Heterogeneity in renal cell carcinoma and its impact no prognosis--a flow cytometric study

Survival in Kidney and Bladder Cancers in Four Nordic Countries through a Half Century

Kidney and bladder cancers share etiology and relatively good recent survival, but long-term studies are rare. We analyzed survival for these cancers in Denmark, Finland, Norway (NO), and Sweden (SE) over a 50-year period (1971-2020). Relative 1- and 5-year survival data were obtained from the NORDCAN database, and we additionally calculated conditional 5/1-year survival. In 2016-2020, 5-year survivals for male kidney (79.0%) and bladder (81.6%) cancers were best in SE. For female kidney cancer, NO survival reached 80.0%, and for bladder cancer, SE survival reached 76.1%. The magnitude of 5-year survival improvements during the 50-year period in kidney cancer was over 40% units; for bladder cancer, the improvement was over 20% units. Survival in bladder cancer was worse for women than for men, particularly in year 1. In both cancers, deaths in the first year were approximately as many as in the subsequent 4 years. We could document an impressive development for kidney cancer with tripled male and doubled female 5-year survival in 50 years. Additionally, for bladder cancer, a steady improvement was recorded. The current challenges are to curb early mortality and target treatment to reduce long-term mortality.

Role of Calcium Homeostasis in Modulating EMT in Cancer

Calcium is essential for cells to perform numerous physiological processes. In cancer, the augmentation of calcium signaling supports the more proliferative and migratory cells, which is a characteristic of the epithelial-to-mesenchymal transition (EMT). By genetically and epigenetically modifying genes, channels, and entire signaling pathways, cancer cells have adapted to survive with an extreme imbalance of calcium that allows them to grow and metastasize in an abnormal manner. This cellular remodeling also allows for the evasion of immune surveillance and the development of drug resistance, which lead to poor prognosis in patients. Understanding the role calcium flux plays in driving the phenotypes associated with invasion, immune suppression, metastasis, and drug resistance remains critical for determining treatments to optimize clinical outcomes and future drug discovery.

SREBP1 site 1 protease inhibitor PF-429242 suppresses renal cell carcinoma cell growth

Renal cell carcinoma (RCC) cells have increased lipogenesis and cholesterol synthesis. Sterol regulatory element-binding protein-1 (SREBP1) is cleaved by site 1 protease (S1P) to release the transcriptionally active amino-terminal domain. PF-429242 is a potent and competitive S1P inhibitor. We here tested its activity in RCC cells. In established and primary human RCC cells, PF-429242 potently inhibited cell proliferation, migration, and invasion. The S1P inhibitor provoked apoptosis activation in RCC cells. Furthermore, shRNA-mediated S1P silencing or CRISPR/Cas9-induced S1P knockout led to RCC cell growth inhibition and apoptosis activation. Conversely, ectopic overexpression of SREBP1 or S1P augmented RCC cell proliferation and migration. Daily i.v. injection of a single dose of PF-429242 robustly inhibited RCC xenograft growth in severe combined immunodeficiency mice. Additionally, intratumoral injection of S1P shRNA lentivirus inhibited RCC xenograft growth in mice. SREBP1, S1P, and its target gene low density lipoprotein receptor (LDLR) were significantly elevated in human RCC tissues. These results suggest that targeting S1P by PF-429242 inhibited RCC cell growth in vitro and in vivo.

Progress in survival in renal cell carcinoma through 50 years evaluated in Finland and Sweden

Global survival studies have shown favorable development in renal cell carcinoma (RCC) treatment but few studies have considered extended periods or covered populations for which medical care is essentially free of charge. We analyzed RCC survival in Finland and Sweden over a 50-year period (1967-2016) using data from the NORDCAN database provided by the local cancer registries. While the health care systems are largely similar in the two countries, the economic resources have been stronger in Sweden. In addition to the standard 1- and 5-year relative survival rates, we calculated the difference between these as a measure of how well survival was maintained between years 1 and 5. Relative 1- year survival rates increased almost linearly in both countries and reached 90% in Sweden and 80% in Finland. Although 5-year survival also developed favorably the difference between 1- and 5-year survival rates did not improve in Sweden suggesting that the gains in 5-year survival were entirely due to gains in 1-year survival. In Finland there was a gain in survival between years 1 and 5, but the gain in 1-years survival was the main contributor to the favorable 5-year survival. Age group specific analysis showed large survival differences, particularly among women. Towards the end of the follow-up period the differences narrowed but the disadvantage of the old patients remained in 5-year survival. The limitations of the study were lack of information on performed treatment and clinical stage in the NORDCAN database. In conclusion, the available data suggest that earlier diagnosis and surgical treatment of RCC have been the main driver of the favorable change in survival during the past 50 years. The main challenges are to reduce the age-specific survival gaps, particularly among women, and push survival gains past year 1.

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.

Prognostic Significance of Cyclin D1 Expression in Renal Cell Carcinoma: a Systematic Review and Meta-analysis

Previous studies indicated that cyclin D1 shown the potential as a tumor biomarker. However, the prognostic value of cyclin D1 in renal cell carcinoma (RCC) remains controversial. This study investigated the correlation of cyclin D1 expression with the prognostic and clinicopathological features in RCC patients. We systematically searched the database of PubMed, Embase, Cochrane, and Web of Science updated on November 26, 2017. Eighteen studies with 2282 patients satisfied the inclusion criteria. Results demonstrated that cyclin D1 overexpression in RCC showed significant favorable prognostic impact on disease-free survival (DFS) (HR 0.57, 95% CI: 0.43-0.74) and disease-specific survival (DSS) (HR 0.59, 95% CI 0.41-0.85) without significant heterogeneity. In subgroup of clear cell RCC, the prognostic effect on DFS was robust and the pooled HR was 0.39 (95% CI: 0.27-0.57). However, no association between overall survival (OS) and cyclin D1 expression was observed. Stratified analysis in DFS studies by sample size, staining patterns race and metastasis status showed similar results. Otherwise, cyclin D1 overexpression predicted a reduced prevalence of high TNM stage (T3 + T4) (OR 0.63, 95% CI: 0.40-0.99), high-grade tumor (G3 + G4) (OR 0.51, 95% CI: 0.31-0.81) and large tumor size (OR 0.35, 95% CI: 0.19-0.62). Our meta-analysis indicated that cyclin D1 overexpression could predict the favorable prognosis in patients with RCC.

miR-9-5p in Nephrectomy Specimens is a Potential Predictor of Primary Resistance to First-Line Treatment with Tyrosine Kinase Inhibitors in Patients with Metastatic Renal Cell Carcinoma

