New Publication for Clinicians Summarizes Evidence on Managing Renal Masses

A new evidence-based publication from AHRQ can help clinicians make informed decisions about managing renal masses and localized renal cell carcinoma – a kidney cancer that affects approximately 65,000 new patients each year. Management of Renal Masses and Localized Renal Cell Carcinoma: Current State of the Evidencesummarizes findings of a systematic review that evaluated the benefits and adverse effects of screening and treating patients with a renal mass that potentially could be localized renal cell carcinoma. Evidence indicates there is no clear method for predicting kidney cancer during diagnosis of renal masses. Tumor size and male gender, however, are highly associated with malignancy. In addition, evidence does not support one management strategy over another; treatment decision-making may be affected by patient factors such as comorbidities, life expectancy, tumor characteristics (e.g., size and location) and patient values and preferences.

Clinician Summary – Jul. 18, 2017

Management of Renal Masses and Localized Renal Cell Carcinoma: Current State of the Evidence

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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 (), some other associations were observed:
- Increased tumor size and male sex were consistently associated with an increased risk of malignancy
  ().
- An increased RENAL nephrometry score** was also predictive 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 ().
- The most common direct complications associated with percutaneous renal mass sampling were hematoma (4.9%) and significant pain (1.2%)().
- 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.