New Study Reveals Tumors Grow Uniformly: Key Insights on Cancer Development and Treatment

Researchers from the University of Cologne and the Centre for Genomic Regulation in Barcelona found that cancer grows uniformly throughout its mass, not just at the edges. This study, published in the journal eLife, challenges long-held beliefs about tumor growth.

Dr. Donate Weghorn, a co-author, explained that tumors are not “two-speed” structures with rapid growth on the surface and slower growth in the core. Instead, all parts of the tumor are active, allowing for the possibility of aggressive mutations everywhere within it.

Prof. Johannes Berg noted that this uniform growth can lead to significant evolutionary changes in cancer. Frequent cell turnover means cancer cells have many chances to develop traits that can help them evade the immune system.

For decades, researchers thought tumor growth was faster at the edges. This theory suggested that surface cells had an advantage due to better access to nutrients and oxygen, while core cells faced more limitations. As tumors grow, the center gets farther from blood supply, leading to reduced resources and increased pressure on core cells.

Using a technique called spatial genomics, researchers studied the genetic information of cells at specific locations within liver tumors. They analyzed mutations from various samples to understand how cancer spreads. Unlike the surface growth model, in which mutations would point outward, the researchers discovered that mutations spread evenly throughout the tumor.

The study also showed that mutations were dispersed, indicating cellular division occurred across the tumor and not just at the edges. To confirm their findings, the team conducted computer simulations of tumors with both surface and volume growth. They found that real tumor mutation patterns matched those from volume growth models, but not surface growth models.

However, this study focused on liver cancer, so the results may not apply to all cancer types. It mainly offered insight into early tumor growth, which may not fully represent larger or metastatic cancers.

Dr. Berg emphasized the importance of understanding mutations that lead to therapy resistance. While this study focused on early-stage tumors, further research on later mutations could provide valuable insights into treatment challenges.

Reference: Angaji A, Owusu M, Velling C, Dick N, Weghorn D, Berg J. High-density sampling reveals volume growth in human tumours. eLife. 2024. doi: 10.7554/eLife.95338.2