Renal cell carcinoma (RCC) is the most common form of kidney cancer. Around 90 percent of all kidney cancers can be attributed to RCC.
The different types of RCC are generally distinguished by the way that cancer cells appear when viewed under a microscope. Keep reading to learn about the three most common subtypes, which account for more than 90 percentTrusted Source of all RCCs.
What is renal cell carcinoma?
Renal cell carcinoma (RCC) is also called hypernephroma, renal adenocarcinoma, or renal or kidney cancer. It’s the most common kind of kidney cancer found in adults.
The kidneys are organs in your body that help get rid of waste while also regulating fluid balance. There are tiny tubes in the kidneys called tubules. These help filter the blood, aid in excreting waste, and help make urine. RCC occurs when cancer cells start growing uncontrollably in the lining of the tubules of the kidney.
RCC is a fast-growing cancer and often spreads to the lungs and surrounding organs.
What causes renal cell carcinoma?
Medical experts don’t know the exact cause of RCC. It’s most commonly found in men between the ages of 50 and 70 but can be diagnosed in anyone.
There are some risk factors for the disease, including:
- family history of RCC
- dialysis treatment
- smoking cigarettes
- polycystic kidney disease (an inherited disorder that causes cysts to form in the kidneys)
- the genetic condition Von Hippel-Lindau disease (characterized by cysts and tumors in various organs)
- chronic abuse of certain prescribed and over-the-counter medications such as nonsteroidal anti-inflammatory drugs used to treat arthritis, and medications for fever and pain relief such as acetaminophen.
How does it spread?
If a cancerous tumor is discovered in one of your kidneys, the usual treatment is to remove part or all of the affected kidney surgically.
If the tumor is left, it’s more likely that the cancer will spread to either your lymph nodes or other organs. The spread of cancer is called metastasis.
In the case of RCC, the tumor can invade a large vein leading out of the kidney. It can also spread to the lymph system and other organs (the lungs are especially vulnerable).
Symptoms of renal cell carcinoma
When RCC is in its early stages, patients may be symptom-free. As the disease progresses, symptoms may include:
- a lump in the abdomen
- blood in the urine
- unexplained weight loss
- loss of appetite
- vision problems
- persistent pain in the side
- excessive hair growth (in women)
Types of Renal Cell Carcinoma
1. Clear cell RCC
In the most common type of RCC, called clear cell or conventional, the cells have a clear or pale appearance. Around 70 percent of individuals with renal cell cancer have clear cell RCC. The growth of these cells can be either slow or fast.
The American Society of Clinical Oncology (ASCO) notes that clear cell RCC often responds well to treatment, such as immunotherapy and treatment that targets certain proteins or genes.
2. Papillary RCC
After clear cell RCC, papillary RCC is the next most common form of renal cell cancer. Under a microscope, the cells have projections that look like fingers.
Approximately 10 to percent of people with RCC have this type. Papillary RCC is divided into two further subtypes, known as type 1 and type 2.
Papillary RCC is generally treated using the same methods as clear cell RCC. However, targeted therapy may not work as well for people with papillary RCC.
3. Chromophobe RCC
Only about 5 percent of people with RCC have the chromophobe subtype.
Although these rare cancer cells may look similar to clear cell RCC, they tend to be bigger and have other distinguishing microscopic features.
Chromophobe RCC tends to be a less aggressive form of the disease. That’s because the tumors can grow to be quite large before spreading to different parts of the body.
Other rare types
There several other types of RCCs that are more rare. These include: collecting duct RCC (very aggressive), multilocular cystic RCC (good prognosis), medullary carcinoma, renal mucinous tubular and spindle cell carcinoma, and RCC associated with neuroblastoma.
Each of these types represents less than 1 percent of RCCs.
There are kidney tumors that don’t fit in any of the other categories. This is because these tumors have more than one cell type visible under a microscope.
These tumors are rare, accounting for only 3 to 5 percent of RCC tumors, but they can be quite aggressive and require prompt treatment.
TMN staging and the stages of kidney cancer
Kidney cancer is described in stages developed by the American Joint Committee on Cancer. The system is better known as the TMN system.
- “T” refers to the tumor. Doctors assign a “T” with a number that’s based on the size and growth of the tumor.
