The influence of previous robotic experience in the initial learning curve of laparoscopic radical prostatectomy

ABSTRACT Introduction: This study analyzed the impact of the experience with Robotic-Assisted Laparoscopic Prostatectomy (RALP) on the initial experience with Laparoscopic Radical Prostatectomy (LRP) by examining perioperative results and early outcomes of 110 patients. LRPs were performed by two ro-botic fellowship trained surgeons with daily practice in RALP. Patients and Methods: 110 LRP were performed to treat aleatory selected patients. The patients were divided into 4 groups for prospective analyses. A transperitoneal approach that simulates the RALP technique was used. Results: The median operative time was 163 minutes (110-240), and this time significantly decreased through case 40, when the time plateaued (p=0.0007). The median blood loss was 250mL. No patients required blood transfusion. There were no life-threatening complications or deaths. Minor complications were uniformly distributed along the series (P=0.6401). The overall positive surgical margins (PSM) rate was 28.2% (20% in pT2 and 43.6% in pT3). PSM was in the prostate apex in 61.3% of cases. At the 12-month follow-up, 88% of men were continent (0-1 pad). Conclusions: The present study shows that there are multiple learning curves for LRP. The shallowest learning curve was seen for the operative time. Surgeons transitioning between the RALP and LRP techniques were considered competent based on the low perioperative complication rate, absence of major complications, and lack of blood transfusions. This study shows that a learning curve still exists and that there are factors that must be considered by surgeons transitioning between the two techniques.

Predicting outcomes in partial nephrectomy: is the renal score useful?

ABSTRACT Introduction and Objective The R.E.N.A.L. nephrometry system (RNS) has been validated in multiple open, laparoscopic and robotic partial nephrectomy series. The aim of this study was to test the accuracy of R.E.N.A.L. nephrometry system in predicting perioperative outcomes in surgical treatment of kidney tumors <7.0cm in a prospective model. Materials and Methods Seventy-one patients were selected and included in this prospective study. We evaluate the accuracy of RNS in predicting perioperative outcomes (WIT, OT, EBL, LOS, conversion, complications and surgical margins) in partial nephrectomy using ROC curves, univariate and multivariate analyses. R.E.N.A.L. was divided in 3 groups: low complexity (LC), medium complexity (MC) and high complexity (HC). Results No patients in LC group had WIT >20 min, versus 41.4% and 64.3% MC and HC groups respectively (p=0.03); AUC=0.643 (p=0.07). RNS was associated with convertion rate (LC:28.6% ; MC:47.6%; HC:77.3%, p=0.02). Patients with RNS <8 were most often subjected to partial nephrectomy (93% x 72%, p=0.03) and laparoscopic partial nephrectomy (56.8% x 28%, p=0.02), AUC=0.715 (p=0.002). The RNS was also associated with operative time. Patients with a score >8 had 6.06 times greater chance of having a surgery duration >180 min. (p=0.017), AUC=0.63 (p=0.059). R.E.N.A.L. score did not correlate with EBL, complications (Clavien >3), LOS or positive surgical margin. Conclusion R.E.N.A.L. score was a good method in predicting surgical access route and type of nephrectomy. Also was associated with OT and WIT, but with weak accuracy. Although, RNS was not associated with Clavien >3, EBL, LOS or positive surgical margin.

Effect of Symptom Graduation on Oncologic Outcomes in Patients with Renal Cell Carcinoma and Hematuria.

Aims: Symptoms associated with renal cell carcinoma characterize high-risk disease. Hematuria is the most common symptom and usually occurs as a result of urothelial invasion. The objective of this study was to evaluate the prognostic value of progressive symptomatic disease in patients with kidney cancer. Place and Duration of Study: Sao Paulo Cancer Institute at University of Sao Paulo School of Medicine between 2005 and 2009. Methodology: Data was prospectively recorded at our database and retrospectively reviewed. Sixty-six individuals who presented with macroscopic hematuria were included in our analysis. Patients were divided into three groups: (1) Exclusive hematuria (27 patients), (2) Hematuria associated with another symptom (23 patients), and (3) Hematuria associated with two or more symptoms. We evaluated these groups for histopathology, kidney function, recurrence, and survival characteristics. Results: Mean tumor diameter was 8.5 cm, 11 cm and 13.4 cm for groups (1), (2) and (3). Recurrence-free survival was 89%, 91%, and 69% and overall survival was 96%, 79%, and 56% for groups (1), (2) and (3), respectively. The mean follow-up time was 97.6 months and the disease-free survival rate was 84.8%. Cox regression analysis showed a death risk 10.5 times higher in group (3) when compared to Group (1). Conclusion: Association of two or more symptoms with hematuria impairs prognosis of patients surgically treated for kidney cancer.

