Smoking and bladder cancer risk in Blacks and Whites in the United States

A population-based case-control study of bladder cancer (2,982 cases and 5,782 controls) conducted in 10 areas of the United States examined the effect of smoking as a risk factor among Blacks and Whites, after adjustment for occupation and other potential confounders. Although the overall risk for smoking was slightly higher in Blacks than Whites (relative risk = 2.7 and 2.2, respectively), this difference was not statistically significant. Estimation of risk by dose and currency of exposure revealed no consistent racial disparities in smoking-related risks. Race-specific, attributable risk estimates indicated that nearly half of bladder cancers among both Blacks and Whites could have been prevented by elimination of smoking.     

Race and sex differences in associations of vegetables,fruits, and carotenoids with lung cancer risk in New Jersey (United States)

We used data from a case-control study conducted in New Jersey between 1980 and 1983 to evaluate race and sex differences in associations of vegetable, fruit, and carotenoid consumption with lung cancer. Cases included 736 White males, 860 White females, 269 Black males, and 86 Black females with incident, histologically confirmed, primary cancer of the trachea, bronchus, or lung. Controls were identified through drivers' license and Health Care Financing Administration files and included 548 White males, 473 White females, 170 Black males, and 47 Black females. Usual intakes of vegetables (predominantly yellow/green) and fruit (predominantly yellow/orange) as well as other food sources of carotenoids were ascertained by a food frequency questionnaire. White females showed significant inverse associations of lung cancer with vegetables, fruit, and carotenoids. White males showed nonsignificant inverse associations with vegetables and carotenoids, and Black females just with vegetables. No inverse associations were found for Black males. Vegetable consumption was associated with risk of all histologic types of lung cancer, but the pattern of increasing risk with decreasing intake was limited to smokers. We infer that consumption of yellow/green vegetables and carotenoids may confer protection from lung cancer to White male and White female smokers. Further studies are needed to clarify the effect in Blacks.Drs Dorgan and Shaw are with the Division of Cancer Prevention and Control, and Drs Ziegler and Hartge, and Ms Falk are with the Division of Cancer Etiology, National Cancer Institute, Bethesda, MD, USA. Authors also are affiliated with the Special Epidemiology Program, New Jersey State Department of Health, Trenton, NJ, USA (Ms Schoenberg and Mr Wilcox) and Information Management Services, Inc., Silver Spring, MD, USA (Ms McAdams). Address correspondence to Dr Dorgan, Division of Cancer Prevention and Control, National Cancer Institute, Executive Plaza North, Room 211, Bethesda, MD 20892, USA.     

Drinking practices and risk of squamous-cell esophageal cancer among Black and White men in the United States

To evaluate whether the fivefold greater incidence rate ofsquamous-cell esophageal cancer in Black compared with White men is due totype of alcoholic beverage consumed or to other qualitative differences inalcohol consumption, we conducted a population-based case-control studywith373 males diagnosed with squamous-cell esophageal cancer (124 Whites and249 Blacks) and 1,364 male controls (750 Whites and 614 Blacks) from threegeographic areas in the United States. Included were all histologicallyconfirmed cases newly diagnosed from 1 August 1986 through 30 April 1989,among White and Black men aged 30 to 79 years. Risks varied to some extentaccording to type of alcohol used, with beer a stronger contributor inWhites, and wine and liquor stronger contributors in Blacks. However, most ofthe differences in the odds ratios by type of alcohol and race wereeliminated after controlling for average weekly amount of total alcoholconsumed. Thus, while alcohol use in all forms is an important risk factorfor squamous-cell esophageal cancer in Whites and Blacks, type of alcoholicbeverage used does not appear to account for the racial differences inincidence.     

