The term “RMC” stands for Renal Medullary Carcinoma.

Renal Medullary Carcinoma (RMC) is a rare and aggressive cancer that attacks the kidney. This cancer has a high mortality rate because it quickly spreads to other organs, often before it is diagnosed. Less than 10% of patients will live beyond three years after being diagnosed with RMC. This cancer is found almost exclusively in young patients of African-American descent with sickle cell trait. These individuals may have symptoms of gross hematuria (blood in urine), belly pain mainly in the flanks, unexplained weight loss, difficulty breathing or cough.

Sickle cell trait (SCT) is a blood disorder that causes the body to produce sickle shaped red blood cells. If an individual has SCT, it means that he or she has inherited one sickle cell gene from one parent and one normal gene from the other parent. SCT can never become sickle cell disease, however it is possible for individuals with SCT to pass the gene to their children. In general, people with SCT enjoy normal life spans with no medical problems related to SCT.

Occasionally people with SCT can have blood in their urine. Under extreme conditions such as high altitude, severe dehydration, or very high intensity physical activity, the red cells can become deformed or sickled and can lead to serious health issues including sudden death. Other complications include muscle breakdown, reduced blood supply to the spleen, or increased pressure in the eye following eye injuries. Finally, a very rare form of kidney cancer (renal medullary carcinoma) has been associated with sickle cell trait.

Approximately 7-10% of the African-American population has SCT, and it is also present in people from Latin America, Asia, India, and the Mediterranean. More than 3 million people in the United States and approximately 300 million people worldwide have SCT.

Although testing newborns for the sickle cell gene has been routine in most states since the late 1970’s, many adults in their mid-20’s and older do not know their status.

Individuals with sickle cell trait or other sickle hemoglobinopathies who develop signs or symptoms (such as blood in the urine) suggestive of RMC can be evaluated using an ultrasound examination of their kidneys.

Treatment of RMC may require the coordinated efforts of a team of specialists who will need to systematically and comprehensively plan an affected patient’s treatment. This may include specialists who diagnose and treat cancer (medical oncologists), specialists who perform surgery on the kidney (urologists), specialists who use ionizing radiation to treat cancer (radiation oncologists), specialists who use minimally-invasive, image-guide technologies to diagnose and treat cancer (interventional radiologists), as well as other healthcare professionals. Psychosocial support for the entire family is also essential.

Specific therapeutic procedures and interventions may vary, depending upon many factors, such as disease stage (how extensive the disease is), the size of the tumor, the presence or absence of certain symptoms, whether the disease has spread (metastasized) to other areas of the body, an individual’s age and general health, and/or other elements. Decisions concerning the use of surgery, radiation, specific drug regimens and/or other treatments should be made by physicians and other members of the health care team in careful consultation with the patient based upon the specifics of his or her case as well as a thorough discussion of the potential benefits and risks, including possible side effects and long-term effects, patient preferences, and other appropriate factors.

Patients with RMC are often treated with chemotherapy. Many of the therapies that are used for other kidney cancers do not work against RMC. If CT or MRI imaging suggests that RMC is confined only to the kidney and has not spread to other areas, then surgery can be considered to remove the whole kidney and the cancer inside it. If the RMC tumor is large, for example larger than 4 cm, then the doctors may decide to use chemotherapy first in order to shrink the tumor and perform the surgery afterwards, even if there is no evidence on CT or MRI that RMC has spread to other areas. Other specific therapeutic procedures may include radiation therapy or other therapies.

The at-risk population for RMC is identified at a young age due to the mandate in the United States requiring sickle cell screening to be included in the newborn testing. It would be beneficial for the at-risk individuals (beginning at infancy) receive annual urine test for blood. If the test is positive for blood, the need for further evaluation, including imaging studies to rule out RMC must be done. Heightened awareness and early diagnosis along with further research could significantly improve outcomes, thus increasing the overall survival rate.

CA-125 is a protein found in the blood that can be used as a marker for RMC. CA-125 levels are often high in people with RMC and tend to increase as the cancer spreads. Doctors can use CA-125 to monitor how well a treatment is working or to detect if the cancer is coming back. It also helps identify patients who might benefit from new therapies targeting CA-125 on the cancer cells. Not every patient with RMC will have high CA-125 in their blood. This is because 30-40% of RMC tumors do not produce CA-125. We do not yet know why some RMC tumors do not produce CA-125.

Exercise has multiple health benefits, including for patients diagnosed with RMC or otherwise healthy individuals with sickle cell trait, sickle cell disease or any hemoglobinopathies. Studies in animals with sickle cell trait suggest that moderate-intensity exercise may actually decrease the risk of RMC compared with having a sedentary lifestyle. On the other hand, early clinical observations and animal studies do suggest that prolonged high-intensity exercise in individuals with sickle cell trait may injure the kidneys in ways that can increase the risk for RMC. Thus, regular exercise done in moderation may benefit all individuals and reduce the risk of RMC, whereas overdoing it may be harmful. This is in line with the general recommendations and precautions by the Centers for Disease Control and Prevention on the role of exercise in athletes with sickle cell trait.

The formal definition of moderate-intensity exercise is between 50 to 70 percent of your maximum heart rate. The maximum heart rate can be calculated by 220 minus your age. Thus, if you are 40 years old, then your maximum heart rate is 180 beats per minute.

When you perform moderate-intensity exercise your breathing may quicken but you are not out of breath. You may develop a light sweat after about 5 to 10 minutes of activity. You can carry on a conversation while exercising but cannot sing.

The formal definition of high-intensity exercise is between 80 percent or more of your maximum heart rate. When you perform high-intensity exercise your breathing may be deep and rapid, you may develop a sweat after just a few minutes of activity, and you cannot say more than a few words without pausing for a breath.

In summary, exercise is not contraindicated for patients with sickle cell trait if it is performed under safe conditions. Universal precautions adopted by athletes and military recruits may prevent deaths and help athletes with sickle cell trait thrive in their sport. These include staying well-hydrated throughout your exercise with frequent stops for drinking. Avoid high caffeine intake and other stimulants around the time of exercise. Avoid repeated high-intensity timed drills with limited recovery time in the first two weeks of new training session. Limit exercise when sick. Provide ample rest and recovery between repetitions especially during “sprints” and intense stations or drills. Make fluids readily available and schedule frequent breaks.

Researchers continue to explore the molecular drivers of this rare disease, but few clinical correlations have been made. As the scientist understand the biological mechanisms of RMC; it is expected that new research opportunities will emerge and new treatment options will be developed for this rare and dismal disease. Currently MD Anderson Cancer Center in Houston, Texas has four active clinical trials specifically designed for patients with RMC and renal cell carcinoma unclassified with medullary phenotype (RMC in patients without sickle cell trait or disease). Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government website.

Our quest for a CURE begins with AWARENESS and RESEARCH