Focus of This Summary
This is a summary of a systematic review that evaluated the recent evidence regarding the benefits and adverse effects of strategies for evaluating and treating patients with a renal mass suspicious for localized renal cell carcinoma. This review includes 147 studies reported in 150 publications from January 1, 1997, through May 1, 2015. This summary is provided to assist in informed clinical decisionmaking. However, reviews of evidence should not be construed to represent clinical recommendations or guidelines.
Background
Kidney cancer affects approximately 65,000 new patients each year, with more than 13,000 deaths annually. Renal cell carcinoma accounts for more than 94 percent of kidney malignancies. The 5-year survival rates for localized renal cell carcinoma range from greater than 85 percent to 95 percent, depending on the stage of the tumor.
All imaging-enhanced solid renal masses and cystic lesions with solid components are suspicious for renal cell carcinoma. About 20 percent of surgically resected renal masses are benign. Most tumors are detected incidentally during an evaluation for unrelated or nonspecific symptoms. Percutaneous renal mass sampling of solid masses may be offered as a diagnostic adjunct to imaging studies such as computed tomography, magnetic resonance imaging, or ultrasonography. Percutaneous renal mass sampling can be performed by fine needle aspiration or core biopsy.
Several options exist for managing clinically localized renal masses suspicious for renal cell carcinoma, including active surveillance, thermal ablation, and surgery (partial or radical nephrectomy). Surgical removal (either partial or radical nephrectomy) is the gold standard for treating renal cell carcinoma. The National Comprehensive Cancer Network (NCCN) Guideline recommends partial nephrectomy as standard treatment for patients with clinical stage T1a tumors (≤4 cm in diameter) and T1b tumors (4–7 cm) and recommends radical nephrectomy for patients for whom partial nephrectomy is not feasible. Thermal ablation and active surveillance are considered options for patients with clinical stage T1a tumors, although these strategies are generally reserved for less-healthy patients. Active surveillance has emerged as a primary management option for patients with a limited life expectancy or with extensive comorbidities. Radical nephrectomy is recommended as the standard of care for most patients with clinical stage T2 tumors.
This systematic review sought to determine the effectiveness and comparative effectiveness of strategies for evaluating and treating patients with a renal mass suspicious for clinical stage T1 or T2 renal cell carcinoma.
Conclusions
Diagnostic evaluation
- No current composite model* reliably predicts malignancy at initial diagnosis in patients with renal masses limited to the kidney parenchyma without evidence for regional or distant metastases.
- Tumor size and male sex are the factors that are statistically significantly associated with malignancy.
- Percutaneous renal mass sampling using core biopsy is a low-risk procedure. However, its usefulness is limited by a 14-percent nondiagnostic rate and data indicating that 37 percent of patients with a negative biopsy result had malignant disease found during surgery.
Management strategies
- Overall survival and cancer-specific survival rates were generally similar across management strategies. The local recurrence rate was higher with thermal ablation than with radical or partial nephrectomy.
- Perioperative outcomes (blood loss and transfusion rates) were lower with thermal ablation than with either type of nephrectomy.
- Thermal ablation and partial nephrectomy offer improved renal functional outcomes over radical nephrectomy.
- Although active surveillance may have reasonable survival outcomes in selected populations, comparative data are lacking.
- While evidence does not support one management strategy over another, patient factors (e.g., comorbidities, life expectancy), tumor characteristics (e.g., size, location), and patient values and preferences play important roles in decisionmaking.
* Composite models include the use of a combination of demographics, clinical characteristics, blood and urine test results, and tumor imaging characteristics.
Overview of Clinical Research Evidence for Diagnostic Evaluation
Preoperative composite profiles (see Appendix Table 1)
- While preoperative composite profiles were not consistently predictive of malignancy in patients with renal masses limited to the kidney parenchyma without evidence for regional or distant metastases ([evidence low]), some other associations were observed:
- Increased tumor size and male sex were consistently associated with an increased risk of malignancy
([evidence medium]). - An increased RENAL nephrometry score** was also predictive of malignancy ([evidence low]).