Biochemical recurrence rates are similar for pT2-positive surgical margins and pT3a

Objective Histological details of positive surgical margins in radical prostatectomy specimens have been related to outcome after surgery in rare studies recently published. Our objective is to assess whether the status of surgical margins, the extent and the Gleason score of positive margins, and the extent of the extraprostatic extension are predictive of biochemical recurrence post-radical prostatectomy.Materials and Methods Three hundred sixty-five radical prostatectomy specimens were analyzed. The length of the positive surgical margin and extraprostatic extension and the Gleason score of the margin were recorded. Statistical analyses examined the predictive value of these variables for biochemical recurrence.Results 236 patients were stage pT2R0, 58 pT2R1, 25 pT3R0 and 46 pT3R1. Biochemical recurrence occurred in 11%, 31%, 20% and 45.7% of pT2R0, pT2R1, pT3R0 and pT3R1, respectively. The extent of the positive surgical margins and the Gleason score of the positive surgical margins were not associated with biochemical recurrence in univariate analysis in a mean follow up period of 35.9 months. In multivariate analyses, only the status of the surgical margins and the global Gleason score were associated with biochemical recurrence, with a risk of recurrence of 3.1 for positive surgical margins and of 3.8 for a Gleason score > 7.Conclusion Positive surgical margin and the global Gleason score are significant risk factors for biochemical recurrence post-radical prostatectomy, regardless of the extent of the surgical margin, the extent of the extraprostatic extension, or the local Gleason score of the positive surgical margin or extraprostatic tissue. pT2R1 disease behaves as pT3R0 and should be treated similarly.

PGC and PSMA in prostate cancer diagnosis: tissue analysis from biopsy samples

Purpose The discovery of new diagnostic tools for the diagnosis of prostate cancer (PCa) has become an important field of research. In this study, we analyzed the diagnostic value of the expression of the pepsinogen C (PGC) and prostate-specific membrane antigen (PSMA) genes in tissue samples obtained from prostate biopsies. Materials and Methods This study was comprised of 51 consecutive patients who underwent transrectal ultrasound (TRUS)-guided prostate biopsies between January 2010 and March 2010. The biopsies were performed with 12 cores, and an additional core was randomly retrieved from the peripheral zone from each patient for study purposes. The expression of the PGC and PSMA genes was analyzed from the cDNA from the samples via the qRT-PCR technology. The expression patterns of patients with PCa were compared with those of patients without a PCa diagnosis. Results PSMA was overexpressed in only 43.4% of PCa cases, and PGC was overexpressed in 72.7% of cases. The median expression of PSMA was 1.5 times (0.1 to 43.9) and the median PGC expression was 8.7 times (0.1 to 50.0) the expression observed in prostatic tissue from TRUS-guided biopsies of normal patients. Analysis of patients with high-risk PCa indicated that PGC was overexpressed in 71.4% of cases (with a median expression of 10.6 times), and PSMA was overexpressed in only 35.7% of cases (with a median expression of 4.5 times). Among patients with low-risk PCa, PGC was also overexpressed in 71.4% of cases (with a median expression of 5.9 times), and PSMA was overexpressed in only 42.8% of cases (with a median expression of 2.5 times). Conclusions PGC gene expression is significantly higher in prostatic tissue in men affected by PCa when compared to normal prostates. Further analyses are necessary to confirm our results. .

