De novo kidney graft tumors: results from a multicentric retrospective national study

Kidney Graft Leiomyosarcoma: A Case Report

BACKGROUND

Kidney transplant (KT) recipients have a higher incidence of malignancy than the general population. Smooth muscle tumors (SMT), including leiomyosarcoma, are rare in kidney transplant recipients, and most cases are associated with Epstein-Barr virus (EBV) infection.

CASE REPORT

A 57-year-old man received a deceased donor kidney transplant at the age of 53 years, with 5 human leukocyte antigen (HLA) mismatches. Before the transplantation, the patient was IgG positive for EBV viral capsid antigen (VCA), negative for IgM EBV VCA, and also negative for IgG EBV nuclear antigen (EBNA), suggesting a prior EBV infection. He received immunosuppressive induction with basiliximab, and maintenance with tacrolimus, mycophenolate mofetil, and prednisolone. Two years after transplantation, he had an acute cellular rejection episode treated with methylprednisolone. An increased graft size was found 4 years after transplantation. A computed tomographic scan showed 3 solid tumors involving the renal graft with extension to the perinephric fat; no secondary localizations were found. A nephrectomy of the graft was performed. The histologic diagnosis was a high-grade leiomyosarcoma. In situ hybridization for EBV was negative. Nine months after nephrectomy, local recurrence was diagnosed. The surgical approach was unsuccessful, and the patient died after a brief period.

CONCLUSION

Kidney leiomyosarcoma is a very rare clinical condition. Most of these neoplasms that arise in transplanted recipients are associated with EBV in tumor tissue. Only one case of renal graft leiomyosarcoma without EBV RNA in the tumor has been previously reported.

Independent Pre-Transplant Recipient Cancer Risk Factors after Kidney Transplantation and the Utility of G-Chart Analysis for Clinical Process Control

Background

The aim of this study is to identify independent pre-transplant cancer risk factors after kidney transplantation and to assess the utility of G-chart analysis for clinical process control. This may contribute to the improvement of cancer surveillance processes in individual transplant centers.

Patients and Methods

1655 patients after kidney transplantation at our institution with a total of 9,425 person-years of follow-up were compared retrospectively to the general German population using site-specific standardized-incidence-ratios (SIRs) of observed malignancies. Risk-adjusted multivariable Cox regression was used to identify independent pre-transplant cancer risk factors. G-chart analysis was applied to determine relevant differences in the frequency of cancer occurrences.

Results

Cancer incidence rates were almost three times higher as compared to the matched general population (SIR = 2.75; 95%-CI: 2.33–3.21). Significantly increased SIRs were observed for renal cell carcinoma (SIR = 22.46), post-transplant lymphoproliferative disorder (SIR = 8.36), prostate cancer (SIR = 2.22), bladder cancer (SIR = 3.24), thyroid cancer (SIR = 10.13) and melanoma (SIR = 3.08). Independent pre-transplant risk factors for cancer-free survival were age <52.3 years (p = 0.007, Hazard ratio (HR): 0.82), age >62.6 years (p = 0.001, HR: 1.29), polycystic kidney disease other than autosomal dominant polycystic kidney disease (ADPKD) (p = 0.001, HR: 0.68), high body mass index in kg/m² (p<0.001, HR: 1.04), ADPKD (p = 0.008, HR: 1.26) and diabetic nephropathy (p = 0.004, HR = 1.51). G-chart analysis identified relevant changes in the detection rates of cancer during aftercare with no significant relation to identified risk factors for cancer-free survival (p<0.05).

Conclusions

Risk-adapted cancer surveillance combined with prospective G-chart analysis likely improves cancer surveillance schemes by adapting processes to identified risk factors and by using G-chart alarm signals to trigger Kaizen events and audits for root-cause analysis of relevant detection rate changes. Further, comparative G-chart analysis would enable benchmarking of cancer surveillance processes between centers.

