text: The discovery that certain toxic chemicals administered in combination can cure certain cancers ranks as one of the greatest in modern medicine. Childhood ALL (Acute Lymphoblastic Leukemia), testicular cancer, and Hodgkins disease, previously universally fatal, are now generally curable diseases. They have also proved effective in the adjuvant setting, in reducing the risk of recurrence after surgery for high-risk breast cancer, colon cancer, and lung cancer, among others.
  The overall impact of chemotherapy on cancer survival can be difficult to estimate, since improved cancer screening, prevention (e.g. anti-smoking campaigns), and detection all influence statistics on cancer incidence and mortality. In the United States, overall cancer incidence rates were stable from 1995 through 1999, while cancer death rates decreased steadily from 1993 through 1999. Again, this likely reflects the combined impact of improved screening, prevention, and treatment. Nonetheless, cancer remains a major cause of illness and death, and conventional cytotoxic chemotherapy has proved unable to cure most cancers after they have metastasized.