Weighty Matters: The Kidney Cancer-Obesity Connection

By Shayne Robinson, R.D., C.S.O, C.D.N

In March, we celebrate both National Nutrition Month and Kidney Cancer Awareness Month. This makes it the perfect time to talk about whether what we eat can play a role in preventing kidney cancer.

So is there a connection between diet, exercise and kidney cancer?

The World Cancer Research Fund International Continuous Update Project seeks to find out. They analyze global cancer prevention and survival research linked to diet, nutrition, physical activity and weight to determine whether certain lifestyle factors affect cancer risk. They then release reports based on the evaluation of this worldwide data.

Map Kidney Cancer Obesity
Image credit: American Institute for Cancer Research, aicr.org

When it comes to the kidneys, there is strong evidence that being overweight or obese increases the risk of developing kidney cancer. In fact, the latest findings showed that maintaining a healthy weight could prevent 24% of all kidney cancers in the United States. The report also found that there was an association between body fatness and kidney cancer, such that the more overweight people were, the greater their risk of developing kidney cancer. Being overweight or obese was assessed by body mass index (BMI), waist circumference and waist-to-hip ratio.

The good news is that this means that we can make healthy lifestyle changes to lose weight and reduce our risk of developing kidney cancer.

Wondering if you should lose weight?

See where you stack up on a BMI chart and measure your waist circumference. To measure waist circumference, place a tape measure around your waist above the tip of your hipbone. Measure your waist after exhaling. For women, a waist measurement of 31.5 inches or more indicates high risk for obesity. For men, a waist measurement of 37 inches or more indicates high risk for obesity. If your BMI is over 25 or your waist circumference is above these numbers, talk to your physician or Registered Dietitian about starting a weight loss program.

Here are 6 tips to get started with a weight loss plan:

  1. Lose pounds the healthy way. Move more and eat less. Avoid fad diets.
  2. Avoid high calorie, energy-dense beverages. This includes fruit juice, soda, sweetened coffee beverages, lemonade and sweetened tea. These beverages don’t provide the satiety you will get from eating solid foods.
  3. Eat your veggies! Cut back on energy-dense, high-calorie foods by making half your plate raw or steamed, non-starchy vegetables. These high-fiber vegetables will fill you up without weighing you down.
  4. Portion control is key. Scale back on portion sizes, except the non-starchy vegetables. Using smaller plates can help.
  5. Get movin’ — Increase your physical activity. For some people, this may mean starting by walking to the mailbox and back. Aim for 30 minutes of physical activity a day. If you can’t do 30 minutes, start small and increase as your fitness improves.
  6. See a professional. Nothing replaces the individualized counseling you will receive from working with a registered dietitian (RD). To see a dietitian at the NewYork-Presbyterian Outpatient Nutrition Practice call (212) 746-0838. A physician referral is required.

Living with One Kidney? 5 Things to Know

Dr. Molina and Dan R.
With many types of kidney cancer, surgical removal of the cancerous part of the kidney is part of treatment. This is also known as a “nephrectomy.” Depending on the size and location of your tumor, you may have had all or part of the kidney removed. People only need one kidney, but it’s very important to protect your remaining kidney function since the kidneys are responsible for filtering your blood and removing wastes from your body.

March is Kidney Cancer Awareness Month and the second Thursday in March is World Kidney Day. After you’ve had all or part of your kidney resected in order to remove a tumor, there are certain things to keep in mind in order to preserve your remaining kidney function. Here are five things you should know:

  1. Certain medications may need to be adjusted or avoided. Medications should be dosed according to your level of remaining kidney function. This is called “renal dosing” and pertains to all medications filtered by the kidneys (which covers a diverse group ranging from certain medications for cholesterol, heart disease, blood pressure, diabetes, infections and pain). A medical oncologist who specializes in kidney cancer should take this into account when prescribing medications, including dosing for cancer treatments. Some over-the-counter drugs are also “nephro-toxic” or harmful to the kidneys. These include non-steroidal anti-inflammatory drugs (NSAIDs), a type of pain medication that includes ibuprofen (Advil®), aspirin and naproxen (Aleve®).
  2. Speak up before imaging tests. Certain imaging tests that might be necessary to see what’s going on in your body and determine whether your cancer has spread, require the injection of contrast dyes. It’s critical to tell the imaging technician that you only have one kidney before undergoing these tests or any procedures. You should also hydrate before and after the test, and you may need to stop taking certain medications beforehand, such as metformin for diabetes. It’s important to discuss your specific situation with your healthcare team before you undergo any procedures.
  3. Drink up! Drinking plenty of water and staying hydrated is important on an ongoing basis, not just when undergoing imaging tests. Being hydrated helps your kidneys filter the wastes and toxins out of your blood so that they can leave your body as urine. Aim for your urine to be clear or pale yellow. Staying hydrated also helps prevent kidney stones.
  4. Watch the sugar and hold the salt. Diabetes and high blood pressure can damage the kidneys, so it’s important to monitor your sugar and salt/sodium intake. People with only one kidney should consume less than 2300mg sodium each day. This is approximately one teaspoon of salt. Those with diabetes should regularly check blood sugar levels. Additionally, maintaining a healthy weight and incorporating physical activity can help prevent developing type II diabetes.
  5. Know your numbers. There are certain blood and urine tests that you’ll want to monitor for changes in your level of kidney function over time. These include your estimated glomerular filtration rate (eGFR) which indicates how well your kidneys are filtering the wastes from your blood, the albumin to creatinine (A:C) ratio which indicates the level of protein in your urine, as well as tests for blood and infection. Work with your primary care physician to make sure you’re receiving these tests on an annual basis and you should see a nephrologist (kidney function specialist) if your eGFR is less than 30 milliliters per minute (ml/min) or if you have large amounts of blood or protein in the urine.

