When Blocked Arteries Feed Cancer

In a major breakthrough, scientists have discovered that restricted blood flow, a common problem in diseases like peripheral artery disease (PAD), can speed up cancer growth by aging the immune system before its time. The research, published on August 19, 2025, in JACC: CardioOncology, connects two health concerns cardiovascular disease and cancer in ways that could change how patients with both conditions are treated.

The work was led by researchers at NYU Grossman School of Medicine, including Dr. Kathryn J. Moore and Dr. Alexandra A. Newman. To explore the effects of blocked blood flow, they used a mouse model of PAD. Female mice were implanted with breast cancer cells and then underwent surgery that restricted blood supply to the hind limb, mimicking PAD. A control group had normal blood flow. Over time, tumors in the mice with restricted blood flow grew more than twice as fast as those in the control group. This showed a clear connection between ischemia (lack of blood flow) and rapid cancer progression.

How Blood Flow Affects the Immune System

The explanation lies in how ischemia disrupts the immune system. Normally, bone marrow stem cells create a balanced mix of immune cells, including T cells that help the body fight off cancer. But when blood flow is blocked, stem cells shift production toward inflammatory cells such as monocytes and neutrophils while reducing T cells.

This imbalance creates what researchers call “inflammaging” a state where the immune system looks and behaves older than it really is. In tumors, this aging immune system allows cancer cells to escape detection. Instead of fighting tumors, the immune environment becomes dominated by suppressive cells, like regulatory T cells, which protect the cancer rather than attack it.

The Molecular Evidence

To dig deeper, the team used advanced tools like single-cell RNA sequencing. They found that ischemia activated genes linked to inflammation and aging, including NLRP3, neogenin-1, and thrombospondin-1. Even more striking, when bone marrow from ischemic mice was transplanted into healthy mice, the cancer-promoting effects carried over. This showed that the changes in the immune system were long-lasting and not just temporary side effects of reduced blood flow.

Dr. Moore explained, “Impaired blood flow drives cancer growth no matter where it happens in the body. This makes it clear that vascular health plays a direct role in how cancers progress.” Dr. Newman added that their findings reveal a mechanism where ischemia reprograms stem cells in ways that mimic aging and create an environment that tolerates cancer.

Building on Past Findings

This discovery builds on earlier work by the same group. In 2020, they showed that heart attack-induced ischemia could accelerate cancer in a similar way. Epidemiological studies have also linked PAD, which affects over 200 million people worldwide, with a significantly higher risk of cancers, including lung, bladder, and colon cancer.

Traditionally, cardio-oncology has focused on how cancer treatments damage the heart. But this study highlights the reverse: how heart and vascular diseases themselves can worsen cancer.

What This Means for Patients

For patients, the findings carry important implications. People with PAD may need earlier or more frequent cancer screenings. Doctors could also consider therapies that target inflammaging, such as anti-inflammatory medications, or encourage lifestyle changes that improve vascular health, like exercise and diet improvements. Looking ahead, clinical studies in human patients will be essential to confirm these findings. If validated, treatments could be tailored to manage both cardiovascular and cancer risks together, leading to more personalized and effective care.

At its core, the study paints a picture of a vicious cycle. Poor blood flow doesn’t just limit oxygen supply to tissues; it also weakens the immune system in ways that allow cancer to flourish. Breaking that cycle by paying attention to vascular health could slow tumor growth and improve survival. For millions living with PAD and other circulation problems, this research offers hope that combining heart care with cancer care may one day lead to better outcomes and perhaps even new ways to stop cancer before it gains the upper hand.