Diagnosis of Kidney Cancer

Executive Summary

Different tests are available to diagnose the development of kidney cancer, depending on signs and symptoms, age and health status, types of tumor, and earlier medical tests. Physical examination, imaging tests, and biopsies are the diagnostic approaches for diagnosing kidney cancer. The most common diagnosis of kidney cancer includes a physical examination, urine and blood tests, biopsy (renal biopsy), imaging tests (Magnetic resonance imaging (MRI), Computed Tomography (CT scan), x-rays, Positron Emission Tomography (PET Scan) and Cystoscopy and nephro-ureteroscopy).

Diagnosis of Kidney Cancer

Doctors use several techniques and tests to diagnose kidney cancer. They also conduct tests and scans to look for signs of cancer spread or metastasis. Imaging tests can help determine whether the cancerous growth has spread to other body parts or not. Cancer diagnosis plays a significant role in deciding the best treatment plan for a patient’s condition.

The doctor may carry out a physical examination of the suspected area as part of cancer diagnosis. But physical examinations may not give accurate results. A biopsy is the most preferred and sure way to detect any form of cancerous growth. In the case of kidney cancer also, a biopsy is preferred as a primary diagnostic method. During a biopsy, the doctor or physician will take a tiny sample of tissue from the suspected area to be sent for testing in the lab. In some cases, a biopsy may not be possible, and in such cases, the doctor or the health care team may suggest other diagnostic tests and procedures.

The diagnosis mode varies from one person’s cancer condition to the other. The doctor may consider the following factors before choosing a particular diagnostic procedure:

  • The cancer type that is suspected.
  • Signs and symptoms associated with the illness.
  • Age and general health condition of the patient
  • Past medical history and tests.

The following are diagnostic procedures used to diagnose kidney cancer ​1​:

  1. PHYSICAL EXAMINATION 

The doctor will conduct a detailed examination of your body to check for unusual growth, lumps or bumps. Physical examinations help your doctor get an initial understanding about your disease condition. The doctor will enquire about the signs and symptoms that you are experiencing. You may also be required to produce your past medical history for reference. The doctor will prescribe more tests and scans to get a precise diagnosis as per the physical examination.

  1. URINE AND BLOOD TESTS

Blood and urine tests are standard tests used to analyse most disease conditions. The doctor may prescribe a blood test primarily to check the number of red blood cells in the blood. A urine test may be prescribed to observe for bacteria, blood or cancer cells. Blood and urine tests can suggest whether a person has kidney cancer or not, but sometimes more tests and scans are required to arrive at a proper diagnosis.

  1. BIOPSY

A biopsy refers to the removal of a tiny sample of tissue from the suspected area to be examined under a microscope. A biopsy always gives a reliable diagnosis; hence, doctors widely prefer it to detect tumours or any abnormal growths. The collected sample is evaluated in the laboratory by a trained pathologist (a specialist in analysing body tissues and detecting diseases or abnormalities). They assess the cells, tissues and organs to detect diseases. The results of the biopsy are extremely vital in designing the treatment strategy. 

A biopsy is usually performed as an outpatient procedure using local anaesthesia, which is administered to the patient by an interventional radiologist. Anaesthesia is a medicine given to a patient during a medical procedure to block the patient’s awareness of pain.  

After analysing the sample, the pathologist will prepare a pathology report, which will become an important, permanent part of the patient’s medical record. The pathological will detail the type of cell involved in causing kidney cancer, and identifying this is vital in deciding the treatment plan. Metastatic kidney cancer refers to cancer that has spread or metastasised beyond the kidney and has invaded other tissues or cells of the body. A medical oncologist will refer to the patient’s pathology report before prescribing any systemic therapy to treat metastatic kidney cancer. A medical oncologist refers to a doctor who use medications to treat cancer. Systemic therapy involves the use of medications that affect the entire body.

In some cases of kidney cancer, surgeons may request a renal biopsy to gather more information to design the treatment plan ​2​. But if an imaging test shows a solid tumor growth, the surgeon may perform surgery and remove the mass first, and later the pathologist will examine it and provide its grade, stage and type. Patients are encouraged to ask questions and doubts to the doctor or healthcare team about all the diagnostic procedures and enquire whether a biopsy is necessary before treatment or not.