Racial differences in cervical cancer survival in the Detroit metropolitan area

BACKGROUND: African-American (AA) women have lower survival rates from cervical cancer compared with white women. The objective of this study was to examine the influence of socioeconomic status (SES) and other variables on racial disparities in overall survival among women with invasive cervical cancer. METHODS: One thousand thirty-six women (705 white women and 331 AA women) who were diagnosed with primary invasive cancer of the cervix between 1988 and 1992 were identified through the Metropolitan Detroit Cancer Surveillance System (MDCSS), a registry in the Surveillance, Epidemiology, and End Results (SEER) database. Pathology, treatment, and survival data were obtained through SEER. SES was categorized by using occupation, poverty, and educational status at the census tract level. Cox proportional hazards models were used to compare overall survival between AA women and white women adjusting for sociodemographics, clinical presentation, and treatment. RESULTS: AA women were more likely to present at an older age (P<.001), with later stage disease (P<.001), and with squamous histology (P=.01), and they were more likely to reside in a census tract categorized as Working Poor (WP) (P<.001). After multivariate adjustment, race no longer had a significant impact on survival. Women who resided in a WP census tract had a higher risk of death than women from a Professional census tract (P=.05). There was a significant interaction between disease stage and time with the effect of stage on survival attenuated after 6 years. CONCLUSIONS: In this study, factors that affected access to medical care appeared to have a more important influence than race on the long-term survival of women with invasive cervical cancer.     

Racial and ethnic disparities in the incidence of invasive cervical cancer in Florida

BACKGROUND:

Although cervical cancer incidence has declined in the past decade, considerable racial and ethnic differences remain. The objective of this study was to examine differences in incidence by histology and cancer stage in Florida stratified further by race, ethnicity, and 5‐year time intervals.

METHODS:

Women who were diagnosed with invasive cervical cancer in Florida between January 1985 and December 2004 were included in the analysis. Age‐adjusted incidence rates by race and ethnicity were estimated for different histologic types and stages of cancer. The annual percentage of change in incidence also was calculated for each histologic type. Rate ratios were estimated by race and ethnicity using whites and non‐Hispanics as the reference group.

RESULTS:

Overall, the incidence in Florida of cervical squamous cell carcinoma and transitional cell carcinoma declined significantly from 9.1 per 100,000 women in 1985 to 5.6 per 100,000 women in 2004 (P < .05), whereas the incidence of cervical adenocarcinoma remained stable (P > .05). The incidence of invasive cervical cancer was 9.6 per 100,000 women among whites and 13.13 per 100,000 women among African Americans from 2000 to 2004. African‐American women were nearly 2 times more likely to be diagnosed at regional and distant cancer stages than white women for all periods examined. Furthermore, among African‐American women aged >40 years, the age‐specific incidence of invasive cervical cancer increased considerably, whereas the rates among other racial groups decreased.

CONCLUSIONS:

The increasing rate of invasive cervical cancer among African‐American women aged >40 years in Florida, coupled with their diagnosis at a later stage of cancer, is of great concern. Most screening organizations recommend stopping screening at age 65 years. The observations from these analyses highlighted the need to focus prevention and screening efforts on African‐American women living in Florida, and particularly on women of postreproductive age. Cancer 2009. © 2009 American Cancer Society.     

Decreasing rates of cervical cancer among American Indians and Hispanics in New Mexico (United States)

Minority women in New Mexico (United States)—including American Indian and Hispanic women—have shown disproportionately high incidence rates of invasive cervical cancer during the 1960s and 1970s. Several public health programs in New Mexico were directed toward early detection of cervical cellular abnormalities, particularly targeting the state's minority women. To evaluate the effectiveness of these programs, we examined the New Mexico Surveillance, Epidemiology, and End Results (SEER) data collected from 1969–92, and calculated average annual, age-specific, and age-adjusted incidence rates by ethnic group (American Indian, Hispanic, and non-Hispanic White) for five-year time intervals. We also calculated age-adjusted mortality rates for cervical cancer in the same ethnic groups using state vital records. Age-adjusted incidence rates for invasive cervical cancer show substantial temporal decreases, especially for minority women in the state. The age-adjusted incidence rate decreased by 66 percent, from 30.3 to 10.3 per 100,000 for American Indian women, and by 61 percent, from 26.1 to 10.2 per 100,000 for Hispanic women. A stage shift to earlier stages of cervical neoplasia occurred over the study period, with a substantially higher proportion of in situ compared with invasive cancers diagnosed in the most recent cf the most remote time period. The ratio of incidence rates of in situ to invasive cancers changed dramatically for both American Indian and Hispanic women. Cervical cancer mortality rates decreased steadily among Hispanic women from 1958 to 1992; the decrease among American Indian women was less stable and fluctuated due to small numbers. Ongoing targeted sceening programs should help to reduce cervical cancer incidence and mortality further in New Mexico.Drs Chao, Becker, Jordan, Darling, Gilliland, and Key are with the New Mexico Tumor Registry/Epidemiology and Cancer Control Program, Albuquerque, NM, USA. Dr Jordan and also Dr Key are with the Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM. Address correspondence to Dr Chao, New Mexico Tumor Registry, University of New Mexico Cancer Research and Treatment Center, 900 Camino de Salud NE, Albuquerque, NM, 87131-5306, USA.     

