PHILADELPHIA (October 12, 2020)—Researchers at Fox Chase Cancer Center recently published a case study that proposes that severe low calcium levels known as hypocalcemia may result from an inflammatory reaction with transient hypoparathyroidism after hyperthermic intraperitoneal chemotherapy (HIPEC) treatment.
During HIPEC, heated chemotherapy drugs are circulated in the abdomen. It is typically used following surgical removal of a tumor. Hypocalcemia is a condition in which there are lower-than-normal levels of calcium in the blood plasma.
“It’s been known—but not widely known—that inflammatory markers can impair the parathyroid function, and that’s what we are proposing in this study,” said Christian A. Koch, MD, PhD, FACP, MACE, director of endocrinology and professor in the Department of Medicine at Fox Chase. Koch was senior author of the letter to the editor in which the case study was discussed.
“The physiological changes in patients undergoing HIPEC are poorly understood,” the authors wrote. “In addition to the toxic effects of the local heat exposure and chemotherapy on cancer cells, a systemic inflammatory response is believed to take place after HIPEC.”
Hypocalcemic events usually occur with large blood transfusions or deficiencies in Vitamin D and albumin or hypomagnesemia. Typically, if none of those conditions exist, calcium levels will only slightly decrease within normal range following a surgical procedure.
In the case study, researchers measured parathyroid hormone (PTH) levels in a patient who had undergone HIPEC and developed severe symptomatic hypocalcemia. Researchers found evidence of transient hypoparathyroidism, a condition in which there are inappropriately low levels of PTH, which regulates calcium and phosphorus in the body.
“PTH is usually responsible for managing calcium homeostasis. If that function is impaired because PTH is not getting released from one or more of these typically four parathyroid glands, you have to ask why,” said Koch.
“Many studies and systematic reviews based on meta-analyses often don’t really go into why certain medical conditions are observed, so when I was called to consult on this, I proposed it may have to do with an underactive parathyroid gland related to that new kind of therapy,” he added.
Koch said the case study could be helpful in providing potential mechanistic insight into hypocalcemic events following treatment with HIPEC.