Surgical enucleation for renal cell carcinoma (RCC). Prognostic significance of tumour stage, grade and DNA ploidy

A 7-case anatomopathology revision in the presence of renal relapse after conservative therapy: implications on surgical technique

Anatomopathology revision of the cases which underwent second surgery because of a renal neoplasm relapsing after conservative surgery in order to find possible relations with the surgical technique.

Materials and Methods.

At our institution, Nephron-sparing surgery (NSS) is currently indicated as elective technique for neoplasms smaller than 4cm in diameter. The technique involves the removal of the neoplasm with a margin of healthy parenchyma and with the perilesional fat. The patients are monitored with a first CT check after 4 months and then with ultrasound/CT checks every 6 months in the first 2 years and then once a year. In the present study we analyze the records of the cases in the period 1994–2005 undergoing a second operation for a renal tumor relapsing in the operated kidney after NSS. All specimens were reviewed by a single experienced uro-pathologist, who determined the size of the surgical margins and the relations between the seat of recidivism and the seat of the preceding enucleoresection.

Results.

Seven cases with renal relapse were found out of 267 undergoing conservative surgery in the same period (incidence: 2.6%). The diagnosis had always been made lacking any other disease localizations at a complete re-staging; the average relapse latency was 19.4 months (8–46 months). In 5 cases the second tumor was found in the seat of the previous NSS: for these cases the minimum margin of the enucleoresection was lower than 3mm (median minimum margin: 1.6 mm). Differently, in the remaining 2 cases, both with a wider surgical margin (median minimum margin: 12.0 mm), the seat of the first and that of the second neoplasm were distant. In particular, in one case a multifocal relapse with a spread microvascular embolization was found, while in the other the two neoplasms showed a different histotype.

Discussion and Conclusions.

In the 5 cases with a little resection margin and relapsing tumor in the seat of the enucleoresection, the persistence of a peritumoral microscopic neoplastic disease can be assumed. In the other 2 cases showing a wider surgical margin the relapse can be attributed to the widespread microscopic multifocality in one case, and to the development of a second de novo neoplasm in the other case. The extension of the surgical margin seems then to have played a role in determining a relapse in the seat of enucleoresection.

Neoplasm Staging and Organ-Confined Renal Cell Carcinoma: A Systematic Review

OBJECTIVES

Several TNM staging system editions were published over the years for renal cell carcinoma (RCC). Using a search strategy similar to the one used by the TNM process Subcommittee for "literature watch", we searched MEDLINE with the intent to critically analyze literature concerning the different TNM editions and the data regarding the optimal breakpoints to substratify localized RCC.

MATERIAL AND METHODS

The electronic search was conducted as follows: "Neoplasm staging" [MeSH] AND "Carcinoma, Renal Cell" [MeSH]. At the end of a process of abstract analysis performed separately by three of the authors, 34 papers were included in the systematic review.

RESULTS

All the 34 selected papers were retrospective studies. According to the 1987 version of TNM classification, no paper showed statistically significant cancer-specific survival probability differences between stage I and stage II RCC. According to the 1997 TNM version, the results were controversial. While a few papers found significantly different cancer-specific survival rates between stage I and stage II RCC, several others failed to do so. With the aim to stratify patients with localized RCC, most of the papers proposed an ideal breakpoint ranging from 4.5 to 5.5 cm.

CONCLUSION

This literature review highlighted that a correct definition of the staging of organ-confined RCC was far from being achieved and provided an appropriate synopsis of the available data for further update of the TNM staging system.

Independent value of tumor size and DNA ploidy for the prediction of disease progression in patients with organ-confined renal cell carcinoma

BACKGROUND

Greater than 20% of patients with apparently localized renal cell carcinoma (RCC) present with disease progression after surgery. The objective of the current study was to improve the ability of clinicians to predict prognosis in patients with localized RCC.

METHODS

The authors studied 154 patients with organ-confined RCC classified as pT1 to pT2-pN0-M0 who underwent radical nephrectomy. Follow-up ranged from 24-128 months (median, 72 months). Several morphologic parameters of the tumor were considered. DNA content was analyzed by flow cytometry and tumor size was determined from the surgical specimen. A Cox proportional hazards regression model was used to identify significant independent prognostic factors for disease progression.

