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Relative Survival (relative + survival)
Terms modified by Relative Survival Selected AbstractsEffects of maternally transferred organochlorine contaminants on early life survival in a freshwater fishENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2005Thomas A. Johnston Abstract Laboratory research has shown that female fish can pass toxic organochlorines (OCs) from their bodies to their eggs, killing their offspring if sufficient quantities are transferred. We conducted a controlled incubation study using gametes from a wild, OC-contaminated walleye (Sander vitreus) population (Bay of Quinte, Lake Ontario, Canada) in order to assess among-female variation in offspring early life survival in relation to ova concentrations of planar OCs (polychlorinated dibenzo- p -dioxins and furans and planar polychlorinated biphenyls) and a suite of other maternal and ova characteristics. Equal volumes of ova from each female were fertilized, pooled, and incubated together as an experimental cohort. Relative survival of each female's offspring was estimated as the proportion of surviving larvae (at ,5 d posthatch) that she contributed to the cohort as determined by microsatellite DNA parentage assignment. Total planar OC concentration (expressed as toxic equivalency of 2,3,7,8-tetrachloro-dibenzo- p -dioxin) of ova was positively related to maternal age and size and to ova lipid content. However, early life survival did not decline with increasing ova planar OC concentrations. Similarly, we observed no significant relationships between early life survival and ova thiamine content, ova fatty acid composition, or maternal age or size. Early life survival was more strongly correlated with date of spawn collection, thyroid hormone status of the ova, and ovum size. Maternally transferred planar OCs do not appear to negatively influence female reproductive success in this walleye population. [source] Breast Cancer in the Middle Eastern Population of California, 1988,2004THE BREAST JOURNAL, Issue 2 2009Kiumarss Nasseri DVM Abstract:, This report presents the patterns of incidence, survival, and mortality of breast cancer in the Middle Eastern (ME) population of California. Cases were identified through surname recognition and population estimates were obtained from census public use files. Rates, trends, and survival in this ethnic group were compared with the non-Hispanic White (NHW) of California, as well as natives in the Middle East. Age-adjusted incidence rates for the insitu (22.8), invasive (126.2), and mortality (23.2) in ME women were significantly lower than similar rates of 26.0, 146.9, and 30.6 in the NHW women. Incidence rate in ME women in California was higher than rates in women in the Middle East. Lower rates for early stage and higher rates for late stage diagnoses in this ethnic population suggest lack of optimal access to preventive healthcare. Relative survival in the two groups is negatively associated with stage at diagnosis and is slightly higher in ME women, probably due to large numbers of lost to follow-up in ME women suggesting the presence of salmon bias. Positive association with socioeconomic standing was detected only in the NHW women. Incidence of breast cancer in ME men was significantly higher than that of NHW men. [source] Cumulative incidence analysis and relative survivalACTA OPHTHALMOLOGICA, Issue 2008T KIVELÄ Purpose To highlight concepts related to competing events in time-to-event data sets. Methods Introduction to cumulative incidence and relative survival analyses and competing risks proportional hazards regression with examples from recent literature. Results Kaplan-Meier and Cox regression analysis were designed to study mortality. They return biased estimates in the presence of competing events that render subjects immune to the event of interest (e.g. one is no longer at risk of vision loss, bleb failure or graft rejection after dying). Kaplan-Meier can then be supplemented with cumulative incidence analysis and Cox with competing risks regression. The data needed are time-to-event or last follow-up, last status (e.g. experienced an event, under follow-up, lost to follow-up) and explanatory or confounding variables. Subjects who experienced a competing event are treated as such and subjects who did not experience any event are "censored" at last follow-up. A set of stepped curves is produced which show the cumulative incidence of each event as a function of time by study group; groups can be compared using dedicated tests. Competing risks regression provides a hazard ratio, adjusted for the effect of other variables in the model. Relative survival is an alternative to cumulative incidence method when analyzing mortality. It does not require that the status at last follow-up be known. Survival of the study group is compared with that of the underlying population. The difference is equivalent to the cumulative incidence of disease-specific death, but cumulative incidences of competing events are not available. Conclusion After this talk, participants should be able to recognize competing events, assess whether Kaplan-Meier and Cox regression were appropriate methods and know alternatives to them. [source] Breast cancer survival in England, Norway and Sweden: a population-based comparison,INTERNATIONAL JOURNAL OF CANCER, Issue 11 2010Henrik Møller Abstract Several international studies have found that survival from breast cancer is lower in