Although there are presently few such medications approved, this approach might be a novel technique to treat additional cancer patients who have cancers that are difficult to reach or inoperable.
The research looked at a new type of treatment known as radiopharmaceuticals, which are medications that deliver radiation directly to cancer cells. In this scenario, the medication is a molecule with two components: a tracker and a cancer-killing payload.
Hundreds of billions of these molecules scavenge cancer cells, latching on to protein receptors on cell membranes.
Radiation is emitted by the payload, which is absorbed by tumor cells within its range.
Dr. Frank Lin, who was not involved in the trial but runs a branch at the National Cancer Institute that assists in the development of such therapy, agreed. “You can treat tumors that you cannot see. Anywhere the drug can go, the drug can reach tumor cells.”
When prostate cancer is contained, radiation can be beamed into the body or injected in pellets. However, in advanced prostate cancer, these techniques are ineffective. Prostate cancer that has progressed and is no longer responding to hormone-blocking therapy affects around 43,000 men in the United States each year.
The study looked at a novel approach to provide radiation therapy to these individuals. There were 831 men with advanced prostate cancer who took part in the study. The radiation medication was administered to two-thirds of the participants, while the rest acted as a control group. The medicine was given to patients by IV every six weeks, up to six times.
Those who received the medicine fared better, on average, after two years. The malignancy was kept at bay for nearly nine months, compared to three months for the others. Survival was also improved, with an average of 15 months compared to 11 months. Although the benefit may not appear to be significant, ASCO president Dr. Lori Pierce, a cancer radiation expert at the University of Minnesota, explained that “these patients don’t have many options.”
Such medications “will be a major thrust of cancer research” in the future, said Dr. Charles Kunos, who worked on radiopharmaceutical research guidelines at the National Cancer Institute before joining the University of Kentucky’s Markey Cancer Center. “It will be the next big wave of therapeutic development.”
Dr. Mary-Ellen Taplin of Dana-Farber Cancer Institute in Boston, who enrolled patients in the research and evaluated the data, said, “there’s great potential” with the medications being investigated for melanoma, breast, pancreatic, and other cancers.
According to research leader Dr. Michael Morris of Memorial Sloan Kettering Cancer Center in New York, “it opens up a range of future strategies” for prostate cancer, including at earlier stages of the illness and in combination with other therapies.