Definition and Overview

Kidney cancer is a kind of cancer or overgrowth that arises from the kidney cells. These tumours are typically solid but may also have cystic components. The most frequently encountered type of cancer of the kidneys is renal cell carcinoma, which accounts for 80% of cases. Other types of kidney cancers include juxtaglomerular cell cancer, transitional cell carcinoma, and squamous cell carcinoma, to name a few.

In children, the most common type of kidney cancer is Wilm's tumour, which is usually seen in children below five years. Some Wilm's tumours may start to grow even if the patient has not been born yet. Kidney cancer occurs more commonly in the male population. It is typically diagnosed in individuals who are 50 years and older.

Kidney cancer is responsible for approximately 2% of cancer cases every year. This corresponds to more than 200,000 cases per year worldwide. Most of the diagnosed cases are from the United States and Europe. Kidney cancer generally has a good prognosis, with survival rate of up to 73% in 5 years.

Cause of Condition

Majority of the cases of kidney cancer occur sporadically and without a known cause. Some factors, however, tend to increase the risk for the development of this condition. Smoking increases the risk by up to 50 percent. Some studies also point to chronic use of nonsteroidal anti-inflammatory drugs or NSAIDs, such as naproxen, as a risk factor for kidney cancer. Other risk factors include going through dialysis, a history of cervical or testicular cancer treatment, and hepatitis C infection.

Genetics also appear to contribute to the development of kidney cancer. Mutations in specific genes bring about the hereditary forms of the disease. An example is the Von Hippel-Lindau syndrome, wherein patients develop several tumours, kidney cancer included. Patients with a family history of this condition are also at risk.

Key Symptoms

Kidney cancer, in its early stages, usually has non-specific symptoms that include loss of appetite, easy fatigue, and weight loss. Patients may also present with hematuria or the presence of blood in the urine.

Larger tumours can present with flank or abdominal pain, usually caused by the stretching of the kidney or compression and invasion of other structures located nearby. Abdominal enlargement or an abdominal mass may also be observed.

If the cancer is already in the advanced stage and has already metastasized or spread, patients can present with symptoms related to the organs involved. The most common sites for cancer spread are abdominal lymph nodes and the lungs, in which case patients can present with difficulty in breathing. Some patients may also have metastatic disease in the bones, and present with pain or fractures.

Around 20% of kidney cancer patients present with paraneoplastic syndromes. These are symptoms that are not directly related to the kidneys, and include fever, heavy sweating and elevated blood pressures. These symptoms are not usually permanent, and generally resolves once the tumour has been taken out.

Who to See and Types of Treatments Available

Patients who are at high risk for kidney cancer, such as those with tuberous sclerosis, or patients with any of the above symptoms should seek consult with a healthcare professional. As medical history and physical examination may not reveal anything specific, patients who are suspected of having the disease, will be required to undergo an imaging study, such as an abdominal ultrasound.

An MRI may also be required to make an accurate diagnosis and to fully evaluate the extent of the cancer. Kidney cancer can spread to the nearby blood vessels, specifically the inferior vena cava. Thrombus in the vena cava can also be detected through a CT scan. Once the cancer has been confirmed, appropriate treatment is initiated.

Treatment for kidney cancer is best managed by a urologist. Patients who have resectable renal tumours will need to undergo surgery. Radical nephrectomy, which involves the removal of the entire kidney, or partial nephrectomy, which only involves the removal of the tumour and sparing normal kidney parenchyma, may be performed. Partial nephrectomy has a higher risk for complications, such as bleeding, than radical nephrectomy. However, the major advantage of partial nephrectomy is that more kidney tissue and function are preserved, and the risk for dialysis is decreased. Minimally invasive or laparoscopic techniques in cancer surgery have greatly improved the recovery period for patients undergoing nephrectomy for kidney cancer. However, surgery can become significantly complicated when there is a presence of a thrombus in the vena cava.

Newer methods for the treatment of kidney cancer include ablative techniques, such as radiofrequency ablation or RFA, and cryotherapy. Ablative techniques involve the destruction of the tumour tissue without removing them. Although extremely more popular, these methods are still not considered as standard therapies. Biological therapies and immunotherapy are also alternative options and are being used for patients in the late stages of the disease. Long-term outcomes of these treatments are still being investigated. Clinical trials are underway for other novel treatment options to significantly improve the prognosis.

Most kidney tumours in adults are generally not responsive to chemotherapy and radiotherapy. In children, however, the treatment of Wilm's tumours usually involves a combination of therapies and modalities, namely surgery, chemotherapy and radiotherapy.

After surgery, lifetime surveillance is recommended for patients. Kidney function needs to be evaluated at regular intervals. Repeat imaging may also be required. Your physician will determine the need for these surveillance examinations.

References:

  • Kidney Cancer Institute: https://kidneycancerinstitute.com/
  • National Cancer Institute: https://cancer.gov/
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