Oral contraceptive use and breast cancer risk among African-American women

Recent epidemiologic studies, most of them in predominantly White populations, have suggested that long duration of oral contraceptive (OC) use may increase the risk of breast cancer at young ages. We assessed the relationship of OC use to the risk of breast cancer in African-American women aged 25 to 59 years, using interview data from a multipurpose hospital-based case-control study. Five hundred and twenty-four cases hospitalized for invasive breast cancer were compared with 1,021 controls with nonmalignant conditions unrelated to OC use. Relative risks (RR) and 95 percent confidence intervals (CI) were estimated relative to a reference category of use for less than 12 months; potential confounders were controlled by multiple logistic regression analysis. Among women under age 45, three or more years of OC use was associated with an increased risk of breast cancer: the RR estimate was 2.8 (CI=1.5–5.0) for three to four years of use, and declined to 1.5 (CI=0.8.3.0) for 10 or more years of use. Recency and timing of use did not explain the observed association. Among women aged 45 to 59, OC use was associated with little or no increase in risk: the RR estimate for three or more years of use was 1.3 (CI=0.7–2.4). The findings add to the evidence from studies of White women and a recent study of Black women which have suggested an increased risk of breast cancer at young ages for moderate or long duration use of OCs.This research was supported by the US National Cancer Institute (grants R01 CA55766 and R01 CA45762). Additional support was provided by the US Food and Drug Administration (FD-U-000082); the views expressed do not necessarily represent the views of the Food and Drug Administration. The Slone Epidemiology Unit also receives support from Hoffmann-La Roche, Inc., and Marion Merrell Dow Inc.     

Racial differences in lung cancer

Although race, in and of itself, is not a relevant biologic variable, racial differences in disease characteristics and outcomes have been reported in many malignancies, including lung cancer. The lung cancer incidence rate in blacks has been consistently higher than that in whites for many years. This racial disparity is seen primarily in men and is significantly greater in younger age groups. The reason for higher lung cancer incidence rates in blacks remains unclear, but racial differences in smoking habits, socioeconomic variables, and the metabolism of tobacco carcinogens may all play an important role. Blacks are also more likely than whites to present with squamous cell carcinoma and with advanced-stage disease. A significant racial difference in survival rates has developed over the past 30 years, with a poorer prognosis noted in black patients, particularly those with local- and regional-stage disease. This disparity appears to be due to a lack of improvement in the survival of black patients with lung cancer, but the biological and/or societal basis for racial variations in survival have not been determined. In summary, significant racial differences exist in lung cancer incidence and survival rates. Further research is required to determine the factors responsible for these differences and to develop effective preventative and therapeutic interventions that will impact favorably on the incidence and prognosis of this disease.     

Family history of cancer and renal cell cancer risk in Caucasians and African Americans

Background:

The association between renal cell carcinoma (RCC) risk and family history of cancer has not been examined with an adequate number of African Americans (AAs).

Methods:

In a population-based case–control study, unconditional logistic regression was used to calculate the association between RCC risk and a family history of cancer among 1217 RCC cases and 1235 controls.

Results:

Increased RCC risk was shown for subjects with at least one first-degree relative with kidney cancer (odds ratio=2.29; 95% confidence interval=1.31–4.00). No differences in risk were observed when analyses were stratified by race. For Caucasians, excess risk was observed among those reporting a sibling with kidney cancer, whereas for AAs, increased risk occurred among subjects reporting either a sibling or parent affected with the disease. A family history of non-renal cancers, and those related to smoking or to the von Hippel–Lindau syndrome, revealed no association with RCC risk.

Conclusion:

The RCC risk associated with a family history of kidney cancer is similar among Caucasians and AAs.     

