CTS Collaborative Transplant Study
November 1, 2003
Because this year's "Cancer Confirmation Questionnaire" will be mailed to you in a couple of weeks, I thought I would provide some justification for my request that each center record accurate data on posttransplant malignant tumors. With the CTS database, we have a unique opportunity of performing comparative analyses of cancer rates in recipients of different types of organ transplants. As an illustration, Figure 1 shows the incidence of non-Hodgkin lymphoma for the critical first posttransplant year.
The variation in tumor incidence is remarkable. In recipients of lung or heart-lung transplants, the 1-year incidence of lymphoma is about ten-fold higher than that observed in recipients of cadaver kidney transplants.
Very interesting differences are also apparent when all types of malignant tumors are analyzed over a 5-year follow up (Figure 2).
Of course, this raises the question of which types of tumors show a particular increase and whether there are any organ-specific differences. Equally interesting are questions such as whether the type and dose of the immunosuppressive regimen has any influence or whether the recipient's genetic background matters. Only a very large database allows a statistically meaningful analysis of these questions. With your help, the CTS can make important contributions to this field of research.
Where cancer statistics are concerned, the most important factor to take into account is the age of the patient. As illustrated in Figure 3, recipient age at the time of transplantation exerts a very strong influence on subsequent tumor occurrence
Of course, the effect of age on cancer incidence is also strong in the non-transplant general population. Therefore, we have spent great efforts on compiling appropriate background statistics for comparison with the transplant population. Figure 4 shows that the observed incidence in cadaver kidney recipients is about 3 times that expected in the normal population.
A most remarkable result is shown in Figure 5. When the incidence of rectal cancer in transplant recipients is compared with the incidence in the normal population standardized for age, gender, and geographical region, we find a paradoxical decrease of rectal cancer both in heart and kidney recipients (Figure 5).
I have pointed this out on previous occasions and asked each center to double-check and verify the correctness of data entries on rectal cancer. For instance, if rectal cancers erroneously had been reported as colon cancers, the statistics would be falsified. I would therefore like to make another appeal for particularly careful checking of all data entries on rectal cancer. For so called "colorectal" cancers the involvement of the rectum must be ascertained. The printout that accompanies the confirmation questionnaire will allow you to make this verification and to notify us of any corrections.
I am sure you will agree that the analysis of posttransplant malignancies is important. This is a particularly good example of an area in which the combined effort of many centers contributes towards a research goal that otherwise would be virtually unreachable. Your contribution is highly appreciated!
I would like to announce some important changes on the CTS website
A new "Data Download" option allows you to view and download your own center's data. Sections 1-4 of the customary printout are accessible. Of course, this function is protected by your center-specific password. Because printing of all sections is rather voluminous, you may choose to only print pages of particular interest. We are planning to reduce the mailing of sections 1-4 to one mailing per year, unless requested otherwise. On the web, the data status of your center will be updated as usual with each quarterly sendout cycle.
Using the download function, you can also print blank registration forms for the various studies. In case you run out of "official" forms, you may use these forms until a new supply arrives in the mail.
Currently, more than 700 graphs illustrating scientific analyses are available on the CTS website. Although the generation of PowerPoint slides has been possible for some time, we realized that the function was too cumbersome. This has now been improved so that the inclusion of CTS website graphs in your PowerPoint presentations will be very simple. As you scroll through the selected graphs, you will note three buttons below each graph. You can select:
a) for printing in black and white
b) for printing in color (color printer required)
c) PowerPoint in color on blue background
Another change concerns the analysis of your own center's data, which has been modified as a first step to allow a more narrow definition of patient subgroups. The development of this "Center Subset Analysis" was prompted by the wish of several users.
We are very pleased that the center analysis function of the website is used so frequently. Our statistics show that approximately 130 users per day are accessing the website and that the analysis of center-specific data is becoming increasingly popular. This is a clear indication that we are making a useful contribution to your own work. The statistics for your center are updated every 3 months. We have developed a relatively painless way for supplying you with your center-specific password upon request. Please do not feel embarrassed to ask for your password in case it has been misplaced.
For the next CTS sendout cycle, scheduled for the end of January, we are planning to release a complete update of all website graphs. Because it will take time to prepare this comprehensive analysis, we would be very grateful if your follow up data could be sent in before the end of this year. Complete clinical follow up is an important precondition for making both your own center-specific analysis as well as the overall CTS analysis meaningful. Each individual center's contribution is very important. Thank you for providing your follow up data in time.
Reminder: The next shipping date for the serum and DNA projects is approaching:
For customs purposes, please be sure to indicate that the samples are of human origin, for in vitro scientific study only, for an international research project in organ transplantation, non-infectious and non-dangerous. Thank you for your cooperation.
I would like to repeat my invitation to all participants for suggestions on adapting the CTS questionnaires in order to capture important new aspects of transplantation medicine. Please do not hesitate to contact me if you have thoughts on how the study can be improved.
Thank you for your most valuable contribution to this international research project.
Sincerely yours,