Valid comparisons and decisions based on clinical registers and population based cohort studies: assessing the accuracy, completeness and epidemiological relevance of a breast cancer query database

Abstract Background Data accuracy and completeness are crucial for ensuring both the correctness and epidemiological relevance of a given data set. In this study we evaluated a clinical register in the administrative district of Marburg-Biedenkopf, Germany, for these criteria. Methods The register contained data gathered from a comprehensive integrated breast-cancer network from three hospitals that treated all included incident cases of malignant breast cancer in two distinct time periods from 1996–97 (N=389) and 2003–04 (N=488). To assess the accuracy of this data, we compared distributions of risk, prognostic, and predictive factors with distributions from established secondary databases to detect any deviations from these “true” population parameters. To evaluate data completeness, we calculated epidemiological standard measures as well as incidence-mortality-ratios (IMRs). Results In total, 12% (13 of 109) of the variables exhibited inaccuracies: 9% (5 out of 56) in 1996–97 and 15% (8 out of 53) in 2003–04. In contrast to raw, unstandardized incidence rates, (in-) directly age-standardized incidence rates showed no systematic deviations. Our final completeness estimates were IMR=36% (1996–97) and IMR=43% (2003–04). Conclusion Overall, the register contained accurate, complete, and correct data. Regional differences accounted for detected inaccuracies. Demographic shifts occurred. Age-standardized measures indicate an acceptable degree of completeness. The IMR method of measuring completeness was inappropriate for incidence-based data registers. For the rising number of population-based health-care networks, further methodological advancements are necessary. Correct and epidemiologically relevant data are crucial for clinical and health-policy decision-making.</p

Valid comparisons and decisions based on clinical registers and population based cohort studies: assessing the accuracy, completeness and epidemiological relevance of a breast cancer query database

BACKGROUND: Data accuracy and completeness are crucial for ensuring both the correctness and epidemiological relevance of a given data set. In this study we evaluated a clinical register in the administrative district of Marburg-Biedenkopf, Germany, for these criteria. METHODS: The register contained data gathered from a comprehensive integrated breast-cancer network from three hospitals that treated all included incident cases of malignant breast cancer in two distinct time periods from 1996–97 (N=389) and 2003–04 (N=488). To assess the accuracy of this data, we compared distributions of risk, prognostic, and predictive factors with distributions from established secondary databases to detect any deviations from these “true” population parameters. To evaluate data completeness, we calculated epidemiological standard measures as well as incidence-mortality-ratios (IMRs). RESULTS: In total, 12% (13 of 109) of the variables exhibited inaccuracies: 9% (5 out of 56) in 1996–97 and 15% (8 out of 53) in 2003–04. In contrast to raw, unstandardized incidence rates, (in-) directly age-standardized incidence rates showed no systematic deviations. Our final completeness estimates were IMR=36% (1996–97) and IMR=43% (2003–04). CONCLUSION: Overall, the register contained accurate, complete, and correct data. Regional differences accounted for detected inaccuracies. Demographic shifts occurred. Age-standardized measures indicate an acceptable degree of completeness. The IMR method of measuring completeness was inappropriate for incidence-based data registers. For the rising number of population-based health-care networks, further methodological advancements are necessary. Correct and epidemiologically relevant data are crucial for clinical and health-policy decision-making

Effects of Celecoxib and Ly117018 Combination on Human Breast Cancer Cells in Vitro

Activation and signalling of estrogen receptor (ER) and COX-2 represent two important pathways in breast cancer cell regulation. Activation of either pathway is associated with breast cancer cell proliferation and eventually malignant progression. Raloxifene analogue, Ly117018, a selective estrogen receptor modulator and celecoxib, a specific COX- 2 inhibitor have been shown to inhibit breast cancer cell proliferation when used alone in vitro and in vivo. In this study, the combined drug effects on hormone-dependent MCF-7 and hormone-independent MDA-MB-435 cells in vitro were evaluated. Cell proliferation assays excluded drug antagonism and revealed a moderate synergistic growth inhibitory activity of Ly117018 and celecoxib on both cell lines when combined in specific concentrations. Growth inhibition of either compound was not associated with cell cycle arrest. In MCF-7 cells, western blot analysis revealed a decreased phosphorylation of the AKT protein by either agent alone or in combination. In MDA-MB-435 cells, celecoxib alone induced an increase in AKT phosphorylation relative to total AKT protein; this effect was decreased in the presence of Ly117018. These results indicate that these two drugs are non-antagonistic; and when combined in specific concentrations, moderate synergistic antiproliferative activity of celecoxib and Ly117018 were observed in hormone-dependent MCF-7 and hormone- independent MDA-MB-435 cells associated with changes in cell cycle distribution and regulation of AKT protein and phosphorylation. These findings further support a central role of the ER- and COX-2 pathways in human breast cancer cells