Cancer patients who receive a combination of low-dose interleukin-2 and retinoic acid after conventional therapy seem to live longer than those who don't get the combination.
Retinoic acid is derived from vitamin A. Interleukin-2, a compound that fortifies the immune system, is approved at high doses to treat "metastatic" melanoma and kidney cancer. Metastatic means that a cancer has spread.
The study showed that "these biological compounds may work at low doses. Bigger doses are not always better," said lead author Dr. Francesco Recchia, director of the oncology department at Civilian Hospital in Avezzano, Italy.
Recchia stumbled upon the possibility of using low-dose interleukin-2 (IL-2) when he switched a patient with metastatic melanoma who didn't tolerate high doses to a lower dose, and the patient had an extended response to the therapy.
This study involved 500 patients who had already responded well to chemotherapy. They had a variety of cancers, including ovarian, lung, colon, stomach, kidney, melanoma, breast and pancreatic.