Successful Endovascular Control of Renal Artery in a Transplant Kidney During Nephron Sparing Surgery (NSS) for Large Centrally Located Tumor

Renal cell carcinoma in a transplant kidney is a rare condition. Nephron Sparing Surgery (NSS) is the treatment of choice. One of the main technical challenges is obtaining adequate vascular control. We present a rare case of large centrally located hillar tumor in a kidney 18 years after transplantation treated with NSS. Vascular control was achieved by using a novel approach. Post-operative course was uneventful with minimal decrease in renal function. We believe that this unique choice of treatment can be used in cases of NSS where the access to the renal pedicle is limited.

De novo papillary carcinoma in a renal allograft: the pros and cons of immunosuppression

We present a case of a multifocal kidney transplant renal cell carcinoma in a 35-year-old lady, presenting 16 years after kidney transplantation, diagnosed during investigation of recurrent urinary tract infections. The patient underwent a graft nephrectomy and subsequently maintained on haemodialysis. She remained disease-free after 4 years of surveillance and thus reactivated on the transplant list. This case reinforces the fact that immunosuppressive therapy has made kidney transplantation possible; however, it is accompanied by a higher incidence of malignancy. It also reinforces the importance of lifelong screening of both native and renal transplant grafts.

A national study of kidney graft tumor treatments: Toward ablative therapy

BACKGROUND

Results of the conservative treatment of renal cell carcinomas arising in functional renal transplants are unknown compared to transplant nephrectomy. Only small series or case reports have been reported.

METHODS

Data were collected from 32 transplantation centers nationwide on cases of de novo tumors in functional renal transplants presumed to be malignant between January 1988 and December 2013.

RESULTS

Among 116 de novo transplant tumors, 62 were treated conservatively including: 48 by partial nephrectomy (PN) and 14 by thermal ablation (TA). These patients were compared to 30 other patients who were treated by transplant nephrectomy. The median age of the transplanted kidneys at the time of diagnosis was 43.5 years old as calculated from the donor's age. Tumors treated by transplant nephrectomy presented more often with symptoms (pain, fever, impaired condition, hematuria) than tumors treated conservatively (P = .019). After PN, final histology showed 27 (47.5%) papillary carcinomas, 19 (32.2%) clear cell carcinomas, 1 mixed carcinoma, and 2 oncocytomas. The median tumor size treated by PN was 24 mm with no difference in comparison to the TA group. Nine patients treated by PN had postoperative complications (21%), including 4 requiring operative intervention (Clavien IIIb). None of the patients treated by TA had complications. Specific survival was 100% at the time of last follow-up (median time after treatment 37 months) for patients treated by PN or TA.

CONCLUSION

PN proved to be efficient in the treatment of small tumors of transplanted kidneys with good long-term functional and oncologic outcomes, including avoiding return to dialysis. TA seems to be an alternative therapy with good results in selected patients.

Multifocal Primary Neoplasms in Kidney Allografts: Evaluation of Two Cases

Renal cell carcinoma (RCC) is the fifth most common malignancy in kidney transplant recipients, with increased risk arising due to immunosuppression. De novo RCC occurrence in kidney allografts is much less common when compared with the native kidneys. Multifocal RCC in allograft kidneys is rarely described. In this report, we discuss two cases of de novo multifocal renal neoplasms in allograft kidneys. Case 1 had three distinct neoplastic lesions of >5 mm, and case 2 had four. Using the World Health Organization 2016 classification of adult renal tumours, case 1 had one clear-cell (cc) RCC (grade 3) and two papillary adenomas; all confined to the kidney. Case 2 had a nodular lesion classified as ccRCC (grade 4) with focal rhabdoid differentiation and some infiltration of renal sinus fat; a cc tubulopapillary RCC; a multilocular cystic renal neoplasm of low malignant potential; and a mucinous tubular and spindle cell carcinoma; the last three all confined to the kidney. This is the first report of mucinous tubular and spindle cell carcinoma in a kidney allograft. When considering multifocal RCC with discordant histology, it is likely that these represent independent tumourigenic events.

