Can a kidney transplant be performed in a patient with a small renal cell carcinoma (RCC)?

Kidney Transplantation with Small Renal Cell Carcinoma

Kidneys with small renal cell carcinomas (<3 cm) can be safely used for transplantation after complete tumor excision with negative margins, without compromising oncological outcomes and with similar functional outcomes to conventional transplants. 1, 2

Donor Kidneys with Small RCC

Evidence-Based Recommendations

• Small renal masses (≤3 cm) discovered in potential donor kidneys can be managed with:
  • Ex vivo tumor excision before transplantation 2
  • Complete resection with negative margins is mandatory 3
  • Careful recipient selection and informed consent 2

Outcomes After Transplantation

• Oncological outcomes:

  • Extremely low recurrence rates (only one reported local relapse after 9 years in a systematic review) 2
  • No documented cases of RCC transmission in OPTN registry data of 21 kidneys following excision of tumor 3

• Functional outcomes:

  • Similar graft survival rates to conventional transplants (95% at 3 years) 2
  • Low reoperation rates (1.6%) 2
  • Recipients maintain good kidney function for years after transplantation 4

Decision Algorithm for Using Kidneys with Small RCC

1. Tumor Size Assessment:

   • Optimal candidates: Tumors <3 cm 1, 2
   • Potentially acceptable: Tumors 3-4 cm (with caution) 2
   • Not recommended: Tumors >4 cm

2. Tumor Characteristics:

   • Favorable: Well-circumscribed, peripheral location, low-grade (G1-G2) 2
   • Less favorable: High-grade, infiltrative pattern, central location

3. Surgical Approach:

   • Ex vivo tumor excision with negative margins 2
   • Nephron-sparing techniques to preserve maximal functional tissue 4
   • Frozen section analysis to confirm complete resection

4. Recipient Selection:

   • Older recipients (>60 years) may be better candidates 5
   • Recipients with longer expected waiting time 5
   • Full informed consent about theoretical recurrence risk

Living vs. Deceased Donors with Small RCC

• Living donors:

  • Comprise majority of reported cases (86% in systematic review) 2
  • Allow for planned, controlled ex vivo excision
  • Better overall outcomes due to shorter cold ischemia time

• Deceased donors:

  • Can also be utilized after tumor excision 3
  • OPTN data shows no RCC transmission in 47 contralateral kidneys and 198 non-renal organs from donors with unilateral RCC 3

Post-Transplant Management

• Regular ultrasound surveillance of the transplanted kidney
• Standard immunosuppression protocols (no evidence supporting modification)
• No mandatory waiting period before transplantation for recipients with incidentally discovered and excised small RCCs (<3 cm) 1

Pitfalls to Avoid

• Inadequate tumor excision margins
• Failure to perform frozen section analysis during surgery
• Using kidneys with high-grade or aggressive RCC subtypes
• Lack of appropriate recipient informed consent
• Insufficient post-transplant surveillance

This approach to using kidneys with small RCC represents an important strategy to expand the donor pool while maintaining excellent outcomes for recipients, addressing the critical shortage of available organs for transplantation.