Survivorship functions were estimated to derive regional relative survival from registry data by fitting a Weibull distribution function.
The first bar in Figure 2 shows the 10-year outcome data available from the SEER registry (survival, and breast cancer and other cause mortality).
The population sizes for the two registries are large: 3.6 million for the Yorkshire data within NYCRIS and 6.5 million for NSWCCR, and rates of cancer survival in the registry populations are similar to the corresponding national rates for the UK and Australia.
For example, as can be seen in Figure 1a, cancer registry survival estimates for some sites in some developing countries are better than recent experience in the United States, or significantly below the trend line with GDP per capita, suggesting that survival may have been overestimated due to small numbers or incomplete case follow-up.
For some countries, only a small proportion of the population was covered by registries contributing to EUROCARE, and critics have suggested that survival from these registries may not adequately reflect national survival (Moran et al, 2000; Threlfall et al, 2001).
Several hip stems have shown very good long-term survival in national registries.
The improved survival observed in registries for prevalent patients may be influenced by survivor bias [ 2, 6, 7].
For example, incidence and survival figures in registries without access to national mortality databases (as in Germany, France, Netherlands, Italy and Spain) may overestimate survival owing to incomplete follow-up for vital status (Steliarova-Foucher et al, 2006).
Future STCS projects will provide novel insight on e.g. infectious disease occurrence, comparison of STCS patient and organ survival with existing registries, the influence of center effects and genetic association studies.
Since cemented components showed the lowest migration throughout the follow-up and have excellent survival in the registries, cement is a safe choice for fixation of the tibial component.
