Two pioneering Northwell Health nephrologists are in the vanguard of shaping a new medical subspecialty, which has been prompted by the explosive number of cancer therapies that pose serious risks to the kidneys.
Onconephrology is the new discipline. It is being ushered into the greater medical arena by Kenar Jhaveri, MD, the health system’s associate chief of nephrology and professor of medicine at the Zucker School of Medicine at Hofstra/Northwell, and Rimda Wanchoo, MD, medical director of hemodialysis and associate professor of Medicine at the medical school.
Their endeavor has been a decade in the making. Onconephrology is a subspecialty whose time couldn’t have arrived soon enough. In 2018, 59 new medications were approved for a large array of medical conditions. A third of those drugs were for various forms of cancer and they added to hundreds of medications for the disease already on the market.
“Northwell is leading this as a subspecialty,” said Dr. Jhaveri, an onconephrologist and editor of a comprehensive textbook on the subject: Onconephrology, Cancer, Chemotherapy and the Kidney. He is chairing an educational session at the American Society of Nephrology’s annual meeting, Kidney Week 2019 starting November 5, which has attracted more than 200 nephrologists eager to learn how this emerging discipline can aid their patients.
“We were one of the first in the country to create this niche and the subject matter has really caught on,” he said.
Cancer therapies have been evolving rapidly in recent years with many treatments increasingly characterized by their ability to recruit a patient’s immune system to thwart the disease. Yet, risks persist amid the promise of treating cancer in new and innovative ways. Some forms of immunotherapy can cause interstitial nephritis, a condition typified by swelling between the organs’ tubules. Symptoms can range from mild to severe. Some patients may experience dark urine, or nausea and vomiting. Still others may become more seriously encumbered by elevated blood pressure and generalized swelling.
Immunotherapies are not alone when it comes to cancer medications that are capable of adversely affecting the kidneys.
Other drugs, such as tyrosine kinase inhibitors, which halt the proliferation of malignant cells by blocking the activity of minuscule protein receptors in tumors, have kidney impairment looming as a consequence. In general, problems caused by cancer therapies can range from electrolyte imbalance to full-blown kidney failure.
“The kidneys are highly vascular organs that receive 20 percent of their blood from the heart. So a lot of drugs that are distributed in the systemic circulation reach the kidneys,” Dr. Wanchoo said.
Like Dr. Jhaveri, she frequently presents data at national meetings based on clinical research that examines cancer drug influences on kidney function.
“These medications are filtered by the kidneys,” Dr. Wanchoo said. “This is why several drugs have a kidney-related effect. In addition, several patients getting these medications are older and might have other risk factors such as chronic kidney disease, diabetes and hypertension, which further increases the risk to the kidneys.”
Dr. Jhaveri and Dr. Wanchoo count numerous cancer drugs — including conventional chemotherapy — as having the potential for a deleterious impact on the twin organs, each roughly the size of a fist. Gemcitabine, for example, a nucleoside anti-metabolite cancer medication, differs dramatically from the chemistry of Selinexor, a selective inhibitor, approved by the US Food and Drug Administration in July. Both are used in the treatment of various forms of cancer and both carry significant risks for kidney impairment.
“A commonly used drug is cisplatin, which is used in testicular, bladder and ovarian cancer,” Dr. Wanchoo, said referring to an older form of chemo. “It causes acute kidney injury in 20 to 30 percent of patients.”
Other cancer medications, such as vascular endothelial growth factor, also called VEGF, and the monoclonal antibody, bevacizumab, sold as Avastin, can cause high blood pressure, protein in the urine and kidney injury. Patients on these medications must be monitored for potential kidney damage.
"As new agents get approved on a daily basis for cancer patients, onconephrologists need to be vigilant about the kidney-related toxicities of these agents,” Dr. Wanchoo said. “Knowledge of this can help the hematologist and oncologist, and patient significantly.”
As word of Northwell’s efforts to forge a new subspecialty has spread throughout the global medical community, nephrologists in the US and beyond have reached out to Drs. Jhaveri and Wanchoo for advice.
Both nephrologists say they work closely with their patients’ oncologists at the Northwell Health Cancer Institute, and in some cases, must decide whether sparing kidney function trumps the need for treatment with a specific cancer agent.
"The decision to continue chemotherapy in the setting of kidney damage depends on the degree of kidney failure,” Dr. Wanchoo said. “If there is a significant degree of damage, we usually stop the chemotherapy and wait until the kidney function improves so that we can reintroduce the drug. With certain drugs we usually ensure that the patient receives a good amount of intravenous hydration prior to administration of the chemotherapeutic drug to minimize the adverse effect.”
Drs. Jhaveri and Wanchoo were colleagues for years in Manhattan before joining Northwell. Both realized about a decade ago that a need existed for the subspecialty. They say Northwell gave them the latitude for clinical research and collaboration with oncologists to fully lay the foundation for the subspecialty.
“Northwell Nephrology is known in the nephrology community as one of `the’ places to learn onconephrology,” Dr. Jhaveri said. “Through our expertise, we will improve outcomes of patients with cancer and kidney disease.”