Breast Tumor Stiffness Influences Immune Response and Treatment Effectiveness

Recent research from the University of Helsinki has shed light on how the physical properties of breast cancer tissues, particularly their stiffness or softness, can significantly impact the immune system's ability to detect and combat tumors. While immunotherapy remains a groundbreaking advancement in cancer treatment, it does not work equally for all patients. The new findings suggest that the mechanical microenvironment of the tumor plays a crucial role in this variability.

The study found that in softer tumor tissues, cancer cells are more capable of evading immune detection, potentially accelerating disease progression. These insights are based on analyses of live breast cancer tissue samples directly obtained from patients, offering a more accurate understanding than traditional cell culture or animal models. A soft microenvironment appears to enable cancer cells to hide from immune cells like tumor-infiltrating lymphocytes (TILs), which hampers the immune response.

Key to this discovery is the observation that tissue stiffness influences chemical signaling pathways, such as COX-FGF2, which promote an immunosuppressive environment. This highlights the significance of the tumor's mechanical properties as part of the broader tumor microenvironment, affecting how the disease progresses and responds to treatment.

These findings could be instrumental in refining treatment strategies. By assessing tissue stiffness, medical professionals may better predict which patients will benefit from immunotherapy and who might require alternative treatments. This approach aligns with the goals of precision medicine, aiming for more personalized and effective cancer care.

The research was made possible through a close collaboration between the University of Helsinki, Helsinki University Hospital, and Kymenlaakso Health and Social Services, leveraging the rare opportunity to study freshly obtained patient tissue samples. This methodology provides a unique and realistic view of tumor behavior, which could lead to improved therapeutic outcomes.

As Professor Juha Klefström emphasizes, the Finnish research environment offers distinctive advantages in this field. The contribution of patients donating surplus tissue is vital for this progress, underpinning future improvements in breast cancer treatment.