Targeting metastatic tumors may improve survival
By Lindy Brounley
Cancer that has spread from the site of an original tumor to other places in the body is often viewed as a death sentence. But if there are just a few of those secondary tumors, called metastases, some patients have a good chance of survival if treated with a type of radiation that precisely targets small tumors, researchers at UF and the University of Rochester report in the International Journal of Radiation Oncology, Biology, Physics.
“The dogma is that this type of disease is incurable and that if there’s a metastatic tumor in one organ, then others must be present throughout the body,” said investigator Paul Okunieff, M.D., director of the UF Shands Cancer Center and chair of the UF College of Medicine’s department of radiation oncology. “It’s considered an all-or-none phenomenon, but the fact is this view is probably not correct. We need to think about metastasis like we think about the primary tumor: determine how much it has spread, then decide whether it’s treatable based on existing technology.”
Nearly 1.6 million Americans were diagnosed with cancer last year, and nearly 600,000 died from the disease, according to the National Cancer Institute. Experts estimate that up to 90 percent of those deaths were from metastases.
The researchers studied 121 patients who had five or fewer tumors that spread from areas such as the breast, colon or lung, to up to three additional organs. Tumors were treated with a one- to two-week radiation course strong enough to kill them and prevent their recurrence while sparing healthy tissue. In about 20 percent of the patients, who were enrolled from 2001 to 2006, long-term follow up revealed that the treated tumors did not return, nor did new ones pop up elsewhere. Very few regrowths occurred among patients who made it to three years.
Breast cancer patients fared even better, with one-third of patients being free of tumor regrowth after three years. Six years after treatment, almost half of breast cancer patients in the study were still alive — five times the survival rate for people with other forms of metastatic cancer.