Cancer after renal transplantation

Incidence of malignancy after living kidney transplantation: a multicenter study from iran

Malignancy is a common complication after renal transplantation. However, limited data are available on post-transplant malignancy in living kidney transplantation. Therefore, we made a plan to evaluate the incidence and types of malignancies, association with the main risk factors and patient survival in a large population of living kidney transplantation. We conducted a large retrospective multicenter study on 12525 renal recipients, accounting for up to 59% of all kidney transplantation in Iran during 22 years follow up period. All information was collected from observation of individual notes or computerized records for transplant patients. Two hundred and sixty-six biopsy-proven malignancies were collected from 16 Transplant Centers in Iran; 26 different type of malignancy categorized in 5 groups were detected. The mean age of patients was 46.2±12.9 years, mean age at tumor diagnosis was 50.8±13.2 years and average time between transplantation and detection of malignancy was 50.0±48.4 months. Overall tumor incidence in recipients was 2%. Kaposis' sarcoma was the most common type of tumor. The overall mean survival time was 117.1 months (95% CI: 104.9-129.3). In multivariate analysis, the only independent risk factor associated with mortality was type of malignancy. This study revealed the lowest malignancy incidence in living unrelated kidney transplantation.

Treatment of advanced rectal cancer after renal transplantation

Renal transplantation is a standard procedure for end-stage renal disease today. Due to immunosuppressive drugs and increasing survival time after renal transplantation, patients with transplanted kidneys carry an increased risk of developing malignant tumors. In this case report, 3 patients with advanced rectal cancer after renal transplantation for renal failure were treated with anterior resection or abdominoperineal resection plus total mesorectal excision, followed by adjuvant chemotherapy. One patient eventually died of metastasized cancer 31 mo after therapy, although his organ grafts functioned well until his death. The other 2 patients were well during the 8 and 21 mo follow-up periods after rectal resection. We therefore strongly argue that patients with advanced rectal cancer should receive standard oncology treatment, including operation and adjuvant treatment after renal transplantation. Colorectal cancer screening in such patients appears justified.

Comparative analysis of regulatory and effector T cells in progressively growing versus rejecting tumors of similar origins

Although regulatory T cells (Tregs) have been detected in clinically apparent and experimentally induced tumors, the significance of their presence is obscured because past studies examined late-stage tumors that had formed in immunocompetent hosts and thus had evolved mechanisms to escape immunologic recognition and/or elimination. Herein, we report the first comparative analysis of the antitumor response to 3'-methylcholanthrene-induced tumors, which either grow progressively (progressor tumors) or are rejected by the immune system (regressor tumors). Surprisingly, we found that both progressor and regressor tumors harbored proliferating (i.e., activated) Foxp3+CD25+Tregs. However, progressor tumors contained a higher percentage of Tregs in the lymphocyte subset versus regressor tumors. The Tregs in progressor tumors were derived from peripheral CD25+ natural Tregs, accumulated early after tumor challenge and were actively proliferating, suggesting that progressor tumors recruited and/or activated endogenous Tregs as a mechanism of escaping immune destruction. To explore whether Tregs directly contributed to the progressive growth phenotype of progressor tumors, we monitored tumor outgrowth in naive wild-type recipients pretreated with either a control monoclonal antibody (mAb) or a depleting CD25-specific mAb. In mice predepleted of CD25+ cells, the tumors that subsequently developed displayed an increased accumulation of proliferating CD8+ T cells and were rejected. These results show that, although Tregs are activated in both regressor and progressor tumors, the ratio of regulatory to effector T cells is critical in determining whether the host successfully rejects the tumor or eventually succumbs to tumor outgrowth.

Hepatocellular carcinoma in renal transplant patients

INTRODUCTION

Chronic liver diseases, especially those related to hepatitis B (HBV) and C viruses (HCV), are a common problem in renal transplant patients. Hepatocellular carcinoma (HCC) is a complication of chronic liver diseases, incidence in the renal transplant cohort is higher than in the general population (1.4% to 4% vs 0.005% to 0.015%).