- Increased tumor size and male sex were consistently associated with an increased risk of malignancy
Percutaneous renal mass sampling (see Appendix Table 2)
- Studies of percutaneous renal mass sampling primarily involved core biopsy, which had a sensitivity of 97.5 percent, specificity of 96.2 percent, and a positive predictive value of 99.8 percent. However, core biopsy had a negative predictive value of 68.5 percent and a nondiagnostic rate of 14 percent ([evidence medium]).
- The most common direct complications associated with percutaneous renal mass sampling were hematoma (4.9%) and significant pain (1.2%)([evidence low]).
- Of those patients with a nondiagnostic biopsy result who underwent surgery, 90.4 percent had malignant tumors.
- Repeat biopsy led to a diagnosis in 80 percent of patients who had initially nondiagnostic biopsy results.
** The RENAL Nephrometry Scoring System is described in a footnote accompanying Appendix Table 1.
Overview of Clinical Research Evidence for Management Strategies
| Outcome | Partial Nephrectomy vs. Thermal Ablation | Partial Nephrectomy vs. Radical Nephrectomy | Radical Nephrectomy vs. Thermal Ablation | Radical Nephrectomy vs. Active Surveillance |
|---|---|---|---|---|
| AS = active surveillance; PN = partial nephrectomy; RN = radical nephrectomy; TA = thermal ablation a This finding was based on a single study in older patients (age ≥75 years) wherein the radical nephrectomy group had tumors with greater oncologic potential. b The improved survival with partial nephrectomy was likely because of the older age and higher comorbidity rates in the thermal ablation group. c Urological complications included hemorrhage, urine leakage, hematuria, loss of kidney function, ureteral injury, or urinary tract infection. Nonurological complications included hematologic (thromboembolic), gastrointestinal, cardiovascular, respiratory, neurological, and wound complications or infectious disease. d The Clavien-Dindo classification system is used to grade complications from urological surgical interventions: Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg. 2004;244:931-7. PMID: 15273542. e This finding was based on a single study in 60 patients. |
||||
| Cancer-Specific Survival | Similar ([evidence low]) |
Similar ([evidence medium]) |
Similar ([evidence medium]) |
Similara ([evidence low]) |
| Overall Survival at 5 Years | Favors PNb ([evidence low]) |
Similar ([evidence low]) |
([evidence insufficient]) |
Similar ([evidence low]) |
| Local Recurrence-Free Survival | Favors PN ([evidence medium]) |
Similar ([evidence medium]) |
Favors RN ([evidence low]) |
([evidence insufficient]) |
| Metastasis-Free Survival | Similar ([evidence medium]) |
Similar ([evidence low]) |
Similar ([evidence low]) |
Similar ([evidence low]) |
| Renal Function | Similar ([evidence low]) |
Better with PN ([evidence medium]) |
Better with TA ([evidence medium]) |
Better with AS ([evidence low]) |
| Perioperative Outcomes: Estimated Blood Loss and Transfusion Rates | Lower with TA ([evidence medium]) |
Lower with RN ([evidence medium]) |
Similar ([evidence low]) |
([evidence insufficient]) |
| Perioperative Outcomes: Length of Hospital Stay | Lower with TA ([evidence medium]) |
Similar ([evidence medium]) |
Lower with TA ([evidence low]) |
([evidence insufficient]) |
| Urological and Nonurological Complicationsc | Varied across studies ([evidence low]) |
Lower with RN ([evidence low]) |
Varied across studies ([evidence low]) |
([evidence insufficient]) |
| Acute Kidney Injury Rates | Similar ([evidence low]) |
Similar ([evidence low]) |
Similar ([evidence low]) |
([evidence insufficient]) |
| Minor and Major Claviend Complication Rates | Similar ([evidence low]) |
Similar ([evidence low]) |
Similare ([evidence low]) |
([evidence insufficient]) |
Strength of Evidence Scale†
High: [evidence high]
High confidence that the evidence reflects the true effect. Further research is very unlikely to change our confidence in the estimate of effect.
