Kidney cancer is a malignant disease arising from the kidney parenchyma (the kidney’s own functioning structure). Kidney cancer is one of the most common urological cancers after prostate and bladder cancer. Early diagnosis of this disease is very important because if it is caught in the early stages, a high rate of success is achieved with surgery. In general, this disease is resistant to radiotherapy and chemotherapy drugs. In this article, I will give up-to-date information about the causes, symptoms, stages, treatment and surgery of kidney cancer, taking into account my own experiences.

What is kidney cancer?

Kidney cancer is a malignant tumor of the kidney that develops in the part of the kidney called the “proximal tubule”. In adults, renal cell carcinoma (RCC, renal cell cancer, renal adenocarcinoma) is the most common malignant cancer of the kidney. Kidney cancer, called Wilms tumor, is more common in young children. Nowadays, the diagnosis of kidney cancer has increased as a result of the widespread use of radiological examinations such as CT, MRI and ultrasonography (USG). Cancers diagnosed randomly or incidentally in this way are called “incidentalomas” (cancers detected by chance). Since these are caught at an earlier stage and while they are in the kidney, their prognosis is very good.

What are the symptoms (signs) of kidney cancer?

 Kidney cancers usually do not cause any symptoms in the early stages. Symptoms vary depending on the stage of the disease. Generally, if there is metastasis, complaints occur depending on the organ with metastasis. Common symptoms (patient complaints) in the late stages are:

• Hematuria: Blood in the urine. It can be microscopic or macroscopic, that is, bleeding that can only be seen under a microscope, or bleeding that is visible to the eye. Sometimes blood clots can occur.
• Side pain: If kidney cancer has grown, there will be pain in the side area where the cancer is located due to stretching of the kidney membrane and pressure on neighboring organs. The characteristic of this pain is that it is continuous.
• Mass in the abdomen: If the kidney cancer has grown, the growth (mass) on the cancerous side can be detected by palpation in thin patients.
• Loss of appetite: It is seen in advanced stage cancers.
• Weight loss: As with all cancers, malnutrition and weight loss occur in kidney cancer and metastasized cancers.
• Fatigue: This is also a condition seen in advanced kidney cancers.
• High fever: In kidney cancer, fever may occur due to some substances secreted by the cancer.
• High blood pressure: Blood pressure may increase due to cancer in patients with kidney cancer. If blood pressure is elevated due to cancer, blood pressure returns to normal as a result of surgical removal of the cancer.
• Cough and bleeding in sputum: It occurs as a result of kidney cancer spreading to the lungs.
• Bone pain: When kidney cancer metastasizes to the bones, that is, as a result of bone spread, bone pain may occur in the metastasized area.

What are the causes (etiology) of kidney cancer?

The causes of kidney cancer are not fully known, but we can list the known causes as follows:

• It is more common in those with a family history of cancer.
• It is common in those exposed to chemicals
• It is more common in those exposed to asbestosis
• Kidney cancer is 2 times more common in smokers than in non-smokers.
• It is more common in obese patients and its course is worse.
• It is more common in diabetic patients. The prognosis is worse in these patients.
• It is more common in people with high blood pressure.
• It is more common in men than women.
• It is common in von Hippel-Lindau disease.
• It is common in chromosome anomalies
• If there is a mutation in tumor suppressor genes (tumor suppressor gene).
• Kidney cancer may occur after a long time in patients who undergo dialysis due to chronic renal failure. Therefore, these patients need to be checked with USG at regular intervals.
• It is common in patients with weakened immune systems.

What are the risk factors for developing kidney cancer?

Risk factors for cancer formation are very important. By knowing these, it is possible to be protected from cancer. Some reasons that predispose to the development of kidney cancer or pose a risk for kidney cancer are:

• Age: Kidney cancer is more common in the elderly. It is most commonly seen between the ages of 50-60.
• Smoking: It is twice as common in smokers.
• Obesity: It is more common in obese people.
• High blood pressure: High blood pressure increases the risk of kidney cancer.
• Dialysis: Those who receive dialysis for a long time due to kidney cancer are at high risk.
• Some hereditary diseases: such as Von Hippel-Lindau disease, Birt-Dube syndrome, tuberous sclerosis, hereditary papillary renal cell carcinoma or familial kidney cancer.
• Diabetes: It is more common and has a worse course in diabetic patients than in those without kidney cancer.

What should be taken into consideration to protect against kidney cancer?

