Targeted Chemotherapy Slow Tumor Growth With Less Toxicity

Targeted Chemotherapy Slow Tumor Growth With Less Toxicity
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 of treating neuroblastoma patients with chemotherapy and lower toxicity. Their research results were presented at the 2015 Clinical Congress of the American College of Surgeons.
Neuroblastoma is a rare childhood cancer, mostly affecting children who are one to two years old. 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 operation to resect the rest of the tumor. The more cancerous tissue the surgeon can resect, the higher that patient's chance of survival and the lower the patient's chance of recurrence.
The good news is that current treatment protocol has achieved high five-year survival rates. More than 90 percent of those young children with neuroblastoma in the lower risk or intermediate risk groups get to celebrate their 6th or 7th birthday.
The bad news is the adverse effect of the chemotherapy. Some of the more serious late effects of chemotherapy for children include cardiomyopathy, neuropathy, infertility, growth problems, learning difficulties, or even secondary cancers.
The research team developed a more targeted method to deliver the chemotherapy, with a goal to increase the dosage and decrease the systemic toxicity. The targeted method involves implanting a device directly into the center of the tumor. The device contains a chemotherapy-loaded silk sponge. The silk fabric binds to the chemo-therapy agent, allowing the researchers to tune the agent's release. The amount of silk used determines how much of the drug is released.
In a mouse model, the researchers simulated neuroblastoma tumor growth in the mice's adrenal glands. They then looked at how the tumors responded to two chemotherapy agents, vincristine and doxorubicin.
They compared delivery methods for the same dosages of each agent. One set of mice received vincristine delivered intravenously, while another set received it through the sustained release of the silk sponge implanted into the center of the tumor. With the sustained release, half of the chemotherapy agents were released immediately, while the remainder was released over the following 20 days. Then, they measured tumor growth using ultrasound.
Though the targeted delivery of doxorubicin was not more effective than intravenous delivery, results showed that sustained release of vincristine on the silk sponge device slowed the rate of the tumor's growth more effectively than delivering it intravenously. Tumors usually reach 1000mm3 in about 10 days. With the sustained release of vincristine it took 30 days for the tumor to reach the same size.
The next steps include more preclinical research to refine the delivery method, dosage, and chemotherapy drug combinations. Ultimately, the researchers seek to add another effective option to help patients beat neuroblastoma.
Based on material originally posted by American College of Surgeons.