Benign pathological findings in 303 Chinese patients undergoing surgery for presumed localized renal cell carcinoma

Objective: To analyze the incidence of benign lesions in Chinese patients undergoing nephrectomies for renal masses identified as localized renal cell carcinoma (RCC) in preoperative imaging. Methods: Between 1999 and 2007, 303 patients (112 female, 191 male) with presumed localized RCC underwent nephrectomy (234 radical nephrectomies and 69 partial nephrectomies). Preoperative computed tomography images and pathological findings were reviewed and analyzed. Results: Pathological examinations revealed 31 (10.2%) benign lesions in the 303 patients. Among these 31 benign lesions, 15 (5.0%) were angiomyolipomas (AML) and only four (1.3%) were oncocytomas. Significantly, 20 (17.9%) of the 112 female patients had benign lesions compared with 11 (5.8%; P = 0.001) male patients. Benign renal lesions were found in five (25.0%) of the 20 patients with renal masses smaller than 2 cm, 13 (13.0%) of the 100 patients with renal masses 2–4 cm in size and 13 (7.1%) of the 183 patients with renal masses larger than 4 cm. Conclusions: Patients in the present study population show a low incidence of benign renal lesions, approximately half of them being AML. Female patients and patients with renal masses smaller than 4 cm are more likely to have benign renal lesions.     

Robotic Partial Nephrectomy for Renal Tumors Larger Than 4 cm

Background

Minimally invasive partial nephrectomy (PN) is most commonly performed for renal tumors ≤4 cm in size. Robotic PN (RPN) for tumors >4 cm has not been assessed.

Objective

To evaluate the safety and feasibility of RPN for tumors >4 cm in the context of patients undergoing RPN for tumors ≤4 cm.

Design, setting, and participants

We reviewed data for 71 consecutive patients who underwent transperitoneal RPN at a tertiary care center between August 2007 and September 2009 by a single surgeon. Patients were stratified into two groups: 15 with tumors >4 cm on preoperative imaging (group 1) and 56 patients with tumors ≤4 cm (group 2).

Intervention

All patients underwent transperitoneal RPN by a single surgeon.

Measurements

Preoperative, perioperative, pathologic, and functional outcomes data were analyzed and compared between groups. We used χ² and student t tests for categorical and continuous variables, respectively. A p value <0.05 was considered statistically significant.

Results and limitations

Mean radiographic tumor size was 5.0 cm (4.1–7.9) for group 1 and 2.1 cm (0.7–3.8) for group 2. No significant differences were found between groups for estimated blood loss, total operative time, hospital stay, complication rates, and change in estimated glomerular filtration rate. Patients with larger tumors had longer median warm ischemia times (25 vs 20 min; p = 0.011). Limitations of our study include the retrospective nature the analysis, small sample size, and single-surgeon experience.

Conclusions

In our initial experience, RPN for tumors >4 cm is safe and feasible, showing comparable outcomes to RPN for smaller tumors, although with longer warm ischemia times. Future studies with extended follow-up are necessary to determine the viability of RPN for large tumors as an effective form of treatment.     

A preoperative prognostic nomogram for solid enhancing renal tumors 7 cm or less amenable to partial nephrectomy

PURPOSE: Small renal masses are increasing in incidence. Most tumors 7 cm or less are treated with radical or partial nephrectomy but clinicians are increasingly relying on ablative therapies and observation for some small renal masses. We present novel nomograms that predict the likelihood of benign, likely indolent or potentially aggressive pathological findings based only on readily identifiable preoperative factors. MATERIALS AND METHODS: Information on all partial nephrectomies performed at a single institution was collected in an institutional review board approved registry. Using retrospectively collected data on all 862 patients who underwent partial nephrectomy for a single, solid, enhancing, clinical T1 (7 cm or less) tumor between 1999 and 2005 tumors were classified as benign or malignant. Grade 3 clear cell renal cell carcinoma, grade 4 renal cell carcinoma of any type and any renal cell carcinoma with vascular, fat or collecting system invasion were considered potentially aggressive. The likelihood of benign, likely indolent or potentially aggressive pathological findings was modeled using multivariable logistic regression models based on age, gender, radiographic tumor size, symptoms at presentation and smoking history. RESULTS: Of 862 small renal masses 20% were benign and 80% were malignant but only 30% of cancers (24% of small renal masses) were potentially aggressive. All 11 patients with systemic symptoms had cancer. The remaining 851 patients underwent further analysis. Factors that were most strongly associated with the likelihood of benign pathology were age, gender, tumor size and smoking history. A nomogram constructed to predict benign histology proved to be relatively accurate and discriminating (bootstrap corrected concordance index 0.644) and calibrated. Small renal masses in older men and younger women were more likely to be benign. With regard to differentiating indolent from potentially aggressive cancers, only advanced age was independently significant on multivariate analysis (p <0.005). The nomogram for this outcome performed with limited ability (concordance index 0.557). CONCLUSIONS: Clinical factors provide substantial predictive ability to predict benign vs malignant pathology for small renal masses amenable to partial nephrectomy. Although most of these small renal masses are benign or indolent, our ability to predict potentially aggressive cancer in this population remains limited.     