Expression profile of microrna-145 in urothelial bladder cancer

Purpose Bladder cancer (BC) is the second most common malignancy of the urinary tract, with high mortality. The knowledge of the molecular pathways associated with BC carcinogenesis is crucial to identify new diagnostic and prognostic biomarkers. MicroRNAs (miRNAs) are short non-coding RNA molecules that play important roles in the regulation of gene expression by acting directly on mRNAs. miR-145 has been considered as a tumor suppressor, which targets the c-MYC, MUC-1 and FSCN1 genes. Our aim was to evaluate the expression profile of miR-145 in low-grade non-invasive and high-grade invasive bladder urothelial carcinomas. Materials and Methods We studied 30 specimens of low-grade, non-invasive pTa and 30 of pT2/pT3 high-grade invasive UC obtained by transurethral resection or radical cystectomy, followed over a mean time of 16.1 months. Normal controls were represented by five samples of normal bladder biopsy from patients who underwent retropubic prostatectomy to treat BPH. miRNA extraction and cDNA generation were performed using commercial kits. Analysis was performed by qRT-PCR, and miR-145 expression was calculated using the 2-∆∆ct method; we used RNU-43 and RNU-48 as endogenous controls. Results miR-145 was under-expressed in 73.3% and 86.7% of pTa and pT2/pT3, respectively, with expression means of 1.61 for the former and 0.66 for the last. There were no significant differences in miR-145 expression and histological grade, tumor stage, angiolymphatic neoplastic invasion and tumor recurrence. Conclusion miR-145 is under-expressed in low-grade, non-invasive and high-grade invasive urothelial bladder carcinoma and may play an important role in the carcinogenesis pathway, being an interesting candidate diagnostic marker. .

Anatrophic nephrotomy as nephron-sparing approach for complete removal of intraparenchymal renal tumors

OBJECTIVE: Partial nephrectomy for small kidney tumors has increased in the last decades, and the approach to non-palpable endophytic tumors became a challenge, with larger chances of positive margins or complications. The aim of this study is to describe an alternative nephron-sparing approach for small endophytic kidney tumors through anatrophic nephrotomy. PATIENTS AND METHODS: A retrospective analysis of patients undergoing partial nephrectomy at our institution was performed and the subjects with endophytic tumors treated with anatrophic nephrotomy were identified. Patient demographics, perioperative outcomes and oncological results were evaluated. RESULTS: Among the partial nephrectomies performed for intraparenchymal tumors between 06/2006 and 06/2010, ten patients were submitted to anatrophic nephrotomy. The mean patient age was 42 yrs, and the mean tumor size was 2.3 cm. Mean warm ischemia time was 22.4 min and the histopathological analysis showed 80% of clear cell carcinomas. At a mean follow-up of 36 months, no significant creatinine changes or local or systemic recurrences were observed. CONCLUSION: The operative technique described is a safe and effective nephron-sparing option for complete removal of endophytic renal tumors.

Significant heterogeneity in terms of diagnosis and treatment of renal cell carcinoma at a private and public hospital in Brazil

PURPOSE: A great number of small renal lesions have now been detected. Nowadays, partial nephrectomy has more frequently been adopted for surgical treatment of earlier stage disease. Previous studies have associated patient, institutional, and health care system factors with surgery type. The aim of this study was to compare the diagnosis and treatment of renal cell carcinoma (RCC) according to hospital type, public versus private, in our country. MATERIALS AND METHODS: We retrospectively evaluated 183 patients with RCC who underwent radical nephrectomy or nephron-sparing surgery between 2003 and 2007 in two hospitals, one private and one public. Patient demographic, clinical, surgery, and pathologic characteristics were analyzed. RESULTS: The radical nephrectomy rate was higher at the public hospital than at the private hospital (75 percent vs. 57 percent, p = 0.008). Overall, patients at the public hospital presented larger tumors than did the patients who were cared for privately. Furthermore, small renal masses were significantly more prevalent in private care (57.8 percent vs. 28.3 percent). Patients at the public hospital showed a higher incidence of capsular invasion (p = 0.008), perirenal fat invasion (p < 0.01), lymph node involvement (p < 0.001), and a lower incidence of initial tumors. pT1 tumors were reported in 41 percent of patients at the public hospital and in 72 percent at the private hospital (p < 0.001). CONCLUSION: Patients with RCC cared for at our public referral hospital showed a more advanced stage than RCC treated at the private institution.

Socioeconomic status is an independent predictor of biochemical recurrence among patients with prostate cancer who undergo radical prostatectomy

