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 also 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 the condition of each patient.

The doctor may carry out a physical examination of the suspected area as part of a 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. A biopsy is generally a primary diagnostic method, in most cancer types. During a biopsy, the doctor or physician will take a tiny sample of tissue from the affected area for testing in the lab. However, 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 according to the cancer condition of each person. The doctor may consider the following factors before choosing a particular diagnostic procedure:

  • 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 to diagnose kidney cancer ​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 of your disease condition. The doctor will enquire about the signs and symptoms that you are experiencing. You may also need to produce your past medical history for reference. The doctor may also prescribe more tests and scans to get a precise diagnosis as per the physical examination.

URINE AND BLOOD TESTS

Blood and urine tests are standard tests to analyze 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 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 than a single test and scan is necessary to arrive at a proper diagnosis.

BIOPSY

A biopsy refers to the removal of a tiny sample of tissue from the affected area for examination under a microscope. A biopsy always gives a reliable diagnosis, hence, doctors widely prefer it to detect tumors or any abnormal growths. A pathologist (a specialist in analyzing body tissues and detecting diseases or abnormalities) analyses this sample in a laboratory. They assess the cells, tissues, and organs to detect diseases. Furthermore, the results of the biopsy are extremely vital in designing the treatment strategy. 

A biopsy is generally an outpatient procedure that uses local anesthesia. It is administered to the patient by an interventional radiologist. Anesthesia helps to block the awareness of the pain of the patient during a medical procedure. After analyzing the sample, the pathologist will prepare a pathology report, which will become an important, permanent part of the medical record. The pathological report will detail the type of cell involved in causing kidney cancer, and identifying this is vital in deciding the treatment plan. A medical oncologist will refer to the pathology report before prescribing any systemic therapy to treat metastatic kidney cancer. A medical oncologist refers to a doctor who uses medications to treat cancer.

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 must 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.

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 is to determine whether the cancerous growth has metastasized to other body parts or not.

Computed tomography (CT or CAT) scan

A CT scan uses x-rays to capture images of the interior of the body. The computer combines the pictures into a clear, detailed three-dimensional image that clearly portrays any tumor growth or other abnormalities. Sometimes, a special dye called a contrast medium is given before the scan. This is to ensure that the images captured are clear and crisp. This dye is usually intravenously to the patient. Renal tumors will take up the contrast medium, but renal cysts will not.

A non-contrast CT image portraying fat in a renal tumor 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 known as a CT urogram. It is essential to note that a PET-CT scan is not to analyze 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 tumors.

X-rays

An x-ray is a way of capturing images of the structures using a minimal amount of radiation. It can be a method to determine or detect tumors 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’s interior. MRI can also measure the size of the tumor. Here a special dye called gadolinium is administered to the patient before the scan. This is to make sure to obtain a clear picture. The dye is injected via the vein of the patient.

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 the general procedures 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 under sedation. 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 is to obtain tumor cells for an extensive examination under a microscope, perform a biopsy, or sometimes eradicate the small tumor cells.

After the diagnostic procedures, 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