Colon cancer incidence: recent trends in the United States

Between 1976–78 and 1985–87, the age-adjusted incidence rates of invasive colon cancer in the United States rose by 15 percent, 3 percent, 21 percent, and 16 percent among White males, White females, Black males, and Black females, respectively. The increases in incidence occurred in all age groups over age 54 and affected each of the major subsites of the colon nearly equally. The larger rates of increase have resulted in higher incidence among Blacks than Whites by the mid-1980s and an increasingly greater excess of this cancer in males. Trends toward earlier diagnosis of invasive colon cancer were found, with increasing rates for localized and regional diseases coupled with stable or decreasing distant-stage disease-rates. The incidence ofin situ colon cancer also rose substantially. The findings suggest that changes in diagnostic trends and risk-factor prevalence may be contributing to these patterns, and that the era when colon cancer predominated among White females is clearly over.Authors are with the Epidemiology and Biostatistics Program, Division of Cancer Etiology, National Cancer Institute, National Institutes of Health. Address correspondence to Dr Chow, National Cancer Institute, 6130 Executive Blvd, EPN Room 407, Rockville, MD 20892, USA.     

Risk of urinary bladder cancer among Blacks and Whites: the role of cigarette use and occupation

A case-control study was conducted in the United States to examine the relationship between urinary bladder cancer, usual occupation and industry, and cigarette smoking. A total of 2,160 bladder cancer cases and 3,979 colon and rectum comparison cases, with complete histories of occupation and tobacco use, were included in the analysis. Ever having smoked cigarettes significantly elevated bladder cancer risk (odds ratio = 2.4). A dose-response relationship was demonstrated between bladder cancer and pack-years of smoking, usual number of cigarettes smoked per day, and number of years having smoked. This study observes greater risk of urinary bladder cancer due to cigarette smoking among Black males and females than among White males and females. A significant excess of bladder cancer was found among armed services personnel; this excess was restricted to White males when the analysis was performed separately by race. Black males with mechanic as their usual occupation had a significant sevenfold excess of bladder cancer. The population attributable risks for occupation and smoking were 25 percent and 51 percent, respectively. The results demonstrate the strength of the association between cigarette smoking and bladder cancer and the need to control for smoking in occupational analyses.Authors are in the College of Human Medicine, Michigan State University. Address correspondence to Dr G. Marie Swanson, Professor of Medicine, College of Human Medicine, Michigan State University, A-211 East Fee Hall, East Lansing, MI 48824-1316, USA. This study was supported in part by grant RO1-OHO2067 from the National Institute for Occupational Safety and Health and by contract NO1-CN-05225 from the National Cancer Institute.     

Racial differences in medical mistrust among men diagnosed with prostate cancer

BACKGROUND:

Mistrust of healthcare providers and systems is a significant barrier to quality healthcare. However, limited empirical data are available on perceptions of medical mistrust among individuals who are diagnosed with cancer. The objective of this study was to identify sociodemographic, clinical, and cultural determinants of mistrust among men diagnosed with prostate cancer.

METHODS:

The authors conducted an observational study among 196 African‐American men (n = 71) and white men (n = 125) who were newly diagnosed with prostate cancer during 2003 through 2007.

RESULTS:

Race, education, healthcare experiences, and cultural factors had significant effects on mistrust. African‐American men (P = .01) and men who had fewer years of formal education (P = .001) reported significantly greater levels of mistrust compared with white men and men who had more education. Mistrust also was greater among men who had been seeing their healthcare provider for a longer period (P = .01) and among men with lower perceptions of interdependence (P = .01).

CONCLUSIONS:

The current findings suggested that efforts to enhance trust among men who are diagnosed with prostate cancer should target African‐American men, men with fewer socioeconomic resources, and men with lower perceptions of interdependence. Reasons for deterioration in trust associated with greater experience with specialty providers should be explored along with the effects of interventions that are designed to address the concerns of individuals who have greater mistrust. Cancer 2009. © 2009 American Cancer Society.     

Differences between Black and White patients with cancer of the uterine corpus in interval from symptom recognition to initial medical consultation (United States)