Approximately 20–30% of patients with metastatic renal cell carcinoma (mRCC) in first-line treatment with tyrosine kinase inhibitors (TKIs) do not respond due to primary resistance to this drug. At present, suitable robust biomarkers for prediction of a response are not available. Therefore, the aim of this study was to evaluate a panel of microRNAs (miRNAs) in nephrectomy specimens for use as predictive biomarkers for TKI resistance. Archived formalin-fixed, paraffin embedded nephrectomy samples from 60 mRCC patients treated with first-line TKIs (sunitinib, n = 51; pazopanib, n = 6; sorafenib, n = 3) were categorized into responders and non-responders. Using the standard Response Evaluation Criteria in Solid Tumors, patients with progressive disease within 3 months after the start of treatment with TKI were considered as non-responders and those patients with stable disease and complete or partial response under the TKI treatment for at least 6 months as responders. Based on a miRNA microarray expression profile in the two stratified groups of patients, seven differentially expressed miRNAs were validated using droplet digital reverse-transcription quantitative real-time polymerase chain reaction (RT-qPCR) assays in the two groups. Receiver operating characteristic curve analysis and binary logistic regression of response prediction were performed. MiR-9-5p and miR-489-3p were able to discriminate between the two groups. MiR-9-5p, as the most significant miRNA, improved the correct prediction of primary resistance against TKIs in comparison to that of conventional clinicopathological variables. The results of the decision curve analyses, Kaplan-Meier analyses and Cox regression analyses confirmed the potential of miR-9-5p in the prediction of response to TKIs and the prediction of progression-free survival after the initiation of TKI treatment.

Nephron-Sparing Surgery — Strategies for Partial Nephrectomy in Renal Cell Carcinoma

The use of partial nephrectomy for renal cell carcinoma has continuously changed in the clinical practice. Previously it was mostly used in imperative cases, in patients with a solitary kidney or in patients with a risk of renal failure. An increased number of incidentally detected renal cell carcinomas are diagnosed due to the advances of the radiological methods. These tumours tend to be smaller and generally with a lower stage. The reported excellent results of partial nephrectomy have promoted the use of nephron-sparing surgery also in patients with a normal contralateral kidney and tumours smaller than 4-5 cm. The technical outcome is excellent with a low operative morbidity and a good oncologic control. Therefore partial nephrectomy has become a standard technique in the treatment of properly selected patients. Laparoscopy with its reduced postoperative pain and shorter rehabilitation time, has encouraged the interest in minimally invasive nephron sparing surgical techniques. Although low, the risk of local tumour recurrence and surgical complications are higher after nephron-sparing surgery compared with radical nephrectomy. Furthermore, long-term renal function remains adequate in most patients with a normally functioning contralateral kidney also after radical nephrectomy. Albeit these facts, there is convincing evidence justifying nephron-sparing surgery to be used routinely for patients with a small renal cell carcinoma and a normal functioning contralateral kidney.

Metabolomic profiling of tumor-bearing mice

Metabolomics is one of the newcomers among the "omics" techniques, perhaps also constituting the most relevant for the study of pathophysiological conditions. Metabolomics may indeed yield not only disease-specific biomarkers but also profound insights into the etiology and progression of a variety of human disorders. Various metabolomic approaches are currently available to study oncogenesis and tumor progression in vivo, in murine tumor models. Many of these models rely on the xenograft of human cancer cells into immunocompromised mice. Understanding how the metabolism of these cells evolves in vivo is critical to evaluate the actual pertinence of xenograft models to human pathology. Here, we discuss various tumor xenograft models and methods for their metabolomic profiling to provide a short guide to investigators interested in this field of research.

Prognostic factors for survival in patients with metastatic renal cell carcinoma treated with targeted therapies

Background:

The most important prognostic factors for survival in patients with metastatic renal cell carcinoma (mRCC) were evaluated in the era of cytokine therapy, and only recently were revalidating in patients receiving targeted therapies (TTs).

Methods:

Clinical data for consecutive patients with mRCC who received TTs were retrieved from the database of Istituto Nazionale dei Tumori of Milan. Variables with a significant association with overall survival (OS) were estimated by proportional hazard regression, and a backward stepwise multivariate analysis identified the independent prognostic factors.

Results:

Data for 336 consecutive patients treated with TTs for RCC during the period 2004–2011 were evaluated. According to the Motzer classification, 32% patients were low risk, 48% were intermediate risk and 20% were poor risk. One hundred and sixty-seven (49.7%) patients received one TT, 116 (34.5%) received a second-line TT, 42 (12.5%) a third-line TT and 11 (3.3%) patients received a fourth-line TT. The median OS was 24 months (95% CI 20.0, 27.0) and the 5-year OS rate was 24.6% (95% CI 18.7, 30.8%). In the uni- and multivariate analysis Motzer risk classification, Fuhrman grade and previous cytokine therapy were identified as independent prognostic factors (P<0.01).

Conclusion:

The Motzer classification was confirmed as an independent prognostic factor for OS in patients with mRCC receiving TTs. Additionally, Fuhrman grade and previous cytokine therapy were independent prognostic factors for clinical outcome.

Limitations of preoperative biopsy in patients with metastatic renal cell carcinoma: comparison to surgical pathology in 405 cases

Study Type--Diagnostic (cohort) Level of Evidence: 2b. What's known on the subject? and What does the study add? Although there have been many investigations of biopsy for small renal masses, there are scant data on the accuracy of biopsy in the setting of metastatic renal cell carcinoma (mRCC). We report a large series of biopsies and compare with nephrectomy pathology in patients with mRCC. The present study highlights the inaccuracy of biopsy in the setting of metastatic disease, which is related to sampling error because of heterogeneity within the tumour and among metastases. These limitations are important to realize when designing trials that depend on pathological findings from biopsy and not nephrectomy. In addition, we found that biopsy of primary tumours were more likely than biopsy of metastatic sites to be diagnostic of RCC. Future studies with multiquadrant biopsies of primary tumours could yield the most accurate pathological results for future studies.

OBJECTIVE

• To evaluate the ability of preoperative biopsy to identify high-risk pathological features by comparing pathology from preoperative metastatic site and primary tumour biopsies with nephrectomy pathology in patients with metastatic renal cell carcinoma (mRCC).

PATIENTS AND METHODS

•  We reviewed clinical and pathological data from patients who underwent biopsy before cytoreductive nephrectomy for mRCC at MD Anderson Cancer Center (MDACC) from 1991 to 2007. • Percutaneous biopsy techniques included fine-needle aspiration, core needle biopsy or a combination of both techniques.

RESULTS

• The pathology of 405 preoperative biopsies (239 metastatic site, 166 primary tumour) from 378 patients was reviewed at MDACC before cytoreductive nephrectomy. • The biopsy and nephrectomy specimens had the same histological subtype in 96.0% of clear-cell renal cell carcinomas (RCCs) and 72.7% of non-clear-cell RCCs. • Of 76 nephrectomy specimens where sarcomatoid de-differentiation was identified, only seven (9.2%) were able to be identified from the preoperative biopsy. • In 38.3% of patients, the same Fuhrman grade was identified in both the biopsy and nephrectomy specimens. • A definitive diagnosis of RCC was more likely to be reported in primary tumour biopsies than in metastatic site biopsies. (P < 0.001).

