Jonathan M. Liff

Adenocarcinoma of the esophagus and esophagogastric junction in White men in the United States: alcohol, tobacco, and socioeconomic factors

In the United States, the incidence of adenocarcinoma of the esophagus, including the esophagogastric (EG) junction, has been increasing rapidly over the past two decades. Except for an association with Barretts esophagus, little is known about the etiology of these cancers. A population-based case-control interview study of 174 White men with adenocarcinoma of the esophagus and 750 controls living in three areas of the United States offered the opportunity to investigate the relationship of these cancers with smoking, alcohol drinking, socioeconomic factors, and history of ulcer. There were significantly elevated risks for men who smoked cigarettes (odds ratio [OR]=2.1) or drank liquor (OR=1.6). For both cigarette smoking and liquor drinking, there were significant dose gradients with amount consumed. No reduction in risk was observed following smoking cessation. Subjects who switched from nonfilter to filter cigarettes experienced half the risk of those who only smoked nonfilter cigarettes. Inverse risk gradients were seen with increasing recent annual income, with the highest risk (OR=3.4) for the lowest category. The risk for a history of ulcer (OR=1.7), especially of the duodenum (OR=2.2), was also significantly elevated. These data suggest that tobacco and alcohol may be etiologic factors for adenocarcinoma of the esophagus and EG junction, but these factors do not appear to explain the rapid rise in incidence of these tumors. The associations with low social class and history of ulcer need to be explored in greater detail along with other factors that may account for the temporal trends in esophageal adenocarcinomas.

Racial differences in diagnosis, treatment, and clinical delays in a population-based study of patients with newly diagnosed breast carcinoma†‡

Few studies have addressed the issue of whether delays in the interval between medical consultation and the diagnosis and treatment of breast carcinoma are greater for African American women than for white women. The authors examined differences with respect to these delays and analyzed the factors that may have contributed to such differences among women ages 20–54 years who had invasive breast carcinoma diagnosed between 1990 and 1992 and who lived in Atlanta, Georgia.

Sexual behaviour, STDs and risks for prostate cancer

A population-based case-control study was carried out among 981 men (479 black, 502 white) with pathologically confirmed prostate cancer and 1315 controls (594 black, 721 white). In-person interviews elicited information on sexual behaviour and other potential risk factors for prostate cancer. Blood was drawn for serologic studies in a subset of the cases (n = 276) and controls (n = 295). Prostate cancer risk was increased among men who reported a history of gonorrhoea or syphilis (odds ratio (OR) = 1.6; 95% confidence internal (CI) 1.2–2.1) or showed serological evidence of syphilis (MHA-TP) (OR = 1.8; 95% CI 1.0–3.5). Patterns of risk for gonorrhoea and syphilis were similar for blacks (OR = 1.7; 95% CI 1.2–2.2) and whites (OR = 1.6; 95% CI 0.8–3.2). Risks increased with increasing occurrences of gonorrhoea, rising to OR = 3.3 (95% CI 1.4–7.8) among subjects with three or more events (Ptrend= 0.0005). Frequent sexual encounters with prostitutes and failure to use condoms were also associated with increased risk. Syphilis, gonorrhoea, sex with prostitutes and unprotected sexual intercourse may be indicators of contact with a sexually transmissible factor that increases the risk of prostate cancer.

Rural–urban differences in stage at diagnosis. Possible relationship to cancer screening

Stage at diagnosis was examined for various malignancies identifiable through screening to determine whether rural–urban differences exist in Georgia. Data were obtained from a population‐based cancer registry which registers all incident cancers among residents of metropolitan Atlanta and ten neighboring rural counties. Black and white patients with a first primary invasive malignancy newly diagnosed between 1978 and 1985 were included in this study. Residents of the rural area were twice as likely to have unstaged cancers (18.3%) as were urban residents (9.6%). Among patients with known stage at diagnosis, rural patients tended to have more advanced disease than urban patients. The relative excess of nonlocalized malignancies in rural Georgia was 21% for whites and 37% for blacks. The rural excess of nonlocalized prostate cancer among blacks was especially pronounced. Differences in access to or utilization of early detection methods may contribute to the rural–urban differential in the extent of disease at diagnosis.

The NICHD Women's Contraceptive and Reproductive Experiences Study: Methods and Operational Results

PURPOSE This paper presents methods and operational results of a population-based case-control study examining the effects of oral contraceptive use on breast cancer risk among white and black women aged 35-64 years in five U.S. locations. METHODS Cases were women newly diagnosed with breast cancer during July 1994 through April 1998. Controls were identified through random digit dialing (RDD) using unclustered sampling with automated elimination of nonworking numbers. Sampling was density-based, with oversampling of black women. In-person interviews were conducted from August 1994 through December 1998. Blood samples were obtained from subsets of cases and controls, and tissue samples were obtained from subsets of cases. A computerized system tracked subjects through study activities. Special attention was devoted to minimizing exposure misclassification, because any exposure-disease associations were expected to be small. RESULTS An estimated 82% of households were screened successfully through RDD. Interviews were completed for 4575 cases (2953 whites; 1622 blacks) and 4682 controls (3021 whites; 1661 blacks). Interview response rates for cases and controls were 76.5% and 78.6%, respectively, with lower rates for black women and older women. CONCLUSIONS The methodologic details of this large collaboration may assist researchers conducting similar investigations.

