150 Years of Advances Against Cancer - 1940s-1950s
|1941||Charles Huggins discovers that blocking the production of male hormones by removing the testicles or administering estrogens induces the regression of prostate tumors. This "hormonal therapy" of prostate cancer is still used today.|
|1943||The Pap test is introduced into medical practice. Widespread use of this test in the United States since the 1950s has helped reduce cervical cancer incidence and mortality by more than 70 percent.|
|1944||Oswald Avery, Colin MacLeod, and Maclyn McCarty identify DNA as the basic genetic material of cells.|
|1945||Terrence Millin introduces retropubic prostatectomy, in which the prostate gland is removed through an incision in the lower abdomen. This surgical procedure, which permits the simultaneous removal of regional lymph nodes for better cancer staging, will soon replace perineal prostatectomy as the preferred surgical approach for treating prostate cancer.|
|1947||Sidney Farber demonstrates that aminopterin, a derivative of folic acid, can inhibit the growth of acute leukemia cells. Aminopterin is the first of a class of drugs known as “antimetabolites.” Because they are structurally similar to chemicals needed for normal cellular processes, antimetabolites can interfere with cell growth and proliferation.|
|1948||George Hitchings synthesizes 6-mercaptopurine (6-MP), an antimetabolite that will be used in the treatment of acute leukemia in children and adults.|
|1949||Nitrogen mustard (mechlorethamine) becomes the first chemical agent approved by the Food and Drug Administration (FDA) for the treatment of cancer. Nitrogen mustard belongs to a class of drugs called alkylating agents, which kill cancer cells by chemically modifying their DNA.|
|1950||Ernst Wynder, Evarts Graham, and Richard Doll identify cigarette smoking as an important factor in the development of lung cancer.|
|1952||Alfred Hershey and Martha Chase show that DNA is the genetic material of a virus called bacteriophage T2. This work also rules out the possibility that proteins function as hereditary material.|
|1953||James Watson and Francis Crick discover the molecular structure of DNA (the double helix).|
Carl Nordling proposes that cancer cells contain mutations in a number of different genes and that cancer-inducing mutations accumulate as a person ages—explaining, in part, why cancer is primarily a disease of the elderly. The multi-step nature of carcinogenesis will be confirmed in many later studies.
The FDA approves methotrexate, an antimetabolite derived from folic acid, and 6-mercaptopurine as anticancer drugs.
|1955||The Cancer Chemotherapy National Service Center (CCNSC) at NCI is created to obtain and test compounds as possible anticancer agents. The CCNSC pioneered the development of methods and tools, such as cell lines and animal models, for chemotherapy drug discovery.|
NCI's Clinical Trials Cooperative Group Program is established to test anticancer agents identified in the NCI drug development program. In the future, the Cooperative Group Program will expand its scope to study combination treatments for cancer, methods of cancer prevention and early detection, and interventions to improve the quality of life of cancer patients.
Roy Hertz and Min Chiu Li achieve the first complete cure of a human solid tumor by chemotherapy. The drug methotrexate is used to cure a patient with choriocarcinoma, a rare type of cancer that forms in tissues of the reproductive system and mostly affects women.
|1957||Alick Isaacs and Jean Lindenmann discover interferon, a virus-fighting protein produced by animal cells. Eventually, three major types (I, II, and III) of interferon will be identified. In addition to fighting virus infections, interferons can also fight tumors.|
Charles Heidelberger develops and patents 5-fluorouracil (5-FU), an antimetabolite that becomes widely used in cancer chemotherapy.
|1958||NCI researchers Emil Frei and James Holland and their colleagues pioneer the use of combination chemotherapy, in which multiple drugs with different mechanisms of action are used together. Partial and complete remissions, as well as prolonged survival, are obtained in children and adults with acute leukemia treated with combinations of 6-mecaptopurine and methotrexate.|
|1959||The FDA approves the drug cyclophosphamide, a nitrogen mustard alkylating agent, for the treatment of cancer. Cyclophosphamide is designed to be inactive until it is taken up by cells, where it is metabolized to the active form. This type of drug is called a pro-drug.|