CONCLUSIONS

• Preoperative biopsy has limited ability to identify non-clear-cell histological subtype, Fuhrman grade or sarcomatoid features. • When surgical pathology is not available, a biopsy obtaining multiple samples from different sites within the primary tumour should be recommended rather than limited metastatic site biopsy to identify patients for clinical trials.

Prognostic factors for survival in metastatic renal cell carcinoma: update 2008

A variety of prognostic factor models to predict survival in patients with metastatic renal cell carcinoma have been developed. Diverse populations of patients with variable treatments have been used for these analyses. A variety of clinical, pathologic, and molecular factors have been studied, but current models use predominantly easily obtained clinical factors. These approaches are reviewed, and current approaches to further refine and develop these techniques are reviewed.

Nonmetastatic renal-cell carcinoma: is it really possible to define rational guidelines for post-treatment follow-up?

Defining rational follow-up guidelines in patients treated for cancer is important, from both a medical and an economical perspective. Renal-cell carcinoma is reputed to be unpredictable in its course and only a few, and often contradictory, follow-up guidelines exist for patients treated for nonmetastatic renal-cell carcinoma. Recent advances in tumor biology have contributed to a better understanding of this cancer and have indicated that personalized follow-up regimens, based on tumor and host molecular characteristics, might be possible in the near future.

Bcl-2 protein and DNA ploidy in renal cell carcinoma: do they affect patient prognosis?

AIM

The aim of the present study was to correlate bcl-2 protein expression and DNA-ploidy status with established prognostic parameters in renal cell carcinoma (RCC) and to examine their impact on disease progression and patient survival.

METHODS

Both parameters were prospectively measured in 50 consecutive radical nephrectomy specimens using flow cytometry. They were correlated with the tumor grade, stage and histological type. Kaplan-Meier survival analysis for all parameters was performed.

RESULTS

Bcl-2 protein expression was higher in RCC compared to normal renal tissue (P < 0.0001). Aneuploid tumors had higher bcl-2 expression compared to diploid tumors (P = 0.015). Bcl-2 expression and DNA content were not correlated with tumor histological types (P = 0.277/P = 0.419), grades (P = 0.690/P = 0.449), T categories (P = 0.637/P = 0.585) or stages (P = 0.726/P = 0.800). Median follow-up time was 46 months (range, 5-84) with a mean overall survival of 61.8 months (95% confidence interval, 53.7-69.9). Tumor stage was the only statistically important prognostic factor (P = 0.0045).

CONCLUSION

Although Bcl-2 expression was correlated with tumor DNA content, the prognostic value of these two parameters following radical nephrectomy was not established.

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

PURPOSES

The TNM classification has been revised for the 2002 edition of the UICC publication to better stratify patients with intracapsular renal cell carcinoma (RCC) but few studies have been published to date to validate this new classification. Moreover, additional prognostic factors seem to be necessary to improve the prediction of intracapsular tumor aggressiveness and the definition of patient subgroups at high risk for metastases. We report the long-term results of the new TNM scheme. We evaluated the impact of DNA content, S-phase and MIB-1 (Dako, Glostrup, Denmark) score.

MATERIALS AND METHODS

A total of 136 patients with intracapsular clear cell RCC and a mean followup of 74 months were reclassified. Tumor specific survival (TSS) was compared with nuclear grade (NG), DNA content and proliferative status (S-phase fraction and MIB-1 score).

RESULTS

TSS was 92%, 81.1% and 40.1% for pT1a, pT1b and pT2, respectively (p <0.05). TSS according to DNA ploidy status (diploid vs aneuploid) was pT1a-95.2% vs 68.6% (p <0.05), pT1b-90% vs 46.7% (p <0.05) and pT2-49.2% vs 25% (p not significant). DNA ploidy was also significantly associated with survival when adjusted for NG. There was no significant association between TSS and MIB-1 score or tumor S-phase fraction.

CONCLUSIONS

The 2002 TNM classification is a useful prognostic factor for evaluating organ confined RCC of the clear cell subtype. Evaluation of the DNA content in clear cell RCC appears to significantly improve the predictive value of the TNM staging system, especially in the pT1a and pT1b categories. Fuhrman NG alone or combined should be routinely used in such patients.

Prognostic significance of clinicopathologic and deoxyribonucleic acid flow cytometric variables in non-metastatic renal cell carcinoma in the modern era

OBJECTIVE

The prognostic value of deoxyribonucleic acid (DNA) ploidy in renal cell carcinoma (RCC) is not well-defined among modern surgical nephrectomy series. We sought to determine which variables correlated with overall survival and recurrence-free survival in the modern era.

METHODS

We reviewed all patients from 1992 to 2000, who prospectively had DNA ploidy analysis of their primary tumor determined at the time of nephrectomy for nonmetastatic RCC. Variables examined included age, gender, ethnicity, presentation (incidental vs. symptomatic), preoperative laboratory studies, American Society for Anesthesiology class, tumor size, tumor-nodes-metastasis stage, histology, Fuhrman grade, and diploid versus nondiploid tumor. Statistical analyses of overall survival and recurrence-free survival were performed using the Kaplan-Meier method, log-rank test, and Cox regression model using commercially available software.

RESULTS

Sixty men and 41 women, median age 61 years (range, 23-85), were included. Pathologic stage included T1 (54 patients), T2 (14), and T3 (33). Eighty-four patients had conventional RCC. A total of 58 patients had well-differentiated (Fuhrman Grade 1 [12] or Grade 2 [46]), 28 had moderately differentiated (Grade 3), 12 had poorly differentiated tumors (Grade 4), and 3 were not specified. There were 52 patients who had diploid tumors, and 49 had aneuploid tumors. Median follow-up was 39 months (range, 0-109). Actuarial 5-year overall survival was 70%, and 5-year recurrence-free survival was 76%. Diploid tumors were significantly associated with better recurrence-free survival (P = 0.02) but not overall survival (P = 0.17). On multivariate analysis, the American Society for Anesthesiology class (P = 0.01), abnormal preoperative platelet count (P = 0.03), and tumor differentiation (P = 0.01) were independent predictors of overall survival, whereas only tumor differentiation (P = 0.05) was an independent predictor of recurrence-free survival.

CONCLUSIONS

In the modern era, DNA ploidy is not an independent predictor of either overall survival or recurrence-free survival in patients with nonmetastatic RCC. The most important predictor of recurrence-free survival is tumor differentiation.