Reproductive factors and subtypes of breast cancer defined by hormone receptor and histology

Reproductive factors are associated with reduced risk of breast cancer, but less is known about whether there is differential protection against subtypes of breast cancer. Assuming reproductive factors act through hormonal mechanisms they should protect predominantly against cancers expressing oestrogen (ER) and progesterone (PR) receptors. We examined the effect of reproductive factors on subgroups of tumours defined by hormone receptor status as well as histology using data from the NIHCD Womens Contraceptive and Reproductive Experiences (CARE) Study, a multicenter case–control study of breast cancer. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) as measures of relative risk using multivariate unconditional logistic regression methods. Multiparity and early age at first birth were associated with reduced relative risk of ER + PR + tumours (P for trend=0.0001 and 0.01, respectively), but not of ER − PR − tumours (P for trend=0.27 and 0.85), whereas duration of breastfeeding was associated with lower relative risk of both receptor-positive (P for trend=0.0002) and receptor-negative tumours (P=0.0004). Our results were consistent across subgroups of women based on age and ethnicity. We found few significant differences by histologic subtype, although the strongest protective effect of multiparity was seen for mixed ductolobular tumours. Our results indicate that parity and age at first birth are associated with reduced risk of receptor-positive tumours only, while lactation is associated with reduced risk of both receptor-positive and -negative tumours. This suggests that parity and lactation act through different mechanisms. This study also suggests that reproductive factors have similar protective effects on breast tumours of lobular and ductal origin.

Racial differences in the expression of cell cycle-regulatory proteins in breast carcinoma: Study of young African American and white women in Atlanta, Georgia

African‐American (AA) women are more likely to be diagnosed with an advanced stage of breast carcinoma than are white women. After adjustment for disease stage, many studies indicate that tumors in AA women are more likely than tumors in white women are to exhibit a high level of cell proliferation and features of poor prognosis. The purpose of the current study was to compare tumor characteristics and cell cycle alterations in AA women and white women that might affect the aggressiveness of breast carcinoma.

Secular Trends in Mortality From Common Cancers in the United States by Educational Attainment, 1993–2001

Background Death rates for the four major cancer sites (lung, breast, prostate, and colon and rectum) have declined steadily in the United States among persons aged 25–64 years since the early 1990s. We used national data to examine these trends in relation to educational attainment. Methods We calculated age-standardized death rates for each of the four cancers by level of education among 25- to 64-year-old non-Hispanic white and non-Hispanic black men and women for 1993 through 2001 using data on approximately 86% of US deaths from the National Center for Health Statistics, education level as recorded on the death certificate, and population data from the US Bureau of Census Current Population Survey. Annual percent changes in age-adjusted death rates were estimated using weighted log-linear regression models. All statistical tests were two-sided. Results Death rates for each cancer decreased statistically significantly from 1993 to 2001 in people with at least 16 years of education in every sex and race stratum except lung cancer in black women, for whom death rates were stable. For example, colorectal cancer death rates among white men, black men, white women, and black women with at least 16 years of education decreased by 2.4% (P < .001), 4.8% (P = .011), 3.0% (P < .001), and 2.6% (P = .030) annually, respectively. By contrast, among people with less than 12 years of education, a statistically significant decrease in death rates from 1993 through 2001 was seen only for breast cancer in white women (1.4% per year; P = .029). Death rates among persons with less than 12 years of education over the same time interval increased for lung cancer in white women (2.4% per year; P < .001) and for colon cancer in black men (2.7% per year; P < .001) and were stable for the remaining race/sex/site strata. Temporal trends generally followed an educational gradient in which the slopes of the decreases in death rate became steeper with higher educational attainment. Conclusion The recent declines in death rates from major cancers in the United States mainly reflect declines in more highly educated individuals.

Relationship between Established Breast Cancer Risk Factors and Risk of Seven Different Histologic Types of Invasive Breast Cancer

Background: Important differences in the contributions of certain exposures to the risks of ductal versus lobular breast carcinomas have been observed, but few studies have evaluated the relationships between established breast cancer risk factors and other histologic types. Methods: Information on family history of cancer and reproductive, hormonal, anthropometric, and lifestyle characteristics were collected in a multicenter population-based case-control study consisting of 3,463 ductal, 274 lobular, 261 ductal-lobular, 91 medullary, 77 tubular, 70 comedo, and 61 mucinous invasive breast carcinoma cases (ages 35-64 years, newly diagnosed 1994-1998) and 4,682 controls. Associations between each of these histologic types and various exposures were evaluated using polytomous regression. Results: Heterogeneity in the risks of different histologic types of breast cancer was observed for three exposures: menopausal hormone use, body mass index (BMI), and alcohol consumption. Specifically, current use of unopposed estrogen was associated with a reduced risk of ductal carcinoma and increased risk of comedocarcinoma, and current use of estrogen and progestin was associated with elevated risks of ductal-lobular and tubular carcinomas. Among postmenopausal women, BMI was only inversely related to risk of ductal-lobular carcinoma, and alcohol use was only positively related to risk of lobular carcinoma. Conclusions: Variations in the associations between known breast cancer risk factors and risk of different breast cancer histologies were observed. Although these findings require confirmation, and the analyses of some histologic groups were limited by small sample sizes, they provide some insight into the different etiologies of various histologic subtypes of breast cancer. (Cancer Epidemiol Biomarkers Prev 2006;15(5):946–54)

Reproductive factors and risk of breast carcinoma in a study of white and African-American women.

Few studies have investigated the association between reproductive factors and the risk of breast carcinoma among African‐American women. The authors assessed whether the number of full‐term pregnancies, age at first full‐term pregnancy, and total duration of breastfeeding were associated with similar relative risk estimates in white and African‐American women in a large multicenter, population‐based case–control study of breast carcinoma.