(UroToday.com) At one of the Kidney Cancer Podium Sessions, Dr. Andrew Carey highlighted the impetus to optimize post-transplant renal cell carcinoma (RCC) management, as no specific treatment guidelines exist currently. Previous studies have demonstrated an increased risk in malignancy after solid organ transplant surgery1. While the drivers of this disposition are unknown, one frequently cited theory is the anti-tumor immune surveillance in these patients, secondary to chronic clinical immune suppression2. The literature estimates the incidence of RCC in kidney transplant patients to be 0.16%-0.7%. Only a fraction of these tumors, which are predominantly clear cell and papillary subtypes, arise in the transplant allograft while the majority are found in the native kidney3.
To improve management strategies for these niche group of patients, Dr. Carey and his team sought to evaluate the outcomes for transplant patients with localized RCC. They conducted a retrospective single-institution review of solid organ transplant recipients with biopsy proven RCC and matched patients as detailed below (Figure 1).
Figure 1: Study Design and Analysis Cohort
There were 81 patients in the post-transplant RCC cohort that had a median age of 57, 27% of which were female. Papillary RCC was significantly more prevalent in this cohort than in the nontransplant match cohort (41% and 18%, respectively). 65% of these transplant patients were treated with surgery; 53 patients underwent radical nephrectomy and the remaining 3 underwent a partial nephrectomy. The remaining were treated with thermal ablation (23%) or active surveillance (12%).
Select outcomes from the active surveillance cohort were: median follow-up (89 months), metastatic progression (0), and overall survival at median follow-up (56%). The only significance identified between the transplant and non-transplant match group in the ablation cohort was RCC subtype (p=0.005). On the other hand, transplant patients treated with surgery were found to be more comorbid and more likely to experience post-op complications compared to their non-transplant counterparts. Similar to the ablation cohort, no significance was found in regard to local recurrence, metastatic progression, or overall survival. Median follow up for the surgery cohort was 65 and 90 months for transplant and non-transplant patients, respectively. Lastly, among all patients, only the Charlson comorbidity index was associated with mortality after adjusting for transplant status, age, grade, RCC subtype, and tumor size.
With these results, Dr. Carey concluded that: For those diagnosed with RCC, having a solid organ transplantation makes no difference in local recurrence, metastatic progression, or overall survival. Mortality was primarily associated with comorbidity. Lastly, they suspect that active surveillance is safe in appropriately selected patients, given that their 9 patients under active surveillance revealed no metastatic progression.
The work of Dr. Carey and his team was widely appreciated by his audience, evidenced by the discussion that followed his presentation. Dr. Carey and his team were certainly commended for their patient selection criteria, especially given that the renal masses were present in the native kidneys of the transplant group. One of the moderators, Dr. Steven Campbell also made the point that “when your local treatment fails, and [patients] need systemic treatment, they can’t get checkpoint inhibitors, and our hands are kind of tied. Making a good decision up front is really important. It’s a complex population, and you’re going to want to use your full array of management options, like you did”. Dr. Carey agreed and confirmed that the vast majority did undergo a biopsy to confirm carcinoma prior to treatment.
Dr. Louis Kavoussi further asked what the team wanted to do with these new findings. Dr. Carey thoughtfully responded “It’s a complex patient population that we don’t fully know how to manage. The takeaway here is that we can manage these patients like non-transplant patients, in the same way we would treat any other patient with localized RCC.”
Another interesting point arose when Dr. Kavoussi asked what transplant doctors may think of this new information. Dr. Daniel Shapiro from the University of Wisconsin stepped in to say that they work closely with their team of transplant surgeons. He shared that prior to these findings the initial tendency was to take all transplant patients to surgery with concern for the effect of immunosuppressants with RCC present. He then went on to explain that “The goal of this was to say that our outcomes are basically the same with these small renal masses. Most of these grew less than 0.5 cm per year if at all.” Overall, this study showed impressive work that was widely accepted amongst the session attendees. It will be interesting to see the future of this work, as the team hopes to expand this to a multi-institutional cohort so that a set of consensus guidelines may be built.
Presented by: Andrew Z. Carey, MD, University of Wisconsin-Madison, PGY3 Department of Urology, Madison, WI
Written by: Amanda McCormac, B.S., University of California Irvine, @MccormacAmanda on Twitter during the 2024 American Urological Association (AUA) Annual Meeting, San Antonio, TX, Fri, May 3 – Mon, May 6, 2024.
References:
- Friman TK, Jäämaa-Holmberg S, Åberg F, Helanterä I, Halme M, Pentikäinen MO, Nordin A, Lemström KB, Jahnukainen T, Räty R, Salmela B. Cancer risk and mortality after solid organ transplantation: A population-based 30-year cohort study in Finland. Int J Cancer. 2022 Jun 1;150(11):1779-1791. doi: 10.1002/ijc.33934. Epub 2022 Feb 3. PMID: 35041762; PMCID: PMC9306582.
- Huo Z, Li C, Xu X, Ge F, Wang R, Wen Y, Peng H, Wu X, Liang H, Peng G, Li R, Huang D, Chen Y, Zhong R, Cheng B, Xiong S, Lin W, He J, Liang W. Cancer Risks in Solid Organ Transplant Recipients: Results from a Comprehensive Analysis of 72 Cohort Studies. Oncoimmunology. 2020 Nov 29;9(1):1848068. doi: 10.1080/2162402X.2020.1848068. PMID: 33299661; PMCID: PMC7714465.
- Chewcharat A, Thongprayoon C, Bathini T, Aeddula NR, Boonpheng B, Kaewput W, Watthanasuntorn K, Lertjitbanjong P, Sharma K, Torres-Ortiz A, Leeaphorn N, Mao MA, Khoury NJ, Cheungpasitporn W. Incidence and Mortality of Renal Cell Carcinoma after Kidney Transplantation: A Meta-Analysis. J Clin Med. 2019 Apr 17;8(4):530. doi: 10.3390/jcm8040530. PMID: 30999706; PMCID: PMC6517974.