higher distant metastases rate than patients with loco-regional control (time-adjusted distant metastases rate at 5 years was 40.7% vs. 29.4%, p = 0.0012). By period analysis, the effect of loco-regional control on distant metastases was found to be significant in the first 2 years from diagnosis. Subgroup analysis showed that loco-regional relapse was associated with significantly higher distant metastases rate in patients with T1, N0, and N1 disease (p = 0.001, 0.001, 0.0226, respectively). The Cox regression model also confirmed loco-regional control as an independent prognostic indicator of distant metastases (p = 0.0001) besides T stage (p = 0.0006) and N stage (p = 0.0001).

CONCLUSION

Loco-regional relapse is a significant risk factor for development of distant metastases. Further effort should be made to improve loco-regional control and to eradicate distant metastases.