The history of leukemia runs from a handful of puzzling autopsies in the 1840s, when doctors noticed blood that looked more white than red, to today’s targeted drugs and engineered immune cells. In under two centuries, leukemia went from a mysterious, uniformly fatal “white blood” disease to a group of cancers that are often controllable and, in many children, curable. This comprehensive look into the history of leukemia follows the key discoveries and explains why each one still shapes how we diagnose and treat patients today.
Leukemia is one of the hematologic malignancies, meaning a cancer of the blood-forming system. It begins in the bone marrow, spills into the blood, and crowds out normal blood cells. Knowing how we learned this helps make sense of the tests and treatments patients meet today.
What Leukemia Is: A Quick Refresher
Leukemia is a group of cancers in which blood-forming cells in the marrow grow out of control. Most types involve an abnormal increase of white blood cells (leukocytes), and these cells do not work properly. As they multiply, they crowd out the healthy cells that carry oxygen, fight infection, and stop bleeding, which disrupts normal blood cell function.
Doctors sort leukemia along two axes. Acute leukemias progress quickly and involve immature cells called blasts, while chronic leukemias progress more slowly and involve more mature-looking cells. The cell family matters too: lymphoid or myeloid. That gives the four main subtypes: acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), and chronic myeloid leukemia (CML). For a broader map of the disease, see our leukemia guide.
The 1800s: Naming a New Disease
Physicians in the early 1800s occasionally described patients with huge spleens and strange, pale, pus-like blood at autopsy. At the time, most assumed this was a severe infection. The turning point came in 1845, when two doctors independently reported similar cases: John Hughes Bennett in Edinburgh and Rudolf Virchow in Berlin.
Bennett called the condition “leucocythemia.” Virchow argued that no infection was present and that the problem lay in the blood cells themselves. In 1847 he coined the term Leukämie, from the Greek for “white blood,” and the name stuck. Virchow also separated a form linked to an enlarged spleen from one linked to swollen lymph nodes, an early glimpse of the myeloid versus lymphoid split we still use.
In the 1870s, Ernst Neumann showed that blood cells are made in the bone marrow and proposed that leukemia starts there. Around the same time, Paul Ehrlich developed staining methods that let microscopists tell different white blood cells apart. Those stains made it possible to classify leukemia by cell type for the first time.
Timeline of Key Milestones
The table below summarizes the landmark moments most historians of hematology agree on.
| Era | Milestone | Why it mattered |
|---|---|---|
| 1845–1847 | Bennett and Virchow describe leukemia; Virchow names it | Recognized as a disease of blood cells, not infection |
| 1870s–1880s | Neumann links it to marrow; Ehrlich’s blood stains | Allowed classification by cell type |
| Late 1940s | Sidney Farber uses antifolate drugs in childhood ALL | First temporary remissions from chemotherapy |
| 1960 | Nowell and Hungerford find the Philadelphia chromosome | First chromosome change tied to a specific cancer |
| 1973 | Janet Rowley shows it is a 9;22 translocation | Opened the path to the BCR-ABL gene |
| 1960s–1970s | Combination chemotherapy and CNS-directed therapy for ALL | Childhood ALL becomes curable for many |
| 1970s onward | E. Donnall Thomas develops bone marrow transplantation | Curative option for high-risk disease |
| 2001 | Imatinib approved for CML | Model for targeted cancer therapy |
| 2017 | First CAR-T therapy approved for ALL | Engineered immune cells as treatment |
The 20th Century: Chemotherapy and Transplant
For a century after it was named, leukemia had no effective treatment. Arsenic and radiation were tried with little lasting benefit. In the late 1940s, pathologist Sidney Farber in Boston gave children with ALL aminopterin, a drug that blocks folic acid. Some children went into remission for the first time, even though the disease came back.
That result launched modern chemotherapy. Researchers learned that using several drugs together, in carefully timed phases, worked far better than any single drug. They also found that leukemia cells could hide in the brain and spinal fluid, so treatment directed at the central nervous system was added. Step by step, childhood ALL moved from a fatal illness to one that most children survive.
At the same time, E. Donnall Thomas and colleagues developed bone marrow transplantation, which replaces a diseased marrow with healthy donor stem cells. His work earned a Nobel Prize in 1990, and allogeneic stem cell transplant remains a curative option for many high-risk or relapsed leukemias.
The Molecular Era: From Chromosomes to Targeted Drugs
In 1960, Peter Nowell and David Hungerford in Philadelphia noticed an unusually small chromosome in cells from patients with CML. This Philadelphia chromosome was the first genetic change consistently linked to a cancer. In 1973, Janet Rowley showed it results from a swap of material between chromosomes 9 and 22.
Later work revealed that the swap fuses two genes, creating BCR-ABL, which makes an always-on enzyme called a tyrosine kinase. That enzyme drives CML. Drug developers designed imatinib to block it, and its approval in 2001 turned CML from a disease that usually progressed into one many patients now manage with daily tablets.
Other molecular discoveries followed. All-trans retinoic acid (ATRA), and later arsenic trioxide, transformed acute promyelocytic leukemia, a subtype of AML. Classification systems also evolved, from the French-American-British (FAB) system based on how cells look to the World Health Organization system that includes genetic findings.
How History Shapes Diagnosis and Treatment Today
Every step of modern diagnosis of leukemia echoes this history. It starts with a blood count and a stained blood smear, the direct descendant of Ehrlich’s work. A bone marrow biopsy then confirms the diagnosis, reflecting Neumann’s insight that the disease begins in the marrow. You can read more about each of these in our guide to leukemia diagnosis tests.
Today’s work-up also includes flow cytometry to identify cell markers, cytogenetics to look for changes like the Philadelphia chromosome, and molecular testing for specific gene mutations. These results decide the subtype, the risk group, and the treatment plan.
Modern leukemia treatment blends all eras: combination chemotherapy, targeted drugs such as tyrosine kinase inhibitors, stem cell transplant, and newer immunotherapies. CAR-T therapy, approved in 2017, reprograms a patient’s own T cells to attack leukemia cells and is used mainly for relapsed or hard-to-treat B-cell ALL.
Key Takeaways
- Leukemia was first described in 1845 and named by Virchow in 1847, from the Greek for “white blood.”
- Neumann and Ehrlich established that it starts in the marrow and can be classified by cell type.
- Chemotherapy began with Farber’s work in the late 1940s; combination treatment made childhood ALL largely curable.
- The Philadelphia chromosome led to imatinib, the model for targeted cancer therapy.
- Transplant and CAR-T therapy offer options when standard treatment is not enough.
Frequently Asked Questions
Who discovered leukemia?
No single person discovered it. John Hughes Bennett and Rudolf Virchow both described it in 1845, and Virchow gave it the name leukemia in 1847. Earlier physicians had seen cases but did not recognize them as a distinct disease.
What does the word leukemia mean?
It comes from Greek words meaning “white blood.” Early doctors saw that blood from affected patients looked pale, because it contained huge numbers of white blood cells.
When did leukemia become treatable?
The first chemotherapy remissions came in the late 1940s in children with ALL. Over the following decades, combination chemotherapy, transplant, and targeted drugs made many forms of leukemia controllable or curable.
Why is the Philadelphia chromosome so important historically?
It was the first proof that a specific genetic change could cause a specific cancer. That insight led directly to imatinib, one of the first drugs designed to hit a precise molecular target.
Is leukemia more survivable today than in the past?
Yes, markedly so. A diagnosis that was once uniformly fatal now has effective treatment for every major subtype, although outcomes still depend on the type, genetic features, age, and overall health.