- “N” describes whether the cancer has spread to a node in the lymph system.
- “M” means the cancer has metastasized.
Doctors also assign RCC a stage. The stage is based on the size of the tumor and the spread of the cancer.
There are four stages:
- Stages 1 and 2 describe cancers in which the tumor is still in the kidney. Stage 2 means that the tumor is growing and is larger than seven centimeters across.
- Stages 3 and 4 mean the cancer has spread either into a major vein, to lymph nodes, or to other organs.
- Stage 4 is the most advanced form of the disease. Stage 4 means that the cancer has metastasized to the lymph system or other organs. Because the adrenal gland is attached to the kidney, the cancer often spreads there first. Stage 4 kidney cancer also means that the cancer may have spread into more than one lymph node near the kidney or elsewhere in the body.
How is renal cell carcinoma diagnosed?
If your doctor suspects that you may have RCC, they’ll ask about your personal and family medical history. They’ll then do a physical exam. Findings that can indicate RCC include swelling or lumps in the abdomen, or, in men, enlarged veins in the scrotal sac (varicocele).
If RCC is suspected, your doctor will order a number of tests to get an accurate diagnosis. These may include:
- complete blood count — a blood test conducted by drawing blood from your arm and sending it to a lab for evaluation
- CT scan — an imaging test that allows your doctor to take a closer look at your kidneys to detect any abnormal growth
- abdominal and kidney ultrasounds — a test that uses sound waves to create a picture of your organs, allowing your doctor to look for tumors and problems within the abdomen
- urine examination — tests used to detect blood in the urine and to analyze cells in the urine looking for evidence of cancer
- biopsy — the removal of a small piece of kidney tissue, done by inserting a needle into the tumor and drawing out a tissue sample, which is then sent to a pathology lab to rule out or confirm the presence of cancer
If you are found to have RCC, more tests will be done to find out if and where the cancer has spread. This is called staging. RCC is staged from stage 1 to stage 4, in order of ascending severity. Staging tests can include a bone scan, PET scan, and chest X-ray.
Approximately one-third of individuals with RCC have cancer that has spread at the time of diagnosis.
Treatments for renal cell carcinoma
There are five kinds of standard treatments for RCC. One or more may be used to treat your cancer.
- Surgery can include different types of procedures. During a partial nephrectomy, part of the kidney is removed. During a nephrectomy, the entire kidney may be removed. Depending on how far the disease has spread, more extensive surgery may be needed to remove surrounding tissue, lymph nodes, and your adrenal gland. This is a radical nephrectomy. If both kidneys are removed, dialysis or a transplant is necessary.
- Radiation therapy involves using high-energy X-rays to kill cancer cells. The radiation can be given externally by a machine or placed internally using seeds or wires.
- Chemotherapy uses drugs to kill cancer cells. It can be given orally or intravenously, depending on what medication is chosen. This allows the drugs to go through the bloodstream and reach cancer cells that may have spread to other parts of the body.
- Biologic therapy, also called immunotherapy, works with your immune system to attack the cancer. Enzymes or substances made by the body are used to defend your body against the cancer.
- Targeted therapy is a newer kind of cancer therapy. Drugs are used to attack certain cancer cells without damaging healthy cells. Some drugs work on blood vessels to prevent blood flow to the tumor, “starving” and shrinking it.
Clinical trials are another option for some patients with RCC. Clinical trials test new treatments to see if they are effective in treating the disease. During the trial, you’ll be closely monitored, and you can leave the trial at any time. Talk with your treatment team to see if a clinical trial is a viable option for you.
Outlook after an RCC diagnosis
The outlook after being diagnosed with RCC depends largely on whether the cancer has spread and how soon treatment is started. The sooner it’s caught, the more likely you are to have a full recovery.
If the cancer has spread to other organs, the survival rate is much lower than if it’s caught before spreading.
According to the National Cancer Institute, the five-year survival rate for RCC is over 70 percent. This means that over two-thirds of those diagnosed with RCC live at least five years after their diagnosis.
If the cancer is cured or treated, you may still have to live with long-term effects of the disease, which can include poor kidney function.
If a kidney transplant is done, chronic dialysis may be required as well as long-term drug therapy.