Prognostic value of uPA, PAI-1, and DNA content in adult renal cell carcinoma

OBJECTIVES

To examine whether urokinase-type plasminogen activator (uPA) and type 1 plasminogen inhibitor (PAI-1), DNA ploidy, and S-phase fraction (SPF) add supplementary prognostic information relative to stage and Fuhrman's grade in renal cell carcinoma.

METHODS

A total of 100 patients with primary renal adenocarcinoma treated by nephrectomy were followed up for a median of 42 months. Of the 100 patients, 78 with Stage M0N0-Nx tumors were studied by multivariate analysis. The study population was dichotomized on the basis of the median cytosolic uPA and PAI-1 concentrations (30 pg/mg protein and 12.7 ng/mg protein, respectively). DNA content was measured by flow cytometry (FCM) on multiple tumor samples from each patient. DNA aneuploidy was observed in 67% of cases. The SPF was calculated for aneuploid samples.

RESULTS

An FCM classification based on a combination of DNA content and SPF was obtained. High-risk patients were those with aneuploid tumors and high SPF values (greater than 1.7%) and included 23% of patients with M0N0-Nx tumors. Cytosolic uPA and PAI-1 levels were not predictive of metastasis. The stage, grade, SPF, and FCM classification were statistically significant prognostic factors in the univariate analysis, in both the overall population and the M0N0-Nx subgroup. In multivariate analysis, tumor grade and the FCM classification were the only independent predictors of disease-free survival (P = 0.018 and P = 0.046, respectively).

CONCLUSIONS

We defined a group of M0N0-Nx patients with aneuploid tumors and high SPF values who are at a high risk of metastasis and who may benefit from closer long-term follow-up.

Telomere shortening and mitotic dysfunction generate cytogenetic heterogeneity in a subgroup of renal cell carcinomas

Most renal cell carcinomas (RCC) show only simple chromosomal changes. However, a more complex cytogenetic pattern has been found in a subgroup of aggressive RCC, indicating that further accumulation of chromosome changes could play a role in tumour progression. To explore the possible mechanisms behind cytogenetic evolution in RCC, a parallel assessment of chromosome mutations and mitotic segregation pattern in eight tumours was performed. In the majority of cases, no abnormalities in the cell division machinery were found and the rate of alterations in chromosome copy number, as measured by interphase FISH, was similar to that in non-neoplastic cells. This was reflected by relatively simple karyotypes, with little cytogenetic intratumour heterogeneity. In contrast, another group of tumours exhibited several cytogenetically related clones with additional structural chromosomal changes at two or more ploidy levels and a frequency of copy number alterations that was higher than in normal cells. In these cases, the telomere repeat sequences were abnormally short and chromosomal breakage-fusion-bridge events were observed at cell division, as well as multipolar configurations and supernumerary centrosomes. Abnormalities of the cell division machinery may thus contribute to the evolution of complex karyotypes and genetic intratumour heterogeneity in a subgroup of RCC.

Nephron-sparing surgery for renal cell carcinoma--long-term results

OBJECTIVES

Renal cell carcinoma (RCC) is most often treated using radical nephrectomy. However, in patients with only one kidney or with bilateral RCC, nephron-sparing surgery (NSS) is mandatory. NSS may also be undertaken in patients with a normal contralateral kidney, providing that the tumour is fairly small and not unfavourably located. The aim of the present study was to determine the long-term results in patients treated with NSS for RCC.

MATERIAL AND METHODS

We reviewed the records of 87 patients with RCC subjected to NSS between 1980 and 1999. The survival rate was determined, as well as the tumour grade (Skinner classification) and stage (1992 World Health Organisation classification).

RESULTS

Cancer-specific survival, in patients with no demonstrable distant metastases and regardless of stage and grade, was 80% and 75% at 5 and 10 years, respectively. Long-term survival was significantly dependent on tumour stage and grade.

CONCLUSION

In this patient series, long-term survival did not differ from the results obtained using radical nephrectomy, judging from the available literature. An exception was found in patients with high-stage RCC, where NSS appeared to be a less favourable procedure. We therefore recommend that NSS should be performed in cases with bilateral tumour disease or an absent/malfunctioning contralateral kidney. NSS may also be considered in cases of low-stage RCC with a normal contralateral kidney, especially in patients with local or systemic conditions that may adversely affect renal function in the future.

Retinoblastoma protein in human renal cell carcinoma in relation to alterations in G1/S regulatory proteins

The retinoblastoma gene product (pRb) is the main substrate for cyclin-dependent kinases (CDKs) during the G1/S transition. Aberrations in cell cycle regulatory proteins, which have been observed in many malignancies, can theoretically cause increased phosphorylation of pRb due to unbalanced CDK activities. The expression and phosphorylation of pRb and potential associations to cell cycle aberrations in renal cell carcinomas (RCC) has only partly been clarified. We therefore evaluated the presence of pRb and the level of pRb-phosphorylation in 216 RCCs arranged in tissue microarrays by using different pRb-antibodies, including pRb-phosphospecific antibodies. Most RCCs (95%) expressed pRb, while cases with the low pRb levels, potentially indicative for pRb-inactivation, were few. In order to detect secondary alterations to a potential pRb-inactivation, the p16 expression was also monitored. None of the tumors exhibited increased p16 levels, confirming that pRb-inactivation is rare in RCC. Phosphorylated pRb was detected in approximately 50% of the RCCs, using Western blotting or immunohistochemistry. The immunohistochemical ppRb(ser807/811) levels were associated with high proliferation, cyclin D1, cyclin E and p27 protein content. Surprisingly, there was no association between pRb-phosphorylation and clinicopathological data. In summary, pRb seemed to be functional and aberrations in G1/S-regulatory proteins were associated with increased phosphorylation of pRb and proliferation. The data supports that pRb might be one of the main cell cycle regulators in RCC.

Tumour vascular endothelial growth factor (VEGF) mRNA in relation to serum VEGF protein levels and tumour progression in human renal cell carcinoma

Angiogenesis is gaining interest because of its importance in tumour growth and metastasis. Renal cell carcinoma (RCC) is known to be a well-vascularized tumour. The aim of this study was to evaluate the expression of VEGF mRNA and receptor flt-1 mRNA (VEGF R1) in a clinical material of RCCs compared with clinicopathological variables and serum VEGF levels. Total RNA was extracted from snap-frozen tumour tissue obtained from 61 patients. Expression of mRNA for VEGF121, VEGF165 and flt-1 were analysed using quantitative RT-PCR. Relative VEGF mRNA levels, corrected for corresponding cyclophilin value, were related to stage, grade, RCC type and survival time. Serum VEGF165 protein was analysed using a quantitative ELISA. Papillary RCC had significantly lower VEGF121 and flt-1 mRNA levels compared with conventional RCC (p=0.001). VEGF121 mRNA levels were significantly lower in locally advanced tumours in relation to tumours limited to the kidney and those with metastatic disease (p=0.047 and p=0.036). This statistical difference disappeared when only conventional RCCs were evaluated. No association was found between VEGF mRNA levels and nuclear grade. Patients with lower VEGF121 mRNA levels had significantly longer survival time compared with those with higher levels (when adjusted to stage, p=0.0097, log rank test). There was an inverse relation between VEGF165 mRNA and serum VEGF165 levels. The trend to lower VEGF121 mRNA levels in locally advanced RCC indicate that angiogenic activity and degradation might be up-regulated in tumours with a high ability to invade. The association with tumour progression shows that VEGF is a promising angiogenic factor especially important in conventional RCCs. VEGF expression might possibly be of help to identify RCCs susceptible for anti-angiogenic therapies.