METHODS

We retrospectively evaluated the incidence of HCC, its clinical presentation, the treatments, and the relation to chronic viral hepatitis among the population transplanted at our center between January 1980 and December 1998 and followed to August 2003.

RESULTS

During the study period, six recipients among 534 renal transplants displayed HCC (incidence 1.12% of the entire population and 2.29% of patients with chronic viral hepatitis). Among the cohort five were men, and all had chronic viral hepatitis: three HBV, one HCV, and 2, a coinfection. HCC was diagnosed 124.1 (range 45 to 244) months after transplantation. All patients presented with abnormal liver function tests and tumors larger than 5 cm. Four had more than three tumors and three had an alpha-fetoprotein level higher than 400 IU/mL. Three patients received no treatment (survivals 1, 1, and 4 months); two patients, chemoembolization (survival 6 and 12 months); and one, surgical ethanol injections (survival 4 months). The overall survival was 4.5 months.

CONCLUSION

HCC in renal transplant recipients is a common complication among patients with chronic viral hepatitis. The outcome was poor because HCC was detected at an advanced stage. Screening strategies for early diagnosis must be prospectively evaluated.

Risk of malignancy with long-term immunosuppression in renal transplant recipients

BACKGROUND

Improvements in immunosuppressive regimens have significantly enhanced patient and graft survival in renal transplant recipients. However, susceptibility to neoplastic disorders is increased as a consequence of prolonged immunosuppression. Available data pertaining to cancer risks in renal transplant recipients have been inconsistent, and much of it is derived from international studies, which may not be truly representative of the United States population.

METHODS

We studied a total of 1979 transplants performed in 1739 patients from a single center in the United States with a mean follow-up of 6.1 years, and a total of 9852 person-years' follow-up.

RESULTS

The mean age at the time of diagnosis of cancer was 50 years, and the mean interval between transplant and diagnosis of cancer was 95 months. Older patients receiving a transplant had a significantly higher risk for developing cancer as opposed to younger patients (RR 6.2 for >60 years compared with <40 years). When compared with the general population using data from the Surveillance, Epidemiology and End Results (SEER) registry, the overall risk for nonskin malignancies was modestly increased in our transplant recipients, with a standardized incidence ratio (SIR) of 1.4 (P= 0.01). When stratified by age groups, younger age at transplant (<40 years) had the highest SIR, at 2.3 (P < 0.001). Similarly, duration post-transplant >10 years had an SIR of 2.4 (P < 0.001).

CONCLUSION

We believe that this study is representative of the United States' renal transplant population, and highlights the need for reduced immunosuppression in the long-term and increased vigilance for cancers in younger patients receiving renal transplantation.

Racial and ethnic variations in incidence and pattern of malignancies after kidney transplantation

Malignancies are a well-recognized complication of renal transplantation. Although the problem is well studied in developed countries, less is known about it in developing countries. Although geographic and ethnic variations have been alluded to in several reports, to our knowledge the subject has not been investigated formally. From April 1976 through March 1999, 41 (7.6%) patients were diagnosed with cancer among a heterogeneous population of renal allograft recipients treated at our institution in Cape Town, South Africa. The incidence of malignancies was comparable in white and nonwhite patients. However, squamous cell cancer and basal cell cancer of the skin (in that order) were the most common cancers in white patients, in whom they occurred exclusively. On the other hand, Kaposi sarcoma was the most common cancer in nonwhite renal allograft recipients, in whom it accounted for almost 80% of all cancers. Review of the world literature suggests that posttransplant cancers are less common in developing countries; Kaposi sarcoma is the most common lesion, with few exceptions. Malignant lymphomas are also more common in developing countries. The impact of different immunosuppressive regimens is controversial. In general, cyclosporine is not associated with a significant increase in the incidence of cancer after renal transplantation, although the time to the first cancer may be reduced. In our experience, the pattern of posttransplant cancers in white and nonwhite patients living in the same geographic region epitomizes the world experience of the disease and suggests that genetic factors, rather than geography, are the more important determinants of cancer development after renal transplantation.