To determine whether Black women with symptoms of uterine corpus cancer had longer times from symptom recognition to initial medical consultation than did White women in the United States, 331 newly diagnosed patients living in Atlanta (GA), New Orleans (LA), and San Francisco/Oakland (CA) during 1985–87 were interviewed to collect information on symptoms, dates of recognition and consultation, and other factors that might affect the interval. Data were analyzed to estimate medical consultation rates and rate ratios following sysptom recognition. Median recalled times between symptom recognition and consultation were 16 days for Black women and 14 days for White women. Although poverty, having no usual source of healthcare, and other factors were associated with lower consultation rates, the adjusted rate among Black women was only somewhat lower (0.87) than among White women, and the 95 percent confidence interval (CI=0.58–1.31) was consistent with no true difference between the races. In addition, the median time to consultation for women with stage IV cancer was only 15 days longer than the time (14 days) for the women with stage I cancer. These results suggest that time from symptom recognition to initial medical consultation does not contribute importantly to the more advanced stage cancer of the uterine corpus commonly found among Black women.Drs Coates and Eley and Ms Click are with the Department of Epidemiology, Rollins School of Public Health of Emory University, Atlanta, GA (USA). Authors are also with the Division of Cancer Prevention & Control, National Cancer Institute, Rockville, MD (Drs Harlan and Edwards); Department of Pathology Obstetrics and Gynecology, Duke University Medical Center, Durham, NC (Dr Robboy); Forsyth Medical Park, Winston-Salem, NC (Dr Barrett); Environmental Epidemiology Section, California State Department of Health Services, Emeryville, CA (Dr Reynolds); Department of Pathology, Louisiana State University Medical Center, New Orleans, LA (Dr Chen); School of Public Health, University of Massachusetts, Amberst, MA (Dr Darity); Office of the President, Northeastern Ohio Universities College of Medicine, Rootstown, OH (Dr Blacklow). Address correspondence to Dr Coates, Department of Epidemiology, Rollins School of Public Health of Emory University, 1518 Clifton Road, NE, Atlanta, GA 30322, USA. This research was supported in part by contracts N01CN-35042-46, N01CN-05227, N01CN-45174, and N01CN-45176 from the National Cancer Institute, US National Institutes of Health.     

Breastfeeding and breast cancer risk

A population-based case-control study of breast cancer with a focus on premenopausal women under 45 years of age, conducted in three geographic regions of the United States, enabled the evaluation of risk in relation to varying breastfeeding practices. Among premenopausal parous women (1,211 cases, 1,120 random-digit-dialing controls), a history of breastfeeding for two or more weeks was associated with a relative risk (RR) of 0.87 (95 percent confidence interval [CI]=0.7–1.0). This relationship was not altered substantially by removing from the reference group women who had problems with breastfeeding in the first two weeks, including those with insufficient milk production. Risk was not related substantially to number of children breastfed or length of breastfeeding, although a relatively low risk was observed among those breastfeeding for the longest duration examined (RR=0.67, CI=0.4–1.1 for an average period per child of 72 or more weeks). Women who began to breastfeed at a young age (<22 years) experienced the greatest reduction in risk, but other timing parameters (e.g., interval since first or last breastfeeding) were not predictive of risk. Risks were not modified substantially by age or menopause status, although the number of menopausal subjects examined was limited. Use of medications to stop breast milk was unrelated to risk (RR=1.04). The results of this study do not support the notion that breastfeeding substantially reduces breast cancer risk; however, this may reflect the fact that most of our study subjects breastfed only for limited periods of time (average breastfeeding per child of 30 weeks). Further studies are needed to clarify the relationship of breastfeeding to breast cancer risk, and to determine possible etiologic mechanisms underlying any observed associations.Drs Brinton, Potischman, and Swanson are with the Environmental Epidemiology Branch, National Cancer Institute, Betbesda, MD, USA. Authors also are affiliated with the Special Epidemiology Program, New Jersey State Department of Health, Trenton, NJ, USA (Ms Schoenberg); Rollins School of Public Health, Emory University, Atlanta, GA, USA (Dr Coates); the Division of Epidemiology, Columbia University School of Public Health, New York, NY, USA (Dr Gammon); and the Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA (Drs Malone, Stanford, Daling). Address correspondence to Dr Brinton, Environmental Epidemiology Branch, National Cancer Institute, Executive Plaza North, Room 443, Bethesda, MS 20892, USA.     

