Organ allocation in the age of the algorithm: avoiding futile transplantation – utility in allocation

Abstract

Purpose of review This review describes and questions the evolution of allocation systems from local team decisions in the 20th century to patient-oriented allocation using complex algorithm predicting transplant benefit. Recent findings The opening years of the 2000s have seen the implementation of prioritization scores aiming at increasing transparency and reducing waitlist mortality. The 2010s have underlined the necessity of drawing the upper limits of how sick a patient can be while still ensuring acceptable survival. More complex algorithms evaluating transplant benefit have been implemented in allocation systems to take this issue into account. Summary Allocation algorithms are becoming more and more complex, integrating numerous parameters from both donor and recipient to achieve optimal matching. The limitations of implementing these complex algorithms are represented by the evermoving waiting list demography, geographic disparities between recipients and donors, team policy adaptation to rule changes, and implicit biases within the transplant community. Survival as the only metric by which to define benefit may be seen as restrictive; quality of life may be a fruitful measure for better defining benefit in organ transplantation in the future.

An interleukin 6-based genetic risk score strengthened with interleukin 10 polymorphisms associated with long-term kidney allograft outcomes

“…An improved understanding of the immunological pathways that drive graft loss is vital to create tailored therapies in transplantation—both to treat elicited alloimmune responses and to prevent the onset thereof. 40 , 41 Herein, human genetic studies provide a complementary model permitting the assessment of causal mechanisms for target validation. 42 , 43 More importantly, therapeutic targets supported by human genetic evidence in disease association studies have a two‐fold increased chance of leading to approved drugs.…”

Predicted Cure and Survival Among Transplant Recipients With a Previous Cancer Diagnosis

“…19 Because of the medical complexity of transplantation (including the need to administer lifelong immunosuppression), transplant programs must make complex decisions that weigh benefits and risks in determining who should be referred for transplantation. 5,6 To our knowledge, the present study is the first to apply a formal statistical framework to inform the evaluation of transplant candidates with a previous cancer diagnosis. We used general population cancer registry data on 10.5 million patients with cancer to model statistical cure and applied these models to calculate individual patients' cure probabilities.…”

“…4 The decision regarding whether a patient is considered eligible for organ transplantation and placed on the waitlist takes account of comorbid medical conditions that would make transplantation high-risk or of limited benefit to the patient. 5,6 Because many cancers recur in the first few years after diagnosis, current guidelines for evaluating transplant candidates with a history of cancer typically recommend a waiting period of several years before a patient is listed, depending on the type of cancer (ie, site) and stage at diagnosis. [7][8][9][10][11] Additionally, such individuals should be carefully evaluated to confirm that there are no signs of residual cancer.…”

“…There is thus a strong rationale for transplant providers to avoid futile transplants and provide transplantation to individuals who will most benefit. 5,6 For patients with a history of cancer, this approach would correspond to selecting individuals for transplantation who have an acceptably low risk of cancer recurrence and death from their cancer (ie, cancer-specific mortality). Second, for patients with a previous cancer, the immunosuppressive medications administered during transplantation could increase their risk of cancer recurrence.…”

Ethics of allocation of donor organs

“…However, the ‘sickest first’ principle may lead to the investment of resources in those who have little chance of benefitting [ 14 ▪ ], what philosophers call the ‘bottomless pit’ objection. Thus, in the absence of ‘upper limits’ [ 15 ], the ‘sickest first’ principle reduces the overall efficiency of the allocation system, and has detrimental effects on the health of the total patient population. This is not in line with the requirements of responsible stewardship [ 9 ▪ ] of scarce medical resources: the system should save and improve the lives of patients.…”