Kidney Cancer – Causes, Symptoms Diagnosis And Treatment
Kidney cancer is also called hypernefrom, clear cell carcinoma or Grawitz tumor. Represents 3% of adult cancers and 85% -90% of renal tumors. Most commonly affects the fifth and sixth decade of life, male / female ratio being 2 / 1.
Reliable cause of kidney cancer is unknown, but have been emitted etiological hypotheses that include occupational and environmental exposures, diet and chromosomal abnormalities. They were discussing of a familial kidney cancer, and one that accompanies congenital afflictions: Hippie-Lindau syndrome (it was found that 2/3 of patients with this disease develop multiple renal caner). Genetic studies have shown changes in chromosomes 3, 8 and 11, both in the hereditary kidney cancer and in the sporadically form of kidney cancer.
There are several risk factors involved in the development of kidney cancer:
- Nephropathy due to analgesic abuse;
- Genetic factors;
- Occupational exposure to cadmium;
- Gained polycystic kidney disease.
Kidney cancer develops from the epithelium of renal proximal tubules. It appears with equal frequency in both kidneys, typically in one of the kidney poles. It develops from renal coretx with continuous increase in the tissue surrounding the kidney or renal pelvis, where it can open.
Macroscopically, kidney cancer is a tumor that usually appears as a mass of variable size (3 cm to 15 cm), rounded or lobulated which protrudes on the surface of the kidney and is well demarcated. On the surface section has an orange – yellow or whitish – gray or brown color, with bleeding, necrotic and cystic areas. It gives the false impression of encapsulation by compressing the renal tissue. An important feature is the tendency of the tumor to invade the renal vein and by producing a solid column in this vessel, invade the inferior vena cava, and then giving the lung and bone metastasis.
Microscopically, kidney cancer is usually a mixed adenocarcinoma, which contains clear cells and granular cells. Clear cells are round or polygonal with abundant cytoplasm that contains cholesterol, triglycerides, glycogen and fat. Granular cells contain less glycogen and lipid, and electron microscopy shows a large number of mitochondria.
Kidney cancer is a vascular tumor with a tendency to expand either by direct invasion through the renal capsule in the surrounding tissue of the kidney or extending into renal vein. Approximately 1/3 of patients are already diagnosed with metastasis. The most common location of metastasis is in the lung, liver, bone, regional lymph nodes or the other kidney.
Symptoms of kidney cancer can be polymorphic, delaying the diagnosis. Classic triad is represented by:
- Macroscopic hematuria;
- Pain in the flank;
- Palpable tumor mass, which represents an advanced manifestation and occur in 10% – 15% from cases.
Sometimes the first symptoms may be caused by metastasis, such as dyspnea or cough, and bone pain.
There may be associated with kidney cancer: poliglobulia, hypertension, hypercalcemia and non-metastatic hepatic dysfunction.
Poliglobulia may occur in 10% of patients, the consequence of eritriopoetin secretion from the tumor or because of regional renal hypoxia.
Hypertension occurs in 40% of cases, possibly through the release of renin by the tumoral tissue.
Hypercalcemia occurs as a consequence of the release of parathyroid-like protein from the tumor or bone calcium mobilization in case of metastases.
Non-metastatic hepatic dysfunction (Stauffer syndrome), with increased alkaline phosphatase and increased bilirubin, hypoalbuminemia, prolonged prothrombin time, hyper-gammaglobulinemia, is possibly caused by one tumoral product which is hepatotoxic.
The presence of paraneoplazic syndrome is not a factor of poor prognostic and its persistence suggests the existence of metastasis after nephrectomy.
- Laboratory – besides the changes described above, may occur anemia, hematuria and ESR acceleration.
- Renal Echography – passed on the first place in detecting and assessing kidney cancer. Kidney cancer occurs as a formation of mixed echogenicity in one renal pole, typically round, with possible calcifications or necrosis inside. Echography, besides location and dimensions, may reveal the existence of mobility of the kidney and associated adenopathy.
- CT scan – confirm the diagnosis of kidney cancer, contributing to the staging by viewing renal hilum, the tissue surrounding the kidney, renal vein and inferior vena cava visualization and regional adenopathy visualization.
- Intravenous urography – may be view the central or peripheral calcifications in direct radiography and urography may reveal changes which are made by a expansive process: amputation of an renal calyx, increasing the distance between the calyx. Sometimes kidney may be radiologicaly muted by parenchyma damage or compression.
- Magnetic resonance imaging – is a diagnostic method of kidney cancer which is superior than CT scan.
The only possible and necessary treatment for kidney cancer is surgical and consists in total nephrectomy with respecting the oncological principles. Adjuvant methods such as radiotherapy, chemotherapy and hormone therapy were less effective and sometimes are used with palliative purpose.