Renal cell carcinoma in functional renal graft: Toward ablative treatments

The occurrence of a kidney transplant tumor is a rare but serious issue with a double risk: the return to dialysis and the development of metastatic cancer. Publications on this topic are mainly case reports. The purpose of this review was to report an exhaustive literature review of functional graft renal cell carcinomas to highlight the impact of tumors on the renal graft outcomes. 201 de novo renal carcinomas in functional renal grafts from 69 publications were included. Incidence was estimated at 0.18%. Graft tumors were mostly asymptomatic (85.9%). Whatever the discovery circumstances of graft tumors, they were mostly documented by graft ultrasounds supplemented by CT-scanning or MR imaging. Nephron sparing surgery (95 patients) was the first treatment performed followed by radiofrequency ablation (38 patients) and cryotherapy (10 patients). The most common tumor graft histology was clear cell carcinoma (46.4%), followed by papillary carcinoma (43.7%). Specific mortality was 2.9% with 6 deaths. Renal graft cell carcinoma is a rare pathology with a low specific death. When possible, conservative treatment should be the first choice.

De novo renal cell carcinoma in a kidney allograft 20 years after transplant

Renal cell carcinoma (RCC) in a kidney allograft is rare. We report the successful diagnosis and treatment of a de novo RCC in a nonfunctioning kidney transplant 20 years after engraftment. A 54-year-old man received a kidney transplant from his mother when he was 34 years old. After 10 years, chronic rejection resulted in graft failure, and the patient became hemodialysis-dependent. Intravenous contrast-enhanced computed tomography (CT) for the evaluation of gastrointestinal symptoms revealed a solid 13 mm tumor in the kidney graft. The tumor was confirmed on ultrasound examination. This tumor had not been detected on a surveillance noncontrast CT scan. Needle biopsy showed that the tumor was an RCC. Allograft nephrectomy was performed. Pathological examination showed that the tumor was a Fuhrman Grade 2 RCC. XY-fluorescence hybridization analysis of the RCC showed that the tumor cells were of donor origin. One year after the surgery, the patient is alive and has no evidence of tumor recurrence. Regardless of whether a kidney transplant is functioning, it should periodically be imaged for RCC throughout the recipient's lifetime. In our experience, ultrasonography or CT with intravenous contrast is better than CT without contrast for the detection of tumor in a nonfunctioning kidney transplant.

De Novo Renal Cell Carcinoma in an Allograft Kidney Treated with Nephron-Sparing Surgery: A Case Report

The development of primary malignant tumors is a distressing complication of organ transplant. However, the emergence of de novo renal cell carcinoma from a kidney allograft is rare. A 60-year-old man underwent living kidney transplant from a spousal donor. Six years after the transplant surgery, computed tomographic evaluation confirmed the presence of a 2.8-cm-diameter solid mass in the lower pole of the allograft. Partial allograft nephrectomy was performed, and the margin surrounding the normal parenchyma was resected. The serum level of creatinine did not decrease. Here, we report a case of renal cell carcinoma in an allograft kidney that was successfully treated with nephron-sparing surgery.

Nephron sparing surgery for De Novo kidney graft tumor: results from a multicenter national study

Nephron sparing surgery (NSS) results in the transplanted population remain unknown because they are only presented in small series or case reports. Our objective was to study renal sparing surgery for kidney graft renal cell carcinomas (RCC) in a multicenter cohort. Data were collected from 32 French transplantation centers. Cases of renal graft de novo tumors treated as RCC since the beginning of their transplantation activity were included. Seventy-nine allograft kidney de novo tumors were diagnosed. Forty-three patients (54.4%) underwent renal sparing surgery. Mean age of grafted kidneys at the time of diagnosis was 47.5 years old (26.1-72.6). The mean time between transplantation and tumor diagnosis was 142.6 months (12.2-300). Fifteen tumors were clear cell carcinomas (34.9%), and 25 (58.1%) were papillary carcinomas. Respectively, 10 (24.4%), 24 (58.3%) and 8 (19.5%) tumors were Fuhrman grade 1, 2 and 3. Nine patients had postoperative complications (20.9%) including four requiring surgery (Clavien IIIb). At the last follow-up, 41 patients had a functional kidney graft, without dialysis and no long-term complications. NSS is safe and appropriate for all small tumors of transplanted kidneys with good long-term functional and oncological outcomes, which prevent patients from returning to dialysis.

