Is Kidney Cancer Fast or Slow Growing?

Sometime watchful waiting, a period of when the treatment is unnecessary but the cancer is continuously monitored, can be suggested when the cancerous tumor is not aggressive – such as in many cases of prostate cancer. How about kidney cancer? Is it fast or slow growing tumor? The answer is dependent on several factors.

Kidney cancer grading

Currently, doctors cannot exactly figure out how cells of kidney cancer will behave. But cancer grading is a useful procedure to help analyze how fast the cancer will grow and develop. The greater grade of cancer you have, the more aggressive it will be. On the other hand, lower grader means it’s likely to grow and develop more slowly, and also less likely to spread (typically indicates a better outlook).

image_illustration417The cancer grade describes how abnormal cells of cancer are compared to normal cells. Doctors can analyze it under microscope. If you’re diagnosed with kidney cancer, your doctors may have their own grading system. But in general, the grade can be described as the following groups:

  1. Grade 1, the cancerous cells are growing slowly and look very similar to normal cells.
  2. Grade 2, the cancerous cells are growing and developing more quickly than normal. And they look unlike normal cells.
  3. Grade 3, the cancerous cells are growing quickly and look very abnormal if compared to normal cells.

Some systems can use more than 3 grades. There is also a condition called GX (grade X or undetermined grade), this means the grade cannot be identified and assessed.

The grade can be taken into account when determining the stage of cancer. Staging is a procedure to analyze how far the cancer has grown and spread. The stage and grade of cancer are important to be assessed since they can play a key role in determining the treatment plan.

The type of kidney cancer

The type of cancer is another issue to concern when it comes to discussing whether kidney cancer is slow or fast growing. There are a number of cancer types that can affect the kidneys. And renal cell (carcinoma) cancer is the most common type.

Renal cell cancer

Alternative names are hypernephroma and renal cell adenocarcinoma. In adults, this type is the most common kidney cancer.

Renal cell cancer is classified into several types, the main ones include:

  1. Chromophobe renal cell carcinoma – about 5 percent of renal cell cancers are this type.
  2. Papillary renal cell carcinoma – about 10 percent of renal cell cancers are this type.
  3. Clear cell, the most common type. It accounts about 75 percent of renal cell cancers.

Renal medullary carcinoma and carcinoma of the collecting ducts are other types of renal cell cancers – these types are very rare.

Transitional cell carcinoma (TCC)

It’s also often called as transitional cell cancer of renal pelvis (essential part of kidney where urine gathers before it flows through ureter to the bladder). TCC affects about 7-8 percent of kidney cancers. Interestingly, the treatment for this type is similar to bladder cancer treatment.

Wilms’ tumor

This kind of kidney cancer usually occurs in children – and it is not same with kidney cancer in adults. It was first discovered by Dr Max Wilms in 1899. It is categorized into group of rare cancers. But in children, it is one of common cancers they can get.

Wilms’ tumor is more commonly found in children younger than age 5. In very rare cases, it may also occur in older children and even adults. Typically it only affects one kidney, though in a few cases it can also affect both kidneys.

The exact cause is not fully known yet. But there are some risk factors of the condition. The risk of developing Wilms’ tumor is relatively greater in children with the following conditions:

  1. Having a family history of Wilms’ tumor.
  2. Those born with certain abnormalities, particularly such as birth defects associated with certain genetic mutations.
  3. Wilms’ tumor is more common in girls than in boys.

Sarcomatoid renal cancer

There is also a rare kidney cancer called sarcomatoid renal cancer (also often called as sarcomatous kidney cancer). Although it is considered rare, it affects about 1 to 15 percent of kidney cancers – according to some different studies.

Cancer cells of sarcomatous kidney cancer are also called sarcomatoid, because they look like cells of cancer called sarcoma (cancer that develops from cells of soft tissue). The bad news, any type of renal cell cancer (clear cell, papillary, chromophobe renal cell, etc) can become sarcomatoid.

In general, sarcomatoid type of kidney cancer is more difficult to treat and has a worse prognosis than non-sarcomatous kidney cancers. Because it is likely to become a fast growing cancer and easier to spread to other parts of the body!