continued “With children, there’s a lot of ground to be covered in brain tumors and solid tumors,” she said. “There have certainly been improvements, but nowhere near the gains we’ve made with leukemia.”
And the biggest leaps have been made since the advent of chemotherapy, which basically works by attacking rapidly growing cells and damaging their DNA.
“Essentially cancer cells are cells that do not go through programmed death,” Kerr said. “Our cells have a limited life span, and we’re constantly renewing ourselves. But in cancer cells, they just grow and divide unchecked. Traditional chemotherapy attacks cells in your body that grow rapidly, not just cancer cells; many of your normal cells are affected. This is the reason for a lot of the side effects like hair loss. Nausea is common because chemotherapy affects the lining of the stomach.”
The era of chemotherapy began after World War II, when the U.S. Army was studying the chemicals used in mustard gas to develop protective measures. That work led to the discovery of a compound called nitrogen mustard, which was found to work against lymphomas. Not long after, scientist Sidney Farber discovered that aminopterin, a compound related to folic acid, could lead children with leukemia into remission.
These early studies resulted in the development of a variety of drugs that block cell replication and growth functions. Those drugs first cured metastatic cancer in 1956 and have since been used to treat people with all kinds of cancer. According to the American Cancer Society, long-term remissions and even cures of many patients with Hodgkin disease and childhood ALL (acute lymphoblastic leukemia) with chemotherapy were first reported during the 1960s. Since physicians started using chemotherapy in the treatment of leukemia and lymphoma, survival rates have skyrocketed.
“Childhood leukemia today has a high cure rate,” Kerr said. “If you looked at the five-year survival rates in 1960, they were about 30 to 40 percent. There was a big leap in the 1970s with the advent of chemotherapy; the survival rates then went up to about 60 percent. Now, with leukemia in general, we’re looking at survival rates in the 80s, with the most common type [having a survival rate] in the 90s.”