the United Kingdom than in some other European countries. We have compared breast cancer survival between the national populations of England, Norway and Sweden, with a view to identifying subsets of patients with particularly good or adverse survival outcomes. We extracted cases of breast cancer in women diagnosed 1996,2004 from the national cancer registries of the 3 countries. The study comprised 303,657 English cases, 24,919 Norwegian cases and 57,512 cases from Sweden. Follow-up was in 2001,2004. The main outcome measures were 5-year cumulative relative survival and excess death rates, stratified by age and period of follow-up. In comparison with Norway and Sweden, the excess mortality in England was particularly pronounced in the first month and in the first year after diagnosis, and generally more marked in the oldest age groups. Compared with Norwegian patients, 81% of the excess deaths in the English patients occurred in the first 2 years after diagnosis. Our findings emphasise the importance of awareness of symptoms and early detection as the main strategy to improve breast cancer survival in the United Kingdom. [source] Up-to-date cancer survival: Period analysis and beyondINTERNATIONAL JOURNAL OF CANCER, Issue 6 2009Hermann Brenner Abstract Since its introduction in 1996, period analysis has been shown to be useful for deriving more up-to-date cancer survival estimates, and the method is now increasingly used for that purpose in national and international cancer survival studies. However, period analysis, like other commonly employed methods, is just a special case from a broad class of design options in the analysis of cancer survival data. Here, we explore a broader range of design options, including 2 model-based approaches, for deriving up-to-date estimates of 5- and 10-year relative survival for patients diagnosed in the most recent 5-year interval for which data are available. The performance of the various designs is evaluated empirically for 20 common forms of cancer using more than 50-year long time series of data from the Finnish Cancer Registry. Period analysis as well as the 2 model-based approaches, one using a "cohort-type model" and another using a "period-type model", all performed better than traditional cohort or complete analysis. Compared with "standard period analysis", the cohort-type model further increased up-to-dateness of survival estimates, whereas the period-type model increased their precision. While our analysis confirms advantages of period analysis over traditional methods in terms of up-to-dateness of cancer survival data, further improvements are possible by flexible use of model-based approaches. © 2008 Wiley-Liss, Inc. [source] Cancer survival in Germany and the United States at the beginning of the 21st century: An up-to-date comparison by period analysisINTERNATIONAL JOURNAL OF CANCER, Issue 2 2007Adam Gondos Abstract Transatlantic cancer survival comparisons are scarce and involve mostly aggregate European data from the late 1980s. We compare the levels of cancer patient survival achieved in Germany and the United States (US) by the beginning of the 21st century, using data from the Cancer Registry of Saarland/Germany and the SEER Program of the US. Age-adjusted 5- and 10-year relative survival for 23 common forms of cancer derived by period analysis for the 2000,2002 period were calculated, with additional detailed age- and stage-specific analyses for cancers with the highest incidence. Among the 23 cancer sites, 5 (10) year relative survival was significantly higher for 1 (2) and 8 (5) cancers in Germany and the US, respectively. In Germany, survival was significantly higher for patients with stomach cancer, whereas survival was higher in the US for patients with breast, cervical, prostate, colorectal and oral cavity cancer. Among the most common cancers, age-specific survival differences were particularly pronounced for older patients with breast, colorectal and prostate cancer. Survival advantages of breast cancer patients in the US were mainly due to more favorable stage distributions. This comprehensive survival comparison between Germany and the US suggests that although survival was similar for the majority of the compared cancer sites, long-term prognosis of patients continues to be better in the US for many of the most common forms of cancer. Among these, differences between patients with breast and prostate cancer are probably due to more intensive screening activities. © 2007 Wiley-Liss, Inc. [source] Interpreting trends in cancer patient survivalJOURNAL OF INTERNAL MEDICINE, Issue 2 2006P. W. DICKMAN Abstract Data on cancer patient survival are an invaluable tool in the evaluation of therapeutic progress against cancer as well as other lethal diseases. As with all quantitative information routinely used in evidence-based clinical management , including diagnostic tests, prognostic markers and comparisons of therapeutic interventions , data on patient survival require evaluation based on an understanding of the underlying statistical methodology, methods of data collection and classification, and, most notably, clinical and biologic insight. This article contains an introduction to the methods used for estimating cancer patient survival, including cause-specific survival, relative survival and period analysis. The methods, and their interpretation, are illustrated through presentation of trends in incidence, mortality and patient survival for a range of different