PURPOSE: Socioeconomic status (SES) may influence cancer characteristics and behavior in several aspects. We analyzed PCa characteristics and behavior among low income uninsured men, and compare them to high income patients with health insurance in a developing country. MATERIALS AND METHODS: A retrospective case-control study was performed on 934 patients with clinically localized PCa who underwent radical prostatectomy between March, 1999 and July, 2009. Patients were divided in two groups, according to their SES. In group 1 (n=380), all had low income, low educational levels and couldn't afford medical insurance. In group 2 (n=554), all had higher income, higher education and had medical insurance. RESULTS: Patients from group 1 were older, had higher Gleason scores, higher rates of seminal vesicle and bladder neck involvement. The Kaplan Meier disease-free survival curve demonstrated that after a follow-up of four years, about 50 percent of uninsured patients had biochemical recurrence, versus 21 percent of insured patients (Log rank test: p < 0.001). A multivariate Cox regression analysis for the risk of disease recurrence demonstrated that only PSA levels, Gleason score, seminal vesicle involvement and SES were statistically significant variables. Patients with a low SES presented 1.8 times the risk of recurrence as compared to patients with a high SES. CONCLUSIONS: Patients with low SES were older, presented more aggressive PCa characteristics and a high rate of disease recurrence. A low SES constituted an independent predictor for disease recurrence.

Early experience with targeted therapy and dendritic cell vaccine in metastatic renal cell carcinoma after nephrectomy

PURPOSE: Metastatic renal cell carcinoma (RCC) is one of the most treatment-resistant malignancies and nephrectomy, isolated or combined with systemic chemotherapy typically has limited or no effectiveness. We report our initial results in patients treated with the association of molecular targeted therapy, nephrectomy, and hybrid dendritic-tumor cell (DC) vaccine. MATERIALS AND METHODS: Two male patients diagnosed with metastatic RCC were selected for the study. They were treated with the triple strategy, in which sunitinib (50 mg per day) was given for 4 weeks, followed by radical nephrectomy after two weeks. DC vaccine was initiated immediately after surgery and repeated monthly. Sunitinib was restarted daily after 2 to 3 weeks of surgery with a 7-day interval every 4 weeks. RESULTS: Both patients had complete adherence to the proposed treatment with DC vaccine therapy combined with sunitinib. Follow-up in these patients at 9 and 10 months demonstrated a stable disease in both, as shown by imaging and clinical findings, with no further treatment required. CONCLUSION: The immune response obtained with DC vaccine combined with the antiangiogenic effect of sunitinib and the potential benefits of cytoreductive nephrectomy in advanced disease could represent a new option in the treatment of metastatic RCC. Further prospective trials are needed not only to elucidate the ideal dosing and schedule, but also to better define the proof-of-concept proposed in this report and its role in clinical practice.

Learning curve for radical retropubic prostatectomy

PURPOSE: The learning curve is a period in which the surgical procedure is performed with difficulty and slowness, leading to a higher risk of complications and reduced effectiveness due the surgeon's inexperience. We sought to analyze the residents' learning curve for open radical prostatectomy (RP) in a training program. MATERIALS AND METHODS: We conducted a prospective study from June 2006 to January 2008 in the academic environment of the University of São Paulo. Five residents operated on 184 patients during a four-month rotation in the urologic oncology division, mentored by the same physician assistants. We performed sequential analyses according to the number of surgeries, as follows: = 10, 11 to 19, 20 to 28, and = 29. RESULTS: The residents performed an average of 37 RP each. The average psa was 9.3 ng/mL and clinical stage T1c in 71 percent of the patients. The pathological stage was pT2 (73 percent), pT3 (23 percent), pT4 (4 percent), and 46 percent of the patients had a Gleason score 7 or higher. In all surgeries, the average operative time and estimated blood loss was 140 minutes and 488 mL. Overall, 7.2 percent of patients required blood transfusion, and 23 percent had positive surgical margins. CONCLUSION: During the initial RP learning curve, we found a significant reduction in the operative time; blood transfusion during the procedures and positive surgical margin rate were stable in our series.

The beginning of the 21st century: a paradigm shift in the surgical management of renal cell carcinoma in South America

PURPOSE: The incidence of renal cell carcinoma (RCC) has been rising by 2.3 to 4.3 percent every year over the past three decades. Previously, RCC has been known as the internist’s tumor; however, it is now being called the radiologist’s tumor because 2/3 are now detected incidentally on abdominal imaging. We compared patients who were treated toward the end of the 20th century to those treated during the beginning of the 21st century with regard to RCC size and type of surgical treatment. MATERIALS AND METHODS: The study included 226 patients. For analysis of tumor size, we considered a cut point of < 4 cm and > 4 cm. For analysis of type of surgery performed, we considered radical and partial nephrectomy. RESULTS: After the turn of the century, there was a reduction of 1.57 ± 0.48 cm in the size of the RCC that was operated on. Nephron sparing surgeries were performed in 17 percent of the cases until the year 2000, and 39 percent of the tumors were < 4 cm. From 2001, 64 percent of the tumors measured < 4 cm and 42 percent of the surgeries were performed using nephron sparing techniques. Mean tumor size was 5.95 cm (± 3.58) for the cases diagnosed before year 2000, and cases treated after the beginning of 21st century had a mean tumor size of 4.38 cm (± 3.27). CONCLUSIONS: Compared with the end of the 20th century, at the beginning of the 21st century due to a reduction in tumor size it was possible to increase the number of nephron sparing surgeries.

