Document jNBm1v7MErwzEv2wjKkvwp8V9

! 64 CHAPTER 3 why eke would identical twins so rarely have the same kind of cancer?25 In 1940, Bauer argued that there were other reasons can cers should be regarded as exogenous in origins. For one thing, there was the fact that heritability was obvious in only a very few cancers. Xeroderma pigmentosum, neuroblastomas of the retina, and polyposis of the colon were well-known examples, but these were all quite rare. There was ako the fact that men and women could have very different cancer rates. Cancer of the larynx, for example, was twenty times more common in men than in women, and lung cancer was five or ten times as likely to strike a man as a woman. Could male and female lungs really be so different--or were environmental influences involved? Lip and stomach cancers were ako found more than twice as often among males, though with gallbladder cancer the ratios were reversed (women were six or seven times more likely to suffer the dkease). It was hard to see how heredity could explain such differences. Male and female lungs and Ups and stomachs were not obviously different in any relevant aspect; the more satisfactory explanation, Bauer sug gested--correctly, as it turned out--was that something in the environments of the two sexes--smoking or drinking habits, for example--must be responsible for the differences. He also pointed out that cancer might well "run in families" for no other reason than that people in those famihes may be exposed to a common environment, as in the families of Schneeberg's uranium miners, longtime sufferers from lung cancer.26 "Lifestyle" theories of carcinogenesis were actually quite popu lar in the Nazi era--even among committed Nazis. In 1939, in a long review of world cancer trends, Arthur Hintze, a leading Ber lin radiologkt and professor of surgery, argued that dietary habits and reUgious practices were important in explaining cancer rates on different parts of the planet. Stomach cancer, for example, was the most common cause of cancer death in both Europe and Japan, but the same disease was rare in Calcutta, accounting for less than 1 percent of all mahgnancies. The difference in the Indian case seemed to have Uttle to do with race; rather, it appeared to stem from economic constraints and religious practices that led local populations to consume very little alcohol and almost no meat. GENETIC AND RACIAL THEORIES 65 Lifestyle factors ako seemed to be at work in the rarity of stomach cancer among the Malays living in Java and Sumatra: one large autopsy study of 3,885 Malays in Batavia found only a single gas tric malignancy, a fairly common disease among the Europeans and Chinese living in that part of the world. Hintze pointed out that most of the Malays were Muslims and therefore avoided al cohol and meat--habits which led to low stomach cancer rates ako among the predominantly Buddhkt Sinhalese of Ceylon. Life style factors were similarly responsible for the high rates of geni tal and bladder cancers among Arabs in the Middle East, a situa tion that, he explained, following Sigismund Peller (a Jew whose books had been banned, interestingly), was most likely a conse quence of infection by pathogens such as bilharzia and the syphilk spirochete. Hintze did not deny that different individuak and perhaps even different races were unequally susceptible to the influence of car cinogens (he mentions the fact that light-skinned peoples are more vulnerable to sun-induced skin cancer); he simply claimed that en vironmental and lifestyle factors played a stronger role than was sometimes acknowledged. The upshot: we should not be fatalktic in thinking of cancer as an unavoidable accompaniment of civiliza tion. Hintze ako noted that demographic variables were the root cause of many "racial" variations: Africans, for example, were often observed to have high sarcoma rates--though part of the rea son, he explained, was that these were cancers which most often struck at an early age. Africans did not live as long as some other peoples, giving rise to the (fake) impression that sarcomas were a particular weakness of the Negro race. He also suggested that the idea that Africans were particularly vulnerable to benign tumors might have something to do with non-Africans' failure to appreci ate the widespread cosmetic practice of ritual scarring.27 I don't want to leave the impression that Hintze was a flaming Boasian--he was not. He was a dedicated Nazi who profited di rectly from the expukion of Jews at the Rudolf Virchow Hospital. Cancer was common among the young in certain populations, he speculated, because those populations were "closer to the youth of humanity"--meaning humans' evolutionary ancestors. He ako