How does cancer spread? Findings of a new study show that cancer cells force healthy tissues to help spread and boost the growth of the disease.

In the study published in the journal Cell on April 14, researchers studied the communication networks of cells from a deadly form of pancreatic cancer known as ductal adenocarcinoma.

They found that cancer cells alter a gene to persuade healthy cells to release unique growth signals that tumors cannot produce by themselves but which they use in order to multiply.

The normal version of the KRAS gene occasionally produces signals telling a cell to divide but once this gene is altered, which often happens in cancer, it becomes hyperactive and contributes to the fast and uncontrolled growth of cancer cells.

KRAS is altered in more than 90 percent of pancreatic cancer and about 20 percent of all cancers.

Mutant KRAS genes can also turn healthy stromal cells, the connective tissue cells of the organs, into allies of cancer.

"Oncogenic mutations regulate signaling within both tumor cells and adjacent stromal cells," the researchers wrote. "Here, we show that oncogenic KRAS (KRASG12D) also regulates tumor cell signaling via stromal cells."

In response to the action of the altered KRAS genes, healthy cells double the capacity of the KRAS to trigger malignant behavior in cancer-infected cells.

"Cancer cells do not drive the growth and spread of tumours alone - they can bully their healthy neighbours into helping them," said study researcher Chris Tape, from The Institute of Cancer Research in London.

According to the researchers, their study has unveiled new therapeutic possibilities. Identifying the role played by the most commonly altered gene in its communication with healthy cells and blocking its effects can lead to an effective cancer treatment.

Figures from the Centers for Disease Control and Prevention (CDC) show that cancer kills more than half a million Americans per year. Cancer follows heart disease as the top leading cause of death in the U.S. with one in every four deaths in the country attributed to the disease.

A breakthrough treatment based on studies of cancer cells may boost survival odds of patients and even possibly reduce deaths linked to this fatal disease.