The name “chromophobe” comes from the way these cancer cells look when examined under the microscope using certain dyes. Scientists first described this specific kind of cancer in the 1980s.
Types of Kidney Cancer
Chromophobe renal cell carcinoma falls into a broader group of kidney cancers called renal cell carcinoma (RCC). “Renal” means “kidney.” “Carcinoma” is a word for cancers that begin in the cells that line the internal organs. About 90% of cancers that start in the kidney are classified as renal cell carcinoma.
Scientists eventually learned that certain kidney cancers behave somewhat differently than others. That is, if someone’s cancer cells looked a certain way under a microscope, they classified them into different categories. And those cancers seemed to share certain similarities, like how well they responded to specific treatments.
Chromophobe renal cell carcinoma is a subtype of renal cell carcinoma. About 5% of people with renal cell carcinoma have this subtype. Compared to people with some other more common subtypes, people with chromophobe renal cell carcinoma are more likely to be female.
People with the chromophobe subtype also tend to be diagnosed at an earlier stage than people with some of the other subtypes. That is, their cancer isn’t as advanced—hasn’t grown and spread as much—compared to people with other subtypes.
Chromophobe Renal Cell Carcinoma Symptoms
Most people with chromophobe RCC don’t have any symptoms at all when they are diagnosed. Instead, the cancer may be discovered on imaging scans done for another reason.
If symptoms are present, they may include the following:
Pain in your lower back (sometimes called “flank pain”)Blood in your urine
You might experience different symptoms if your cancer has already traveled to other places in your body (called metastatic cancer). In this case, some possible symptoms include:
Bone painWeight lossFeverCoughSwelling of your legs
Causes
Scientists are still learning about what causes chromophobe renal cell carcinoma. A lot of complex genetic and environmental factors seem to be involved.
Like other kinds of cancer, chromophobe RCC develops partly due to changes in a person’s genetic material. Many factors may cause your genetic material—your DNA—to become slightly damaged during your lifetime. This is known as an acquired genetic mutation.
Usually, this isn’t a big deal. However, if a specific cell inside your kidneys gets several mutations, it might start to behave abnormally. For example, it might begin to grow and reproduce when it normally shouldn’t. In other words, it turns into cancer.
Certain things might increase the risk of dangerous mutations. For example, the following sometimes increase the risk of renal cell carcinoma:
SmokingHigh blood pressureOther kinds of kidney diseaseExposure to certain toxins
People in certain jobs are more likely to be exposed to these toxins, such as mechanics or people who work in dry cleaning. However, most of the time, a clear cause can’t be found.
It’s complex, but certain parts of your DNA—specific genes—seem to be damaged in chromophobe renal cell carcinoma. For example, a gene called TP53 is commonly affected in people who have the disease.
Genetic Syndromes and Chromophobe Renal Cell Carcinoma
Some people are also at greater risk of getting chromophobe renal cell carcinoma because of medical conditions they inherited from their parents and were present from birth.
For example, people with Birt-Hogg-Dubé syndrome, a condition that produces numerous benign (noncancerous) skin tumors, have a higher risk of chromophobe renal cell carcinoma than the general public. Most people with chromophobe renal cell carcinoma do not have such syndromes.
Diagnosis
To make a diagnosis, first, your doctor will take your medical history, asking you about current symptoms and your other medical conditions. That, paired with a physical exam, may point to kidney cancer as a potential concern.
Although they can’t be used for definitive diagnosis, a number of medical tests can provide some clues. They might also rule out other potential causes of your symptoms. Some of these include:
Urinalysis: Analysis of a urine sample to look for blood and other characteristics Creatinine: To check for kidney function Alkaline phosphatase: To give clues about potential spread to the bones
Imaging tests can also be important for diagnosis. These can reveal if something abnormal is present on the kidney. For example, these might include one or more of the following:
Computed tomography (CT) scan of the kidney (most common) Intravenous pyelogram (an X-ray study using dye to show the urinary tract better) Ultrasound of the kidney Magnetic resonance imaging (MRI) of the kidney
When combined, these tests can give doctors a very good idea of whether a person has some type of kidney cancer. However, a specialist must examine a sample of tissue from the suspected cancerous area of the kidney under a microscope for a definitive diagnosis.
