Over 20 years ago, a small group of women with advanced breast cancer took part in a clinical trial. They were given an experimental cancer vaccine.
Today, every one of those women is still alive. This is extremely rare for people with metastatic breast cancer, where the cancer has spread to other parts of the body.
Most patients with this stage of cancer do not survive very long. That’s why this group of long-term survivors caught the attention of scientists at Duke University.
The research team, led by Dr. Herbert Kim Lyerly, began studying the women’s immune systems. What they found was truly surprising.
Even after two decades, the women still had powerful immune cells that could recognize their cancer. These special immune cells carried a marker called CD27, which helps the body remember and fight off harmful invaders, including cancer cells.
The results of this study were published in the journal Science Immunology. The researchers believe that targeting CD27 could be the key to making cancer vaccines much more effective in the future.
Dr. Zachary Hartman, a senior scientist involved in the study, said they were shocked to see such strong immune responses lasting so many years. It made them wonder if there was a way to make this kind of response even stronger.
To explore this, the scientists ran tests in mice. They used a vaccine that targeted a protein called HER2, which is found on some breast cancer cells. They gave the mice the vaccine along with a CD27-targeting antibody.
The results were amazing. About 40% of the mice had their tumors disappear completely. In comparison, only 6% of the mice who got the vaccine alone had that result.
The antibody worked by boosting a type of immune cell called CD4+ T cells. These cells are usually known as “helper” cells because they support other immune cells.
However, this study showed that CD4+ cells can play a much bigger role than we thought. In this case, they helped create a long-lasting memory in the immune system and gave other immune cells the boost they needed to fight cancer better.
Later, the team added another antibody to the treatment that helped another kind of immune cell, CD8+ T cells, which are usually the “attack” cells. With this triple approach, tumor rejection in the mice improved to nearly 90%.
What makes this even more exciting is that the CD27 antibody only had to be given once, at the same time as the vaccine. This means the treatment could be easier to use with other existing cancer therapies, like immune checkpoint inhibitors or antibody-drug combinations that are already used in hospitals.
This new discovery could change the way we think about cancer vaccines. For years, scientists have believed that cancer vaccines have great potential, but real-world results have been limited. Now, this study shows that boosting the right immune cells at the right time might finally make these vaccines work the way we hoped.
By focusing on both CD4+ and CD8+ cells, and by using smart combinations of treatments, scientists believe we’re closer than ever to making long-lasting, powerful cancer vaccines a reality. The survival of the women in the original trial is not just a medical mystery—it may be a sign of what’s possible in the future of cancer care.
If you care about cancer, please see recent studies about new way to increase the longevity of cancer survivors, and results showing new way to supercharge cancer-fighting T cells.
For more information about health, please see recent studies about how drinking milk affects risks of heart disease and cancer and results showing that vitamin D supplements could strongly reduce cancer death.
The study is published in Science Immunology.
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