Assessment of chimerism in epithelial cancers in transplanted patients

Cancer is now the most severe complication in the long term in transplant recipients. As most solid-organ or hematopoietic stem-cell transplantations are allogeneic, chimerism studies can be performed on cancers occurring in recipients. We summarize here the different methods used to study chimerism in cancers developing in allogeneic-transplant recipients, analyze their respective advantages and report the main results obtained from these studies. Chimerism analyses of cancers in transplant recipients require methods suited to tissue samples. In the case of gender-mismatched transplantation, the XY chromosomes can be explored using fluorescent in situ hybridization on whole-tissue sections or Y-sequence-specific PCR after the laser microdissection of tumor cells. For cancers occurring after gender-matched transplantation, laser microdissection of tumor cells enables studies of microsatellite markers and high-resolution melting analysis of mitochondrial DNA on genes with marked polymorphism, provided these are different in the donor and the recipient. The results of different studies address the cancers that develop in both recipients and in transplants. The presence of chimeric cells in these two types of cancer implies an exchange of progenitor/stem-cells between transplant and recipient, and the plasticity of these progenitor/stem-cells contributes to epithelial cancers. The presence of chimeric cells in concomitant cancers and preneoplastic lesions implies that the oncogenesis of these cancers progresses through a multistep process.

Metastatic renal cell carcinoma: update on epidemiology, genetics, and therapeutic modalities

The treatment of advanced renal cell carcinoma (RCC) remains a major therapeutic challenge for clinicians. Despite advances in the understanding of the immunobiology of RCC and the availability of several novel targeted agents, there has been little improvement in the survival of patients with metastatic RCC. This review will focus on the recent understanding of risk factors and treatment options and outcomes of metastatic RCC, in particular, targeted therapeutic agents that inhibit vascular endothelial growth factor and mammalian target of rapamycin pathways. Prospective studies are required to determine whether sequential targeted therapy will further improve progression-free survival in RCC. Ongoing research to develop novel agents with better tolerability and enhanced efficacy in the treatment of metastatic RCC is required.

Human de novo papillary renal-cell carcinomas in a kidney graft: evidence of recipient origin with adenoma-carcinoma sequence

Papillary renal-cell carcinoma (pRCC) is unusual for its occurrence in kidneys with chronic dysfunction, for its frequent multifocality and for its common association with papillary adenoma, a benign renal lesion morphologically indistinguishable from pRCC. Concomitant development of papillary adenoma and pRCC in five transplanted kidneys, where donor and recipient characteristics are well established, provided a unique opportunity for molecular studies of de novo pRCC carcinogenesis. We aimed to study this tumor type to determine whether or not the different papillary tumors have the same origin, and whether or not papillary adenomas are precursor lesions of pRCC. We performed XY-FISH in sex-mismatched kidney transplants, and polymorphic microsatellite DNA and high-resolution melting of mitochondrial DNA analyzes in all five patients on laser-microdissected tumor cells, then compared these molecular profiles to donor and recipient profiles. This study (i) identified the recipient origin of de novo papillary adenomas and pRCCs in a kidney transplant, (ii) demonstrated an identical origin for precursor cells of papillary adenomas and pRCCs and (iii) showed additional genetic alterations in pRCCs compared to papillary adenomas. This molecular approach of papillary tumors developed in transplanted kidney identified successive steps in carcinogenesis of human de novo papillary renal-cell carcinoma.

