Radium and cancer
Almost by accident the Curies discovered that if they were burned by radium, perfectly healthy skin rather than scar tissue formed. They immediately recognised that radium might have uses in the treatment of cancers. The radioactivity could be used to destroy tumours. Radium therapy (still used today) - and the radium industry - was born.

In 1903 Marie was finally awarded the doctorate she so desired, and shortly afterwards she and Pierre made an amazing decision. They had developed the technique for the isolation of radium from spent pitchblende, and now there was a huge medical market for the rare element. People all over the world were clamouring for details on how to extract radium to treat cancers of several different types. The Curies had a choice - they could publish their results freely for anyone to use or they could patent their methods. Patenting would limit their use but would also make the Curies very wealthy as anyone using their methods of extraction would have to pay to do it. For Marie there was no choice - patenting would be contrary to the scientific spirit. In making this decision the Curies made radium treatment available to thousands around the world, but condemned themselves to many more years of poverty and working without a proper laboratory.

Marie Curie spent many years working with radium from the time she first discovered it until the end of her life. Finding out the potential of her special element for curing cancer gave her great satisfaction. But Marie Curie eventually discovered something else about radium and radioactivity - it can cause enormous damage to the cells of the body. By 1934, when she was still only 67, she was desperately ill. She died because her bone marrow had been destroyed by the long years of exposure to radiation, and she could no longer make enough blood cells to live.