Targeted Chemotherapy Shows Early Signs of Slowing Tumor Growth With Less Toxicity
CHICAGO, IL—Surviving neuroblastoma as a child can come with just as many challenges as the cancer itself, mainly because of the toxic effects of chemotherapy. But a team of surgeons is in the nascent stages of developing a more targeted method for delivering chemotherapy, with lower toxicity. Their research results were presented at the American College of Surgeons Clinical Congress 2015.
Neuroblastoma is a rare childhood cancer, with only approximately 700 new cases each year, mostly affecting children age 1 to 2 years old, reports the American Cancer Society. The cancer normally presents as a tumor in the adrenal glands.
Normally, treatment of high-risk patients involves a surgical procedure to biopsy the tumor, followed by several rounds of chemotherapy to shrink the tumor, then another surgery to resect the rest of the tumor, explained Bill Chiu, MD, FACS, assistant professor of surgery at the University of Illinois in Chicago. The more cancerous tissue the surgeon can resect, the higher that patient's chance of survival and the lower the patient's risk for recurrence.
The good news is that current treatment protocol has achieved high 5-year survival rates. More than 90% of those young children with neuroblastoma in the lower- or intermediate-risk groups get to celebrate their sixth or seventh birthday, reports the American Cancer Society.
The bad news is the adverse effect of the chemotherapy. "Chemotherapy is usually given intravenously through a central line. It goes through the body and every cell in the body will experience the chemo," explained Chiu. "Chemotherapy is basically poison. You're hoping that the poison will kill the tumor before it kills the host."
Some of the more serious late effects of chemotherapy for children include cardiomyopathy, neuropathy, infertility, growth problems, learning difficulties, or even secondary cancers, according to the American Society for Clinical Oncology.
Chiu and his team have begun developing a more targeted method to deliver the chemotherapy.
"The ultimate goal is to create an alternative way to deliver chemotherapy to people with neuroblastoma so we can increase the dosage of chemotherapy but, at the same time, decrease the systemic toxicity," he said.
The targeted method involves implanting a device directly into the center of the tumor. The device contains a chemotherapy-loaded silk sponge. The chemotherapy agent binds to the silk fabric, allowing Chiu and his team to tune the agent's release. The amount of silk used determines how much of the drug is released.
"Silk has been used in humans for a long time. Certain sutures are made from silk," Chiu said. "There's very little inflammatory reaction with silk."
The research team examined this approach in a mouse model with simulated neuroblastoma tumor growth in the mice's adrenal glands and found promising results.
"The way we deliver chemotherapy hasn't changed much in the last 50 years. The cycles may change. The dose may vary, but we're always giving it intravenously," Chiu explained. "But a complementary way to give it in a targeted way, such as going directly to the tumor and giving a lot of it, can decrease the systemic toxicity and hopefully prevent secondary malignancies."