cancers. Our aim was to lay out the strengths and limitations of survival analysis as a tool in the evaluation of progress in the diagnosis and treatment of cancer. [source] The incidence and survival of acute de novo leukaemias in Estonia and in a well-defined region of western Sweden during 1982,1996: a survey of patients aged ,65 yearsJOURNAL OF INTERNAL MEDICINE, Issue 1 2004E. Luik Abstract. Objectives., To compare the incidence and survival of acute de novo leukaemias with particular reference to political/socio-economic and environmental factors in two neighbouring countries over the three 5-year periods (1982,1996). Patients., The present report covers only patients diagnosed when aged ,65 years. Setting., A well-defined area of Sweden, the so-called Western Swedish Health Care Region and Estonia. Population-wise, the western Swedish Region and Estonia are very similar; area-wise they are also well comparable. Results., The number of acute de novo leukaemias was quite dissimilar in the two countries (Estonia, n = 137, Sweden, n = 354). The age standardized incidence rates regarding the total number of acute de novo leukaemias was 5.31 per 100 000 inhabitants/year for Estonia and 7.99 for Sweden, this difference being statistically significant. However, the difference was merely attributable to incidence rates as regards acute myeloblastic leukaemias (AML); on the contrary, differences as regards acute lymphoblastic leukaemias (ALL) and non-classifiable, undifferentiated or biphenotypic acute leukaemias (uAL) were negligible. The relative survival for the total material of patients was significantly higher for Swedish when compared with Estonian patients (P < 0.001). Thus, the relative survival for the total material of patients aged ,65 years in Estonia at 1 year was 8.5% and at 3 years 3.5% respectively. The corresponding figures for the Swedish patients were considerably higher, 22.7 and 7.7% respectively. This difference, however, applied only for patients with AML (P < 0.001), whereas the results for patients with ALL and uAL were equally dismal. Conclusion., The results clearly reflect how political and socio-economic factors may influence the survival of acute leukemia patients in two neighbouring countries. [source] Quantitative comparison of the cytocidal effect of seven macrolide antibiotics on human periodontal ligament fibroblastsJOURNAL OF PERIODONTAL RESEARCH, Issue 4 2002Noriko Maizumi The cytocidal effect of seven macrolide antibiotics on human periodontal ligament fibroblasts (Pel cells) was studied. Pel cells were exposed for 48 h to erythromycin (EM), clarithromycin (CAM), roxithromycin (RXM), azithromycin (AZM), josamycin (JM), midecamycin (MDM), and rokitamycin (RKM), and allowed to form colonies. The cytocidal effect of the macrolides was measured as a decrease in colony-forming efficiency and was found to increase with the concentration. To obtain a quantitative measure of the cytocidal effect, the LD50, i.e. the concentration that decreases colony-forming efficiency 50% relative to control cells, was extrapolated from the concentration-response curves. The rank of the macrolides according to their cytocidal effect (LD50) was RKM > RXM > CAM > AZM > JM > MDM , EM. RKM, RXM, CAM, AZM, and JM were at least 1.7,12.2 times more cytocidal than MDM or EM. When extrapolated from the concentration-response curves, the relative survival of the Pel cells exposed to each of the macrolides at the MIC90 concentrations for periodontopathic bacteria was estimated to be: ,,53.8% for RKM, , 92.7% for RXM, , 94.6% for CAM, , 97.1% for AZM, and , 86.2% for EM. The effect of the antibiotics on the mRNA expression of alkaline phosphatase (ALP) and type I procollagen (COL) was examined in Pel cells exposed for 48 h to RXM, CAM, AZM, and EM, which exhibited strong, moderate, and weak cytocidal activity. The constitutive levels of both ALP and COL mRNA were retained in cells exposed to RXM at ,3 ,M, CAM at ,10 ,M, and AZM or EM at ,3 ,M. The MIC90 against periodontopathic bacteria is ,4.8 ,M for RXM, 5.3 ,M for CAM, 2.7 ,M for AZM, and 21.8 ,M for EM. These results suggest that topical administration of CAM or AZM to the gingival crevice at their MIC90 concentration for periodontopathic bacteria would have little adverse effect on the growth and differentiation of the periodontal ligament. It is important to note, however, that these findings have yet to be extrapolated to in vivo conditions. [source] Dietary conservatism may facilitate the initial evolution of aposematismOIKOS, Issue 3 2003R. J. Thomas It has generally been assumed that warningly coloured organisms pay a cost associated with their increased visibility, because naïve predators notice and eat them. This cost is offset by their enhanced protection from educated predators who associate the colour pattern with unprofitability. However, some studies have suggested that avoidance of novel prey by avian predators ("dietary conservatism") can actually place novel colour morphs at a selective advantage over familiar ones, even when they are highly conspicuous. To test this idea, we experimentally simulated the appearance of a single novel-coloured mutant in small populations (20 individuals) of palatable artificial prey. The colour morph frequencies in each "generation" were determined by the relative survival of the previous generation under predation by birds. We used wild-caught European robins Erithacus rubecula foraging on pastry "prey" of different