A recent study shows just how fragile the relationship between reported news and truth can be. The recent drop in reported myeloid leukemias over the last decade may be just a classification error.
The number of blood cancers falling under the category of myeloid leukemias has been dropping since 2001.
But researchers found that a change in Medicare billing in that year might be responsible, rather than improved treatment or earlier detection.
A team from the Moffitt Cancer Center went looking for the answer, finding that in 2001 the guidelines had changed to avoid reporting multiple cases in the same patient, which is a common development in this type of cancer.
No reporting system is perfect, but since research funding is developed through the statistics reported to the federal government, it is important that the numbers are as accurate as possible.
Researchers were floored by how much that simple policy change had altered the numbers.
In some cases, up to half of patients weren’t reported as having the leukemia because they were already registered as with another type of cancer. The leukemia went completely unreported in the official government statistics.
The reporting was already complicated by the need to do a biopsy on the bone marrow where the cancerous cells are created, but the change in reporting made it even more difficult to report this type of cancer properly.
“The big surprise from our findings wasn’t that myeloid leukemias were missed; it was the magnitude of uncaptured cases,” said Christopher R. Cogle, MD, professor at the University of Florida.
“U.S. cancer registries have the difficult challenge of capturing blood cancers and solid tumors. Our results beg for more resources to be committed to them,” Dr. Cogle said. “Improved case capture will generate better data for policy makers, scientists, physicians and patients.”
The study authors disclosed no financial conflict of interest.
Research was published March 21, 2012 in the journal Cancer Epidemiology, Biomarkers and Prevention.
According to the Leukemia and Lymphoma Society, there are over 245,000 people in the United States living with some form of leukemia, and over 44,000 new cases will be diagnosed each year. Among children with cancer, one out of every three will have some form of leukemia. However, over 90% of all cases of leukemia occur in adults.
Leukemia broadly defines a number of different cancers that originate in the bone marrow and blood cell lines, and typically produces an abnormal increase in the number of white blood cells in the body. Leukemias are subdivided into whether they are acute (occur rapidly) or chronic (develop over many years) and then further subdivided into what type of blood cell they start from, lymphocytic (usually from white blood cells that fight infection, like B-cells) or myelogenous (arising from cells in the bone marrow that eventually produce red blood cells). These categories make up the four most common types of leukemia:
- Acute Lymphoblastic (ALL): Affects adults over age 65 (50% survival); also the most common form of leukemia in children (85% survival)
- Chronic Lymphocytic (CLL): Affects mostly men over age 55 (75% survival)
- Acute Myelogenous (AML): Affects mostly adult men (40% survival)
- Chronic Myelogenous (CML): Affects mainly adults (90% survival)