Prognostic factors in renal cell carcinoma

Several well-established prognostic factors are now available for RCC and have proven utility for patient counseling and management. Consideration of these factors allows for a rational stratification of patients into clinical trials and facilitates the comparison of reports from diverse institutions. Tumor stage remains the most important prognostic factor for RCC, but compelling data have also been accumulated in support of various clinical signs and symptoms, tumor grade, size, histologic subtype, and DNA content and nuclear morphometry. Novel efforts to integrate these factors show great promise and are likely to incorporate molecular factors in the near future.

Expression of cyclin D1, D3, E, and p27 in human renal cell carcinoma analysed by tissue microarray

Aberrations in the G1/S transition of the cell cycle have been observed in many malignancies and seem to be critical in the transformation process. Few studies have delineated the presence of G1/S regulatory defects and their clinical relevance in renal cell carcinoma (RCC). Therefore, we have examined the protein contents of cyclin D1, D3, E, and p27 in 218 RCCs, using tissue microarray and immunohistochemistry. The results from a subset of tumours were confirmed by Western blotting and immunohistochemical staining of regular tissue sections. Interestingly, low protein contents of cyclin D1 and p27 were associated with high nuclear grade, large tumour size, and poor prognosis for patients with conventional tumours. We further observed substantial differences in the pattern of G1/S regulatory defects between the different RCC subtypes. The majority of both conventional and papillary cases expressed p27; however, chromophobe tumours generally lacked p27 staining. In addition, conventional RCCs often expressed high cyclin D1 protein levels, while papillary RCCs exhibited high cyclin E. In summary, we have shown that G1/S regulatory defects are present in RCC and are associated with clinico-pathological parameters. The pattern of cell cycle regulatory defects also differed between RCC subtypes.

Expression of the free beta-subunit of human chorionic gonadotropin in renal cell carcinoma: prognostic study on tissue and serum

Expression of the free beta-subunit of human chorionic gonadotropin (hCGbeta) in malignant tumors is frequently associated with aggressive disease. We have shown previously that the pretreatment serum concentration of hCGbeta is an independent prognostic variable in patients with renal cell carcinoma (RCC). We now compare the serum levels with the expression of hCGbeta antigen and mRNA in tumor tissue and studied whether these are associated with the clinical outcome. Serum samples were collected before surgery from patients with RCC (n = 256) and from 84 apparently healthy controls. HCGbeta in serum was measured by a time-resolved immunofluorometric assay. Tissue expression was detected by immunohistochemical staining of a tissue microarray (TMA) comprising 229 samples, and in selected cases by reverse transcription polymerase chain reaction (RT-PCR) of hCGbeta mRNA (n = 20) from tumor tissue. The prognostic value of hCGbeta in serum and tissue and the association with usual clinicopathological variables was analyzed by the Kaplan-Meier method, the log-rank test, Cox multiple hazard regression, Mann-Whitney U-test or Kruskal-Wallis test. The serum concentrations of hCGbeta were increased in 27% of the RCC patients and patients with increased hCGbeta levels had significantly shorter survival time than those with levels below the median (cut-off 1.2 pmol l(-1), p = 0.0044). HCGbeta antigen was detected in 15% (35 of 229) of the tumors by immunohistochemistry, and hCGbeta mRNA in 8 of 20 samples (40%) by RT-PCR. Tissue positivity for hCGbeta antigen was not associated significantly with mRNA expression, serum concentrations of hCGbeta or survival. In multivariate analysis tumor stage, grade, size and serum hCGbeta were independent prognostic variables. The serum concentration of hCGbeta is an independent prognostic variable in RCC. Tissue expression of hCGbeta detected by immunohistochemistry occurs in 15% of RCCs but it is not significantly associated with prognosis. Expression at the mRNA level seems to be associated with other predictors of adverse outcome.

Cyclin E and p27 protein content in human renal cell carcinoma: clinical outcome and associations with cyclin D

Aberrations in the G1-S transition have been observed in several malignancies, suggesting that cell cycle defects are linked to the activation of oncogenes and inactivation of suppressor genes involved in the transformation process. The frequency of G1/S aberrations in human renal cell carcinoma (RCC) has not been fully clarified. We have therefore analyzed the cyclin E content, using Western blotting, in 79 RCC and 12 corresponding kidney cortex tissues as well as the fraction of p27-positive cells in 73 RCCs, using immunohistochemistry. Most of the tumors (65%) exhibited higher cyclin E levels than corresponding normal kidney cortex tissues. However, only a small fraction of the tumors (3 of 80) had excessive levels of cyclin E when cyclin E levels were compared with proliferation. Cyclin E levels higher than the median value were associated with aneuploidy (p = 0.025), high stage (p = 0.027), high grade (p = 0.013) and high erythrocyte sedimentation rate (ESR; p = 0.005). Cyclin E was further inversely correlated with cyclin D1 (p = 0.023) and positively correlated with cyclin D3 (p = 0.003). Most tumors (76%) demonstrated a normal fraction of p27-positive cells. There was an inverse correlation between p27 positivity and tumor size (p = 0.007), despite a lack of correlation between p27 and proliferation. Patients with p27 low tumors had a poor survival (p = 0.002). There was no correlation between p27 and cyclin E levels. In summary, the results suggest that protein expression of cyclin E and/or p27 is linked to tumor behavior.

The free beta-subunit of human chorionic gonadotropin as a prognostic factor in renal cell carcinoma

The free beta-subunit of human chorionic gonadotropin beta is expressed in several nontrophoblastic tumours and this is usually associated with aggressive disease. Little is known about human chorionic gonadotropin beta expression in renal cancer. We determined the pretreatment levels of human chorionic gonadotropin beta in serum of patients with renal cell carcinoma, and studied whether elevated levels predicted the clinical outcome. Serum samples were collected before surgery from 177 patients with renal cell carcinoma and from 84 apparently healthy controls. Human chorionic gonadotropin beta in serum was measured by a highly sensitive time-resolved immunofluorometric assay. The prognostic value of human chorionic gonadotropin beta, and of usual clinical and pathological variables was analyzed by the Kaplan-Meier method, the log rank test and Cox multiple hazard regression. The serum concentrations of human chorionic gonadotropin beta were increased in 23% of the renal cell carcinoma patients and they were significantly higher in patients with renal cell carcinoma than in controls (P<0.0001). The concentrations did not correlate with clinical stage and histopathological grade, but patients with increased human chorionic gonadotropin beta levels had significantly shorter survival time than those with levels below the median (cut-off 1.2 pmol l(-1), P=0.0029). In multivariate analysis human chorionic gonadotropin beta, tumour stage and grade were independent prognostic variables. The serum concentration of human chorionic gonadotropin beta is an independent prognostic variable in renal cell carcinoma. The preoperative value of human chorionic gonadotropin beta in serum may be used to identify patents with increased risk of progressive disease.

