Chemo Patients Can Cause Relapse

Chemotherapy drugs, is the first line of defense to adult leukemia. But chemotherapy can make the illness of patients suspected of recurrence within 5 years but if not chemotherapy patients of acute myeloid leukemia (AML) can die within a few months.

The study was conducted by researchers from Washington University School of Medicine in St.. Louis. The researchers took samples from eight patients diagnosed with acute myeloid leukemia (AML). Patients with AML who are not receiving chemotherapy typically die within several months.

But of patients receiving chemotherapy treatment and following treatment, approximately 80 percent relapsed and died within 5 years thereafter.

The goal of this research is to try to understand the causes of relapse of AML.

The research team has conducted genome sequencing, ie build a complete DNA sequence of a person's genome. Genome sequencing performed on three different patients, the normal healthy genome, the genome after the patient was diagnosed with leukemia, and the genome after patients received the chemotherapy drug, and eventually relapse.

The researchers conducted genome sequencing of cancer cells each almost 600 times. The researchers were eventually able to create a timeline of how cells mutate during diagnosis.

Tumors that same always come back. Every time the tumor comes back, usually have a couple of new mutations but not in large numbers. A small tumor may come back and become resistant to treatment.

In order to combat AML, chemotherapy drugs cause DNA damage in both cancer cells and healthy. The researchers found that, of the new mutations that arise with the return of the damage, many of which contained tumor DNA.

These changes, known as transversions, is much higher in patients who relapsed compared with the original tumor. Patients received chemotherapy drugs to combat cancer are very likely to cause relapse. Other findings from the main team is that there are differences in the pattern of evolution of cancer cells associated with relapse of AML.

Some tumors are really only has one large population of tumor cells. Others have a single large and small from subclones. Some of the subclones eliminated by therapy but occasionally a very small one would be one that will recur on and off .

Chemotherapeutic drugs are not able to kill the clones that make up the founders of the original tumor and all patients will relapse. While the results of their research is surprising, they did not want to stop looking for the treatment of chemotherapy patients.

Without the initial chemotherapy, all patients will die within a few months. So the therapy used, so far is still quite helpful even have a problem. But the need to fix it because these therapies contribute to relapse.