Uncovering the Roots of Recurring Cancer
The biggest fear of cancer survivors is that the cancer could recur later. In rare cases, it can return even when patients have been cured and free of it for years. But the good news is that scientists have presented genetic evidence that gives insight into why some cancers return. This might be helpful in preventing cancer from returning.
According to the evidence, cancer cells can go to sleep and avoid being affected by treatment. They could wake up years, or even decades later. Scientists at the Institute of Cancer Research in London explained that this research could mean finding ways of extinguishing those sleeping cancer cells.
The study examined blood and bone marrow samples from a patient who has had a rare type of leukemia extending over 20 years. The samples analyzed were taken when the patient was four years old and 25 years old. Cancer returned after 22 years in remission. It is known that rare forms of leukemia can return when it seems to be cured, but this study shows evidence that cancer cells can be dormant for years and escape treatment. Later on they can acquire new mutations that can cause the disease to recur.
Dr. Mel Greaves, the professor who led the study, noted that these cancer cells are behaving like blood stem cells that often fluctuate between dividing quickly and being dormant. He also said that this research is valuable because the growth of these precancerous cells could be accelerated in the future. The goal is to reduce the risk of recurrence by targeting these dormant cells and killing them.
Greaves and his team recognized DNA mutation of two genes (ABL1 and BRC) in the blood samples taken 22 years apart. This demonstrates a lineage between the original and the recurring cancer and implies that cancer cells escaped chemotherapy by going to sleep. Then they woke up after a long period of time.
This study suggests that dormant cells are responsible for relapses because they were dividing slower than other cells, avoiding treatment which targets rapidly growing cells only. Therefore, the study might give the researchers an understanding of how to root out the cancer cells. What they found out is that recurring cancer cells had similar features to a group of cancer precursor cells that preceded even the earliest bout of cancer. It was also found out that the recurring cancer cells had undergone many genetic changes.
Dr. Greaves believes that researchers are one step closer to reducing the risk of cancer relapse with these findings.
The research was first published in the journal Leukemia.