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The problem: applying these findings to man. At dozens of laboratories in the U.S. and elsewhere, material from human victims of both leukemia and solid tumors is being tested in animals. Some success is reported by Dr. Steven O. Schwartz of Chicago's Hektoen Institute, who has generated leukemia in mice with an extract from the brains of human leukemia victims. At the University of Texas' M. D. Anderson Hospital in Houston, Dr. Leon Dmochowski has taken electron-microscope photographs of what he is confident are virus particles from human leukemia. Other investigators want more proof, but this suggestive evidence helps to close the ring.
Mighty Molecule. The virus theory of cancer causation long seemed to be far out in leftfield, but growing knowledge tends to link it with other anti-cancer plays. Most fundamental of these involves nucleic acids, currently regarded as the secret of life itself (TIME, July 14, 1958). Human cells, tiny as they are, normally contain 46 chromosomes, each containing in turn up to 1,000 molecules of nucleic acid. Each of these molecules, invisible even to the electron microscope under most conditions, is a huge chemical complex embracing tens of thousands of atoms. In mammalian cells the master molecule is one of the thousands of forms of deoxyribonucleic acid (DNA). The vital nucleus of many viruses, especially those causing disease in plants and animals (e.g., cowpox, which gives man immunity against smallpox), is also a form of DNA. Most viruses of human diseases have a nucleus of the slightly simpler ribonucleic acid (RNA). Whether polyoma virus has a heart of DNA or RNA is not yet known.
On how to weave these threads of evidence together there are almost as many theories as researchers. But they converge on this general line: DNA is the master molecule of life, with the power to reproduce itself and also to dictate how chromosomes and entire cells shall reproduce. So an abnormal DNA molecule might not only spawn more abnormal DNA, but also trigger the multiplication of abnormal cells that defy the body's usual chemical regulators—in a word, cancer. A DNA viral nucleus, entering a cell, may substitute part of itself for part of a normal DNA, thus scramble the signals for reproduction given by the master molecule.
To the layman, the most puzzling question remains: If any human cancers are caused by viruses, why have none been clearly identified? (The lowliest of benign tumors, the common wart, is definitely caused by a virus that can cause cancer in animals.) Dr. Eddy explains: "In human disease, it may be that the virus starts the cancerous process, but by the time we detect the tumor, there is so little virus left—or in an altered form—that we cannot detect it." Dr. Stewart sums up: ''Perhaps we just haven't hit upon the right method." To find the right method, National Cancer Institute is doubling its outlays for virus research, through grants to independent investigators, to about $4,500,000 in this fiscal year.
Early Detection. As for detection, treatment and cure of cancer. Dr. Heller sees the most exciting new development in chemotherapy—treatment of the disease with drugs. But before the disease can be attacked, it must be detected, and all too often detection comes too late for treatment to do all that it might.