Diagnosis of renal cell carcinoma by bone marrow aspiration biopsy

We report a patient who presented with persistent unclear fever, anaemia and leucopenia. A bone marrow aspiration biopsy was performed due to these symptoms, revealing malignant adenocarcinoma cells with a suspicion of renal origin. A computerized tomography confirmed the diagnosis. The patient progressed rapidly and died of widespread metastatic papillary renal cell carcinoma.

p53 expression in correlation to clinical outcome in patients with renal cell carcinoma

OBJECTIVE

The aim of this study was to evaluate the role of p53 as prognostic factor in renal cell carcinoma (RCC) and its relation to clinicopathological factors.

MATERIAL AND METHODS

The nuclear accumulation of p53 protein was determined by immunohistochemical analysis in RCC specimens from 90 patients and was correlated with clinical stage, grade, DNA ploidy, S-phase fraction and cancer-specific survival.

RESULTS

p53 overexpression was observed in 17 of 90 (19%) tumours. There was a significant correlation to stage (p = 0.016) and grade (p = 0.020) but not to DNA ploidy or S-phase. Patients with high p53 immunoreactivity had shorter cancer-specific survival (p = 0.003) than those with normal p53 protein expression. This difference was found in papillary and chromophobe tumour types (p < 0.0001) but not in conventional RCC.

CONCLUSIONS

In patients with RCC, significant correlations between p53 protein expression and tumour stage, grade and survival time were observed. For patients with chromophobe and papillary tumour types, but not in conventional RCC, p53 immunoreactivity gave prognostic information, suggesting that the prognostic differences in p53 immunoreactivity might be due to disparate genetic abnormalities in the different RCC types.

Alarming wear of the first-generation polyethylene liner of the cementless porous-coated Biomet Universal cup: 107 hips followed for mean 6 years

Wear of the socket liner and resulting osteolysis are the major causes of failure in cementless hip arthroplasties. We report alarming wear of the first-generation polyethylene liner of the cementless porous-coated Biomet Universal cup. Radiographs of 107 primary hip arthroplasties were analyzed retrospectively. The mean follow-up time was 74 (47-91) months. The linear wear of the polyethylene liners was assessed using a modification of the Livermore method. The median linear wear was 1.0 (0-6.2) and the median linear wear rate was 0.17 mm/year. There was a statistically significant difference between the 28 mm and 32 mm femoral head groups both in the volumetric wear and in the volumetric wear rate. The median linear wear was 0.28 mm/year and 0.14 mm/year for the 32 mm and 28 mm heads, respectively. So far, 14 revisions have been performed or have been scheduled because of excessive wear of the polyethylene liner. In regression analysis, the factors related to the wear rate were the 32 mm size of the femoral head and screw fixation of acetabular shell. We found that the cases with calcar rounding were associated with significantly greater wear. Possible reasons for increased wear of the Hexloc liner may be the cylindrical design, thin polyethylene, and poor quality of the polyethylene. Regular clinical and radiographic follow-ups are recommended especially for hips with 32 mm femoral heads or with screw fixation. If progressive wear of the liner is observed, revision must be considered.

Nuclear DNA content-derived parameters correlated with heterogeneous expression of p53 and bcl-2 proteins in clear cell renal carcinomas

BACKGROUND

p53 and bcl-2 are two key genes involved in cell cycle and cell death regulation. Altered expression or mutation of these genes has been found in human cancers and also has been identified in clear cell renal carcinoma (RCC). Their role in RCC progression, however, is still unclear. By contrast, the prognostic significance of ploidy and S-phase fraction (SPF) have been studied extensively in RCC. To better characterize the biologic role of p53 and bcl-2 oncoproteins in RCC, we offer a multisample correlative analysis of the expression of these two proteins with ploidy and SPF.

METHODS

Ploidy and SPF along with p53 and bcl-2 expression were analyzed in 296 specimens, selected by multiple sampling of 33 consecutive operable RCCs. The expression of p53 and bcl-2 proteins was studied by immunohistochemistry, and SPF and tumor ploidy were studied by flow cytometry.

RESULTS

In our study, 4 of 32 (12.5%) were found to be diploid, and 28 of 32 (87.5%) cases showed an abnormal DNA content. Among the aneuploid tumors, 14 of 28 (50%) were multiploid. Heterogeneous DNA content was detected in 21 of 32 (65.6%) tumors and was correlated with the more advanced Robson stage tumor (P = 0. 03). Intratumor heterogeneity also was detected for p53 and bcl-2 protein expression. Expression of p53 protein correlated with the lack of bcl-2 protein expression (P = 0.0032), aneuploidy (P < 0. 0001), and high SPF (P = 0.0006), whereas bcl-2 expression was associated with a normal DNA content (P < 0.0001) and low SPF (P = 0. 035).

CONCLUSIONS

Within each RCC, p53 and bcl-2 expression is markedly heterogeneous. Our results depicted a scenario in which bcl-2 protein, expressed by normal renal parenchyma, is still present in euploid cell clones of RCC but disappears during the progression of renal neoplasm toward a more aggressive phenotype characterized by overexpression of p53 protein, aneuploidy, and high SPF.

Distinction between HLA class I-positive and -negative cervical tumor subpopulations by multiparameter DNA flow cytometry

BACKGROUND

The study of the molecular-genetic basis of heterogeneity of HLA class I expression in solid tumors is hampered by the lack of reliable rapid cell-by-cell isolation techniques. Hence, we studied the applicability of a flow cytometric approach (Corver et al.: Cytometry 2000;39;96-107).

METHODS

Cells were isolated from five fresh cervical tumors and simultaneously stained for CD45 or vimentin (fluorescein isothiocyanate fluorescence), Keratin (R-phycoerythrin fluorescence), HLA class I (APC fluorescence), and DNA (propidium iodide fluorescence). A dual-laser flow cytometer was used for fluorescence analysis. Tissue sections from the corresponding tumors were stained for HLA class I antigens, keratin, vimentin, or CD45.

