INTRACAPSULAR CLEAR CELL RENAL CARCINOMA: PLOIDY STATUS IMPROVES THE PROGNOSTIC VALUE OF THE 2002 TNM CLASSIFICATION

A non-diploid DNA status is linked to poor prognosis in renal cell cancer

Purpose

DNA ploidy measurement has earlier been suggested as a potentially powerful prognostic tool in many cancer types, but the role in renal tumors is still unclear.

Methods

To clarify its prognostic impact, we analyzed the DNA content of 1320 kidney tumors, including clear cell, papillary and chromophobe renal cell carcinoma (RCC) as well as renal oncocytoma and compared these data with clinico-pathological parameters and patient prognosis.

Results

A non-diploid DNA content was seen in 37% of 1276 analyzable renal tumors with a striking predominance in chromophobe carcinoma (74.3% of 70 cases). In clear cell carcinoma, a non-diploid DNA content was significantly linked to high-grade (ISUP, Fuhrman, Thoenes; p < 0.0001 each), advanced tumor stage (p = 0.0011), distant metastasis (p < 0.0001), shortened overall survival (p = 0.0010), and earlier recurrence (p < 0.0001). In papillary carcinoma, an aberrant DNA content was significantly linked to high Fuhrman grade (p = 0.0063), distant metastasis (p = 0.0138), shortened overall survival (p = 0.0010), and earlier recurrence (p = 0.0003).

Conclusion

In summary, the results of our study identify a non-diploid DNA content as a predictor of an unfavorable prognosis in clear cell and papillary carcinoma.

Electronic supplementary material

The online version of this article (10.1007/s00345-020-03226-8) contains supplementary material, which is available to authorized users.

VHL and HIF-1α: gene variations and prognosis in early-stage clear cell renal cell carcinoma

Von Hipple-Lindau gene (VHL) inactivation represents the most frequent abnormality in clear cell renal cell carcinoma (ccRCC). Hypoxia-inducible factor-1α (HIF-1α) expression is regulated by O2 level. In normal O2 conditions, VHL binds HIF-1α and allows HIF-1α proteasomal degradation. A single-nucleotide polymorphism (SNP) has been found located in the oxygen-dependent degradation domain at codon 582 (C1772T, rs11549465, Pro582Ser). In hypoxia, VHL/HIF-1α interaction is abolished and HIF-1α activates target genes in the nucleus. This study analyzes the impact of genetic alterations and protein expression of VHL and the C1772T SNP of HIF-1α gene (HIF-1α) on prognosis in early-stage ccRCC (pT1a, pT1b, and pT2). Mutational analysis of the entire VHL sequence and the genotyping of HIF-1α C1772T SNP were performed together with VHL promoter methylation analysis and loss of heterozygosis (LOH) analysis at (3p25) locus. Data obtained were correlated with VHL and HIF-1α protein expression and with tumor-specific survival (TSS). VHL mutations, methylation status, and LOH were detected in 51, 11, and 12% of cases, respectively. Our results support the association between biallelic alterations and/or VHL silencing with a worse TSS. Moreover, we found a significant association between the HIF-1α C1772C genotype and a worse TSS. The same association was found when testing the presence of HIF-1α protein in the nucleus. Our results highlight the role of VHL/HIF-1α pathway in RCC and support the molecular heterogeneity of early-stage ccRCC. More important, we show the involvement of HIF-1α C1772T SNP in ccRCC progression.

In vivo aneuploidization during the expansion of renal adenocarcinoma

BACKGROUND/AIMS

A correlation has been observed between DNA ploidy and other prognostic parameters such as tumor stage and grade. The present study evaluates tumor aneuploidization during renal adenocarcinoma expansion and growth.

METHODS

A total of 252 renal tumors were analyzed between 1969 and 2001. Evaluated variables were age, TNM, Fuhrman classification, histology, size and DNA. A tumor was homogeneous when all the samples were diploid or aneuploid, and a heterogeneous tumor was the coexistence of aneuploid and diploid samples, or all-aneuploid with different aneuploid clones.

