June 1, 2000
The new CTS website release includes more than 300 graphics which show the results of transplants performed from 1985-1999. In addition to many new graphs, follow-up on existing graphs was performed to incorporate data up to the end of 1999. I am convinced you will find that these updates further increase the value of the website as an interesting and comprehensive reference source.
Most CTS participants were able to meet the deadline for inclusion of their data in the current website update. Late arrivals will be included in the next update which is scheduled after the summer.
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Because the graphs contained in the previous website release have now been updated, we have built an "archive" of graphs for reference purposes. All graphs are identified by a unique code on the lower right. This code allows the easy retrieval of original graphs from the website archive. The identification code is also intended to be used for citation in publications.
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The CTS website is a very convenient place for accessing the e-mail addresses of transplant centers. You can directly contact other centers by selecting the section "Participants" followed by a simple click on the e-mail address. Any address change can be reported by e-mail to the CTS web administrator. Contact addresses of some centers are still missing. We are attaching address submission forms for your convenience.
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Barring unforeseen obstacles, the first version of the announced online analysis capability for individual centers should be realized by September. This innovation will add another interesting dimension to the CTS website project. Of course, your analysis will be only as good as your own data. To avoid disappointments, please check your current printout for completeness and accuracy and report any missing data in time. Be aware that the computer is unforgiving and that any detail that was either omitted or recorded incorrectly will affect your analysis. A complete and accurate data status will ensure that you gain the full benefit that this new feature intends to provide.
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The recent New England Journal of Medicine article on improved graft survival in the United States was particularly interesting for us because it confirmed the CTS experience reported at many congresses and meetings. For a long time we were in disagreement with the much-quoted conventional UCLA/UNOS point of view, maintaining that the longterm results of kidney transplantation had not improved since the early 80s. In fact, we noticed gradually improving success rates throughout the years.
Figure 1
Figure 1 summarizes the evolution of graft survival rates for first cadaver kidney transplants, grouped in three-year intervals according to time of transplantation (with the exception of the most recent interval which covers only the two years 1997 and 1998).
Figure 2
Associated with these results is a striking improvement of half-life times over the years (Figure 2). It should be pointed out that the half-life computation for the latest time period (1997-98) is only an "early guess" because it is based on only two observation points (1 year and 2 years). The half-life result for this latest period is therefore preliminary; most likely, it is too optimistic.
Figure 3
Figure 4
A similarly strong improvement effect was observed for HLA 1-haplotype matched related donor transplants (Figures 3 and 4), whereas the improvement effect was relatively modest for HLA-identical sibling transplants (Figures 5 and 6).
Figure 5
Figure 6
The survival rate of heart recipients was clearly better for patients transplanted after the 1985-87 period, however, the success rate was remarkably stable during the last 10 years. Accordingly, the half-life projection for heart transplants has stayed around 16 years for a decade (Figures 7 and 8).
Figure 7
Figure 8
Although the longterm results of lung transplants show some improvement, the success rate remains far below those of the other organs (Figures 9 and 10).
Figure 9
Figure 10
Figure 11
Quite different was the evolution of liver transplants where a remarkable improvement in the success rate was noted. Interestingly, the improvement primarily affected the early failure rate (Figure 11). The half-life time, which was traditionally high in liver transplantation, improved moderately (Figure 12).
Figure 12
Liver recipients are often retransplanted after primary graft
failure. The eventual success rate is therefore commonly assessed
by calculating "patient survival" rather than
graft survival. This type of analysis shows a clear improvement
in longterm half-life as shown in
Figure 13.
Figure 13
The most remarkable evolutionary improvement is found for pancreas
transplant survival. Figure 14 illustrates the increase in
the rate of pancreatic function for transplants performed since
1985. The associated improvement of the half-life time is equally
impressive
(Figure 15).
Figure 14
Figure 15
On the whole, the CTS data show remarkable improvements in the results of organ transplantation, however, the improvement rates for different organs show interesting differences. The very optimistic longterm projections based on the 1997-98 interval are probably overestimations and it remains to be seen whether the survival rates will be sustained when complete follow up data become available. At least from the distant viewpoint of the CTS registry, the improvements are not simply attributable to changes in the immunosuppressive regimens. Even when transplants were stratified according to the "intention to treat" immunosuppressive treatment regimen, the results behaved like those shown in the graphic illustrations. Factors that cannot be easily measured, such as improvements in patient management, prophylaxis and treatment of infections, diagnosis and treatment of rejections, etc., must have contributed to the improved transplant results.
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In a few weeks we will again distribute the yearly Cancer Confirmation Questionnaires, asking for confirmation of the accuracy and completeness of your reports on posttransplant malignancies. I should like to stress the particular importance of registering all rectal and anal cancers as well as all skin cancers (please identify basal cell and squamous cell cancers separately). These tumors show very unusual incidence rates in transplant recipients and we would like to be sure that reporting errors do not falsify our analyses. Of course, all other tumors should be reported accurately as well.
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Thank you for your continued support of the international study.
Sincerely yours,