RESULTS

Flow cytometry enabled the simultaneous measurement of normal stromal cells (vimentin positive), inflammatory cells (CD45 positive), epithelial cells (keratin positive), and DNA content readily. Normal stromal/inflammatory cells served as intrinsic HLA class I-positive as well as DNA-diploid references. Good DNA histogram quality was obtained (average coefficient of variation < 4%). Intratumor keratin positive subpopulations differing in HLA class I expression as well as DNA content could be clearly identified. Losses of allele-specific HLA class I expression found by immunohistochemistry were also detected by flow cytometry.

CONCLUSIONS

We conclude that multiparameter DNA flow cytometry is a powerful tool to study loss of HLA class I expression in human cervical tumors. The method enables flow-sorting of discrete tumor and normal cell subpopulations for further molecular genetic analysis.

Factors of importance for prediction of survival in patients with metastatic renal cell carcinoma, treated with or without nephrectomy

OBJECTIVE

The indications for nephrectomy in patients with metastatic renal cell carcinoma remain controversial. A number of variables were analysed to identify factors that might predict the survival time, and these factors were used to obtain guidance as to which patients might benefit from palliative nephrectomy.

MATERIAL AND METHODS

We reviewed the medical records for 106 consecutive patients with primary metastatic renal cell carcinoma, including clinicopathological factors, routine laboratory data and metastatic spread. The association of the different factors to survival time was evaluated by univariate and multivariate analysis.

RESULTS

A number of factors correlated to survival time in univariate analysis, including solitary versus multiple metastases, serum albumin and DNA ploidy, but after Cox multivariate analysis their significance was lost. The remaining independent prognostic factors were performance status, number of metastatic sites, erythrocyte sedimentation rate (ESR), calcium in serum and vein invasion with tumour thrombus formation. The factors with no association to survival time were the metastatic sites, tumour size and nuclear grade. Patients treated with nephrectomy had a significantly longer survival time than those who did not undergo nephrectomy (p < 0.001). None of the 28 patients who did not undergo nephrectomy survived for 2 years, compared with 38 of the 78 patients who were nephrectomized.

CONCLUSIONS

Patients who can be expected to survive longer, and who might be recommended for nephrectomy despite metastatic disease, would have the following independent factors: a good performance status, metastases limited to one organ, low ESR, normal calcium in serum and no tumour thrombus formation.

Accuracy of diagnosis by guided biopsy of renal mass lesions classified indeterminate by imaging studies

OBJECTIVES

To define the accuracy, safety, and impact of percutaneous biopsies of indeterminate mass lesions as an additional diagnostic tool. The vast majority of renal mass lesions are routinely diagnosed by radiographic features alone. However, with the increased use of computed tomography scanning and ultrasound, many smaller renal masses, which are "indeterminate" (refractory to categorization on the basis of imaging alone), are now being discovered.

METHODS

We retrospectively reviewed 583 patients (364 male and 219 female) with indeterminate renal mass lesions diagnosed by imaging studies that were further investigated by percutaneous biopsy. Patients were followed up for at least 5 years if the biopsy result demonstrated a benign lesion, or they underwent surgical exploration if the biopsy result demonstrated a malignancy. Biopsy or aspiration material was assessed by histopathologic and cytologic evaluation and, when appropriate, with biochemistry, Gram stain, culture, and sensitivity. The biopsy site was localized by computed tomography, ultrasound, or fluoroscopy.

RESULTS

Five hundred eighty-three patients with indeterminate renal mass lesions (representing 7.2% of all renal masses diagnosed from 1967 through 1996) were diagnosed by imaging studies complemented by guided biopsy. Sixty-six patients were lost to follow-up, leaving 517 patients who were analyzed. In 393 cases (76%), the imaging-guided biopsy provided a definitive diagnosis. The incidence of false diagnoses was 1.2% (7 biopsies). In 124 of the cases (21%), imaging-guided biopsy was unable to determine the etiology of the lesion with acceptable confidence; of these, 21 biopsies did not provide enough material to establish the diagnosis (16.9%).

CONCLUSIONS

Overall, percutaneous biopsy of the kidney has proved to be a safe and accurate diagnostic procedure, with impact on the management of cystic or solid renal lesions.

Improving accuracy in the grading of renal cell carcinoma by combining the quantitative description of chromatin pattern with the quantitative determination of cell kinetic parameters

The determination of grade and stage in renal cell carcinomas (RCCs) often fails to predict the actual clinical outcome for individual patients. The aim of the present work was to investigate whether it is possible to significantly improve the prognostic accuracy of the grading system by using the combination of two independent computer-assisted microscopy techniques. The first technique relates to the quantitative description of morphonuclear and nuclear DNA content features by means of the image analysis of Feulgen-stained cell nuclei, and the second quantitatively characterizes tumor growth by means of different cell kinetic parameters. These parameters consist of a duplication of a time-related parameter determined by means of the technique of using silver-stained proteins in interphase nucleolar organizer regions (AgNOR), a proliferation index determined by means of MIB-1 immunohistochemistry, and an apoptotic index determined by means of the terminal dUTP nick end labeling technique. The prognostic value of these quantitative features was investigated in a series of 60 RCCs. The quantitative analysis of Feulgen-stained nuclei made it possible to identify subgroups of patients with significantly different prognoses in both grade II and grade III RCCs. We labeled the RCCs associated with the most favorable prognoses as grade II- and III- and those with the least favorable ones as grade II+ and III+. The two most important kinetic variables to identify patients with different clinical outcomes were the MIB-1 index and the mean AgNOR area in the MIB-1-positive cells. Three significantly different survival curves were obtained for the 53 grade II and III RCC patients. Our results show that conventional RCC grading can be significantly improved by the quantitative analysis of Feulgen-stained nuclei, by cell kinetic parameter determination, and, more importantly, by combining the proliferation index with the mean AgNOR area parameter.

Follow-up guidelines for nonmetastatic renal cell carcinoma based on the occurrence of metastases after radical nephrectomy

OBJECTIVE

To define guidelines for the follow-up management of nonmetastatic renal cell carcinoma (RCC), by assessing tumour recurrences and the clinical course in patients who had undergone radical nephrectomy.

PATIENTS AND METHODS

The records of 187 patients with pT1-3, N0-X, M0 RCC who underwent radical nephrectomy between 1982 and 1997 were reviewed prospectively. Clinicopathological variables were compared with the time of first recurrence, site of metastasis and reason for diagnosis.

RESULTS

Metastases were diagnosed in 98 sites in 56 of the 187 patients (30%). The risk for developing metastases increased with stage; 80% of the patients had their metastases diagnosed within 3 years (median 14.5 months) after nephrectomy. The time to first diagnosis was longer for patients with pT1 tumours and for those with skeletal metastases. The cause-specific 5-year survival rate for pT1 tumours was 95%, for pT2 87% and for pT3 tumours 37%. All patients with diploid pT1-2 RCC survived, having a survival advantage over those with aneuploid pT1-2 tumours (P=0.018). Also, pT1-2 tumours of < 5 cm were associated with better survival rates. Among 74 patients with pT3 tumours, 45 got metastases; DNA ploidy in these tumours did not influence survival. Of 30 patients with lung metastases, 28 were diagnosed during follow-up, while 25 of 26 other metastatic sites were diagnosed because of symptoms.