RESULTS

At 5 and 10 years of follow-up, disease free survival was found to be 87% and 86%, respectively. Univariate analysis revealed that DNA content, Furhman grade, and tumor size had a statistically significant predictive value for disease progression, whereas, with regard to grade, the difference was significant only between patients with Grade 3 tumors and all other patients with Grade 1-2 tumors (P < 0. 0001). Although DNA content was found to correlate with tumor size (P < 0.0001), multivariate analysis showed that these were the only significant independent predictors of disease progression. The sum of DNA content and tumor size therefore was considered to distinguish separate risk groups. For a patient with diploid RCC, the risk of progression increased from 4% if the tumor size was 3 cm to 43% if the tumor size was 10 cm. For a patient with nondiploid RCC, this risk was 32% if the tumor size was 3 cm, increasing to 99% for tumors measuring 10 cm.

CONCLUSIONS

Stratification of organ-confined RCC according to tumor size and DNA content could possibly provide more information that could be useful in the selection of individuals with significantly different risks of disease progression.

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.

Renal cancer in families with hereditary renal cancer: prospective analysis of a tumor size threshold for renal parenchymal sparing surgery

PURPOSE

Patients with hereditary forms of renal cancer are at risk for new tumors and metastases. Renal parenchymal sparing surgery has been performed to preserve renal function and quality of life, and prevent metastases. We evaluated a 3 cm. threshold for performing renal parenchymal sparing surgery in patients with von Hippel-Lindau disease and hereditary papillary renal cancer.

MATERIALS AND METHODS

Patients with von Hippel-Lindau disease or hereditary papillary renal cancer and renal cancer were identified by screening affected kindred and by kindred history. Patients with small tumors were followed with serial imaging studies until the largest renal tumor was 3 cm., when renal parenchymal sparing surgery was performed. Renal tumors greater than 3 cm. were resected without delay. Parenchymal sparing techniques were used when possible in each group.

RESULTS

The 3 cm. surgical threshold was evaluated in 52 patients with von Hippel-Lindau disease (group 1) at a median followup of 60 months (range 6 to 205). None of these patients had metastatic disease and none has required renal transplantation or dialysis. In 44 patients with von Hippel-Lindau disease (group 2) renal tumors larger than 3 cm. developed. Median followup from the initial radiological diagnosis of renal cancer in this group was 66.5 months (range 0 to 321). Patients in group 1 underwent parenchymal sparing surgery instead of nephrectomy more frequently than those in group 2 (46 of 48 operations or 96% versus 45 of 72 or 63%, Fisher's exact test p <0.0001). In contrast to patients in group 1, metastatic renal cancer developed in 11 of the 44 in group 2 (25%) (Fisher's exact test p <0.0001). A total of 23 patients with hereditary papillary renal cancer were also identified. Median followup in these cases was 44 months (range 0 to 237). Ten patients had tumors less than 3 cm. No patient with tumors less than 3 cm. and 2 of the 13 (15%) with larger tumors had metastases.

CONCLUSIONS

Using a 3 cm. renal tumor diameter as an indication for renal surgery no patient with renal cancer and von Hippel-Lindau disease or hereditary papillary renal cancer had metastatic disease regardless of the number of tumors. Using a lesion size of 3 cm. as a threshold for performing renal parenchymal sparing surgery may help to prevent metastatic disease, unnecessary renal damage due to frequent surgery and renal dialysis or transplantation.

Cystic renal cell carcinoma is cured by resection: a study of 24 cases with long-term followup

PURPOSE

The true incidence and biological behavior of cystic renal cell carcinoma are not known. To our knowledge we present the largest series of patients with cystic renal cell carcinoma with long-term followup.

MATERIALS AND METHODS

We reviewed the Mayo Clinic surgical pathology files of renal cell cancer cases with a cystic component resected from 1969 to 1997, and arbitrarily chose 75% tumor involvement by cysts as a cutoff for inclusion in the study.

RESULTS

We identified 24 cases of clear cell renal cell carcinoma with 75% or greater involvement by cysts comprising 0.79% of 3,047 renal cell cancer cases resected at our institution between 1969 and 1997. Mean patient age was 62.7 years (range 40 to 83). A total of 11 patients (46%) underwent radical nephrectomy, 4 (17%) simple nephrectomy, 3 (12%) partial nephrectomy and 6 (25%) tumor enucleation. Mean tumor involvement by cysts was 84% (range 75 to 95) and in 11 cases (46%) involvement was 90% or greater. Cancer stage was T1 in 20 patients (83%), T2 in 1 (4.4%) and T3a in 4 (12.5%). Cancers were diploid in all but 1 case. Mean followup was 77.6 months (range 8 to 428, median 51). A total of 22 patients (92%) had no evidence of cancer and 2 died of intercurrent disease.

CONCLUSIONS

Our results indicate that cystic renal cell carcinoma is uncommon and usually cured by resection, regardless of size, stage or number of cysts. These patients may benefit from nephron sparing surgery, such as partial nephrectomy.