ABSTRACT
BACKGROUND: Accurate selection of patients for radical treatment of esophageal cancer is essential to avoid early recurrence and death (ERD) after surgery. We sought to evaluate a large series of consecutive resections to assess factors that may be associated with this poor outcome. METHODS: This was a cohort study including 680 patients operated for esophageal cancer between 2000 and 2010. The poor outcome group comprised 100 patients with tumor recurrence and death within 1 year of surgery. The comparison group comprised 267 long-term survivors, defined as those surviving more than 3 years from surgery. Pathological characteristics associated with poor outcome were analyzed using logistic regression to determine odds ratios (OR) and 95% confidence intervals (CI). RESULTS: On the adjusted model T stage and N stage predicted poor survival, with the greatest risk being patients with locally advanced tumors and three or more involved lymph nodes (OR 10.6, 95% CI 2.8-40.0). Poor differentiation (OR 2.8, 95% CI 1.4-5.5), chemotherapy response (OR 3.6, 95% CI 1.2-10.6), and involved resection margins (OR 2.7, 95% CI 1.2-6.0) were all significant independent prognostic markers in the multivariable model. There was a trend toward worse survival with lymphovascular invasion (OR 2.0, 95% CI 0.9-4.2) and low albumin (OR 1.9, 95% CI 0.8-4.4) but not of statistical significance in the adjusted model. CONCLUSIONS: Esophageal cancer patients with poorly differentiated tumors and three or more involved lymph nodes have a particularly high risk of ERD after surgery. Accurate risk stratification of patients may identify a group who would be better served by alternative oncological treatment strategies.
Subject(s)
Esophageal Neoplasms/mortality , Esophageal Neoplasms/pathology , Esophagectomy , Neoplasm Recurrence, Local/diagnosis , Neoplasm Recurrence, Local/mortality , Adult , Aged , Aged, 80 and over , Cell Differentiation , Cohort Studies , Esophageal Neoplasms/surgery , Esophageal Neoplasms/therapy , Esophagectomy/mortality , Female , Follow-Up Studies , Humans , Kaplan-Meier Estimate , London/epidemiology , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Grading , Neoplasm Invasiveness , Neoplasm Recurrence, Local/etiology , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/therapy , Neoplasm Staging , Odds Ratio , Predictive Value of Tests , Prognosis , Risk Assessment , Risk Factors , Time Factors , Treatment OutcomeABSTRACT
The gap plasmon mode of an eccentric coaxial waveguide is analyzed by the effective index method. The results agree-well with fully-vectorial numerical calculations. In the eccentric structure, there is extreme subwavelength field localization around the narrowest gap due to the gap plasmon. Furthermore, the effective index of the lowest-order waveguide mode increases considerably, for example, to 3.7 in the structure considered with a 2 nm minimum gap. The nanostructure waveguide geometry and wavelength (4 microm) are comparable with recent experiments on coaxial structures, except that that position of the center island is shifted for the eccentric coaxial structure; therefore, the proposed structure is a good candidate for future fabrication and experiments. In the visible regime, the effective index increases to over 10 for the same structure. The influence of symmetry-breaking in the eccentric coaxial structure is discussed as a way to enhance the local field and improve optical coupling.
