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The relationship between the use of cigarettes and other tobacco products and the risk of multiple myeloma was examined in a cohort of nearly 250,000 American veterans followed prospectively for 26 years. Compared with men who had never tobacco, the risk of death from myeloma was not increased among current (relative risk [RR] = 0.9, 95 percent confidence interval [CI] = 0.8-1.2) or former (RR = 1.0, CI = 0.8-1.3) cigarette smokers, nor among users of chewing tobacco or snuff (RR = 1.0, CI = 0.4-2.3). Risk was only slightly and nonsignificantly increased among pipe or cigar smokers (RR = 1.2, CI = 0.9-1.5). There was no indication of increasing risk with amount of tobacco used or earlier age at first use. With over 90 percent power to detect a 30 percent increased risk of this tumor occurring among current cigarette smokers, this study provides the strongest evidence to date against an association of cigarette smoking with multiple myeloma.

A cohort of 1041 men who were discharged from the hospital with a diagnosis of acromegaly were examined for subsequent cancer. With a mean follow-up time of 8.3 years, an increased rate of cancers of the digestive organs was observed (27 cases; standard incidence ratio [SIR], 2.0; 95% confidence interval [CI], 1.3 to 2.9). Rates were elevated for cancers of the esophagus (7 cases; SIR, 3.1), stomach (4 cases; SIR, 2.5), and colon (13 cases; SIR, 3.1). The increased risk of colon cancer in acromegaly is consistent with previous clinical reports and suggests opportunities for etiologic research and early cancer detection. It would seem prudent to also evaluate this risk in current research on the use of growth hormone in older individuals to increase muscle mass and reduce body fat.

Lung cancer risk in relation to indoor radon was examined in three case-control studies in Stockholm (Sweden), New Jersey (United States), and Shenyang (People's Republic of China). Year-long measurements of radon gas were made in current and past homes of 966 women who developed lung cancer and of 1,158 control women, included in the combined analysis. Nearly 14 percent of the participants were estimated to have a time-weighted, mean, radon concentration in their homes of more than 4 pCi/l (150 Bq/m3) during the period from five to 35 years prior to the date of lung cancer diagnosis (or comparable date for controls). There was a tendency for risk to increase with increasing levels of radon in NJ and Stockholm, but the trends for individual studies and overall were not statistically significant. The estimates of the excess relative risk for indoor exposure per pCi/l were 0.18 (95 percent [CI] = -0.04-0.70) in NJ, 0.06 (CI = -0.05-0.34) in Stockholm, and -0.02 (CI = -infinity-0.03) for Shenyang; these estimates did not differ significantly from each other. The overall excess RR per pCi/l was 0.00 (CI = -0.05-0.07); the confidence limits were sufficiently broad, however, that the overall estimate was still compatible with extrapolations of risks from miners. Cigarette smoking was the predominant cause of lung cancer with the RR significantly elevated in all studies. Within smoking categories, the trend in risk with increasing mean radon concentration was inconsistent. Analyses of data from several studies are complicated by the possibility that there may exist important differences in study bases which might affect results, and which may be controlled only partially through adjustment procedures. Future efforts to combine various residential studies will need to be attentive to the intrinsic limitations of studies to detect low levels of risk as well as the unique uncertainties associated with estimating, accurately, cumulative exposure to indoor radon.

The risk of childhood cancer was evaluated among 35,582 twins born in Sweden between 1952 and 1967. Cancers were identified through linkage with national cancer and mortality registries. Overall, 59 childhood cancers and 41 deaths from cancer occurred before the age of 16. For both sexes combined, the cancer incidence was similar to that in the general population of primarily single-born children (number observed/number expected [O/E] = 1.0, 95 percent confidence interval [CI] = 0.7-1.2). For males under age five, cancer incidence was reduced significantly (O/E = 0.3, CI = 0.1-0.7). There was a substantial increase in all-cause mortality among twins (O/E = 3.7), attributable to a high mortality during the first year of life. Excluding this first year, the O/E for death (all causes) was 1.1 (CI = 1.0-1.3). For cancer mortality of both sexes, the O/E was 0.9 (CI = 0.6-1.2), with no significant reduction of risk in any sex-age group. We conclude that with the possible exception of males aged 0-4 years, the childhood cancer risk of twins appears similar to that of singletons.