Simple enucleation for the treatment of renal cell carcinoma between 4 and 7 cm in greatest dimension: progression and long-term survival

PURPOSE: We present our findings in a series of patients treated with simple enucleation for RCC 4 to 7 cm in greatest dimension. We specifically report the incidence of local and systemic recurrence, and the disease specific survival rate. MATERIALS AND METHODS: We retrospectively reviewed clinical and pathological data on 71 patients who underwent nephron sparing surgery by simple enucleation between 1986 and 2004 for sporadic, unilateral, pathologically confirmed, 4 to 7 cm RCC. Patients with a solitary kidney due to previous RCC treated with radical nephrectomy were excluded from study. None of the patients had preoperative or intraoperative suspicion of positive nodes. All patients were free of distant metastases before surgery (M0). Patient status was last evaluated in May 2005. Mean followup was 74 months (median 51, range 12 to 225). RESULTS: Pathological review according to the 2002 TNM classification showed that 42% of the tumors (30 of 71) were pT1a, 44% (31 of 71) were pT1b and 14% (10 of 71) were pT3a. Mean tumor greatest dimension +/- SD was 4.7 +/- 0.81 cm (median 4.5, range 4.0 to 7.0) cm. None of the patients died within the first 30 days of surgery. There were no major complications requiring open reoperation, such as bleeding and urinary leakage/urinoma. Five and 8-year cancer specific survival was 85.1% and 81.6%, respectively. Five-year cancer specific survival in patients with pT1a (4 cm), pT1b and pT3a disease was 95.7%, 83.3% and 58.3%, respectively (pT1a vs pT1b p = 0.254, pT1a vs pT3a p = 0.006 and pT1b vs pT3a p = 0.143). Overall 10 patients experienced progressive disease (14.9%), of whom 3 had local recurrence (4.5%) alone or local recurrence associated with distant metastases. CONCLUSIONS: Simple tumor enucleation is a useful and acceptable approach to nephron sparing surgery for 4 to 7 cm RCC. It provides long-term cancer specific survival rates similar to those of radical nephrectomy and is not associated with a greater risk of local recurrence than partial nephrectomy for RCC less than 4 cm in greatest dimension.     

Comparison of outcomes in elective partial vs radical nephrectomy for clear cell renal cell carcinoma of 4-7 cm

OBJECTIVE: To compare the outcomes of patients who had a elective partial nephrectomy (PN) or radical nephrectomy (RN) for clear cell renal cell carcinoma (RCC) of 4-7 cm. PATIENTS AND METHODS: From March 1998 to July 2004, 45 and 151 patients underwent PN and RN, respectively, for clear cell RCC. A multivariate Cox model was constructed for disease-free survival with adjustment for markers of disease severity, and a propensity-score approach used as a confirmatory analysis. RESULTS: In the PN and RN cohorts the treatment failed in one and 20 patients, respectively; the median follow-up was 21 months. The hazard ratio (95% confidence interval) for PN after adjusting for disease severity was 0.36 (0.05-2.82; P = 0.3). Using planned PN as a predictor (intent-to-treat analysis) the hazard ratio was 1.06 (0.32-3.53; P = 0.9). In the propensity-score model, planned PN was associated with a hazard ratio of 1.75 (0.50-6.14; P = 0.4). The serum creatinine level 3 months after surgery was significantly lower in patients who had PN, with a difference between the means of 0.36 (0.23-0.48; P < 0.001). CONCLUSIONS: Renal function was preserved after PN for 4-7 cm clear cell RCC tumours. When comparing the outcomes of PN and RN it is important to consider the intended operation as an independent variable. There was no clear evidence that PN was associated with worse cancer control, although a continued follow-up of this and other cohorts is warranted.     

