Renal Cancer (or) Kidney Cancer

Diagnosis

The diagnosis of kidney cancer is done using one the following methods:

• Medical history and physical examination: The patient undergoes a comprehensive physical examination to check for any signs of kidney cancer, such as an abnormal lump in the abdomen. The oncologists may also ask the patients about symptoms in more detail, such as the duration of symptoms or their progression. The medical history of the patients is also evaluated to rule out if the symptoms are due to pre-existing conditions. In addition, family history helps determine the risk factors for kidney cancer.
• Urine analysis: Renal cancer affects the filtering capacity of the kidney, which can be evaluated through urine analysis. There is also an increased expression of several biomarkers in renal cancer, such as aquaporin-1 and adipophilin. The levels of these biomarkers in urine help in diagnosing renal cancer at an early stage.
• Blood tests: There is no blood test to diagnose kidney cancer. However, the results of several blood tests indicate a kidney problem. A loss of blood in urine in renal cancer may lead to anemia. It can be detected by testing the complete blood cell count. Further, the creatinine levels in the blood also provide vital information about kidney function. The other blood tests that can be helpful in initial cancer screening include blood calcium levels, liver enzymes, and blood urea nitrogen.
• CT scan: CT scan is significantly effective in diagnosing kidney cancer. A study reported that the accuracy rate in diagnosing kidney tumors with CT scans is greater than 99 percent. However, a biopsy is still required to confirm the diagnosis and staging of renal cancer. CT scan also provides crucial information about the spread of kidney cancer to other organs outside the kidney or surrounding lymph nodes.
• MRI scan: MRI scan plays an important role in the diagnosis and staging of renal cancer, especially in patients with ambiguous or unclear results, pregnancies, and allergic reactions, as it involves the use of non-ionizing radiation and provides superior resolution of soft tissues. Although the performance of contrast-enhanced MRI is better than diffusion-weighted MRI, patients with kidney dysfunction are at increased risk for nephropathy due to contrast dye.
• Ultrasound: Ultrasound is a widely used, inexpensive, established, and non-invasive technique that allows screening of renal cell carcinoma without radiation exposure. However, it has less sensitivity and specificity than CT for detecting kidney lesions. The rate of detection of ultrasound depends on the size of the lesions. It has an approximately 85-100% detection rate for tumors greater than 3 cm, but only 67-82% for 2-3 cm size tumors.
• Chest x-ray: Chest x-rays are done to check if renal cancer has spread to the lungs in patients who are already diagnosed with renal cancer. It is also done as a part of follow-up care to determine the recurrence of renal cancer as pulmonary metastasis.
• Angiography: Angiography is a test to determine the health of the blood vessels. Earlier, angiography was performed by injecting the dye into the renal artery and visualizing the area of blood vessels outlined by the dye through an x-ray. It helps in detecting the blood vessels that supply blood to the tumor. This information is used during surgical interventions. It may also play a role in diagnosing renal cancers. Currently, angiography is combined with MRI, and CT scans to minimize the use of contrast dye.
• Bone scan: The patients may undergo a bone scan to detect if renal cancer has spread to the bones. The test is performed by injecting a low-dose radioactive material that is taken up by the abnormal parts of the bone. It is done in case the blood test reports indicate an increase in serum calcium level.
• Kidney biopsy: Kidney biopsy is sometimes not needed because imaging tests provide adequate information to oncosurgeons to plan the surgery. The mass or part of the kidney removed during the surgery is sent to the laboratory for further examination. A biopsy involves obtaining a small tissue sample from the tumor and sending it to the laboratory to determine the presence of cancerous cells. The techniques for kidney biopsy include needle core biopsy and fine needle aspiration. The sample can also be obtained for other areas of the body where the cancer is believed to be metastasized. Oncologists use the Fuhrman grade to determine the speed at which cancer grows and spreads.