Moderate: [evidence medium]
Moderate confidence that the evidence reflects the true effect. Further research may change our confidence in the estimate of effect and may change the estimate.
Low: [evidence low]
Low confidence that the evidence reflects the true effect. Further research is likely to change our confidence in the estimate of effect and is likely to change the estimate.
Insufficient:[evidence insufficient]
Evidence is either unavailable or does not permit a conclusion.
†The overall evidence grade was assessed based on the ratings for the following domains: study limitations, directness, consistency, precision, and reporting bias. Other domains that were considered, as appropriate, included dose-response association, plausible confounding, and strength of association (i.e., magnitude of effect). For additional details on the methodology used to assess strength of evidence, please refer to: Owens DK, Lohr KN, Atkins D, et al. AHRQ series paper 5: grading the strength of a body of evidence when comparing medical interventions—Agency for Healthcare Research and Quality and the Effective Health-Care Program. J Clin Epidemiol. 2010 May;63(5):513-23. PMID: 19595577.
Gaps in Knowledge and Other Issues
- The applicability of results from analyses of renal mass biopsy are limited by:
- The localization and characteristics of the biopsied mass
- The significant heterogeneity in tumor characteristics observed in renal tumors
- The lack of a standardized biopsy protocol
- Weak study designs (e.g., retrospective studies)
- The lack of reporting on the levels of surgeon/pathologist/radiologist expertise
- Poor reporting of clinical staging
- Inconsistent reporting of treatment outcomes
- Currently, there is no composite model that reliably predicts malignancy at initial diagnosis in patients with renal masses limited to the kidney parenchyma without evidence for regional or distant metastases.
- Most of the patient populations in the reported composite models had a mean age of 60 years or older, and details about their specific preoperative or tumor characteristics were limited. As such, younger patients and those with other comorbidities may have differing risks of malignancy from those reported in the studies.
- The evidence regarding management strategies for renal masses suspicious for localized renal cell carcinoma is based almost entirely on retrospective studies. Selection bias plays a prominent role in treatment selection, thereby limiting the applicability of the findings from retrospective observational studies to specific patient groups.
- Although patient demographics, clinical characteristics, and disease stage are important in evaluating interventions used to manage renal cancer, all these data were dramatically underreported.
- The strength of evidence was insufficient to permit determination of the effectiveness of any of the treatment strategies for quality of life.
- The lack of sufficient data comparing active surveillance with other treatment approaches limits the applicability of the review's findings pertaining to this management strategy.
- The emergence of new technologies could also affect the applicability of the results of studies related to thermal ablation and minimally invasive nephrectomies.
- Additional research into genetic tools for subtyping tumors is needed to improve prediction of outcomes in patients.
Key Points for Discussions With Patients and Caregivers
- Patients might be aware that biopsies are performed for the diagnosis of various types of cancer. Clinicians may wish to discuss with patients if a biopsy is warranted and what the potential benefits and risks of doing a biopsy are based on their personal and tumor characteristics. A consultation with a urologist may also be suggested.
- Based on the patient's personal and tumor characteristics, the clinician may wish to discuss which treatment options might be suitable and what their respective benefits and harms could be.
Source
The information in this summary comes from Pierorazio PM, Johnson MH, Patel HD, Sozio SM, Sharma R, Iyoha E, Bass EB, Allaf ME. Management of Renal Masses and Localized Renal Cancer. Comparative Effectiveness Review No. 167. (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No. 290-2012-00007-I.) AHRQ Publication No. 16-EHC001-EF. Rockville, MD: Agency for Healthcare Research and Quality; February 2016.
This summary was prepared by the John M. Eisenberg Center for Clinical Decisions and Communications Science at Baylor College of Medicine, Houston, TX. It was written by Geetha Achanta, Ph.D., Charles Steiger, M.D., Frank Domino, M.D., and Michael Fordis, M.D.