平均直径7cm肾癌腹膜后镜与开放根治性肾切除术5年经验比较

目的:判断腹膜后镜根治性肾切除术对于平均直径7cm肾癌的临床治疗价值。方法:回顾性分析36例2002年1月~2006年7月行腹膜后镜根治性肾切除术患者的资料,并与同期46例行开放根治性肾切除术患者的临床资料进行比较。腹膜后镜组肿瘤直径为4~9(7.4±1.5)cm,开放组为4~10(7.6±1.2)cm(P>0.01)。所有患者术后病理均证实为肾细胞癌。结果:腹膜后镜治疗组与开放治疗组的手术时间分别为80~220(172±35)min,60~190(165±40)min(P>0.01);术中出血量两组分别为40~300(210±30)ml,50~450(410±100)ml(P<0.01);术后进普食天数两组分别为3~8(3.9±1.0)天,5~11(7.4±2.0)天(P<0.01);术后平均住院日两组分别为5~8(7.0±1.3)天,7~13(8.5±1.8)天(P<0.01)。所有患者平均随访27(9~50)个月,随访期间均未出现手术切口种植转移。结论:腹膜后镜根治性肾切除术具有创伤小,出血少,术后恢复快的优点,随访中发现两种治疗方式对于患者短期的生存率没有影响。对于直径4~10cm肾肿瘤,腹膜后镜根治性肾切除术可以取代开放根治性肾切除术。     

Renal tumors in young adults

PURPOSE: The clinical and pathological features of solid or complex cystic renal masses in young adults have not been defined. We present our experience with patients 17 to 45 years old with such renal masses to define the incidence of malignant vs benign lesions, familial tendencies and clinical outcomes. MATERIALS AND METHODS: The medical records of all patients 17 to 45 years old who presented with a solid or suspicious complex cystic renal mass at 2 tertiary care hospitals between 1988 and 2002 were retrospectively reviewed. Pertinent clinical information was compiled, including age, gender, mode of presentation, renal function, year and type of surgery, pathological analysis and survival data. RESULTS: There were 114 evaluable patients who underwent a total of 119 nephrectomies. Mean patient age was 37.1 years and males comprised 56.1% of the population. Twelve patients had familial renal cell carcinoma (RCC), the von Hippel-Lindau syndrome. Mode of presentation for patients with sporadic disease was symptomatic (55.9%), incidental (35.3%) or unknown (8.8%). Radical nephrectomy, partial nephrectomy and nephroureterectomy were performed in 80 kidneys (67.2%), 37 (31.1%) and 2 (1.7%), respectively. Malignant lesions comprised 79.8% of all masses and 95.8% of these were renal cell carcinoma. Of the RCCs 75.8% were grade 1 or 2 and 89% were organ confined. Young women were much more likely than men to have a benign lesion (36.0% vs 9.5%, p <0.01) and the diversity of histologies was impressive (of the 24 total benign masses 9 were different tumor types). With an average followup of 38.3 months overall survival is 90.2%. Among patients with RCC 84.9% are alive and cancer-free, 11.6% are dead from disease and 3.5% are alive with recurrent disease. CONCLUSIONS: We report the largest known series of solid or suspicious complex renal masses in young adults. As expected, familial tumors are more common in this population. While RCC is the most common tumor, a wide variety of potential pathological outcomes are possible, particularly in women, who were much more likely to have a benign lesion. RCC in this patient population appears to have a favorable prognosis, despite symptomatic presentation in the majority of cases.     

Overall Survival and Development of Stage IV Chronic Kidney Disease in Patients Undergoing Partial and Radical Nephrectomy for Benign Renal Tumors

Background

Although partial nephrectomy (PN) has been associated with improved renal function compared with radical nephrectomy (RN) for renal cell carcinoma, the impact on overall survival (OS) remains controversial.

Objective

To evaluate comparative OS and renal function in patients following PN and RN for a renal mass where malignancy was not a confounding factor.

Design, setting, and participants

Using the Mayo Clinic Nephrectomy Registry, we retrospectively identified 442 patients with unilateral sporadic benign renal masses treated surgically with PN or RN between 1980 and 2008.

Outcome measurements and statistical analysis

The primary outcome measures were OS and the incidence of new-onset stage IV chronic kidney disease (CKD), determined using the Kaplan-Meier method. Cox models were used to test the association of nephrectomy type with these outcomes.

Results and limitations

Overall, 206 and 236 patients with benign renal masses were surgically treated with RN and PN, respectively. Patients who underwent RN were older (median age: 67 vs 64 yr; p = 0.02) and had larger tumors (median size: 5.0 vs 2.7 cm; p < 0.001). Median follow-up for patients still alive at last follow-up was 8.3 yr (range: 0.1–27.9 yr). Estimated OS (95% confidence interval [CI]) rates at 10 and 15 yr were 69% (62–76%) and 53% (45–62%) for RN compared with 80% (73–87%) and 74% (65–83%) following PN (p = 0.032). After adjusting for covariates of interest, patients treated with RN were significantly more likely to die from any cause (hazard ratio [HR]: 1.75; 95% CI, 1.08–2.83; p = 0.023) or develop stage IV CKD (HR: 4.23; 95% CI, 1.80–9.93; p < 0.001) compared with patients who underwent PN. Limitations include the retrospective design, selection bias for surgical approach, and referral bias to a tertiary care facility.

Conclusions

Our data suggest that PN may confer a clinical benefit for improved renal function and better OS compared with RN after excluding the confounding effect of malignancy.