Two drugs previously used as a heart disease treatment and a contraceptive have been given a new lease of life against cancer.
The research found a possible new treatment
Doctors at the University of Birmingham have discovered that the pair may be able to help persuade cancer cells to "commit suicide".
The finding, published in the scientific journal Leukaemia, could help children and adults with a particularly virulent form of the disease called Burkitt's Lymphoma.
Burkitt's tumours have been known to double in size in just 24 hours.
The condition often arises in patients with Aids, who may not be able to tolerate conventional chemotherapy.
Clofibric Acid and medroxyprogesterone acetate have been around for some time, but this is first time they have been tried against this particular cancer.
It is thought they target receptors on the cancer cells which are involved in a process called "natural cell death".
Cells have to die when they reach a certain age in order to make way for new cells, and this process triggers death at the right moment.
In cancer cells, this process is often switched off, leading to uncontrolled tumour growth.
In laboratory studies, the two drugs force Burkitt's lymphoma cells to undergo natural cell death.
Dr Chris Bunce, one of the researchers, said: "Originally we were looking to see whether these drugs could make these Burkitt cells more sensitive to an existing leukaemia treatment.
"But to our delight we found that, when used together, they kill the cancer cells without the need for the conventional treatment."
Dr David Grant, from the Leukaemia Research Fund, which paid for the research, said: "The development of additional treatments such as these which are inexpensive and have low levels of toxicity, would represent a major advance in the global management of the disease."
There are three types of Burkitt's lymphoma - the first two being an endemic type found mainly in young children in Equatorial Africa, and sporadic cases in Western Europe and the US, with approximately 100 new cases in the UK every year.
Finally, "immunodeficiency associated Burkitt's lymphoma" happens in patients with depleted immune systems - most notably those with the HIV virus, often occurring as the first sign that Aids has emerged.