Alcohol and pancreatic cancer in blacks and whites in the United States

A population-based, case-control study of pancreatic cancer based on direct interviews with 307 white and 179 black incident cases and 1164 white and 945 black population controls was conducted in three areas of the United States to determine the role alcohol drinking plays as a risk factor for pancreatic cancer and to estimate the extent to which it may explain the higher incidence of pancreatic cancer in blacks compared to whites. Our findings indicate that alcohol drinking at the levels typically consumed by the general population of the United States is probably not a risk factor for pancreatic cancer. Our data suggest, however, that heavy alcohol drinking may be related to pancreatic cancer risk. Among men, blacks and white who drank at least 57 drinks/week had odds ratios (ORs) of 2.2 [95% confidence interval (CI) = 0.9-5.6] and 1.4 (95% CI = 0.6-3.2), respectively. Among women, blacks who drank 8 to < 21 drinks/week had an OR of 1.8 (95% CI = 0.8-4.0), and those who drank at least 21 drinks/week had an OR of 2.5 (95% CI = 1.02-5.9), but whites with the same levels of alcohol intake experienced no increased risk. Compared to whites, blacks had significantly higher ORs associated with heavy alcohol drinking (> or = 57 drinks/week) in men (P = 0.04) and with moderate-to-heavy drinking (> or = 8 drinks/week) in women (P = 0.03). Additional research is needed to determine whether heavy alcohol drinking is causally related to pancreatic cancer and whether the risk of alcohol-related pancreatic cancer is greater in blacks than in whites.

Harassment of women physicians

This paper reviews current knowledge about the prevalence, characteristics, and costs of sexual harassment of women medical students and physicians. It also addresses the limited research on other forms of physician and student harassment, and notes the kinds of information that are still needed.

Cigarette smoking and pancreas cancer: a case-control study based on direct interviews

BACKGROUND

Cigarette smoking is the most consistently reported risk factor for pancreas cancer, yet the dose-response relationship in many pancreas cancer studies is weak. Because of the poor prognosis for pancreas cancer, many case-control studies have been based largely on interviews with proxy respondents, who are known to report less reliable information on detailed smoking habits than original subjects.

PURPOSE

Our purpose was to evaluate cigarette smoking as a risk factor for pancreas cancer based on data obtained only from direct interviews and to estimate the effects of quitting smoking and of switching from nonfiltered to filtered cigarettes on risk. Our objective also was to estimate the contribution of cigarette smoking toward explaining the higher pancreas cancer incidence experienced by black Americans compared with white Americans.

METHODS

A population-based, case-control study of pancreas cancer was conducted during 1986-1989 in Atlanta, Ga., Detroit, Mich., and 10 counties in New Jersey. Direct interviews were successfully completed with 526 case patients and 2153 control subjects aged 30-79 years, making this the largest population-based, case-control study of pancreas cancer to date based only on direct interviews.

RESULTS

Cigarette smokers had a significant, 70% increased risk of pancreas cancer compared with the risk in nonsmokers. A significant, positive trend in risk with increasing duration smoked was apparent (P < .0001), with long-term (> or = 40 years) smokers experiencing a modest 2.1-fold risk. We also observed a negative trend in risk with increasing years quit smoking. Smokers who quit for more than 10 years experienced about a 30% reduction in risk relative to current smokers; quitters of 10 years or less experienced no risk reduction. Switching from nonfiltered to filtered cigarettes did not appear to decrease risk. Compared with nonsmokers, subjects who smoked only filtered cigarettes had a 50% elevated risk and those who smoked only nonfiltered cigarettes had a 40% elevated risk. The proportion of pancreas cancer attributable to cigarette smoking was 29% in blacks and 26% in whites.

CONCLUSIONS

The relationship between cigarette smoking and pancreas cancer risk is likely to be causal, despite the weakness of the dose-response data. Long-term smoking cessation clearly reduces risk, whereas switching from nonfiltered to filtered cigarettes may not be beneficial. Cigarette smoking appears to explain little of the excess pancreas cancer risk experienced by blacks.

IMPLICATIONS

Elimination of cigarette smoking would eventually prevent approximately 27% of pancreas cancer, saving 6750 lives in the United States annually.

An epidemiologic perspective on biomarkers

The authors discuss biological markers from an epidemiologic perspective, emphasizing the importance of integrating biomarkers into large-scale observational and intervention studies. Whereas any biologic phenomenon can be considered a biomarker, an intermediate end-point is defined as being on the causal pathway between exposure and disease. An intermediate end-point is a valid surrogate for a disease in relation to a given exposure if, and only if, that exposure causes a similar change in the occurrence of both the intermediate end-point and the disease. Cancer studies using surrogate end-points may be shorter, smaller and cheaper than those using malignancy per se as an outcome. Three types of studies may be carried out to determine whether a given biomarker is an intermediate end-point and whether it can serve as a surrogate: (i) exposure-marker studies, (ii) marker-disease studies, and (iii) studies comprising all three elements, exposure, marker, and disease. The authors discuss statistical aspects of these three types of studies and provide examples from investigations of alcohol-hormone-breast cancer, diet-epithelial proliferation markers-large bowel adenomatous polyps, and reproductive risk factors-human papillomavirus infection-cervical cancer.

