Conversion to Sirolimus in Posttransplant Renal Neoplasms

Conservative treatment of de novo renal carcinoma on kidney graft

BACKGROUND

De novo renal carcinoma in kidney transplants is an uncommon but not exceptional condition and is of significant importance due to the potential for recipient mortality and graft loss. The aim of our study was to determine the management and outcome of these tumors in our Kidney Transplantation Unit.

MATERIAL AND METHODS

We analyzed cases of de novo kidney tumors among patients who underwent transplantation in the last 17 years in our Kidney Transplantation Unit. We detected 3 cases of clear cell carcinoma and 1 case of papillary carcinoma on the graft. We conducted follow-up on the tumor and renal function and analyzed patient responses to changes in immunosuppression.

RESULTS

Tumorectomy was performed in all cases, and subsequent transplantectomy was required for patients with papillary carcinoma. None of the patients had relevant surgical complications. We also changed the patients' regimen to a proliferation signal inhibitor or mTOR inhibitor and completely withdrew all anticalcineurin agents. With a mean follow-up of 43.5 months (15-61), the 3 patients with clear cell carcinoma survived with good graft function and with no evidence of tumor recurrence. The patient with papillary carcinoma underwent follow-up at another hospital center.

CONCLUSIONS

Conservative surgery along with conversion to a proliferation signal inhibitor appears to be a safe option for treating primary tumors in kidney grafts and offers good oncological and renal function results in the short and medium term.

[Malignant neoplasms and kidney transplantation]

Together with cardiovascular disorders and metabolic changes, malignant diseases are considered as great challenges in clinical transplantation. As far as long-term function of transplanted organs is concerned, an impact of malignancies is obvious. However, it is important to distinguish between neoplastic disease originating from preexisting lesions in the transplanted organs and de novo graft tumors. Further, there is also a high risk of developing malignant disease during the dialysis, likely due to potential harmful metabolic changes associated with this procedure. After curative management of tumors in such patients, an interval of 2 years for surveillance should be adhered to before patients are put back on the waiting list. The overall risk of transmission of a malignant disease with the transplanted graft has been considered to be as low as <0.2%. In this context, and considering the continual shortage of donated organs, there is an international consensus about the use of kidney grafts with a history of small tumors (<2 cm in diameter und low-grade, i.e., G1). However, the lesions should have been removed with subsequent histopathologic characterization before the acceptance of the organ for transplantation. Early diagnosis and management of de novo malignant disease in transplant patients is crucial for the prognosis of graft function and patient survival. Genitourinary malignancies are frequent among de novo malignancies in transplanted patients. Thus, there is a need for clearly structured concepts for screening of transplant patients in order to detect early malignancies. The incidence of malignant disease correlates directly with the extent of immunosuppression in patients with end-stage renal disease (ESRD) on dialysis, as well as after transplantation with life-long immunosuppressant therapy. In addition, also geographic factors seem to play a role in the differential incidence of tumors among different populations. For instance, the highest incidence of malignancies among immunosuppressed patients has been observed in Australia followed by the USA and Europe. This might be due to the high incidence of de novo skin cancer, which has been linked to the extent of UV exposure.

Evaluation of the efficacy and safety of conversion to sirolimus in 85 renal transplant recipients

OBJECTIVE

Treatment with sirolimus (SRL) is a potential therapeutic option for renal transplant recipients, especially those who have developed chronic graft nephropathy (CGN) or a neoplasm. Our aim was to analyze the efficacy and safety of conversion to SRL in renal transplant recipients.

MATERIALS AND METHODS

We undertook a retrospective study of 85 patients converted to SRL, 47% for tumors, 39% for CGN, and 14% for other causes. The follow-up period was 34 months (range, 1-93 months).

RESULTS

Baseline creatinine was 1.8 +/- 0.69 mg/dL (1.6 +/- 0.59 for tumors and 2.3 +/- 0.6 for CGN). At 1 year, the creatinine was the same in both groups: 1.8 mg/dL (P = NS). Graft survival at 12 months was 89% (81% for tumors, 81% for CGN, and 100% for other causes). SRL was withdrawn in 34% of patients: 18% for severe side effects, 7% for patient death, and 9% for graft loss. The serum creatinine and proteinuria were significantly increased among those subjects who returned to dialysis because of CGN compared with those with conserved renal function. Patients who developed pneumonitis showed a lower baseline aMDRD, but no difference in SRL levels. Side effects occurred in 40% of patients, with no difference in renal function, proteinuria, or SRL levels. Renal function showed a significant improvement in the patients who continued SRL (aMDRD 45.7 vs 50.7 mL/min/1.73 m(2) at 12 months; P = .08), more marked among those who converted due to CGN. Increases were seen in levels of serum lipids, as well as in the percentage of patients treated with statins. Proteinuria increased significantly, as did the percentage of patients treated with ACE inhibitors/ARA2.