As with all cancers and chronic diseases, it is possible to protect against cancer development in kidney cancer. We can list some precautions and life changes that should be taken to protect against kidney cancer as follows:

• Quit smoking: Smoking is an important risk factor for kidney cancer. By quitting smoking, the risk of cancer is also reduced.
• Weight loss: Obesity is among the causes of kidney cancer. Losing weight in a healthy way protects against kidney cancer.
• Controlling high blood pressure: Hypertension is a risk factor for kidney cancer. Controlling blood pressure with a healthy diet, regular exercise and, if necessary, blood pressure-lowering medications reduces the risk of developing kidney cancer.
• Limiting foods of animal origin: Reducing animal proteins and eating fruits and vegetables is protective against cancer.
• Staying away from chemicals: Since cancers are common in some workers in the chemical industry, care should be taken against them.
• Control of diabetes: It is important for diabetic patients to have their blood sugar under control.

How is kidney cancer diagnosed?

A detailed anamnesis (patient questioning) and examination are important to diagnose kidney cancer. After this, some laboratory tests and radiological examinations are requested to help and confirm the diagnosis and to determine the stage of the disease.

• Medical history: Anamnesis, that is, medical interrogation of patients, is very important in the diagnosis of kidney cancer. Patients are asked the following questions;
  • You are asked whether there is pain and bleeding and for how long.
  • Patients are asked if there is a family history of cancer, especially kidney cancer.
  • Alcohol, smoking habits and lifestyle are asked.
  • Whether he/she has been exposed to chemicals and his/her occupation are asked.
• Examination: General urological examination and kidney examination are performed in patients with suspected kidney cancer. Kidney examination is performed while the patient is in a supine position. When kidney cancer is very small and at an early stage, no findings are detected during examination. However, especially in weak patients, if the mass in the kidney is large, it can be noticed manually during examination. If the cancer is limited to the kidney only and has not surrounded the surrounding organs, the mass will move with the kidney upon examination, but if it has surrounded the neighboring organs, the kidney will not move.
• Laboratory tests: Laboratory tests are very important to diagnose cancer. There are special markers (tumor markers) for some cancers, but there are no markers for kidney cancer. In patients suspected of having kidney cancer, the following blood tests are performed:
  • Tumor markers: There is no PSA-like marker used in kidney cancer and prostate cancer. There are many studies on this subject in research, but today there is no routine marker (cancer marker) to be used in the diagnosis and follow-up of treatment of kidney cancer.
  • Blood tests: There is no special blood test for the diagnosis of kidney cancer. Sometimes anemia may occur due to bleeding or the spread of cancer.
  • Urine test: Microscopic or macroscopic bleeding in the urine may occur in patients with kidney cancer.
  • Liver tests: If there is spread (metastasis) to the liver, liver tests will deteriorate.
  • Stauffer syndrome: In kidney cancer, there is deterioration in liver tests even though there is no spread to the liver. This is called Stauffer syndrome, named after the person who described it. It is thought that this situation is the result of damage to the liver by some substances produced by cancer. Cancer is not detected in the liver in radiological examinations. This situation is corrected by removing the kidney.
• Radiological examinations: Radiological examinations have an important place in cancer diagnosis and staging. Radiological tests we frequently use in the diagnosis of kidney cancer are:
  • Evaluations such as the size of the tumor in the kidney and its relationship with neighboring organs are made through radiological examinations such as CT, MRI, X-ray, and ultrasonography (USG). It helps determine the tumor stage.
  • Vena cavography and angiography: Vena cavography and angiography may be requested to show vascular involvement (vena cava and renal vein). However, since vascular involvement can be demonstrated with MRI, there is no need for angiography.
  • Scintigraphy: May be requested to investigate metastases
• Kidney biopsy: There is no need to take a biopsy in every patient with kidney cancer. If radiological examinations confirm that there is cancer, a further biopsy is not required. In patients with suspected kidney cancer, a biopsy is taken in the following cases:
  • If the patient has only one kidney
  • If there is spread from another organ, to investigate the main source of the cancer
  • If the distinction between cancer cannot be made clearly.

Staging in kidney cancer

If the doctor diagnoses cancer in the patient, he will stage the disease. Staging, that is, learning the extent of the disease, the extent of the disease, such as its spread to neighboring and distant organs of the kidney, is important for good treatment and follow-up. For staging purposes, CT, MRI and, if necessary, other advanced examinations are requested. Staging of kidney cancer is done according to TNM stage. T: Shows the size of the tumor, that is, cancer, N: Shows whether there is cancer in the lymph node, and M: Shows the metastasis of the cancer, that is, its spread to other organs. In staging, kidney cancer is divided into 4 stages and these are classified with Roman numerals I-IV. Stage I: means cancer limited to the kidney, stage IV means it has spread to the lymph nodes and other organs of the body.

