Some Facts and Fancies about Cancer

SOME FACTS AND FANCIES ABOUT CANCER FRANKL. HORSFALL,JR., M.D.* The flood ofprinted comments about cancer seems to increase steadily and, in view ofthe speed and efficiency ofmodern faculties for communication , there appears to be small likelihood that the trend will diminish. It isnowfeasibletopublish sopromptlythatlaypublicationsmaybethought to be far ahead of professional publications in keeping abreast of new findings and new concepts about this disease. This facility in communication may be advantageous when advances are occurring rapidly and new facts which can stand up to independent studies are emerging. But it may not be so advantageous if it serves to confuse fact and fancy or fails to distinguish between verifiable relationships and wishful thinking. As has been known for a long time, the cry of "wolf' too frequently repeated may lead to a lack ofconcern, and too much emphasis on the imminence ofa hoped-for millennium may lead to disbeliefin its possibility. In an earlier address at the Medical School ofthe University ofAlberta presented some seven months ago, an effort was made to evaluate current concepts of cancer in terms of the evidence that is available to support them [i]. Inpreparing this lecture, a similar objective seemed desirable and a solid effort will be made to distinguish between established facts and assumptions or hypotheses which, for our present purpose, may be considered fancies. There is, ofcourse, no reason to expect that each distinction will be acceptable to all students ofcancer, but there is some reason to think that they willnot run counter to views that areheld by many. In addition , it needs to be emphasized that both the relevance and the significance offacts frequently change as more is learned, and that the value and importance ofhypotheses are measured bythe findings to which theylead. * President and Director, Sloan-KetteringInstitute for Cancer Research, New York, N.Y. 10021. Thispaperwaspresented astheGeorgeM. KoberLectureat GeorgetownUniversity Medical School, Washington, D.C., April 23, 1964, and is reprinted here from The Georgetown Medical Bulletin, Vol. 18, No. i, August, 1964, by kind permission. I67. Because ofthe nature and the relentless course ofmost untreated cancers andthe frequencywithwhichtheseneoplasms occur, manhas beenheavily concerned with them for centuries, and the extent ofhis concern has increased appreciably in recent times. As a result ofthis deepening interest, a large lore about malignant tumors has accumulated, some ofwhich is either not wholly valid or remains unsubstantiated. For example, it is often said that cancer is an incurable disease and that modern treatment, although beneficial, does not save even though it may prolong life. This is clearly an erroneous belief, as overwhelming evidence now attests, and the results of modern surgery, radiation therapy, and chemotherapy have abundantly established. It is also often said that cancer is a disease of unknown cause and that the incitants which initiate the cancerous change in cells are yet to be discovered. This is simply not true, as extensive work during this century with ionizing radiation, chemical cancerigens, and oncogenic viruses has solidly demonstrated. Finally, it may be supposed that the change in rank ofcancer as a cause ofdeath, a change from fifth place to second during the past thirty years, reflects an increase in the frequency with which the disease occurs. Such an idea is counter to the farts, for the age-specific death rate for cancer has not increased and appears to have declined slightly during recent years. The change in rank for cancer as a cause ofdeath can be accounted for by the effectiveness with which it has been possible, with antimicrobial agents and viral vaccines, to achieve control ofother major diseases which some thirty years ago led to more deaths. Almost all that is known about the causes of cancer has been learned during this century. The beginnings of information about the nature of the incitants that can induce the cancerous change in cells were kid more then fifty years ago. The association between exposure to ionizing radiation , particularly X-rays, and the development ofcancers was recognized by 1907 [2]. That a virus could induce solid malignant tumors in animals was discovered in 1911 [3]. That chemical compounds could lead to the development ofcancers in animals was demonstrated in 1915 [4]. The risks associated with ionizing...