Blood cancer is not just one disease. It is a group of cancers that affect the blood, bone marrow, and lymphatic system. These include leukemia, lymphoma, and several related conditions.
In most cases, blood cancer begins with mistakes in DNA. These mistakes, also called mutations, slowly build up over time as people age. The more mutations a person has, the higher their risk of developing cancer. This is a normal part of aging, and it happens to everyone.
However, doctors have long noticed something puzzling. Some people carry cancer-related mutations in their blood cells but never develop blood cancer. Even as they grow older, their bodies seem to resist the disease. Until recently, scientists did not understand why this happens.
A new study published in the journal Science has now provided an important answer. Researchers have discovered a rare genetic change that can protect people from developing several types of blood cancer. This genetic variant works by slowing down a process that often happens before blood cancer begins.
That process is called clonal hematopoiesis. Clonal hematopoiesis starts in blood-forming stem cells, which live in the bone marrow. These stem cells are special because they can turn into all types of blood cells, including red blood cells, white blood cells, and platelets.
Sometimes, one of these stem cells gains a DNA mutation that gives it a growth advantage. When that happens, the mutated cell begins to multiply faster than normal cells and creates a large group of identical cells carrying the same mutation.
On its own, clonal hematopoiesis does not cause cancer. Many people have it without knowing. But it increases the risk that additional mutations will appear later, which can eventually lead to leukemia or other blood cancers. Clonal hematopoiesis is also linked to heart disease and other age-related conditions.
In this new study, researchers wanted to know why clonal hematopoiesis grows quickly in some people but stays slow and harmless in others. To find the answer, they studied genetic data from more than 640,000 people. This included about 43,000 individuals who had clonal hematopoiesis and around 600,000 who did not.
By comparing these large groups, the scientists found a rare genetic variant that clearly reduced the risk of clonal hematopoiesis. This variant is known as rs17834140-T and is located on chromosome 17. It does not change a gene directly. Instead, it controls how strongly a nearby gene is turned on or off.
To understand how this variant works, the researchers ran detailed lab experiments. They added the protective variant into human blood stem cells and then observed how these cells behaved when grown in mice. The results were striking.
The protective variant lowered the activity of a protein called MSI2. This protein normally acts like a growth accelerator for stem cells. In many blood cancers, high levels of MSI2 help mutated cells grow fast, crowd out healthy cells, and take over the bone marrow. This rapid growth increases the chance that cancer will develop.
When MSI2 levels were lower, the mutated stem cells grew much more slowly. They were no longer able to dominate the bone marrow.
This reduced the chance that clonal hematopoiesis would expand and turn into leukemia. According to the study, people who carry this genetic variant have up to a 30 percent lower risk of developing clonal hematopoiesis.
This discovery is important because it shows that the human body already has natural ways to resist cancer. Instead of waiting for cancer to form and then trying to destroy it, scientists may be able to prevent cancer much earlier by copying these natural defense systems.
The researchers believe that future treatments could be designed to lower MSI2 activity in people who are at high risk of blood cancer. This might be done using new medicines or advanced genetic tools. By slowing down dangerous stem cells before cancer appears, doctors could stop the disease before it starts.
This study also sends a hopeful message. Cancer risk is not determined only by bad luck or aging. Some people inherit protective traits that make them more resilient. By studying these traits, scientists can learn how to build better prevention strategies for everyone.
Review and analysis of the findings show that this research shifts the focus of cancer science. Instead of only targeting tumors after they appear, it highlights the power of prevention at the earliest stages.
The study proves that inherited genetic differences can slow or block cancer-related processes long before disease develops. While more research is needed before new treatments reach patients, this work opens the door to a future where blood cancer may be prevented rather than treated.
If you care about cancer, please read studies that artificial sweeteners are linked to higher cancer risk, and how drinking milk affects risks of heart disease and cancer.
For more health information, please see recent studies about the best time to take vitamins to prevent heart disease, and results showing vitamin D supplements strongly reduces cancer death.
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