Prof. Dr. Mustafa SOFİKERİM | Urology

Kidney Cancer

Kidney cancer is a malignant cell (a tumor) growth in the kidney. Its medical name is renal cell carcinoma. Tumors can also be benign.

Kidney cancer is a general term. There are different tumor types and different disease stages in the kidney.

Renal cancers constitute approximately 2% of all cancers diagnosed worldwide. In the last 25 years, the number of kidney cancer patients has increased in Europe. But the survival rate has increased in many regions. Due to advances in imaging technologies such as ultrasound and CT, and more frequent use, more kidney cancer is now diagnosed early.

Men have a higher risk of kidney cancer than women. Most people are diagnosed between 60-70 years of age.

Kidney Cancer Symptoms

The kidneys are a pair of organs in the upper abdomen that form the urine. The urine is transferred to the bladder through two thin tubes called ureters. The kidneys are located on the back of the rib cage on the back and are protected against external influences by strong back muscles and lower ribs. It is covered with a thick sheath called the Gerota sheath, and its top surface is covered with a membrane, just like the outer red shell of an apple.

While the main artery (Aorta) comes with blood from a vein, the collector vein is discharged into the main veins (Vena Cava). Its main function is removing harmful substances and excess water from the urine after metabolism in the body. They also play a role in blood pressure and blood production.

Kidney cancer usually occurs between the ages of 50-70. It is 2-3 times more common in males than females. The cause of kidney cancer is not yet known. Kidney cancer types are divided into two groups as benign and malignant. The most common mass in the kidneys are simple renal cysts. Renal cyst is a benign mass and is completely different from cancer. Often, coincidental renal cysts never threaten human life. Patients with renal cysts are unnecessarily panicked and seek treatment. In fact, kidney cysts often do not require treatment, only monitoring is always sufficient. Kidney cancer is a malignant mass and can be a threat to human life, unlike kidney cysts. Renal cell carcinoma originates in the kidneys that drain blood and urinate. As kidney cancer grows, the lymph glands around it can spread to the liver, large intestine and pancreas. In addition, tumor fragments detached from the main tumor can be located in other distal parts of the body (metastasis).

Stages of kidney cancer

There are different stages of kidney cancer. If the tumor is limited and not spread in the kidney, it is called localized kidney cancer. In locally advanced kidney cancer, the tumor is enlarged to the surrounding tissue outside the kidney, extending to the veins, adrenal gland and lymph nodes. If it has spread to the distant lymph nodes or other organs, the doctors start talking of a metastatic disease.

Risk factors for kidney cancer

It is often difficult to determine the causes of kidney cancer. General risk factors include smoking and obesity.

Those with first-degree relative kidney cancer and high blood pressure are also at risk. Some lifestyle changes, most importantly, the cessation of smoking, the maintenance of healthy weight can reduce the risk of developing kidney cancer.

Diagnosis of Kidney Cancer

In the diagnosis of renal parenchymal cancers, visible hemorrhage, flank pain, and palpable mass in the urine known as the classic triad are seen in only 10-15% of patients. Many cases are incidentally detected during imaging for any reason. A small number of patients may also be diagnosed with metastatic complaints (such as cough breathlessness, bone pain or bone fractures in bone metastases). With the widespread use of imaging modalities, the proportion of renal cancers diagnosed incidentally increases. Today, it is reported that 3/4 of renal cancers are diagnosed incidentally. The increase in this rate depends on the widespread use of ultrasonography in "check up" programs. Therefore, the rate of early diagnosis has increased. Abdominal ultrasonography should show a renal solid mass and suggest renal parenchymal cancer. Pre-diagnosed patients should be further evaluated with further imaging methods such as computed tomography (CT) or magnetic resonance (MRI).

Kidney cancers can metastasize to the lung most. Less frequently it can spread to the liver, bones, adrenal gland, brain and lymph nodes. The greater the tumor diameter, the greater the risk of metastasis. If the physician deems necessary, chest radiographs, bone scintigraphy, positron emission tomography should be examined.

Treatment of Kidney Cancers

Primary treatment of renal parenchymal cancer is the surgical removal of the tumor. According to the size and localization of the tumor around it, total removal of the kidney along with the adrenal gland and oily renal tissues around it (radical nephrectomy) is the most outstanding treatment method. These operations, which have been performed by traditional open surgery for years, can be performed by standard laparoscopic or robotic laparoscopic methods. In this method, the scar on the patient is much smaller than the open surgery, blood loss is very low and the patients get their daily normal lives more quickly after the surgery. If the tumor has a diameter of 4 cm or less, it is sufficient to remove only the tumor (partial nephron sparing surgery). The removal of the tumor with normal renal tissue can be performed by conventional open surgery or by standard laparoscopic or roboticlaparoscopy. Traditional open radical nephrectomy should be performed in cases where the tumor is too large and there is a tumor thrombus in the kidney vein.

The place of chemotherapy and radiotherapy in the treatment of renal parenchymal cancer is very limited. New agents that are highly resistant to chemotherapy are developed and presented for clinical use. Radiotherapy is only useful in the treatment of metastatic lesions (bone, brain).