Key Facts About Kidney Cancer

Renal cell carcinoma (RCC) is the most common type of kidney cancer. It has two subtypes—clear cell renal cell carcinoma and non-clear cell renal cell carcinoma. Clear cell RCC accounts for about 80% of RCC diagnoses and responds well to treatment. Non-clear cell renal cell carcinomas include papillary RCC and chromophobe RCC. The former has further subtypes, is characterized by cells with finger-like projections, and is less responsive to treatment. The latter is considered a less aggressive type of kidney cancer.

This type of cancer forms in the kidney's hollow pelvis or the ureter, which is the tube that transports urine to the bladder. It's sometimes referred to as urothelial carcinoma and is more common in men and older adults over the age of 65. Rare types of renal pelvis and ureter cancer include adenocarcinoma and squamous cell carcinoma.

Renal sarcomas are quite rare—less than 2% of malignant kidney tumors fall under this category. Renal sarcomas originate in the kidney's blood vessels or soft tissue, such as the connective tissue or fat around the kidneys. Leiomyosarcomas (LMSs) seem to be more common in females in their 30s and 50s.

When young children receive a kidney cancer diagnosis, it's often a kind called Wilms' tumor, also referred to as nephroblastoma. This type of cancer is possible but rare in adults. It is usually unilateral, meaning it is present in only one kidney for the most part, but up to 10% of kids with Wilms tumors have them in both kidneys. The tumors grow to be large but are often found before they can spread to other parts of the body. Around 10% of Wilms tumors have cancer cells that look especially odd and are spread throughout the tumor (diffuse anaplasia), which makes them harder to treat.

Rare RCCs include collecting duct RCC, multilocular cystic RCC, neuroblastoma-associated RCC, medullary carcinoma, and mucinous tubular and spindle cell carcinoma (MTSCC). Collecting duct RCC accounts for approximately 1% of all cases and is aggressive. Multilocular cystic RCC has a better prognosis. MTSCC can have a favorable outcome when diagnosed early.

It's not known what the causes of kidney cancer are, but there are factors that put folks at more risk. Smoking is a lifestyle factor worth noting, and the risk gradually drops in individuals who stop inhaling the carcinogens in tobacco. Obesity causes hormonal shifts that can lead to RCC, and the long-term use of painkillers like acetaminophen or aspirin may be connected to RCC. In terms of medical conditions, high blood pressure increases the risk of kidney cancer, as does chronic kidney disease or the long-term use of pain medications, for example.

If your workplace exposes you to arsenic, cadmium, or trichloroethylene, it increases the risk for RCC. Some risk factors, such as a family history of kidney cancer or being ethnically American Indian/Alaska Native, are beyond your control. The same goes for inherited conditions such as sickle cell trait, Cowden syndrome, Birt-Hogg-Dubé (BHD) syndrome, and von Hippel-Lindau disease. If one or more of these risk factors applies to you, it doesn't mean that a cancer diagnosis is a sure thing. It simply means that the odds of you getting kidney cancer are higher.

In the early stages of kidney cancer, there are generally no warning signs. But as the cancer advances, individuals may notice blood in their urine, which can look brownish, red, or pink. Back or side pain can become constant. Inexplicable fever and fatigue may become an issue, and appetite loss can lead to dropping pounds. Other symptoms of kidney cancer to watch out for include high blood pressure, a lump near the kidneys, or annual blood tests that show anemia or high calcium levels.

These symptoms can result from benign diseases, so if you're concerned, it's best to consult a doctor to confirm a diagnosis and receive appropriate treatment. The earlier you take action, the better.

With imaging tests and CT scans becoming more routine for various health concerns, kidney cancers are often found in the early stages.

During a physical, a doctor examines the abdomen for unusual masses. Lab tests with blood and urine samples, MRIs, and biopsies can confirm a kidney cancer diagnosis. Then, tests establish the stage of cancer, the overall health of an individual, and their suitability for surgery. Kidney cancer is different from many other cancers in that, often, imaging tests alone can tell doctors whether surgery is necessary.