• Stage-I: The largest dimension of the tumor is <7 cm or less, limited to the kidney
• Stage-II: The largest dimension of the tumor is greater than 7 cm and is limited to the kidney
• Stage-III: The tumor extends to the main vessels or surrounding tissues, but has not penetrated into the unilateral adrenal gland and Gerota’s fascia. The tumor extends to the renal vein or its segmental branches, or the tumor involves the kidney periphery and/or renal sinus fat (peripelvic fat), but is confined within Gerota’s fascia.
  • The tumor has extended to the vena cava below the diaphragm.
  • The tumor extends to the vena cava above the diaphragm or involves the vena cava wall.
• Stage- IV: Stage IV cancer are divided into two subgroups;
  • The tumor spreads beyond Gerota’s fascia (the membrane surrounding the kidney and the surrounding fat layer) (there is spread to the adrenal gland on the same side), and there is involvement in regional lymph nodes.
  • Cancer has spread to other organs: There is spread to bone, liver, lung, brain, adrenal gland or distant lymph nodes.

How is pathological evaluation (grade) done in kidney cancer?

Pathological evaluation in kidney cancer is made according to the Fuhrman grading system (Fuhrman grade). Here, cancerous kidney tissue is divided into grades 1 to 5. Fuhrman grade 1 is the best cancer, Fuhrman grade 5 is the worst grade and has the worst prognosis.

Treatment of kidney cancer

Today, the first option in the treatment of kidney cancer is surgical treatment, that is, surgery. The 5-year disease-free survival rate with radical nephrectomy is close to 100% in early stage cancers that are limited to the kidney and have not spread. In this regard, early diagnosis is very important in kidney cancer. Chemotherapy and radiotherapy are generally not effective in the treatment of kidney cancer. To decide on the type of surgery, factors such as the patient’s age, general condition, and stage of the cancer are taken into consideration.

A- Kidney cancer surgery-surgical treatment: Chemotherapy and radiotherapy are not very effective in kidney cancer. The most effective treatment is surgical treatment, that is, surgery. In surgery, depending on the stage of the disease, either the kidney is removed completely (radical nephrectomy) or only the cancerous part is removed (partial nephrectomy). With radical nephrectomy, the kidney, the upper ½ part of the ureter, the adrenal gland if the kidney is in the upper pole, and the lymph nodes palpable during surgery are removed along with Gerota’s fascia, which narrows the kidney.

Type of anesthesia, duration of surgery, length of stay

• Surgery is performed under general anesthesia
• Surgery time varies (may take 2-3, sometimes 4 hours)
• Hospitalization period: Varies between 2-3 days

Things to do before surgery are as follows:

• Blood thinners are stopped 1 week in advance.
• If the patient has diabetes or heart-blood pressure, it would be beneficial for him to see his doctor beforehand.
• Blood is adjusted according to the situation before the surgery, kidney cancer is a bloody surgery.
• It is necessary to stop eating and drinking 5-6 hours before the surgery.
• On the day of surgery, you apply to the hospitalization unit with your ID and necessary documents.

What to do after surgery

• Stitches are removed after 1 week
• Performs daily activities after 1-week and 10 days
• You should avoid heavy exercise and heavy work for 4-6 weeks.

Treatment for cancers that do not metastasize: There is no need for additional radiation or drug treatment (chemotherapy) as a result of surgical removal of kidney cancers that do not metastasize, that is, do not spread. The most effective treatment is surgery.

There are two surgery options for non-metastatic kidney cancer:

Radical nephrectomy: In this surgery, the entire kidney, the fatty tissues around the kidney, the upper half of the ureter and, if cancer has involved the adrenal gland, the adrenal gland on the same side are removed.

Radical nephrectomy surgery can be performed by 3 methods:

• Radical nephrectomy is performed with open surgery
• Can be done by laparoscopic method
• It can be done by robotic method.

Partial nephrectomy: In this surgery, the entire kidney is not removed, only the cancerous part is removed with a few millimeters of normal tissue around it. This is also called nephron-sparing surgery. In this way, the kidney is protected.

Partial nephrectomy is performed in the following cases:

• If the cancer is smaller than 4 cm (sometimes it is performed on larger tumors depending on the situation)
• If the cancer is not located in the inner part of the kidney
• If the cancer is far from the main vessels of the kidney and the urinary tract

Partial nephrectomy can be done in 3 ways:

• It is done with open surgery
• Can be done by laparoscopic method
• It can be done by robotic method.

Robotic and laparoscopic kidney cancer surgery is not performed in the following cases, open surgery is performed instead:

• If the cancer is very large and attached to major vessels and neighboring organs
• If he/she has previously had surgery on the same kidney or abdomen.
• If the cancer is very large
• The advantages of robotic and laparoscopic surgeries over open surgery are as follows:
• Smaller incision results in surgery scars
• The patient spends less time in the hospital
• The patient feels less pain
• There is less bleeding during surgery
• The patient starts daily activities earlier

What kind of surgery should be performed if there is cancer in both kidneys?

