Abstract: TH-PO1006
Effect of Pretransplant Waiting Time After Colon Cancer on Kidney Transplant Outcomes
Session Information
- Transplantation: Clinical - Outcomes, Malignancy, and Pathology
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 2002 Transplantation: Clinical
Authors
- Vendeville, Nicolas, University Health Network, Toronto, Ontario, Canada
- Kim, Joseph, University Health Network, Toronto, Ontario, Canada
- Kitchlu, Abhijat, University Health Network, Toronto, Ontario, Canada
- Naimark, David M., Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
Background
Active malignancy is a contraindication to transplant however some patients may become eligible after a disease-free interval. Current AST guidelines are based on a benchmark 5-year cancer-survival of >80%. Colon cancer is categorized as low, intermediate, and high-risk and it is recommended to wait 1, 2-5, and 5 years after treatment respectively prior to transplant. However, living-donor kidney transplant (LDKT) offers significant survival advantage compared to remaining on dialysis and thereby delays may be harmful. A prospective trial of wait-times would not be possible however it can be modeled. We have developed a Markov chain Monte Carlo simulation to evaluate the effect of wait-time on kidney transplant outcomes.
Methods
The model allows the user to input baseline patient characterstics such as age, sex, colonc cancer stage (I to III), and GFR or dialysis vintage. The patient is cloned and runs through a probablistic Markov chain over a time-horizon of 20 years (see Fig. 1). Published data was modeled as Weibull curves to generate probability transitions between states, with applied hazard ratios for recurrent cancer. Different wait-time strategies were compared 1-5 years vs. never. Deceased donor transplant was not included in the model.
Results
1000 simulations per strategy were required to achieve model stability. Age was varied from 45-74 years, stage was varied from I-III, and sex and dialysis vintage were held constant. Life expectancy per strategy over 20 years was consistently higher for earlier wait-times across all stages (see Fig. 2) despite a higher rate of recurrence.
Conclusion
This analysis suggests that benefits of early LDKT may exceed the risk of recurrent colon cancer. Further analysis is required to recommend changes to current guidelines.
Figure 1: Markov Model
Figure 2: Results