Colorectal carcinoma after renal transplantation: Screening looks like a valuable option

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C.A.J. Oudmaijer, J.I. Roodnat, J. Kal-van Gestel, I. Lansdorp-Vogelaar, A.J. Hoitsma, T. Luth, J. van de Wetering

Chair(s): Drs. F.E. van Reekum & dr. M.C. Warlé

Wednesday 8 march 2017

17:30 - 17:42h at Johan de Meesterzaal

Categories: Parallel - Klinisch

Parallel session: Parallelsessie VII - Klinisch 2 - Nazorg na orgaantransplantatie

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Introduction:
The risk of developing colorectal carcinoma (CRC) is increased after transplantation. Screening for CRC is performed from the age of 55 years in the Netherlands. We investigated the incidence and characteristics of CRC in Dutch renal transplant recipients (RTRs) and evaluated whether and when screening is required after transplantation.

Methods:
After linking the Dutch Organ Transplant Registry (NOTR) with the Dutch Cancer Registration (IKNL), we registered all RTRs who developed CRC. We calculated the incidence rate of CRC in the RTRs in total, per age category, per year after transplantation and per years of immunosuppression, using the incidence in the general population as reference. Further statistical analysis calculated survival, age at diagnosis and mean time till diagnosis of CRC.

Results:
Between 1968 and October 2014, 21016 renal transplantations were performed in 17771 RTRs in the Netherlands. 198 Patients developed 208 CRCs after transplantation. Overall incidence of CRC in our renal RTRs was increased by a ratio of 2.34 (2.04-2.86). When divided per age group at diagnosis we found significantly increased ratios; 35-39 yrs.: 5.26(1.97-14.03), 45-49 yrs.: 2.48(1.41-4.36) and 50-54 yrs.: 2.38(1.61-3.53), when compared with the general population. The incidence ratio gradually increased along the years of immunosuppression. An exposure of 5 yrs. resulted in a relative risk of 1.4(1.08-1.82), till 4.8(2.59-8.13) after 31-35 years of immunosuppression. RTRs developed CRC at a mean age of 60-64, compared to 70-74 years in the general population. The absolute risk of CRC in RTRs was comparable to that of a 10-year older person in the general population. Median survival time after diagnosis of CRC is 2 years (range 0-19). Using a binary logistic regression, we found that more years of immunosuppression (starting at 1-5 yrs, using 5 year categories) respectively gave a RR of 1.3, 2.3, 2.8, 4.4 and 5.2 of developing CRC. Higher age at transplantation is also associated with increased risks (using categories 26-40, 41-55, 56-70 and 71-100; 1.4, 2.2, 4.0, 5.0 respectively). There was no interaction.

Discussion:
Age at transplantation and years of immunosuppressive treatment significantly increased the incidence for CRC in Dutch RTRs compared with the general population. The absolute risk of CRC in RTRs at the age of 45 years is similar to that of the general population at 55 years, which makes it necessary to start screening 10 years earlier.