RESULTS

A total of 224 tumors were included (coefficient of variation <8). The DNA study classified 129 (57.6%) as diploid and 95 (42.4%) as aneuploid. The percentage of aneuploid tumors increased significantly with the pathological stage. Both aneuploid patterns were also significantly more frequent in advanced pathological stages. Tumors with multiple aneuploid clones (n = 17) were significantly more frequent in tumors measuring `4 cm. Both aneuploid patterns showed no differences in survival (p = 0.83), indicating that the heterogeneous pattern probably represents an intermediate step between diploid and homogeneous aneuploid tumor status.

CONCLUSIONS

The aneuploid pattern is more common in more advanced stages of the disease, with no clear correlation to primary tumor size. This suggests gradual aneuploidization with tumor expansion and growth.

Prognostic role of histological necrosis for nonmetastatic clear cell renal cell carcinoma: correlation with pathological features and molecular markers

PURPOSE

We defined the prognostic role of tumor necrosis and its extent in nonmetastatic clear cell renal cell carcinoma. Also, we further investigated its pathogenesis by correlating this tumor feature with other pathological characteristics and molecular markers related to the von Hippel Lindau-hypoxia inducible factor pathway and to tumor proliferation.

MATERIALS AND METHODS

A total of 213 patients with nonmetastatic clear cell renal cell carcinoma were evaluated. Mean followup was 66 months. The presence and extent of histological necrosis were correlated with clinicopathological factors, Ki-67 antigen expression calculated by the MIB-1 (Ki-67 antibody) index, pVHL, HIF-1alpha, the tumor infiltrating lymphocyte subset and cancer specific survival.

RESULTS

Histological necrosis was present in 63.8% of clear cell renal cell carcinoma cases. Necrosis was significantly associated with grade and the degree of tumor infiltrating lymphocytes, while its extent correlated significantly with grade, the degree of tumor infiltrating lymphocytes and stage. Tumor necrosis was a significant prognostic factor, which was confirmed even when limiting analysis to patients with intracapsular renal cell carcinoma. On multivariate analysis histological necrosis was not an independent predictor of cancer specific survival. The extent of tumor necrosis was not a significant prognostic factor. The presence and extent of histological necrosis was not associated with high Ki-67 expression and it did not correlate with pVHL expression or with nuclear and cytoplasmic HIF-1alpha expression.

CONCLUSIONS

Based on our results we cannot support histological necrosis and its extent as prognostic factors for clear cell renal cell carcinoma. Efforts should be made to develop nomograms that use routinely available and objective predictor variables. The precise mechanism that causes tumor necrosis remains unknown but the host immune response might significantly contribute to its development.

Re: prognostic relevance of capsular involvement and collecting system invasion in stage I and II renal cell carcinoma

Klatte and coworkers examined the prognostic relevance of capsular involvement with no invasion of the perinephric fat and collecting system invasion in a series of 519 patients with intracapsular renal cell carcinoma (RCC) treated with partial or radical nephrectomy and followed for a median of 49 mo (range: 1-199 mo). Capsular involvement and collecting system invasion were reported in 21.6% and 7.5% of patients, respectively. Capsular involvement was significantly associated with a higher nuclear grade and larger tumors, whereas collecting system invasion was significantly associated only with microvascular invasion. In addition, capsular involvement and collecting system invasion were not associated with each other, but had a significant impact on recurrence-free survival (p = 0.007 and p < 0.001, respectively). Interestingly, patients with capsular involvement had the same recurrence-free survival as patients diagnosed as having pT3a N0 M0 RCC. In multivariate analysis, both capsular involvement and collecting system invasion were independent predictors of recurrence-free survival with a reported risk ratio of 1.84 and 3.78, respectively.

