Sung Goo Chang

Comparison of postoperative estimated glomerular filtration rate between kidney donors and radical nephrectomy patients, and risk factors for postoperative chronic kidney disease

To compare post‐nephrectomy renal function between kidney donors and renal cell carcinoma patients, to evaluate trends in recovery, and to identify factors relevant to renal failure.

Deficiency of MSH2 expression is associated with clear cell renal cell carcinoma

DNA hypermethylation plays a major role in the regulation of gene expression in differentiation, development and diseases. The DNA mismatch repair system, which includes Mut-S-Homologon-2 (MSH2) protein, is essential to maintain the stability of the genome during repeated duplication. This study aimed to investigate tumoral MSH2 immunohistochemical expression in clear cell renal cell carcinoma (RCC), and the associations between tumoral MSH2 immunohistochemical expression and clinicopathological parameters. Previously, we reported a high-throughput method for analyzing the methylation status of 807 preselected genes; Illumina’s GoldenGate Methylation Cancer Panel I microarray. The MSH2 gene was identified to be hypermethylated in cancer tissue compared with normal tissue. From January 2000 to December 2012, 129 clear cell RCC cases (median age, 61 years) were included in the immunohistochemical analysis of the present study. Patients were divided according to MSH2 expression status (MSH2-negative, n=53; MSH2-positive, n=76). T stage was significantly higher in the MSH2-negative group than in the MSH2 positive-group (P=0.021). There was no significant difference in terms of N stage, M stage and Fuhrman’s nuclear grade between the MSH2-negative and MSH2-positive group (N stage, P=0.072; M stage, P=0.759; Fuhrman’s nuclear grade, P=0118). The MSH2-negative group showed decreased rates of recurrence-free survival, progression-free survival and overall survival, without statistically significant results (P=0.232, P=0.268 and P=0.311, respectively). MSH2 protein expression may be a useful marker for predicting TNM stage and prognosis and, thus, MSH2 may be a prognostic factor in clear cell RCC.

Factors Affecting the Time to Recurrence After Radical Nephrectomy for Localized Renal Cell Carcinoma

Purpose The objective of this study was to determine the factors affecting the time to recurrence after radical nephrectomy for localized renal cell carcinoma. Materials and Methods We retrospectively evaluated 321 patients who received radical nephrectomies for localized renal cell carcinoma (pT1a-pT2b N0M0). Of 29 patients with disease recurrence, 9 had recurrence more than 5 years after radical nephrectomy. We evaluated the clinicopathological factors, with the use of a retrospective study design. Results Tumor necrosis was statistically different between the late recurrence group and the recurrence free group (Fisher exact test, p=0.046). Hematuria at diagnosis (chi-square test, p=0.045) was statistically significant in early recurrence. In the univariate logistic regression analysis, tumor necrosis (odds ratio [OR], 4.629; 95% confidence interval [CI], 1.106 to 19.379; p=0.036) and pT stage>1 (OR, 7.232; 95% CI, 1.727 to 30.280; p=0.007) were risk factors of late recurrence. In the multivariable logistic regression analysis, pT stage>1 (OR, 7.143; 5% CI 1.706 to 29.912, p=0.007) was associated with late recurrence. Regarding early recurrence, initial symptoms at diagnosis and pathologic T stage>1 were statistically significant in both univariate and multivariable logistic regression analysis. In terms of recurrence site, patients with late recurrence tended to have unusual metastasis sites other than lung, liver or bone (chi-square test, p=0.012). Conclusions These data suggest that tumor necrosis may affect late disease recurrence. Patients with initial symptoms and hematuria at diagnosis are vulnerable to recurrence in a shorter period after nephrectomy. Patients with late recurrence showed a tendency to have unusual metastasis site other than lung, liver or bone.

Which Patients Should We Follow up beyond 5 Years after Definitive Therapy for Localized Renal Cell Carcinoma

Purpose Up to 10% of recurrences develop beyond 5 years after curative treatment of localized renal cell carcinoma (RCC). Clinicopathologic features were evaluated to determine which factors are associated with late recurrence. Materials and Methods A total of 753 patients were diagnosed with localized RCC from January 2000 to June 2008. We enrolled 225 patients who were treated surgically and had a minimal recurrence-free survival of 60 months. Patients who had recurrence beyond 5 years after nephrectomy were defined as the late recurrence group and the remaining patients as the recurrence-free group. Multivariate logistic regression analyses and the Cox proportional hazard model were used for determination of features associated with late recurrence. Results In multivariate analyses, age older than 60 (p=0.030), Fuhrman grade ≥ 3 (p=0.042), and pT stage ≥ pT2 (p=0.010) showed statistical association with late recurrence. The Cox proportional hazard model showed significant differences in recurrence-free survival when we classified the patients based on pT2 (p=0.007) and on patient age ≥ 60 years (p=0.039). Conclusion Patient age greater than 60 years, Fuhrman grade ≥ 3, and tumor stage ≥ pT2 are independent risk factors of recurrence more than 5 years after surgery in patients with RCC. Therefore, close lifelong follow-up is recommended for patients with these risk factors.