Gene expression profile of renal cell carcinoma clear cell type

PURPOSE: The determination of prognosis in patients with renal cell carcinoma (RCC) is based, classically, on stage and histopathological aspects. The metastatic disease develops in one third of patients after surgery, even in localized tumors. There are few options for treating those patients, and even the new target designed drugs have shown low rates of success in controlling disease progression. Few studies used high throughput genomic analysis in renal cell carcinoma for determination of prognosis. This study is focused on the identification of gene expression signatures in tissues of low-risk, high-risk and metastatic RCC clear cell type (RCC-CCT). MATERIALS AND METHODS: We analyzed the expression of approximately 55,000 distinct transcripts using the Whole Genome microarray platform hybridized with RNA extracted from 19 patients submitted to surgery to treat RCC-CCT with different clinical outcomes. They were divided into three groups (1) low risk, characterized by pT1, Fuhrman grade 1 or 2, no microvascular invasion RCC; (2) high risk, pT2-3, Fuhrman grade 3 or 4 with, necrosis and microvascular invasion present and (3) metastatic RCC-CCT. Normal renal tissue was used as control. RESULTS: After comparison of differentially expressed genes among low-risk, high-risk and metastatic groups, we identified a group of common genes characterizing metastatic disease. Among them Interleukin-8 and Heat shock protein 70 were over-expressed in metastasis and validated by real-time polymerase chain reaction. CONCLUSION: These findings can be used as a starting point to generate molecular markers of RCC-CCT as well as a target for the development of innovative therapies.

Undergrading and understaging in patients with clinically insignificant prostate cancer who underwent radical prostatectomy

PURPOSE: The aim of our study is to evaluate the undergrading and understaging rates in patients with clinically localized insignificant prostate cancer who underwent radical prostatectomy. MATERIALS AND METHODS: Between July 2005 and July 2008, 406 patients underwent radical prostatectomy for clinical localized prostate cancer in our hospital. Based on preoperative data, 93 of these patients fulfilled our criteria of non-significance: Gleason score < 7, stage T1c, PSA < 10 ng/mL and percentage of affected fragments less than 25 percent. The pathologic stage and Gleason score were compared to preoperative data to evaluate the rate of understaging and undergrading. The biochemical recurrence free survival of these operated insignificant cancers were also evaluated. RESULTS: On surgical specimen analysis 74.7 percent of patients had Gleason score of 6 or less and 25.3 percent had Gleason 7 or greater. Furthermore 8.3 percent of cases showed extracapsular extension. After 36 months of follow-up 3.4 percent had biochemical recurrence, defined by a PSA above 0.4 ng/mL. CONCLUSIONS: Despite the limited number of cases, we have found considerable rates of undergrading and understaging in patients with prostate cancer whose current definitions classified them as candidates for active surveillance. According to our results the current definition seems inadequate as up to a third of patients had higher grade or cancer outside the prostate.

Tumor banks: the cornerstone of basic research in urology

PURPOSE: Tumor banks have the primary responsibility for collecting, cataloging, storing and disseminating samples of tissues, cells and fluids, which are used by researchers to identify diagnostic molecular markers, prognostic indicators and therapeutic targets. The objective of this review was to describe a simple, reliable and reproducible protocol for obtaining and storing samples of urological tumors. MATERIALS AND METHODS: Urogenital tumor tissues were collected by the surgeons from the Urology Division of University of Sao Paulo Medical School. The obtained surgical specimens were immediately placed in liquid nitrogen, dry ice or in a tube containing RNAlater ®, and then stored by cryopreservation (-80°C). A mirror fragment was fixed in 10 percent formalin processed routinely and embedded in Paraplast®. RESULTS: We developed a protocol for the collection, cataloging, storage, conservation and use of tumor samples. During a period of one year the Urological Tumor Bank of the Urology Division stored 274 samples of prostate, bladder, kidney, penis and testicle tumors of different histological types, 74 urine and 271 serum samples. CONCLUSIONS: Having biological materials characterized and available along with the clinical patient information provides an integrated portrait of the patients and their diseases facilitating advances in molecular biology. It also promotes the development of translational research improving methods of diagnosis and cancer treatment.

