Tumors of the renal parenchyma
Cancers of the kidney represent only 2 to 3% of all human malignant tumors. Renal cell carcinoma (RCC) is by far the most frequent and accounts for up to 90% of all kidney tumors. The widespread use of modern diagnostic tools today has led to ever more frequent chance diagnosis of small asymptomatic tumors. Earlier symptoms of hematuria, flank pain and abdominal tumor mass were the first indication of an already large far advanced kidney tumor.
Tumor stage remains the most predictive prognostic factor. As long as the tumors are small and confined to the kidney the prognosis is excellent with a 70-80% 5-year survival rate. Radical nephrectomy is the treatment of choice. Before any operation it is necessary to determine if the tumor has extended into the vena cava. Venous invasion seems to be an adverse prognostic factor. In case of a non functioning contralateral kidney, bilateral tumors or patients with Von Hippel-Lindau disease, nephron-sparing surgery has proved to be curative as long as the general rules of oncological surgery are respected. In parenchymal sparing surgery, intraoperative sonography can be used to define tumors in relation to the hilar anatomy. This permits a partial nephrectomy to be safely performed while avoiding important hilar structures.
Chemotherapy for metastatic renal cancer has been disappointing, giving at best a 15% partial response rate. Interleukin-2 which increases autoimmune defense activity elicits a measurable response in about 20% of patients, and a complete remission in about 5%.
Follow-up with assessment of symptoms, liver function studies, and ultrasound exam of the other kidney and chest X-ray is recommended every 6 months for 3 years and then yearly.