Update on the epidemiology and biology of renal cortical neoplasms

A new era is developing in the understanding of the diagnosis, classification, and management of renal-cell carcinoma (RCC). Historically, RCC has been divided into subtypes on the basis of the histopathologic findings alone. Now, genetic alterations, nuclear characteristics, and clinical criteria are routinely incorporated into the classification. The greater use of axial imaging that began in the 1980s dramatically increased the incidence of RCC, but there has not been a decrease in the percentage of cases that are metastatic. Nevertheless, many incidental lesions prove to be benign, so there is renewed enthusiasm for biopsy before treatment is selected. Genetic conditions associated with RCC, such as Von Hippel Lindau and Birt-Hogg-Dube syndromes, along with genetic analyses of tumors, have provided considerable insight into the pathogenesis of these lesions. Renal-cell carcinoma is resistant to chemotherapy, and high-dose interleukin-2 is the only regimen currently approved by the Food and Drug Administration for the treatment of advanced RCC. Stem cell transplantation is an evolving therapy. The vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), platelet-derived growth factor (PDGF), and transforming growth factor-alpha pathways are promising targets for medical therapy of RCC. Bevacizumab, a monoclonal antibody that acts as a competitive blocker of the VEGF receptor; sorafenib, an oral well-tolerated tyrosine kinase inhibitor that blocks the intracellular second-messenger system associated with the VEGF receptor; sunitinib, a multitarget inhibitor of kinases associated with the VEGF and PDGF receptors; temsirolimus (CCI-779), a kinase blocker that inhibits the mammalian target of rapamycin pathway; and erlotinib, an inhibitor of the tyrosine kinases associated with the EGF receptor, have shown promise. Combinations of the above therapies and cytokines also are being investigated, as there may be synergistic effects.

Staging refinements in renal cell carcinoma

PURPOSE OF REVIEW

Accurate pathologic staging systems provide valuable prognostic information. As our understanding of the biology of renal cell carcinoma improves, so does the staging system has undergo periodic modification. The modification of the tumor-node-metastasis staging system in 2002 has been applied to various populations, and several changes have been proposed.

RECENT FINDINGS

The tumor diameter chosen as a break point in the staging system for noninvasive tumors is debated. Although 4 cm, the break point between T1a and T1b tumors, was chosen, in part, to select tumors amenable to partial nephrectomy, newer data show that this may no longer be appropriate. Size appears to have continual prognostic significance, especially in the range of 4-6 cm. T3a tumors with adrenal involvement appear to have a poor prognosis similar to T4 tumors. In addition, while renal sinus invasion may have a worse prognosis, perinephric fat invasion appears to have less impact on survival than overall tumor size.

SUMMARY

Refinements of the current staging system on the basis of current understanding of tumor characteristics will improve prognostic accuracy. The addition of molecular markers and other features should be considered while not allowing increased complexity to disrupt clinical utility.

Simple Enucleation for the Treatment of Renal Cell Carcinoma Between 4 and 7 cm in Greatest Dimension: Progression and Long-Term Survival

PURPOSE

We present our findings in a series of patients treated with simple enucleation for RCC 4 to 7 cm in greatest dimension. We specifically report the incidence of local and systemic recurrence, and the disease specific survival rate.

MATERIALS AND METHODS

We retrospectively reviewed clinical and pathological data on 71 patients who underwent nephron sparing surgery by simple enucleation between 1986 and 2004 for sporadic, unilateral, pathologically confirmed, 4 to 7 cm RCC. Patients with a solitary kidney due to previous RCC treated with radical nephrectomy were excluded from study. None of the patients had preoperative or intraoperative suspicion of positive nodes. All patients were free of distant metastases before surgery (M0). Patient status was last evaluated in May 2005. Mean followup was 74 months (median 51, range 12 to 225).

RESULTS

Pathological review according to the 2002 TNM classification showed that 42% of the tumors (30 of 71) were pT1a, 44% (31 of 71) were pT1b and 14% (10 of 71) were pT3a. Mean tumor greatest dimension +/- SD was 4.7 +/- 0.81 cm (median 4.5, range 4.0 to 7.0) cm. None of the patients died within the first 30 days of surgery. There were no major complications requiring open reoperation, such as bleeding and urinary leakage/urinoma. Five and 8-year cancer specific survival was 85.1% and 81.6%, respectively. Five-year cancer specific survival in patients with pT1a (4 cm), pT1b and pT3a disease was 95.7%, 83.3% and 58.3%, respectively (pT1a vs pT1b p = 0.254, pT1a vs pT3a p = 0.006 and pT1b vs pT3a p = 0.143). Overall 10 patients experienced progressive disease (14.9%), of whom 3 had local recurrence (4.5%) alone or local recurrence associated with distant metastases.

CONCLUSIONS

Simple tumor enucleation is a useful and acceptable approach to nephron sparing surgery for 4 to 7 cm RCC. It provides long-term cancer specific survival rates similar to those of radical nephrectomy and is not associated with a greater risk of local recurrence than partial nephrectomy for RCC less than 4 cm in greatest dimension.