Researchers at the CU Anschutz Cancer Center announced on Mar. 25 that breast cancer cells spreading to the lungs may take advantage of the organ's natural healing response, and that a common medication could slow this process. The findings were published in Cancer Research Communications.
The discovery is significant because breast cancer becomes harder to treat once it spreads, especially when it reaches the lungs. About one third of people with metastatic breast cancer develop lung metastases, and current treatment options are limited.
The research team found that when breast cancer spreads to the lungs, it damages small air sacs essential for breathing. Normally, specialized alveolar type II lung cells help repair this damage. However, in the presence of cancer cells, these lung cells release signals that promote tumor growth instead of just repairing tissue. This leads to chronic inflammation and creates an environment where tumors can expand.
To address this problem, researchers tested Roflumilast—a drug approved for treating Chronic Obstructive Pulmonary Disease (COPD)—in mouse models with metastatic breast cancer. The drug slowed tumor cell growth and reduced tumor size in the lungs by preventing the local environment from supporting tumors rather than directly killing cancer cells.
"This suggests a new strategy for treating metastatic cancer," said Jennifer K. Richer, PhD, senior author of the study and professor of pathology at CU Anschutz Cancer Center. "In addition to targeting cancer cells themselves, we may also be able to target the environment that allows them to thrive." Researchers believe Roflumilast's existing approval could speed up studies into its use against metastatic cancers.
Future research will explore how Roflumilast might work alongside chemotherapy or immunotherapy and whether inhaled versions could deliver treatment directly into patients' lungs. "We are very excited to translate these findings to the clinic and evaluate roflumilast as a treatment for patients with triple-negative breast cancer to prevent recurrence in the lungs," said Jennifer R. Diamond, MD, professor of medical oncology and medical director of CU Anschutz Cancer Center's Cancer Clinical Trials Office.