  1. IMAGING TESTS

Imaging tests can be instrumental in diagnosing cancer. The standard imaging techniques used by doctors to detect kidney cancer are Magnetic resonance imaging (MRI), Computed Tomography (CT scan), x-rays, Positron Emission Tomography (PET Scan) and Cystoscopy and nephro-ureteroscopy. Some of these imaging tests can help doctors understand the location and dimension of the tumour before any surgical procedure. A PET scan can be used to determine whether the cancerous growth has metastasised to other body parts or not.

  • Computed tomography (CT or CAT) scan:

A CT scan uses x-rays to capture images of the body’s interior. The x-ray is taken from different angles. Once the pictures are captured, a computer combines them into a clear, detailed three-dimensional image that clearly portrays any tumour growth or other abnormalities. Sometimes, a special dye called a contrast medium is given before the scan to ensure that the images captured are clear and crisp. This dye is usually given intravenously to the patient. Renal tumours will take up the contrast medium, but renal cysts will not. A non-contrast CT image portraying fat in a renal tumour indicates a benign angiomyolipoma, and the doctor may suggest non-surgical treatment options to eliminate it. A contrast medium is not used in patients with chronic kidney disease or kidney failure. A CT scan of the urinary tract is called a CT urogram. It is essential to note that a PET-CT scan is not used to analyse a renal cell carcinoma as the contrast used in most PET scans gets excreted via the kidneys and bladder, limiting the ability to detect kidney tumours.

  • X-rays:

An x-ray is a way of capturing images of the body’s structures using a minimal amount of radiation. X-rays are used to detect tumours in the kidney.

  • Magnetic Resonance Imaging (MRI):

An MRI scan uses magnetic fields instead of x-rays to capture and produce detailed images of the body interior. MRI can also measure the size of the tumour. Here a special dye called gadolinium is administered to the patient before the scan to obtain a clear picture. The dye is injected via the patient’s vein.

  • Cystoscopy and nephro-ureteroscopy:

For determining a urothelial cancer of the renal pelvis or upper urinary tract, a special diagnostic test called cystoscopy and nephron-ureteroscopy is done in some cases ​3​. These diagnostic procedures are not used to determine renal cell carcinomas unless the other imaging tests find a tumor, mass or stone in the bladder. During a Cystoscopy and nephro-ureteroscopy, the patient is sedated and, a tiny lighted tube is inserted into the urinary bladder through the ureter and from there into the kidney ​4​. (Sedation refers to any medication given to the patient to stay relaxed, calm or sleepy during the procedure). This diagnostic procedure can be used to obtain tumor cells for detailed examination under a microscope, perform a biopsy, or sometimes eradicate the small tumor cells.

Once all these diagnostic procedures are done, the doctor will examine the results thoroughly and discuss the observations with you. Based on these test results, the doctor will design the treatment strategy to treat and cure the disease condition.

References

  1. 1.
    Gray R, Harris G. Renal Cell Carcinoma: Diagnosis and Management. Am Fam Physician. 2019;99(3):179-184. https://www.ncbi.nlm.nih.gov/pubmed/30702258
  2. 2.
    Hogan JJ, Mocanu M, Berns JS. The Native Kidney Biopsy: Update and Evidence for Best Practice. CJASN. Published online September 2, 2015:354-362. doi:10.2215/cjn.05750515
  3. 3.
    Waisbrod S, Natsos A, Wettstein MS, et al. Assessment of Diagnostic Yield of Cystoscopy and Computed Tomographic Urography for Urinary Tract Cancers in Patients Evaluated for Microhematuria. JAMA Netw Open. Published online May 10, 2021:e218409. doi:10.1001/jamanetworkopen.2021.8409
  4. 4.
    Potretzke AM, Knight BA, Potretzke TA, Larson JA, Bhayani SB. Is Ureteroscopy Needed Prior to Nephroureterectomy? An Evidence-Based Algorithmic Approach. Urology. Published online February 2016:43-48. doi:10.1016/j.urology.2015.08.046