Partial Nephrectomy for Renal Cell Carcinoma - An Overview

Introduction

Over the past years, many indications regarding the safety and efficacy of nephron-sparing surgery and renal cell carcinoma have developed. Today nephron-sparing surgery is an established approach for individuals with localized renal cell carcinoma when the preservation of renal function is significant.

What Is Partial Nephrectomy?

Partial nephrectomy is a surgical procedure used to treat kidney cancer. When the cancer cells have not spread to other tissue, portions of the kidney with abnormally growing cells are removed and leave as much as a healthy portion of the organ. The most common kidney cancer involves renal cell carcinoma. They affect cells that line the tubules of the kidney.

What Is a Positive Surgical Margin?

The margin is considered positive when the cancer cells are still present on the surgical margins, which means the cancer cells have not been completely removed.

What Is the Clinical Presentation for Partial Nephrectomy?

Renal cell carcinoma does not present with symptoms until late in its course. Consequently, lesions detected incidentally are smaller, of lesser grade, and thus more compliant with conservative surgery.

Differential diagnoses of incidentally detected renal masses include:

• Angiomyolipoma.

• Oncocytoma.

• Transient cell carcinoma.

• Complex cyst.

• Hypertrophied column of berlin.

The characteristics of most of these imaging studies, such as computed tomography and their clinical presentation, help in the differential diagnosis. Solid lesions are considered radiographically enhanced with intravenous contrast to renal cell carcinoma until proven otherwise. 10 % to 15 % of these lesions are oncocytomas. Needle biopsies are shown to give false negative rates. Nephron-sparing surgeries provide curative surgeries and help eliminate uncertainties in individuals with good, expected longevity. The goal of conservative resection of renal cell carcinoma is the complete local surgical removal of the malignancy and preservation of renal function. Partial nephrectomy is an effective alternative to radical nephrectomy for several benign conditions that affect the kidney. It provides optimal surgical treatment and simultaneously rules out over-treatment.

What Are the Indications for Partial Nephrectomy?

• Synchronous bilateral tumors and a poorly functional contralateral renal unit are commonly absolute indications for partial nephrectomy. These could result from the concomitant presence of unilateral renal cell carcinoma and a contralateral kidney with chronic pyelonephritis, calculus, systemic, and renal arterial disease. Partial nephrectomy in a solitary kidney could be challenging, but good clinical outcomes can be achieved.

• Partial nephrectomy is indicated in individuals with renal cell carcinoma with a normal contralateral renal unit, especially in younger individuals with an incidental, localized, single small (less than 4 centimeter) renal cell carcinoma. 10 % to 15 % of small (less than 3 cm) solid renal tumors are oncocytomas. A partial nephrectomy would prevent the unwarranted removal of a kidney for a benign lesion.

• Recently the indications for partial nephrectomy have expanded to include all T1 lesions, even in a normal contralateral kidney. Therefore, individuals are appropriately selected and counseled.

• Other indications for partial nephrectomy include hereditary papillary renal cell carcinoma and renal cell carcinoma associated with von Hippel Lindau syndrome. These syndromes are associated with multiple and multifocal renal lesions with a whole spectrum of cysts, from cystic renal neoplasms to solid renal neoplasms.

• These tumors are detected earlier than conventional sporadic renal cell carcinoma and are generally treated with partial nephrectomy. As small renal masses have relatively low metastatic potential, lesions smaller than 3 cm are monitored with careful surveillance to delay the onset of dialysis. When the lesion is more than 3 cm, partial nephrectomy is advocated when compilable to delay the onset of end-stage kidney disease. The location of the lesion in the kidney is crucial.

What Are the Contraindications for Partial Nephrectomy?

Partial nephrectomy is generally contraindicated in the presence of obvious nodal metastasis. This is detected by preoperative cross-sectional imaging. Computed tomography will detect extensive lymphadenopathy, usually due to secondary tumor metastasis. CT scanning does not rule out limited lymph node involvement, and few individuals are found to have enlarged lymph nodes on CT scans that may not be involved with the tumor at the time of surgery. Intraoperative frozen sections can examine the status of equivocal lymph nodes. Partial nephrectomy is also contraindicated in the cases of inferior vena cava thrombus and a normal contralateral kidney.

Is Partial Nephrectomy Commonly Performed?

Currently, cancers of the renal pelvis and kidneys are the sixth most common cancer among men accounting for 5 % of the cases, and the ninth most common among women, accounting for 3 % of cases. The American Cancer Society has stated that in two years, 79,000 cases of malignant tumors of the kidney and renal pelvis will be diagnosed. Renal cell carcinoma is expected for most of the incidence and mortality rates.

Partial Nephrectomy Workup:

Routine preoperative laboratory studies, including electrolyte assessment, complete blood cell count, blood urea nitrogen, and creatine assessment, are obtained:

• No set level of serum creatinine precludes partial nephrectomy; the individual's baseline renal function is important. Not all individuals with chronic renal insufficiency require renal replacement therapy in the short term and can be treated medically for long durations.

• Radical nephrectomy can place the individual in need of immediate renal replacement therapy. If anatomically possible partial nephrectomy can delay the onset of dialysis without compromising cancer care in the selected case of chronic renal insufficiency.

The individual's blood is typed and crossmatched. Other blood tests include serum ferritin assessment and liver function test. However, tests to detect metastases are not always necessary in the small, incidentally detected mass that is amenable to partial nephrectomy.

Imaging Studies:

• Computed tomography and magnetic resonance imaging of the abdomen may be beneficial to rule out metastatic or locally extensive disease.

• Magnetic resonance imaging also has a role in evaluating the inferior vena cava for the presence of tumor thrombus and its distal and proximal extent. Magnetic resonance angiography defines the vascular anatomy and the segmental vascular anatomy for surgical planning.

Conclusion:

After partial nephrectomy, the individual may have overall normal kidney function. To preserve kidney function, the healthcare provider may recommend a healthy diet, engage in daily physical activity and get regular assessments done to monitor kidney health. If the individual develops chronic kidney disease after partial nephrectomy, the healthcare provider may recommend additional lifestyle changes, including dietary and medication vigilance.