Kidney Cancer – It Takes a Team

By Ana M. Molina, M.D.

Each year, about 63,000 people in the United States are newly diagnosed with kidney cancer. Whether you’re still undergoing testing to determine whether you have kidney cancer or have already been diagnosed, you may be wondering where to turn next and who to trust.

Kidney cancer requires a multidisciplinary, team-based approach to treatment and that includes you as a key member of the team. For advanced cancers, your medical oncologist should act as your quarterback to help you navigate your next play. Your medical oncologist will work with you and recommend treatments and next steps based on your wishes and goals for treatment. The oncologist will account for factors such as the type of kidney cancer you have, the size and placement of the tumor and whether the cancer has spread to other organs throughout your body. This can also be referred to as the process of cancer staging and management.

From the time of your diagnosis and throughout the course of your treatment, you will be meeting with a variety of specialists who all provide different expertise.

Kidney Cancer_It Takes a Team

In honor of March being National Kidney Cancer Awareness Month, here’s an overview of all the players:

Urologist: Urologists specialize in diseases of the urinary tract, including the kidneys, and the male reproductive organs. Within this field, there are sub-specialists who specifically focus on urological cancers. A urologic surgeon who specializes in oncology will be the one who determines whether the tumor can be surgically removed. Based on the size and placement of the tumor, all or part of the kidney may be removed. If only the cancerous part of the kidney is removed, it is called a partial nephrectomy. If the entire kidney is removed, the procedure is called a radical nephrectomy. Whenever possible, it is advantageous to have a partial nephrectomy in order to save nephrons – the kidneys’ filtering units—and preserve kidney function. Following surgery, you will meet with the urologist to review the pathology results and discuss next steps.

Medical Oncologist: This doctor specializes in monitoring and treating your kidney cancer using medical intervention. A medical oncologist can recommend a wide-range of treatment options such as clinical trials, chemotherapy, immunotherapy, combination therapies and targeted therapies. At the Weill Cornell Genitourinary (GU) Oncology Program, we also offer personalized care in the form of precision medicine. This involves tumor profiling to analyze the genetic makeup of your kidney cancer. Based on the results of this analysis, we’re able to select treatment choices that most closely match the vulnerabilities of your specific tumor(s). The medical oncologist will refer you to a urologic surgeon or radiation oncologist if these interventions will offer the best course of treatment for your specific situation.

Radiation Oncologist: This specialist delivers cancer treatment using x-rays and other forms of radiation to treat metastatic kidney cancers. At Weill Cornell, we currently offer clinical trials that combine immunotherapy and radiation which has been shown to have an abscopal effect, meaning that this combined treatment has been able to activate the body’s immune system in order to eliminate tumors that weren’t directly targeted by the radiation.

Radiologist and Interventional Radiologist: Radiologists are the doctors who review imaging tests ordered by your urologist or medical oncologist to determine the location of your cancer and whether it has spread. Imaging tests you may receive include: computed tomography (CT) scans, magnetic resonance imaging (MRI), positron emission tomography (PET), ultrasonography and x-rays. A sub-specialty within radiology, the interventional radiologist is the person who will use image-guided tests to conduct minimally invasive procedures. For example, the interventional radiologist will biopsy organs and tissue in order to collect samples from your tumor. These samples will be examined by pathologists and may ultimately be used for precision medicine and to test out which treatments may be most beneficial to your specific cancer.

Nephrologist: This is the doctor who specializes in treating kidney disease and preserving your remaining kidney function. Nephrologists also work with your healthcare team to help manage other risk factors for kidney failure such as diabetes and hypertension, and to ensure you’re on a kidney-protective regimen. Since many medications are “cleared” by the kidneys, this may involve changing your medications to reduce the stress on the kidneys to filter these medications out of your body as waste.

Palliative Care Physician and Social Worker: Palliative care is often wrongly interpreted as a synonym for end-of-life care and hospice. The field of palliative care, or supportive medicine, is more accurately described as the services that help improve quality of life. It is beneficial for this team to get involved early, as these experts help alleviate some of the symptoms of kidney cancer and its treatment, while even helping to extend life. A palliative care physician can help manage pain and help to reduce uncomfortable side effects such as diarrhea and nausea. They also provide counseling and other therapeutic interventions to help people cope with the emotional impact a cancer diagnosis can have on patients and their loved ones.

At the Weill Cornell GU Oncology Program, we have weekly tumor board meetings in which many of the specialists listed above all meet together to discuss our patients’ care. This close collaboration with experts across kidney cancer sub-specialty areas helps ensure that our patients are receiving the best, most comprehensive and cutting-edge treatment. Because we have a shared system of medical records across the Weill Cornell Medicine healthcare network, communication between our physicians is integrated and seamless.

We understand that it’s not only your medical team that provides support and care during the course of cancer treatment. Our Kidney Cancer Support Group brings together other patients, caregivers and loved ones so that you’re part of a community that “has been there” and understands what you’re going through.