The relationship of tobacco use with risk of primary liver cancer was investigated using data from a 26-year mortality follow-up of nearly 250,000 US veterans, mostly from World War I. Significantly increased risks for liver cancer (289 deaths) were associated with most forms of tobacco use, including pipe and cigar smoking. Elevated relative risks (RRs) were seen for current cigarette smokers (RR = 2.4; 95 percent confidence interval [CI] 1.6-3.5) and former cigarette smokers (RR = 1.9, 1.2-2.9). A strong dose-response relationship (P less than 0.001) was found for cigarette smoking, with smokers of 40 or more cigarettes per day having almost a fourfold risk (RR = 3.8, 1.9-8.0). Risks were also found to increase significantly with years of cigarette use and with earlier age at the start of cigarette smoking. These results are consistent with those of other cohort and case-control studies, suggesting that cigarette smoking may be related to the risk of liver cancer.

Reports from the United Kingdom have described increases in leukemia and lymphoma among young persons living near certain nuclear installations. Because of concerns raised by these reports, a mortality survey was conducted in populations living near nuclear facilities in the United States. All facilities began service before 1982. Over 900,000 cancer deaths occurred from 1950 through 1984 in 107 counties with or near nuclear installations. Each study county was matched for comparison to three "control counties" in the same region. There were 1.8 million cancer deaths in the 292 control counties during the 35 years studied. Deaths due to leukemia or other cancers were not more frequent in the study counties than in the control counties. For childhood leukemia mortality, the relative risk comparing the study counties with their controls before plant start-up was 1.08, while after start-up it was 1.03. For leukemia mortality at all ages, the relative risks were 1.02 before start-up and 0.98 after. For counties in two states, cancer incidence data were also available. For one facility, the standardized registration ratio for childhood leukemia was increased significantly after start-up. However, the increase also antedated the operation of this facility. The study is limited by the correlational approach and the large size of the geographic areas (counties) used. It does not prove the absence of any effect. If, however, any excess cancer risk was present in US counties with nuclear facilities, it was too small to be detected with the methods employed.

Subjects in the National Academy of Sciences-National Research Council Twin Registry of 31,848 male twin veterans were followed for mortality from 1 January 1946, or from the date of entry into military service if that was later, to 31 December 1978. During this time 3,573 deaths occurred among them, 837 due to trauma and 2,712 due to disease. Mortality from all causes for the entire follow-up period was 10.2% among 11,350 monozygotic (MZ) twins and 11.4% among 14,450 dizygotic (DZ) twins. Mortality of veterans is known to be favorable compared to U.S. males. Among U.S. males of the same ages as the two respective twin zygosity groups, a mortality of 13.9% would have been expected during this time period. Observed mortality from trauma was 2.3% for MZ twins and 2.5% for DZ twins, with 3.0% expected in either group. Observed mortality from all disease was 7.9% for MZ twins and 8.8% for DZ twins, with 10.9% expected in either group. For total mortality, the case twin concordance rates, based on individual deaths, were 28.2% among MZ twins and 17.7% among DZ twins. For trauma, respectively by zygosity, these concordance rates were 6.9% and 3.9%. In this sample, familial factors appear to be of little consequence in trauma deaths. For all disease the concordance rates were 30.1% and 17.4%. Estimating heritability of liability to death from disease, as proposed by Edwards (1969), provides values of h2 = r = 0.51 for MZ twins, h2 = 2r = 0.48 for DZ twins, and h2 = 2(rMZ-rDZ) = 0.54 using data for the two zygosity groups combined.

In a survey having a 90 percent chance of detecting a quadrupling of risk, no significant increase in leukemia has been observed in the offspring of persons exposed to atomic bomb radiation in Hiroshima and Nagasaki. In the children with leukemia who were born to previously irradiated parents, there was no unusual finding in regard to the interval from parental exposure to onset, age at onset, or type of leukemia. Failure to demonstrate a radiation effect does not mean that there is no such effect. It merely means that within the experience thus far open to observation, no effect is to be seen. There now is sufficient experience to justify a long period of observation of the F1 and subsequent generations for a possible increase of leukemia.

A follow-up study was performed on 690 white diabetic patients 2 to 5 years after their blood had been analyzed for lipoprotein and cholesterol to determine if these lipid measures had any predictive value for development of future cardiovascular complications. The work was done in parallel to the national project in which 15,000 normal persons were followed for 1 to 2 years. 5