In 1960, if your child was diagnosed with acute lymphoblastic leukemia — the most common cancer in children — doctors had almost nothing to offer. The disease, in which the bone marrow produces vast numbers of abnormal white blood cells that crowd out healthy ones, was considered almost universally fatal. Treatment existed, technically: a handful of chemotherapy drugs developed in the 1940s and 1950s could temporarily reduce the cancer burden. But the disease invariably returned, and when it did, it was more aggressive. Five-year survival rates stood at fewer than **10%**.
Today, that figure is **above 90%**.
In the space of 70 years, childhood ALL has been transformed from one of medicine's most desperate diagnoses to one of its greatest success stories — a transformation achieved not through a single eureka moment, but through seven decades of clinical trials, international collaboration, and thousands of incremental discoveries that each moved the needle a fraction of a percent.
**The Drug That Started Everything**
The modern era of childhood leukemia treatment began in Boston, in the laboratory of Dr. Sidney Farber. In 1948, Farber administered an anti-folate compound called aminopterin to 16 children with ALL. In 10 of them, the leukemia went temporarily into remission — the first time any cancer had been pushed back by a chemical agent. The children died eventually (the remissions lasted months, not years), but the proof of concept changed oncology forever: cancer could be treated with drugs.
The 1950s and 1960s saw an explosion of chemotherapy development. Researchers discovered that different drugs attacked the cancer through different mechanisms — and that combinations of drugs were more effective than any single agent, and made drug resistance harder to develop. The concept of **combination chemotherapy** was born.
**The Protocol Era (1960s–1980s)**
The critical advance of the 1960s was not a new drug but a new approach to using existing ones. Dr. Donald Pinkel at St. Jude Children's Research Hospital in Memphis — which was founded in 1962 specifically to research childhood catastrophic illness — developed the first comprehensive protocol for childhood ALL: a defined sequence of chemotherapy agents, delivered at specific doses and intervals, followed by **cranial radiation** to eliminate leukemia cells that had retreated to the central nervous system.
Pinkel's Total Therapy protocol, first published in 1968, achieved 5-year survival rates of around 50% in selected patients — transformative compared to the decade before, but still leaving half of all children diagnosed with the disease to die of it.
Over the next two decades, St. Jude and cancer centres around the world ran a continuous series of clinical trials — Total Therapy I through Total Therapy XV and beyond — each refining the protocol, each extracting another few percentage points of survival. Cranial radiation was gradually reduced and eventually eliminated in most patients, as researchers found that certain chemotherapy drugs, delivered directly into the spinal fluid, could protect the brain without the long-term cognitive damage that radiation caused.
**The Molecular Revolution (1990s–2010s)**
By the 1990s, survival rates in high-income countries had climbed past 70%, then 80%. The next leap came from genetics. Researchers discovered that childhood ALL is not one disease but many: subtypes defined by specific chromosomal abnormalities, each with its own biology, prognosis, and optimal treatment approach.
Some subtypes — like the one driven by a fusion of chromosomes 12 and 21 (ETV6-RUNX1) — turned out to be highly curable with standard chemotherapy. Others, like the *Philadelphia chromosome*-positive ALL (driven by the BCR-ABL gene fusion), were far more resistant.
Then came **imatinib (Gleevec)**, approved in 2001: a drug specifically designed to block the BCR-ABL enzyme. Combined with standard chemotherapy, it transformed Philadelphia-positive ALL — previously one of the worst subtypes — from a near-certain killer to a condition that many children now survive. Imatinib represented the arrival of **targeted therapy**: drugs designed for specific molecular targets rather than attacking all rapidly-dividing cells indiscriminately.
**CAR-T Therapy: The Latest Revolution**
In 2017, the FDA approved **tisagenlecleucel (Kymriah)** — the first CAR-T cell therapy — specifically for children and young adults with relapsed or refractory ALL. The technology reprograms a patient's own T cells to recognise and destroy leukemia cells. In clinical trials, Kymriah achieved remission in **81% of patients** who had failed all other treatments — patients who had exhausted every other option.
For a disease that once killed 90% of those it touched, the idea that 81% of the *most treatment-resistant* patients could achieve remission with a new approach would have seemed impossible to the oncologists of the 1960s.
**Where We Are Today**
The latest SEER (Surveillance, Epidemiology, and End Results) data from the US National Cancer Institute, published in 2025, places the 5-year survival rate for childhood ALL at **91.7%**. In the best-performing treatment centres, for certain subtypes, that figure climbs above 95%.
The progress is not limited to wealthy nations. Initiatives like the **Childhood Cancer Initiative** (supported by WHO, St. Jude, and SIOPE) are systematically working to extend modern treatment protocols to low- and middle-income countries, where the majority of the world's childhood cancer diagnoses occur but where survival rates have historically lagged far behind. Early results from implementation sites in sub-Saharan Africa and South and Southeast Asia show survival rates climbing from below 30% toward 60–70% as modern protocols and supportive care are introduced.
**The Number That Matters Most**
Every year, approximately 400,000 children worldwide are diagnosed with cancer. Acute lymphoblastic leukemia is the most common.
In 1960, 9 out of every 10 of those children died.
In 2026, in countries with access to modern care, 9 out of every 10 survive. Many of them grow up, have children of their own, and live full lives with no evidence of the disease that once would have killed them within months of diagnosis.
That is what 70 years of incremental scientific progress looks like, measured in human lives. 💙
*Sources: St. Jude Children's Research Hospital · National Cancer Institute SEER Database (2025) · American Cancer Society Cancer Statistics 2025 · FDA (Kymriah approval) · The Lancet Oncology — Global Childhood Cancer Survival Study · WHO Childhood Cancer Initiative · American Society of Hematology*