Laboratory and epidemiologic studies of fecapentaenes

Fecapentaenes are a class of conjugated ether lipids which have been identified as the major component of human fecal mutagenicity in the Ames Salmonella mutagenesis assay. Human epidemiologic data have indicated that most healthy North American populations eating a western diet do excrete detectable levels of fecapentaenes. Excreted fecapentaene levels seem to reflect levels throughout the colonic lumen, and levels vary characteristically between individuals. Those individuals found to excrete high levels of fecapentaene appear, based on limited data, to be at decreased risk of colorectal neoplasia. Carcinogenicity studies in rats and mice have been predominantly negative, however, increased tumor incidence in mice exposed to fecapentaenes as neonates has recently been reported. Fecapentaenes are direct-acting genotoxins, which may react with DNA through free radical mechanisms, and/or aldehyde formation. Mechanisms by which fecapentaene-induced DNA damage may mediate carcinogenesis are discussed.

Sex hormones in lesbian and heterosexual women

The authors measured plasma testosterone (T), androstenedione (A), and cortisol (C) levels in seven lesbian and seven heterosexual women matched for age and socioeconomic status. In addition, psychiatric symptoms, physical activity levels, depression, subjective sense of stress, and sexual behavior variables were assessed. There were no significant differences in sex hormone levels between the two groups of women, who were also comparable in psychiatric symptom levels, depression, and self-perceived stress. Lesbian women reported significantly more current physical activity relative to peers. Other than the sexual orientation difference which was a prerequisite for entry into the study, there were virtually no significant differences in sexual behavior although lesbian women tended to have achieved psychosexual milestones at a younger age. We were not able to corroborate the finding of Gartrell, Loriaux, and Chase (1977) that lesbian women have higher T levels, possibly due to the fact that the two groups were closely matched on several behavioral variables potentially affecting testosterone levels.

Improved radioimmunoassay technique for measuring serum thymopoietin

An improved radioimmunoassay technique for measuring serum thymopoietin has been developed which obviates the spurious displacements previously obtained with serum samples, and increases sensitivity to 20 pg. Key improvements involved further purification of labeled thymopoietin, sequential incubations to enhance sensitivity and the use of charcoal-treated serum blanks to render controls and unknown samples comparable to the standard curve.

Induced movement based on subtraction of motion from the inducing object

Induced movement occurs not only when an object surrounding a stationary one moves below threshold but when it moves above threshold. The above-threshold effect is particularly puzzling and seemingly irrational because the relative displacement should be fully accounted for by perceiving the moving object in motion. The accepted theory has been that such excess motion can be explained in terms of a separation of systems: The enclosed object is governed by the relationship to its immediately surrounding frame of reference, and the latter is governed either by the relationship to its surrounding frame of reference or to the observer. An alternative explanation is that when induced motion occurs, the moving object is perceived to be either stationary or moving less than is warranted by its actual motion. Evidence is presented supporting this hypothesis according to which the relative displacement is apportioned phenomenally to either the induced object, the inducing object, or both. The objective motion of the inducing object is thus in whole or part transferred to the induced object. Thus, excess phenomenal motion does not occur, and induced movement can be regarded as the rational solution to a problem.

Induced movement based on subtraction of motion from the inducing object

Induced movement occurs not only when an object surrounding a stationary one moves below threshold but when it moves above threshold. The above-threshold effect is particularly puzzling and seemingly irrational because the relative displacement should be fully accounted for by perceiving the moving object in motion. The accepted theory has been that such excess motion can be explained in terms of a separation of systems: The enclosed object is governed by the relationship to its immediately surrounding frame of reference, and the latter is governed either by the relationship to its surrounding frame of reference or to the observer. An alternative explanation is that when induced motion occurs, the moving object is perceived to be either stationary or moving less than is warranted by its actual motion. Evidence is presented supporting this hypothesis according to which the relative displacement is apportioned phenomenally to either the induced object, the inducing object, or both. The objective motion of the inducing object is thus in whole or part transferred to the induced object. Thus, excess phenomenal motion does not occur, and induced movement can be regarded as the rational solution to a problem.

Simple bone cysts: factors of age dependency

Patient age plays a significant role in the presentation and clinical behavior of bone cysts. In children, cysts behave more aggressively than in adults and the recurrence rate for patients in the first decade of life is four times that in the adolescent. Simple bone cysts are less frequent after 17 years of age and 80% of cysts in the young are located in the proximal end of the shaft of the humerus and femur. Pathological fractures will call attention to the cyst and the highest incidence of fractures is in childhood (0--10 years).