colours. The aim was to test whether prey selection by predators prevented or facilitated the novel colour morph persisting in the prey population over successive generations. We found that the novel colour morph quickly increased to fixation in 14/40 prey "populations", and at least once each in 8 of the 10 birds tested. Novel mutants of the classic aposematic colours (red and yellow) reached fixation most frequently, but even the green and blue novel morphs both increased to fixation in 2/40 trials. Novel colours reached fixation significantly faster than could be accounted for by drift, indicating active avoidance by the birds. These results suggest that a novel colour morph arising in a prey population can persist and increase under the selective pressure imposed by predators, even to the local exclusion of the original morph, despite being fully palatable. The consequences of this finding are discussed in relation to receiver psychology, the evolution of aposematism and the existence of polymorphism in Müllerian mimics. [source] Laryngeal Cancer in the United States: Changes in Demographics, Patterns of Care, and SurvivalTHE LARYNGOSCOPE, Issue S111 2006FACS, Henry T. Hoffman MD Abstract Background: Survival has decreased among patients with laryngeal cancer during the past 2 decades in the United States. During this same period, there has been an increase in the nonsurgical treatment of laryngeal cancer. Objective: The objectives of this study were to identify trends in the demographics, management, and outcome of laryngeal cancer in the United States and to analyze factors contributing to the decreased survival. Study Design: The authors conducted a retrospective, longitudinal study of laryngeal cancer cases. Methods: Review of the National Cancer Data Base (NCDB) revealed 158,426 cases of laryngeal squamous cell carcinoma (excluding verrucous carcinoma) diagnosed between the years 1985 and 2001. Analysis of these case records addressed demographics, management, and survival for cases grouped according to stage, site, and specific TNM classifications. Results: This review of data from the NCDB analysis confirms the previously identified trend toward decreasing survival among patients with laryngeal cancer from the mid-1980s to mid-1990s. Patterns of initial management across this same period indicated an increase in the use of chemoradiation with a decrease in the use of surgery despite an increase in the use of endoscopic resection. The most notable decline in the 5-year relative survival between the 1985 to 1990 period and the 1994 to 1996 period occurred among advanced-stage glottic cancer, early-stage supraglottic cancers, and supraglottic cancers classified as T3N0M0. Initial treatment of T3N0M0 laryngeal cancer (all sites) in the 1994 to 1996 period resulted in poor 5-year relative survival for those receiving either chemoradiation (59.2%) or irradiation alone (42.7%) when compared with that of patients after surgery with irradiation (65.2%) and surgery alone (63.3%). In contrast, identical 5-year relative survival (65.6%) rates were observed during this same period for the subset of T3N0M0 glottic cancers initially treated with either chemoradiation or surgery with irradiation. Conclusions: The decreased survival recorded for patients with laryngeal cancer in the mid-1990s may be related to changes in patterns of management. Future studies are warranted to further evaluate these associations. [source] Assessing the dominance of Phleum pratense cv. climax, a species commonly used for ski trail restorationAPPLIED VEGETATION SCIENCE, Issue 2 2009Francis Isselin-Nondedeu Abstract Questions: (1) Are some species used for ski trail restoration too dominant to allow native species to re-establish? (2) What plant traits can be used to predict which species are good competitors? We tested the hypothesis that limited native species establishment on ski trails is caused by (1) the dominance of Phleum pratense cv. climax (PPC) and (2) the asymmetry of competitive interactions. Location: Sub-alpine area in the northern French Alps. Methods: PPC was cultivated outdoors over 2 years with 15 alpine species in a systematic design with high- and low-nutrient soil conditions. For each species relative survival, competitive performance and relationships with plant traits were measured. Results: PPC exerted strong dominance on most of its neighbouring species. Survival performance of Anthyllis vulneraria, Luzula sudetica and Lotus alpinus were dramatically reduced. Results of above-ground competition showed that species were trapped in asymmetric competition. Festuca rubra, Trifolium repens, Alchemilla xanthochlora, Trifolium pratense and Plantago alpina best counteracted PPC. Below-ground competition was more symmetric, particularly at the high nutrient level. Plant traits such as biomass, canopy size and specific leaf area were positively correlated with competitive performance of the species. Conclusion: The study has implications for the management of restored ski trails since PPC may hinder the establishment of native sub-alpine species. Consequently, recommendations should focus on (1) maintaining a low proportion or decreasing the proportion of PPC seeds in the revegetation mix and (2) reducing soil fertilization. Plant traits and competition experiments can help to predict changes in restored grasslands. [source] Estimating breast cancer-specific and other-cause mortality in clinical trial and population-based cancer