Renal cell carcinoma (RCC) is the most common type of kidney cancer. Most people with RCC develop cancer in only one kidney. But in rare cases, it can affect both kidneys. This is called bilateral RCC. “Bilateral” means “both sides.”

Although bilateral RCC is rare, it can be a serious condition. Because both kidneys are involved, treatment may be more complex. In bilateral RCC, the main goal of treatment is to remove the cancer while saving as much kidney function as possible.

In this article, we’ll explain what bilateral RCC is, what symptoms it may cause, and how it’s treated. You’ll also learn what makes it different from cancer in just one kidney and how to take care of yourself during and after treatment.

How Common Is Bilateral Renal Cell Carcinoma?

Only about 3 out of every 100 people with kidney cancer are diagnosed with tumors in both kidneys. It may be synchronous (both kidneys at the same time) or metachronous (at different times). This is because most people don’t have symptoms early on.

Sometimes, RCC is linked to inherited conditions (diseases passed down in genes from parents to children), such as von Hippel-Lindau disease or tuberous sclerosis. These inherited syndromes can cause tumors to grow in both kidneys, often at a younger age.

The good news is that bilateral RCC doesn’t always mean late-stage (advanced) cancer. If the tumors are found early and haven’t spread to other parts of the body, treatment can be very effective. Your healthcare team will keep a close eye on both kidneys using regular follow-ups to catch any new tumors early.

Causes, Risk Factors, and Subtypes of Bilateral RCC

Doctors don’t always know what causes bilateral RCC. However, certain things can raise your risk of developing tumors in both kidneys. As mentioned above, some hereditary conditions can raise the risk of bilateral RCC, including:

• Von Hippel-Lindau disease
• Tuberous sclerosis
• Birt-Hogg-Dubé syndrome

Bilateral RCC can also develop in people without any family history or inherited genes that raise their risk. In these cases, it’s called sporadic bilateral RCC. According to the American Cancer Society, risk factors for kidney cancer include being male, younger in age, and Black. These same factors may also play a role in bilateral RCC, although more research is needed.

There are also different types of RCC. Clear cell RCC is the most common. Others include papillary, chromophobe, and rare types like collecting duct RCC. Some types, like papillary RCC, are more common in hereditary cases and may be more likely to cause bilateral tumors.

Knowing your subtype helps doctors choose the best treatment options. If you have a genetic condition or multiple tumors, your doctor may recommend genetic testing and regular scans to check for new growths.

Symptoms of Bilateral RCC

Kidney cancer doesn’t always cause obvious signs or symptoms right away. Many people feel fine at first, even if they have tumors in both kidneys. When symptoms do appear, they may include:

• Blood in the urine, which may appear pink, red, or brown
• Pain in the side or lower back not caused by an injury
• A mass (lump) or swelling in the belly
• Weakness or fatigue
• Unexplained weight loss

These symptoms can happen with one kidney tumor or two. But with cancer in both kidneys, your chances of feeling symptoms may be slightly higher. That’s because there’s more tumor tissue, which may affect how well your kidneys work.

Treatment Options for Bilateral RCC

Treating cancer in both kidneys can be more challenging than treating it in just one. Because it’s so rare, there are different recommendations for treating bilateral RCC. Your doctor may recommend several kidney cancer treatment options, depending on the size, location, and type of kidney tumor, as well as your overall health.

Surgery

Surgery is often the first step in treating RCC, including bilateral RCC. However, it can be more complex when both kidneys are involved. A person needs at least part of one kidney working to survive. If neither kidney works or if both are removed, it’s necessary to get regular dialysis (to clean your blood) or a kidney transplant.

In a partial nephrectomy, only the tumor is removed, leaving the rest of the kidney intact. When possible, this is often the best option because it helps you avoid dialysis. If the tumor is large or in a hard-to-reach location, doctors may need to do a radical nephrectomy, which removes the whole kidney, as well as nearby tissue and sometimes the adrenal gland.

In bilateral RCC, doctors try to do partial nephrectomies on both kidneys. If that’s not possible, they may remove one kidney and do a partial nephrectomy on the other.

Minimally Invasive Options

Some kidney tumors can be treated without major surgery. Minimally invasive options include ablation techniques, which destroy the tumor without removing it surgically. Two common types are radiofrequency ablation, which uses heat, and cryoablation, which uses extremely cold temperatures.

Ablation is done with a needle through the skin using computed tomography (CT) scans or ultrasound to guide the way. It may be a good option for people with small bilateral tumors and those who aren’t good candidates for surgery. Ablation techniques can be repeated if new renal masses (kidney tumors) appear later. Ablation can sometimes help save kidney function and avoid dialysis.

Systemic Therapy

If the cancer has metastasized (spread) or can’t be fully removed using surgery or ablation, doctors may use systemic therapies. They may also be used after surgery to reduce the chances of the cancer coming back. These are medicines that work throughout your whole body. For bilateral RCC, two common types are:

• Immunotherapy — Helps your immune system find and kill cancer cells
• Targeted therapy — Blocks cancer cells’ growth signals, especially those in blood vessels

Some targeted drugs stop the cancer from building a new blood supply, which limits growth. Others block specific proteins that help it grow. The type of immunotherapy or targeted therapy you receive depends on the unique features of your kidney tumor.

People may get one or both types of treatments. Some are taken as pills, while others are given intravenously (through a vein).

Prognosis for Bilateral RCC

Having cancer in both kidneys doesn’t necessarily mean a worse prognosis (outcome). What matters most is the stage and grade — how far the cancer has spread and how aggressive the tumor cells are. However, having cancer in both kidneys makes treatment more complicated.

In one large study, people with metachronous bilateral RCC had a five-year cancer-specific survival (CSS) rate of 94 percent. CSS rate measures the percentage of people who are still alive after five years, not counting deaths from other causes. So, 94 out of 100 people with metachronous RCC were alive after five years and hadn’t died from kidney cancer. Those with synchronous bilateral RCC had a CSS rate of 52 percent.

When estimating your prognosis, your doctor will also take into account the tumor subtype, how aggressive the cancer cells are (called the tumor grade), and your overall health. If both kidneys are damaged or removed, you may need dialysis or, if eligible and a donor is available, a kidney transplant.

Taking Care of Yourself With Bilateral RCC

Living with bilateral RCC can be tough, but you don’t have to face it alone. Reach out to trusted friends or family members, or seek extra support through kidney cancer support groups.

Taking care of your mental health, staying active, and following your treatment plan as prescribed can make a big difference. Eat well, get enough rest, and be sure to attend all follow-up appointments. If you feel anxious or unsure about what the future holds, reach out to your healthcare team. With the right support and care, many people with bilateral RCC continue to live well and enjoy a high quality of life after treatment.

Talk With Others Who Understand

On MyKidneyCancerTeam, the social network for people living with kidney cancer and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with kidney cancer.

Have you been diagnosed with bilateral renal cell carcinoma? What tests led to your diagnosis? Share your story in the comments below, or start a conversation by posting on your Activities page.