This process—called metastasis—causes about 90% of all cancer deaths.
The Otago findings, published in the international journal Oncotarget, may pave the way for new therapies to prevent melanoma and other cancers from spreading deadly secondary tumours.
Melanoma kills more than 300 New Zealanders each year and this country has one of the highest melanoma rates in the world.
Pathology department postdoctoral fellow Dr Aniruddha Chatterjee and Prof Mike Eccles, also of the department, led the research team and are lead authors in the study.
The causes of the spread of cancer within the body had once been unknown.
However, the Otago research was helping clarify some of the drivers of cancer spread and this work could also help counter this country’s "major problem" with melanoma, Dr Chatterjee said.
The study investigated epigenetic changes in melanoma cells.
Epigenetics includes non-genetic influences on gene expression.
After comparing primary and metastatic melanoma cells from the same patients, researchers identified thousands of epigenetic changes and several that were common in all the metastatic cells.
These might be "the key drivers that allow melanoma to metastasise", the researchers said.
And the team identified a new function in melanoma of a gene called Early B Cell Factor 3 (EBF3).
When the researchers used techniques that decreased EBF3 expression, both primary and metastatic melanoma cells grew less aggressively and were less invasive.
Dr Chatterjee said that if the key changes underpinning metastasis were understood, their presence could be potentially monitored.
And new therapies could be developed to "target" them and prevent tumours spreading, he said.