Pediatric Cancer Awareness Month: Why one family moved to Houston to treat daughter’s histiocytosis

Histiocytosis is an abnormal increase of histiocytes, a type of white blood cell, in various tissues.

HOUSTON – Langerhans Cell Histiocytosis (LCH) is a rare disease of white blood cells in which an overabundance of abnormal dendritic cells causes damage to the skin, bone, and other organs, according to Texas Children’s Hospital.

The disease affects both children and adults, with peak incidence occurring in children between 5 and 10 years old.

It can manifest in an alarming variety of ways: As a scaly rash that does not respond to treatment; As bone pain, headaches, and severe leg pain; As severe gastrointestinal pain, vomiting, diarrhea, bleeding from the esophagus, weight loss and failure to thrive; As swelling and inflammation in the mouth, face, ears, scalp and lymph nodes; Texas Children’s Hospital reports.

When Kaelan and Jordan Brennan first took their one-year-old, Hadlee, to see a doctor because she was screaming in pain, they weren’t sure why the medical staff seemed more alarmed about her rash.

“They’re making a lot of emphasis on the skin rash, which is the last thing on our mind,” Kaelan Brennan recalled.

“I was like, ‘Who cares about this rash?’ You know, it’s [like] she’s got some kind of illness happening, like a cold or strep or something else,” Jordan Brennan explained.

However, they were stunned to hear the next recommendation was to meet with an Oncologist. They said that’s when they realized they were headed toward a cancer diagnosis.

“I can’t even really put into words what it was like. It was just such a blow to your system. It’s something you never imagine. You’re going to get told that your 1-year-old has cancer,” Jordan Brennan said.

Baby Hadlee’s rash was a telltale sign of histiocytosis, a rare pediatric cancer.

“It has the same incidences of childhood Hodgkin’s lymphoma, and everybody knows about Hodgkin’s lymphoma,” said Dr. Kenneth McClain, Pediatric Hematology Oncology Specialist at Texas Children’s Hospital.

Dr. McClain developed the histiocytosis program at TCH, called the LCH Research Program at Texas Children’s Cancer Center. The program’s goal is to identify genes that lead to the disease. By knowing the genes, and how lesions are formed, they may ultimately understand better treatments and a cure for the disease.

For now, McClain said typical treatment includes chemotherapy and steroids.

“But that therapy overall is disappointing because 50% of patients will either not respond, progress, or relapse off therapy,” McClain explained.

Hadlee wasn’t getting any better while she was on the standard treatment.

However, Dr. McClain tried her on a new inhibitor that targets her specific mutation.

Now she’s improving and may soon be able to end chemotherapy treatment.

“Could not be happier,” Kaelan said. “Certainly, if there’s anyone out there, we’re proof that this is a great place to treat your child.”

Dr. McClain’s research continues to search for better understanding and treatment of histiocytosis. Interestingly, one finding is how there’s an association with other gene abnormalities, one of which is more prevalent in Hispanics.

As the disease continues to present questions, McClain and his team continue to seek answers.