Incidence of benign lesions according to tumor size in solid renal masses

Objective: The incidence of solid renal masses has increased sharply in recent years due to widespread use of abdominal imaging studies. The aim of the present study was to evaluate the incidence of benign lesions in solid renal masses according to tumor size. Materials and Methods: The authors retrospectively reviewed the records of 305 patients with 328 renal solid masses treated by surgery. Based on a report by one pathologist, the specimen tumor size and the histology of each lesion were tabulated. The frequency of renal cell carcinoma and benign renal lesions was evaluated and a correlation between tumor size and pathological features of the masses was observed. Results: The frequency of malignant lesions in the 328 renal masses was 83.2 percent. When lesions were stratified into groups with diameters ¡Ü 3 cm or > 3 cm, the incidence of benign histology was 22.9 percent and 13.3 percent, respectively (p = 0.026). The odds ratios for finding a benign lesion in masses ¡Ü 3 cm was 1.93 (IC 95 percent, 1.07 - 3.46) compared to masses > 3 cm. Conclusion: The incidence of benign lesions is significantly higher in renal masses smaller than 3 cm in diameter, which should be taken in account when the treatment of renal solid masses is planned.

Histopathological findings in extended prostate biopsy with PSA ≤ 4 ng/mL

OBJECTIVE: Cancer detection has been reported in up to 27 percent of patients when lowering the PSA cutoff to 2.5 ng/mL. Although this practice could increase the number of biopsies performed, it also could lead to more frequent detection of significant prostate cancers at an organ-confined stage and/or a less aggressive state. This study describes the incidence of malignancy and tumor characteristics in extended prostate biopsies with PSA ≤ 4 ng/mL. MATERIALS AND METHODS: Prostate biopsies from 1081 patients where examined, 275 (25.4 percent) patients had PSA level ≤ 4 ng/mL. RESULTS: Cancer was diagnosed in 32.0 percent and 35.7 percent of patients with PSA ≤ 4 ng/mL and > 4 ng/mL, respectively (p = 0.906). The median Gleason score was 7 independent of PSA > or ≤ 4 ng/mL (p = 0.078). The median number of cores positive for tumor was 4 and 3, respectively, for PSA > 4 ng/mL and PSA ≤ 4 ng/mL (p = 0.627). There was a difference in the total percent of tumors involving all cores, 11 percent and 7 percent for PSA > or ≤ 4 ng/mL (p = 0.042). Fifty-six patients underwent radical prostatectomy, 12 had PSA ¡Ü 4 ng/mL. In both groups, a diagnosis of cancer was accurate with no differences in Gleason score, tumor volume or staging for both groups. CONCLUSION: When PSA is below 4 ng/mL, cancer is detected in a proportion equal to the proportion diagnosed with a PSA > 4 ng/mL, and tumor characteristics are similar between the two groups. Only clinically significant tumors were diagnosed following radical prostatectomy.

Prognostic relevance of the histological subtype of renal cell carcinoma

OBJECTIVE: According to several studies, when the histological subtype of renal cell carcinoma is established it is possible to attribute a different life expectancy to each patient. We analyzed the prognostic significance of the histological subtype in renal cell carcinoma. MATERIALS AND METHODS: The authors retrospectively analyzed the follow-up of 230 patients after radical or conservative renal surgery. The histological characteristics of the different subtypes of tumor were obtained and the disease-free and cancer-specific survival curves for the clear cell, cromophobic, papillary, collecting duct (Bellini) subtypes and those with sarcomatoid differentiation were individualized. RESULTS: The disease-free and cancer-specific survival rates for clear cell tumors were 76.6 percent and 68.0 percent respectively, 71.2 percent and 82.1 percent respectively for the cromophobic type, 71.1 percent and 79.8 percent respectively for the papillary type, 26.9 percent and 39.3 percent respectively for the sarcomatoid type, and 0.0 percent and 0.0 percent respectively for the collecting ducts (p < 0.001). CONCLUSION: The histological subtypes of renal tumors can stratify patients into different prognostic groups only when the sarcomatoid differentiation is present.