Survival rates for cancer depend on where you live — at least partially.

Urban patients tend to do better than rural patients. Researchers have long tried to figure out how that divide happens in the first place.

And a new study out of the Pacific Northwest may hold some answers. It found that when patients are enrolled in a clinical trial, the rural-urban disparity disappears.

Joseph Unger with the Fred Hutchinson Cancer Research Center in Seattle thinks researchers may have been looking for answers in the wrong places.

Instead of looking at general cancer population data, he looked at clinical trials.

“And what we found was that cancer patients treated in rural areas, receiving the same treatment on clinical trials, had essentially the same outcomes as corresponding urban cancer patients,” he said.

Basically, when urban and rural patients got the same treatment, the disparity disappeared.

What that means, Unger said, is that health policy should focus on getting rural patients the same access to affordable health insurance, specialists and medical treatments as their urban counterparts.

Our findings suggest that the best means to improve these outcomes is simply to improve their access to the same kind of quality, guideline-based care that patients receive in clinical trials,” Unger said.

The study results are published in the Journal of American Medical Association Network Open. It’s the first study to comprehensively compare survival outcomes in rural and urban cancer patients enrolled in clinical trials.

The new analysis was conducted by the Southwest Oncology Group, a cancer clinical trials network funded by the National Cancer Institute based at the Knight Cancer Institute at Oregon Health & Science University.