RRestricted blood flow, or ischemia, can accelerate bone marrow aging and weaken the immune system’s ability to fight cancer. In a recent study on mice with breast tumors, restricting blood flow to the legs caused tumors to grow twice as fast. This occurs because ischemia disrupts bone marrow function, shifting the production of immune cells toward types that suppress anti-tumor responses and away from lymphocytes, such as T cells, that are critical for attacking cancer.
Normally, bone marrow stem cells produce a balanced mix of white blood cells to fight infections and tumors. When blood flow is limited, more myeloid cells are generated, which dampen immune activity, while lymphocyte output declines. This imbalance mirrors age-related changes in immunity, explaining why impaired circulation anywhere in the body can promote cancer growth.
These findings reveal a systemic connection between vascular health and tumor progression, highlighting the importance of managing cardiovascular risk factors as part of comprehensive cancer care.