Scientists have developed a new locally applied treatment for retinoblastoma, a childhood cancer of the eye arising from immature retinal cells in one or both eyes and can developed from anytime between gestation until up to 5 years of age. This relatively uncommon condition affects about 1 out of every 15,000 live births, or about 250-300 children in the US each year.

Based on the theory that a molecule called MDMX prevents apoptosis or programmed cell death in retinoblastoma cancer, scientists used a combination of nutlin-3, which blocks MDMX and topotecan, another retinoblastoma drug candidate. Local delivery of the two-drug combo was found to be effective, reducing tumor size significantly more than the most effective known combination of standard chemotherapy drugs.

"Our finding with locally applied nutlin-3 also has major implications for certain forms of adult cancers, since some forms of breast, lung, prostate and colon cancer are caused by abnormally large quantities of MDMX," Dyer explained. "So knocking out MDMX in those cancers might also dramatically reduce tumor size."

This alternate method of delivery circumvents the side effects associated with conventional treatment, i.e. chemotherapy. According to researchers, this is the first example of local delivery of a targeted chemotherapy drug for any childhood cancer.

Read more from St. Jude Children's Research Hospital.

[Photo: St Jude]