registry cohortsCANCER, Issue 22 2009James J. Dignam PhD Abstract BACKGROUND: To compute net cancer-specific survival rates using population data sources (eg, the National Cancer Institute's Surveillance, Epidemiology, and End Results [SEER] Program), 2 approaches primarily are used: relative survival (observed survival adjusted for life expectancy) and cause-specific survival based on death certificates. The authors of this report evaluated the performance of these estimates relative to a third approach based on detailed clinical follow-up history. METHODS: By using data from Cancer Cooperative Group clinical trials in breast cancer, the authors estimated 1) relative survival, 2) breast cancer-specific survival (BCSS) determined from death certificates, and 3) BCSS obtained by attributing cause according to clinical events after diagnosis, which, for this analysis was considered the benchmark "true" estimate. Noncancer life expectancy also was compared between trial participants, SEER registry patients, and the general population. RESULTS: Among trial patients, relative survival overestimated true BCSS in patients with lymph node-negative breast cancer; whereas, in patients with lymph node-positive breast cancer, the 2 estimates were similar. For higher risk patients (younger age, larger tumors), relative survival accurately estimated true BCSS. In lower risk patients, death certificate BCSS was more accurate than relative survival. Noncancer life expectancy was more favorable among trial participants than in the general population and among SEER patients. Tumor size at diagnosis, which is a potential surrogate for screening use, partially accounted for this difference. CONCLUSIONS: In the clinical trials, relative survival accurately estimated BCSS in patients who had higher risk disease despite more favorable other-cause mortality than the population at large. In patients with lower risk disease, the estimate using death certificate information was more accurate. For SEER data and other data sources where detailed postdiagnosis clinical history was unavailable, death certificate-based estimates of cause-specific survival may be a superior choice. Cancer 2009. © 2009 American Cancer Society. [source] Cumulative incidence analysis and relative survivalACTA OPHTHALMOLOGICA, Issue 2008T KIVELÄ Purpose To highlight concepts related to competing events in time-to-event data sets. Methods Introduction to cumulative incidence and relative survival analyses and competing risks proportional hazards regression with examples from recent literature. Results Kaplan-Meier and Cox regression analysis were designed to study mortality. They return biased estimates in the presence of competing events that render subjects immune to the event of interest (e.g. one is no longer at risk of vision loss, bleb failure or graft rejection after dying). Kaplan-Meier can then be supplemented with cumulative incidence analysis and Cox with competing risks regression. The data needed are time-to-event or last follow-up, last status (e.g. experienced an event, under follow-up, lost to follow-up) and explanatory or confounding variables. Subjects who experienced a competing event are treated as such and subjects who did not experience any event are "censored" at last follow-up. A set of stepped curves is produced which show the cumulative incidence of each event as a function of time by study group; groups can be compared using dedicated tests. Competing risks regression provides a hazard ratio, adjusted for the effect of other variables in the model. Relative survival is an alternative to cumulative incidence method when analyzing mortality. It does not require that the status at last follow-up be known. Survival of the study group is compared with that of the underlying population. The difference is equivalent to the cumulative incidence of disease-specific death, but cumulative incidences of competing events are not available. Conclusion After this talk, participants should be able to recognize competing events, assess whether Kaplan-Meier and Cox regression were appropriate methods and know alternatives to them. [source] Tumour location is a prognostic factor for survival in colonic cancer patientsCOLORECTAL DISEASE, Issue 1 2008O. H. Sjo Abstract Objective, To evaluate survival and prognostic factors in a consecutive series of colon cancer patients from a defined city population in Norway. Method, All patients with adenocarcinoma of the colon diagnosed between 1993 and 2000 were registered prospectively. Five-year actuarial survival and 5-year relative survival rates were calculated. Cox regression analyses were used to study the effect of prognostic factors on survival. Results, In the study period 627 patients were admitted. Overall 5-year relative survival was 50% in females and 52% in males. Five-year relative survival in 410 (65%) patients operated with curative intent, was 74% for females and 79% for males. Tumour location in the transverse colon, splenic flexure and descending colon (OR = 1.8), emergency operation (OR = 1.7), TNM stage (OR = 1.8,2.9), blood transfusion of more than two units (OR = 1.8) and age (OR = 4.0,7.1) were independent negative prognostic factors. Conclusion, Colon cancer located in the transverse and descending colon is associated with poor prognosis. Comparison of results from different centres is difficult due to selection and classification differences, and different methods used for calculation of survival. [source] |