CONCLUSIONS

The risk for tumour progression depends mainly on stage; these results indicate no need for follow-up in patients with diploid pT1-2 tumours or with aneuploid pT1 tumours of < 5 cm. For patients with aneuploid pT1-2 tumours of > 5 cm and pT3 tumours, follow-up is indicated.

Intratumoral heterogeneity of DNA content in renal cell carcinoma and its prognostic significance

BACKGROUND

A multiple sampling study was performed on 124 specimens of renal cell carcinomas to analyze the consistency and reliability of DNA measurements. The authors investigated intratumoral DNA heterogeneity and its role as a adverse prognostic factor for disease progression.

METHODS

DNA content was analyzed by flow cytometry on three different samples of the same tumor. The Cronbach alpha coefficient was used to assess the reliability and a Cox proportional hazards model was used to test the effect of DNA ploidy heterogeneity on time of disease progression.

RESULTS

The agreement among the DNA ploidy samples was high. The number of aneuploid findings increased significantly with the number of samples analyzed. The presence of non-diploid cell populations was a significant adverse predictive value for disease progression. However, the authors were unable to demonstrate that intratumoral heterogeneity DNA content had any influence on the biological behavior of the tumor.

CONCLUSIONS

Determination of DNA ploidy based on single samples may be inaccurate. Spatial variation in DNA ploidy is a feature of renal cell carcinoma; however, its biologic significance remains to be demonstrated.

Unusual chromosome patterns of renal cell carcinomas common to two brothers

In this study, we describe two renal cell carcinomas (RCC) that occurred at the same time in two brothers, yielding information on the carcinogenic process. We used flow cytometry (FCM) to evaluate nuclear DNA content, and performed cytogenetic analysis. We also carried out fluorescence in situ hybridization (FISH) with a panel of centromeric probes for chromosomes 3, 7, 8, 9, 12, 17, 20, and Y in interphase cells. Flow cytometry analysis revealed diploid histograms in the tumor and "nonmalignant" samples of patient 1, while an aneuploid cell subpopulation was found in the tumor and "nonmalignant" samples of patient 2. Tumor samples from the two brothers were studied by FISH, and had common numerical chromosome aberrations: trisomy of chromosomes 3 and 7, and monosomy and trisomy of chromosomes 9 and 17. Moreover, in normal samples from both brothers, we found monosomy 9, and in a normal sample from patient 1, monosomy 17. Cytogenetic analysis revealed trisomy 3 in some cells grown from normal kidney tissue of each brother. The identification of the same chromosome alterations in both brothers appears to provide evidence of an unusual process of carcinogenesis, probably due to a common genetic basis.

Cyclin-D1 expression in human renal-cell carcinoma

Cyclin-D1 over-expression represents one of several common alterations in the G1-S transition associated with malignancies. Conclusive evidences indicate that cyclin D1 is a proto-oncogene and the gene is amplified or rearranged in different tumour types. Since very little is known about aberrations in the G1-S transition in human renal-cell carcinoma (RCC), we have characterized the expression of cyclin D1 in 80 human renal-cell carcinomas and 12 normal kidney cortex tissues using Western blotting. The cyclin-D1-protein content varied considerably and 75% of the tumours expressed higher levels than normal kidney cortex, in contrast to 25% of the tumours either lacking cyclin D1 or with low protein levels. Although it is difficult to define aberrant expression of cyclin D1, the results might indicate that the proto-oncogene was activated in a sub-set of RCC. It is also possible that low expression of cyclin D1 represents an aberrant down-regulation of the protein. Immunohistochemical assessment of cyclin D1 in a sub-set of the tumours showed large variations in the fraction of cyclin-D1-positive cells, supporting the Western-blot analyses. Surprisingly, cyclin-D1 expression did not correlate with proliferation determined by Ki-67-antigen expression or S-phase analyses. In non-papillary renal-cell carcinomas, high cyclin-D1 expression was associated with a diploid DNA profile and smaller tumour size, but there was no association between cyclin-D1 expression and tumour stage or nuclear grade. In nonpapillary tumours, high cyclin-D1 expression was further significantly associated with a better prognosis according to univariate and multivariate analyses (p = 0.005 and 0.002 respectively), as compared with highly aggressive tumours with low cyclin-D1 levels.

The cellular basis of tumor progression

Variability in disease presentation and course is a hallmark of cancer. Variability is seen among similarly diagnosed cancers in different patients or animal hosts and in the same cancer at different periods of time. This latter type of variability, termed "tumor progression," was defined by Foulds in a series of six rules that describe the independent behavior of individual cancers and the independent evolution of different cancer characteristics. Tumor progression is believed to result from variability among subpopulations of tumor cells within individual cancers and from selection of these subpopulations by conditions within the cancer environment, such that different subpopulations come to prominence over the course of cancer development and growth. Interactions among subpopulations, however, modulate tumor behavior as well as tumor evolution. The leading hypothesis for the origin of tumor subpopulations is the genetic instability of cancer cells. There are a number of possible mechanisms of genetic instability, some internal to cancer cells (mutation, amplification, mutator phenotypes, DNA repair deficiencies) and some present in the tumor microenvironment (endogenous mutagens). There are also potential epigenetic mechanisms of variability, including alterations in gene regulation, differentiation, adaptation, and cell fusion. Regardless of mechanism, the heterogeneity of tumor subpopulations poses a number of challenges to the practice of cancer research, including the design of reproducible and meaningful experiments. Tumor heterogeneity also has significant consequences for the clinical assessment of tumor prognosis and the development of effective treatment regimens.

The cell cycle in breast cancer

Breast cancer is a heterogeneous disease regarding morphology, invasive behavior, metastatic capacity, hormone receptor expression and clinical outcome. For prediction of prognosis, tumor cell kinetics is an important feature, traditionally evaluated by estimation of cell growth-associated parameters such as mitotic index, S-phase fraction and expression of proliferation coupled proteins, for example proliferating cell nuclear antigen (PCNA) and Ki-67 antigen. Recent data indicate that deregulation of the cell cycle can occur at different levels in cancer and that the "deregulation pattern" can be of clinical significance. In the present overview we give a short description of approaches used for cell proliferation assessments, whereafter more recent data on cell cycle deregulation are discussed. Alterations of importance in breast cancer include overexpression of cyclins D1 and E, down-regulation of cyclin-dependent kinase inhibitors, such as p16, and inactivation of the retinoblastoma and p53 tumor suppressor proteins.