For decades researchers in the lab have studied cancer cells in flat, shallow Petri dishes. As a result, assumptions about how cancer behaves in the body have been based on two-dimensional models. Now, new research is turning long-held beliefs about cancer upside down. Johns Hopkins researchers have discovered that cancer actually moves quite differently in the three-dimensional human body than it does in the lab.

How Cancer Spreads in 3D vs. 2D Models

In two-dimensions cancer cells move in a slow, aimless fashion called a “random walk.” Until now researchers had assumed that cancer cells moved in the same random way in the three-dimensional human body, making it virtually impossible to determine where cancer might land when it metastasizes.

The new findings indicate that cancer cells are more directional than random when moving through three-dimensional spaces like the human body. New 3D modeling may allow cancer experts to predict the most likely path of metastasis should cancer spread.

How Cancer Cells Move Explained

“Cancer cells that break away from a primary tumor will seek out blood vessels and lymph nodes to escape and metastasize to distant organs,” Denis Wirtz, director of Johns Hopkins Physical Sciences Oncology Center, explained on HUB. “For a long time, researchers have believed that these cells make their way to these blood vessels through random walks. In this study, we found out that they do not. Instead, we saw that these cells will follow more direct, almost straight-line trajectories. This gives them a more efficient way to reach blood vessels—and a more effective way to spread cancer. This means that the time these cancer cells need to make their way out of connective tissues is much shorter than previous estimates.”

The new 3D model may lead to more effective advanced targeted immune therapies and cancer vaccines designed to protect against metastasis.