The high rate of de novo graft carcinomas in renal transplant recipients

BACKGROUND

To investigate the incidence, the clinical characteristics and outcomes of renal graft carcinomas in the same renal transplant population.

METHODS

From April 1989 to April 2012, 1,037 consecutive renal transplantations were performed in our department. Data were collected prospectively in an extensively maintained database. For all recipients, monitoring consisted of clinical examination and an abdominopelvic CT scan or ultrasonography at least once a year.

RESULTS

After 1,037 renal transplantations, 48 men and 14 women (sex ratio 3:4) with a mean age of 54 years (25.1-78.9) were included for urological malignancies. Eight graft carcinomas were identified: 7 renal cell carcinomas (5 papillary carcinomas and 2 clear cell carcinomas of the renal graft) and 1 transitional cell carcinoma of the ureteral graft (incidence 0.78%). Nephron-sparing surgery was chosen for 5 patients with good outcomes. All graft renal cell carcinomas were classified as pT1a and the mean size of tumors was 28.4 mm (range 6-45). The 5-year specific survival rate was 100%. No recurrence was observed with a mean follow-up of 36.8 months (4.1-84.3).

CONCLUSION

Thus confirming an increased risk of de novo graft cancer, close monitoring of renal transplant recipients should be discussed with at least an abdominopelvic ultrasonography and PSA measurement once a year. Renal cell graft carcinomas seemed to be mostly small and of papillary type and low grade.

Plasminogen Activator Inhibitor-1 Deficiency Has Renal Benefits but Some Adverse Systemic Consequences in Diabetic Mice

BACKGROUND

Elevated plasma levels of plasminogen activator inhibitor-1 (PAI-1) are observed in patients with obesity, hypertension and diabetes, and several observations suggest that PAI-1 mediates diabetic vascular complications. Although increased intrarenal expression of PAI-1 is also a feature of diabetic nephropathy, evidence that PAI-1 plays a primary pathogenetic role in the renal pathology is lacking.

METHODS

This study was designed to investigate the renal effects of genetic PAI-1 deficiency in db/db mice with obesity, hyperinsulinemia and hyperglycemia. For comparison the effects of PAI-1 deficiency were also examined in a cohort of mice with insulin-deficient streptozotocin (STZ)-induced diabetes. The findings are reported for 4 study groups at 8 months of age: PAI-1+/+ controls, PAI-1+/+ diabetics, PAI-1-/- controls and PAI-1-/- diabetics.

RESULTS

PAI-1 deficiency had an unexpected negative impact on the db/db mice. Overall 33% of the diabetic mice died prematurely, and 63% of the db/db PAI-1-/- males had an obese body habitus but were runts. The final analyses were limited to the female db/db mice. Several nephropathy parameters were improved in the db/db PAI-1-/- group compared to the db/db PAI-1+/+ group including: albumin-to-creatinine ratios (57 +/- 45 vs. 145 +/- 71 microg/mg x10), change in glomerular extracellular matrix (ECM) area (decrease of 10% compared to controls vs. an increase of 31%) and increased total kidney collagen (47% increased vs. 96% in the PAI-1+/+ diabetics). The serum glucose levels were 15-25% lower in the PAI-1-/- nondiabetic control groups and remained lower in the db/dbPAI-1-/- mice. The STZ study was performed in males. None of the mice developed a runted phenotype or died prematurely. After diabetes of 6 months' duration changes in glomerular ECM area (-15 vs. +64%) and total kidney collagen (+8 vs. +40%) were lower in the PAI-1-/- mice compared to the PAI-1+/+ mice. The serum cholesterol levels were significantly lower in the PAI-1-/- mice, both controls (47 +/- 3 vs. 53 +/- 10 mg/dl) and diabetics (48 +/- 3 vs. 74 +/- 9 mg/dl).

CONCLUSION

These data suggest a direct role for PAI-1 in renal matrix expansion and metabolic control in diabetes, but they also highlight important adverse outcomes that include male runting and premature death in mice with diabetes due to an inactive leptin receptor.