JAMA : the journal of the American Medical Association
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An underappreciated characteristic of prostate cancer screening is that it may detect some prostate cancers solely by serendipity or chance. Serendipity, previously described in the detection of colonic neoplasms, could affect prostate cancer detection when a screening test result is abnormal for reasons other than the presence of prostate cancer, but prostate cancer is coincidentally detected during the subsequent evaluation of the abnormal screening result. We reviewed published articles about prostate cancer screening, searching for evidence of serendipity. ⋯ Whether serendipity is advantageous in prostate cancer screening depends on the as yet uncertain outcomes for men with smaller prostate cancers. However, given our estimates of the potential magnitude of the impact of serendipity, the currently popular DRE- and PSA-based screening strategy may not be optimal. If smaller prostate cancers are important, then we are not finding enough; if they are unimportant, then we are finding too many that we may feel compelled to treat aggressively.
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The few published prospective studies of smoking and mortality in China have reported low relative risks, but the durations of follow-up were short. ⋯ Previous prospective studies of smoking-related mortality in China tended to underestimate the risks, probably because of short durations of follow-up. We have demonstrated that smoking is a major cause of death in China, and the risks are similar to those seen in the United States and the United Kingdom. Thus, about half of the 300 million smokers in China will eventually die of smoking-related diseases if urgent tobacco-control measures are not instituted to prevent this growing epidemic.
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In recent decades, there has been a rapid and substantial increase in tobacco consumption in China, particularly by men, but little is known from local epidemiologic studies about the pattern of smoking-related deaths. ⋯ Cigarette smoking is already a major cause of death in China, and among middle-aged Shanghai men, about 20% of all deaths during the 1980s were due to smoking. The excess was greatest among men who began smoking before the age of 25 years, about 47% of whom would, at 1987 mortality rates, die between the ages of 35 and 69 years (compared with only 29% of nonsmokers). These estimates reflect the consequences of past smoking patterns. The future health effects of current smoking patterns are likely to be greater because of the recent large increase in cigarette consumption, particularly at younger ages, in China.
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Virtually all new cars now are equipped with passenger air bags. Determining whether passenger air bags are saving lives is important, particularly because passenger air bags have caused some deaths among children and adults. ⋯ Passenger air bags were associated with substantial reductions in fatalities among right front passengers in frontal crashes. However, more children are being killed than are being saved by air bags. Immediate countermeasures to reduce the dangers of air bags to children and adults are suggested.
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Breast cancer is a major cause of mortality among women. It is important to identify modifiable risk factors for this disease. ⋯ Avoiding adult weight gain may contribute importantly to the prevention of breast cancer after menopause, particularly among women who do not use postmenopausal hormones.