That also means that 15 percent of the patients have a recurrence. After 10 years, a quarter of the patients have a recurrence. For many cancers, being disease-free for five years means the odds are good that the disease has been cured. Unfortunately, when it comes to talking about cancer causes and cures, physicians, epidemiologists, and researchers alike must talk in terms of rates and risks, percentages and probabilities. There's good reason for that.
Cancer is a much more complex disease than, say, a bacterial infection.
Cancer, on the other hand, has many different causes. In addition, a physician can give an antibiotic such as penicillin to a patient with bacterial pneumonia and cure the disease within weeks. But scientists doubt that anyone will ever find a treatment that is specific for cancer in the way that antibiotics are specific for bacterial infections. Antibiotics work because the biochemistry of bacteria is far different from that of human beings. But the biochemistry of cancer cells differs little from that of normal cells, making it impossible so far to develop a poison that kills cancer cells only.