Research Reveals Clues to Breast Cancer's Spread

MONDAY, July 6 (HealthDay News) -- A U.S. research team says it has spotted key signals that help breast cancer cells survive in the bone marrow of patients who've undergone treatment.

The finding, reported in the July issue of the journal Cancer Cell, could lead to new treatments to prevent breast cancer's return, according to the researchers.

"We sought to identify signaling pathways that support the survival of metastasized breast cancer cells and thereby extend the period during which metastasis may emerge after the diagnosis and removal of a breast tumor," senior study author Dr. Joan Massague, of the cancer biology and genetics programs at Memorial Sloan-Kettering Cancer Center and the Howard Hughes Medical Institute, explained in a journal news release.

The researchers analyzed samples from more than 600 breast tumors and found that a cancer-related enzyme called Src was associated with late-onset bone metastasis. This link was independent of breast cancer subtype and was selective and specific for breast cancer cell survival in bone marrow.

Massague and colleagues then identified Src-regulated signaling molecules that were expressed in bone marrow and promoted survival of breast cancer cells. They also found that Src increased resistance to a key cell death-inducing signal.

The findings provides insights into breast cancer's spread, "and suggests strategies to hasten the attrition of disseminated breast cancer cells," the researchers concluded. They also noted that drugs designed to inhibit Src have recently been developed "that may be worthy of consideration" to help fight tumor recurrence.