CONCLUSIONS

Conversion to SRL in patients with CGN was safe when renal function had not undergone marked worsening and there was no proteinuria. Patients who were converted experienced an improvement in renal function.

Lung cancer and lung transplantation: a review

With the increase in the number of lung transplants, it is expected that there will be a corresponding increase in the number of lung cancers reported in these patients. Longevity of the transplant recipients, lung transplantation for chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis, a history of smoking, and the increasing age of the lung donors make lung cancer more likely. Nodules and masses seen in chest imaging in lung transplant patients call for work up until a final diagnosis is achieved because there is a high likelihood of a serious infection or malignancy. The presence of a native lung is a major risk factor for lung cancer occurring in the transplant setting. Lung cancer of donor origin is rare. Bronchioloalveolar carcinoma confined to one lung can potentially be treated by transplanting the affected lung. Treatment for patients with lung cancer in the lung transplant setting has to be individualized because of the complexity of their medical problems and multiple medications. Attention needs to be focused on detecting lung cancer early in these patients to achieve a favorable outcome.

The role of mTOR inhibitors in the management of posttransplant malignancy

Organ transplant recipients given mammalian target of rapamycin inhibitor (mTORi) have reduced incidence of de novo posttransplant malignancies (dNPTMs). Posttransplant Kaposi's sarcoma and nonmelanotic skin malignancies (NMSC) frequently undergo remission/regression after conversion to mTORi immunosuppression (IS), especially early, small, and low-grade lesions, whereas larger, aggressive, and metastatic skin tumors are less likely to respond. mTORi-based IS is effective and well tolerated in orthotopic liver transplant patients with hepatocellular carcinoma (HCC) achieving excellent survival and disease-free intervals, particularly with extended criteria tumors, although the evidence that mTORi prevents HCC recurrence after orthotopic liver transplantation is only suggestive. Regression of metastatic HCC and other tumors and various forms of posttransplant lymphoproliferative disease have occurred after mTOR conversion. Documentation of regression/remission of other solid-organ dNPTM (colon, stomach, breast, etc.) after mTORi conversion is essentially absent with only anecdotal reports lacking follow-up data. Unfortunately, there is not a single reported prospective clinical trial powered for looking at the effect of mTORi IS in transplant recipients. Nevertheless, reduced incidence of all of dNPTMs and remission/regression of the commonest posttransplant tumors with mTOR therapy are strong reasons to expand the use of mTORi.

Potential combination chemotherapy approaches for advanced adult-type soft-tissue sarcoma

Soft-tissue sarcomas (STS) include a spectrum of histologically and clinically different tumors. Patients with these tumors are typically relatively young and the course of disease is characterized by early metastasis as well as limited response to chemotherapy. However, a few subtypes, such as small round-cell tumors and rhabdomyosarcoma (other than pleomorphic), are considered chemotherapy sensitive. In addition, reflecting successful translational research of recent years, gastrointestinal stromal tumor and dermatofibrosarcoma protuberans have become model diseases for targeted oncologic therapy. We summarize current treatment options for metastatic STS, including established first-line chemotherapy approaches, mainly with anthracyclines and/or ifosfamide and second-line treatment choices beyond anthracyclines. Until only a few years ago, treatment choices for metastatic STS were easy to review because of the very limited number of active compounds available. However, with the advent of novel therapeutic strategies such as the anti-angiogenic approach and a multitude of novel compounds available both outside and within clinical studies, it has potentially become more difficult to keep track of currently available treatment options for STS and their clinical safety and efficacy. In this practice-oriented article, we therefore review treatment goals in advanced STS and provide an overview of compounds with proven activity in this setting. Anthracyclines with or without ifosfamide are still considered standard of care for most STS subtypes, especially for high-grade tumors. There is no evidence-based recommendation regarding use of second-line treatment options. However, a number of established compounds, including dacarbazine/temozolomide, gemcitabine, taxanes, trofosfamide, DNA topoisomerase I inhibitors, DNA minor groove binders, and bendamustine have shown activity. Recently, trabectedin, a DNA minor groove binder initially isolated from a sea sponge, has proven effective and received European approval for use in treatment-refractory STS. In addition, novel compounds such as bevacizumab, multi-tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, imatinib, and the thrombospondin agonist ABT 510 represent attractive partners for the above-mentioned cytostatic agents, or may even be effective single agents in the clinically advanced setting. Novel combinations are being evaluated in clinical studies. In order to be successful, it may be necessary to combine not only different compounds but also different targets beyond the proliferation machinery of sarcoma cells such as tumor angiogenesis, the tumor stromal compartment, or tumor cell oncogene products.