There are four stages of kidney cancer. The higher the number, the more the cancer has spread. Kidney cancer staging uses the TNM system—T for the extent of the tumor, N for whether cancer has spread to nearby lymph nodes, and M for metastasis if there's been a spread to the adrenal glands, distant lymph nodes, or other organs such as the lungs. The information from tests, scans, and biopsies enables healthcare professionals to stage cancer.

At stage I of kidney cancer, the tumor is less than 2.8 inches and is confined to the kidney. But by stage III, the focus isn't on the tumor's size but on the fact that it's spread to close lymph nodes or blood vessels. Stage I kidney cancer might not necessitate immediate treatment unless active surveillance shows the tumor has grown.

At stage 4, the spread may mean that surgery is no longer a treatment option.

Once oncologists arrive at a diagnosis, there are various treatments for kidney cancer, and care teams first establish whether a tumor is removable. If it is, surgery is the main treatment—a radical nephrectomy removes the whole kidney, a conservative nephrectomy removes just part of it, and the lymph nodes may be removed, too, if necessary. When the cancer has spread further, tumors elsewhere may be removed, either with the intention to cure or as a palliative treatment. Immunotherapy and targeted drugs are used to treat advanced kidney cancer or as adjuvant therapy to prevent the return of cancer. They tend to be more effective than standard chemo drugs, at least for RCC.

If someone isn't well enough for surgery, ablation can suffice for tumors less than 1.5 inches across. Cryotherapy uses extreme cold and radiofrequency ablation (RFA), which uses heat to destroy a tumor with probes. Advanced radiation therapy or other newer treatments may also be explored, and the possibility of participating in a clinical trial may be on the table.

Surgery always comes with risks, such as reactions to anesthesia, bleeding, clots, or infections. Chemotherapy and radiation treatment often have side effects, including hair loss at the site of radiation, sunburn-like skin changes and fatigue. The side effects of targeted drugs and immunotherapy depend on the drugs used. With immunotherapy, fever, rashes, and nausea may occur, but cancer care teams can treat these side effects, and they generally go away when treatment stops. Some targeted drugs result in hypertension or low blood counts.

Talk to your oncologist, and they will advise you on strategies for managing side effects—early intervention is optimal for your comfort and to prevent interruptions to your treatment. For example, with hair loss, you should switch to a neutral pH shampoo, or you could get a prescription for a wig. Skin reactions may mean getting used to cooler showers and avoiding harsh detergents or fragranced cosmetics, for starters.

A cancer diagnosis can be devastating, but treatments have come a long way in the last decade. Maintaining a positive outlook with the support of loved ones or a professional counselor can help. Focus on the lifestyle changes you can begin to implement, such as stopping smoking or drinking and adopting healthy behaviors such as exercising or an improved diet. Prioritize practicing self-care, whether that be with a massage, retail therapy, making time for hobbies that make you happy, or saying "no" to some of the demands on your time and energy.

In addition, an oncologist may decide that treatment is not urgent after a Stage 1 diagnosis. A tumor may be benign or small, and it will be monitored with frequent screenings. Avoiding surgery or ablation is prudent when patients are older or have other health conditions.

We've touched on some of the healthy lifestyle choices that can prevent kidney cancer or its recurrence. If you have an increased risk of kidney cancer, getting regular physical exams and imaging tests done even at a young age can mean early detection and a greater chance of a cure. You may also want to consider genetic testing and counseling for more insight into your cancer risk.

The 5-year relative survival rate for localized kidney cancer is high at 93%, so if you receive a kidney cancer diagnosis, there's much cause for hope. Early detection is a key determinant in the possibility of a cure. If you're experiencing symptoms associated with kidney cancer, make an appointment with a doctor at your earliest convenience.