This can happen in different ways. The clinician can often tell from all these other indicators that kidney cancer is very likely. If so, they might plan to go ahead with surgical removal of the kidney or part of the kidney.
After that happens, they can send a portion of suspected cancerous tissue to the laboratory. A pathologist (a doctor specializing in laboratory science) examines the cells and determines if cancer is present and what type it is. This is when you might be told that you have chromophobe RCC specifically.
Less commonly, a person might have a kidney biopsy before surgery if it’s not clear yet that cancer is the problem. In this case, a sample of tissue is also sent to the laboratory. There, an expert can definitively diagnose chromophobe RCC.
Treatment
Treatment for chromophobe renal cell carcinoma will depend a lot on the cancer’s stage. That refers to how much the cancer has spread throughout your body.
Stages 1–3 Disease
For people with stage 1, stage 2, or stage 3 cancer, surgery is the main approach. Your surgeon might recommend total removal of your kidney (radical nephrectomy). If your cancer is very small, you might only need to have part of it removed (partial nephrectomy).
The idea is to completely remove the cancer from your body through surgery. Usually, no further treatment is needed. For example, radiation therapy—sometimes used for other types of cancers—is not a standard part of treatment.
However, your doctor will probably want to monitor your kidneys for signs that your cancer has returned. For example, you might need periodic imaging tests (like CT scans) of the area.
Some other procedures are alternatives to traditional surgery that may make sense for some people. These don’t require large cuts to be made through the area. Instead, they are techniques that burn or freeze away the cancerous part of the kidney. For example, you might hear these referred to as:
Cryosurgery: The cancerous tissue is frozen. Radiofrequency ablation: An electrical current is applied to the cancerous tissues. Microwave ablation: Microwave energy is applied through a probe to the cancerous tissues.
One of these alternatives might be a good option for you are at high risk for surgery, if you have a very small tumor, or if you only have one kidney. However, it is much more likely that your cancer will grow back if you pick one of these methods instead of standard surgery.
Stage 4 Disease
In people with stage 4 disease, their cancer has already spread more extensively throughout the body. Surgery alone can’t cure the disease. However, surgery is still sometimes helpful, such as to reduce symptoms even though it won’t cure your disease.
People with stage 4 chromophobe RCC usually need additional treatments as well. For instance, chemotherapy may help slow the tumor’s growth and help you live longer with fewer symptoms. Scientists are still learning about the best combinations of drugs to use.
Checkpoint inhibitors are a newer class of drug that blocks proteins that regulate the immune response. By blocking these proteins, the body can fight cancer more effectively. Approved checkpoint inhibitors include Opdivo (nivolumab) and Keytruda (pembrolizumab).
A group of drugs called angiogenesis inhibitors may be tried. These drugs block the tumor’s ability to form new blood vessels, so they reduce the spread of the tumor. Some of these are:
Sutent (sunitinib)Zortress (everolimus)
Sometimes a combination of drugs is used, like Lenvima (lenvatinib) and Zortress (everolimus).
Prognosis
Compared to people with some other subtypes of renal cell carcinoma, people with chromophobe renal cell carcinoma tend to do better. Partly this is because they tend to be diagnosed at an earlier cancer stage.
About 90% of people diagnosed at stage 1 or stage 2 will be alive five years after their diagnosis. However, this rate is lower for people who already have advanced cancer when they are first diagnosed.
Summary
Chromophobe renal cell carcinoma is a rare type of kidney cancer. Many people are diagnosed before they have symptoms. When this cancer is at an early stage, it is usually detected when a scan performed for another condition discovers it incidentally.
Diagnosis is made by imaging and biopsy of the tumor. Treatment for early stages is the removal of all or part of the kidney. For advanced stages, treatment may include drugs to inhibit the growth of the cancer.
A Word From Verywell
It can be devastating to learn that you or a loved one has been diagnosed with any kind of cancer. However, the good news is that many people diagnosed with chromophobe renal cell carcinoma can be completely cured. Get as much information as you can from your doctor about your options. That will help you make the best health decisions for yourself and your family.