If there is cancer in both kidneys and partial nephrectomy can be performed, partial nephrectomy is performed on both sides. If one side is suitable for partial nephrectomy, partial nephrectomy is performed here and radical nephrectomy is performed on the opposite side. If the cancer in both kidneys is large and not suitable for partial treatment, radical nephrectomy is performed on both kidneys and the patient spends the rest of his life on dialysis.

What should be done if the patient has only one kidney and it has cancer?

If the patient has a single kidney and there is cancer in this kidney: If the cancer is suitable for partial removal, partial nephrectomy is performed; if it is not suitable for partial removal, radical nephrectomy is performed and the patient is placed on the dialysis program.

Can a kidney transplant be performed on a patient who has lost both kidneys due to kidney cancer?

This is a very special situation. The decision is made by a committee that deals with these issues after considering various factors such as the patient’s age, general health condition, life expectancy, and whether the cancer has been completely eliminated.

Treatment for metastatic (advanced, out-of-kidney) cancers: Treatment methods applied in cases where cancer goes beyond the kidney and spreads to distant organs are as follows:

• Radical nephrectomy: If the kidney can be removed by surgery in case of metastasized kidney cancer, it should definitely be removed. This is called “cytoreductive surgery.”
• Metastatectomy: After the cancerous kidney is removed, if metastatic cancer is in a position to be removed (for example, in organs such as liver, kidney, brain, etc.), the kidneys must also be surgically removed. This is called “metastatectomy”.
• Chemotherapy: Classic chemotherapy drugs are not effective in kidney cancer.
• Immunotherapy-immune check point inhibitors: With this method, it is aimed to destroy the cancer that has spread throughout the body by stimulating the body’s immune system. Cytokine treatments have been used in the past for this purpose, but they did not provide much benefit. Today, immune check point inhibitors are used for this purpose.
• Targeted treatment: These are drugs that prevent the proliferation of cancer cells by affecting specific mechanisms in cancer treatment. These drugs are:
  • Antiangiogenic drugs (drugs that prevent cancer vascularization)
  • Tyrosine kinase inhibitors
  • mTOR inhibitors
• Radiotherapy (radiation therapy): kidney cancer is generally radiotherapy-resistant cancer. Radiation treatments applied to these areas can be effective in metastatic cancers.

B- Non-surgical treatment methods for kidney cancer: In cases where patients are very old or their general health condition is not good enough to undergo surgery, alternative treatment methods to surgery are as follows:

• Cryoablation (freezing cancer cells) method: Special needles are inserted into the cancer tissue under USG guidance, and cancer cells are frozen and destroyed by disintegration.
• Radiofrequency ablation (applied to cancer cells with high heat): Similarly, cancerous tissue is destroyed with high heat by placing cancer-specific needles under USG guidance, without any surgery.

C- It is important to give support and morale to patients: Cancer patients and their relatives need morale. For this purpose, patients and their relatives should be helped.

• Patients need accurate information about their diseases: Patients should be accurately informed about kidney cancer, the stage of the disease, treatment processes and the effectiveness of treatments from the beginning.
• It is very important for patients to take care of themselves: From the moment they are diagnosed with cancer, patients should eat healthy, exercise regularly (mainly fruits and vegetables), and sleep regularly.
• Patients should make time for themselves: Patients should try to relieve stress by making time for themselves, such as reading and music.
• Mental health is very important: Psychiatric support should be received if necessary.

D- What is “palliative care” in metastatic kidney cancer?

If surgery and other treatments are no longer very effective in advanced stage cancer patients, all procedures performed to improve the quality of life of these patients are known as palliative care. In developed countries, there are special palliative care centers for advanced cancer patients. Here, patients are given psychological support and all practices that improve their quality of life, such as nutrition and pain treatment, are carried out.

Life expectancy (prognosis) in kidney cancer patients according to stages

The same standards may not be valid for every patient, but according to the results of many scientific studies, we can summarize the 5-year disease-free survival times according to the stages of kidney cancer as follows:

• Stage-I and Stage-II: 5-year disease-free survival 80-100%
• Stage-III: 5-year survival 50-60%
• Stage-IV: The 5-year survival rate in patients with metastatic cancer, that is, cancer that has spread throughout the body, is 16-32%.

In summary: Kidney cancer is the most common cancer of the urinary system after prostate and bladder cancer. It is more common in men. Radiotherapy and chemotherapy are generally not effective in treatment, but are applied in appropriate cases. The most effective treatment method for kidney cancer is surgery. Surgical treatment is performed open, laparoscopic or robotic. Radical or partial nephrectomy is performed depending on the location and size of the cancer. We have been successfully performing surgical procedures in the treatment of kidney cancer for many years.

Prof. Dr. Emin ÖZBEK

Urology Specialist

Istanbul- TURKEY