Racial and ethnic differences in breast cancer survival

BACKGROUND: The reasons for race/ethnicity (R/E) differences in breast cancer survival have been difficult to disentangle. METHODS: Surveillance, Epidemiology, and End Results (SEER)-Medicare data were used to identify 41,020 women aged > or =68 years with incident breast cancer between 1994-1999 including African American (2479), Hispanic (1172), Asian/Pacific Island (1086), and white women (35,878). A Cox proportional hazards model assessed overall and stage-specific (0/I, II/III, and IV) R/E differences in breast cancer survival after adjusting for mammography screening, tumor characteristics at diagnosis, biologic markers, treatment, comorbidity, and demographics. RESULTS: African American women had worse survival than white women, although controlling for predictor variables reduced this difference among all stage breast cancer (hazards ratio [HR], 1.08; 95% confidence interval [95% CI], 0.97-1.20). Adjustment for predictors reduced, but did not eliminate, disparities in the analysis limited to women diagnosed with stage II/III disease (HR, 1.30; 95% CI, 1.10-1.54). Screening mammography, tumor characteristics at diagnosis, biologic markers, and treatment each produced a similar reduction in HRs for women with stage II/III cancers. Asian and Pacific Island women had better survival than white women before and after accounting for all predictors (adjusted all stages HR, 0.61 [95% CI, 0.47-0.79]; adjusted stage II/III HR, 0.61 [95% CI, 0.47-0.79]). Hispanic women had better survival than white women in all and stage II/III analysis (all stage HR, 0.88; 95% CI, 0.75-1.04) and stage II/III analysis (HR, 0.88; 95% CI, 0.75-1.04), although these findings did not reach statistical significance. There was no significant difference in survival by R/E noted among women diagnosed with stage IV disease. CONCLUSIONS: Predictor variables contribute to, but do not fully explain, R/E differences in breast cancer survival for elderly American women. Future analyses should further investigate the role of biology, demographics, and disparities in quality of care.     

Screening endoscopy and risk of colorectal cancer in United States men

Objectives: The purpose of this study was to describe the effect of screening endoscopy (sigmoidoscopy or colonoscopy) on colorectal cancer incidence and mortality. Methods: We used data from a prospective cohort study of 24,744 men aged 40 to 75 years in 1986, free from cancer and colon polyps, followed until 1994. The outcomes are diagnosis of colorectal cancer and death from colorectal cancer. Results: Screening endoscopy in 1986-87 was associated with a lower risk of all colorectal cancer (multivariate relative risk [RR]=0.58, 95 percent confidence interval [CI]=0.36-0.96); cancer in the distal colon or rectum (multivariate RR=0.40, CI=0.19-0.84); Dukes stage A&B (multivariate RR=0.66, CI=0.35-1.25); and Dukes stage C&D (multivariate RR=0.50, CI=0.20-1.26) colorectal cancer; and death from colorectal cancer (multivariate RR=0.56, CI=0.20-1.60), after adjusting for age and a wide range of colon cancer risk factors. Screening endoscopy in 1988-87 appeared to provide strong protection against distal stage C&D cancers (age-adjusted RR=0.16, CI=0.02-1.23) but no protection against proximal stage C&D cancers (age-adjusted RR=0.96, CI=0.32-2.91). Conclusions: This study provides strong evidence for a protective effect of screening sigmoidoscopy on colorectal cancer incidence and mortality and supports recommendations for screening sigmoidoscopy as an approach to colon cancer prevention.     

Obesity and cancer risk among white and black United States veterans

BACKGROUND: Obesity has been linked to excess risk for many cancers, but the evidence remains tenuous for some types. Although the prevalence of obesity varies by race, few studies of obesity-related cancer risk have included non-white subjects. METHODS: In a large cohort of male US veterans (3,668,486 whites; 832,214 blacks) hospitalized with a diagnosis of obesity between 1969 and 1996, we examined risk for all major cancer sites and subsites. Person-years accrued from the date of first obesity diagnosis until the occurrence of a first cancer, death, or the end of the observation period (September 30, 1996). We calculated age- and calendar-year adjusted relative risks (RR) and 95% confidence intervals (CI) for cancer among white and black veterans, comparing obese men to men hospitalized for other reasons, with obesity status as time-dependent. For selected cancers, we performed additional analyses stratified by specific medical conditions related to both obesity and risk of those cancers. To determine whether obesity-related cancer risks differed significantly between white and black men, we evaluated heterogeneity of risk for each cancer site. RESULTS: Among white veterans, risk was significantly elevated for several cancers, including cancers of the lower esophagus, gastric cardia, small intestine, colon, rectum, gallbladder and ampulla of vater, male breast, prostate, bladder, thyroid, and connective tissue, and for malignant melanoma, multiple myeloma, chronic lymphocytic leukemia (CLL), and acute myeloid leukemia (AML). Excess risks initially observed for cancers of the liver and pancreas persisted among men without a history of diabetes or alcoholism. Among black veterans, risks were significantly elevated for cancers of the colon, extrahepatic bile ducts, prostate, thyroid, and for malignant melanoma, multiple myeloma, CLL and AML. CONCLUSIONS: Obese men are at increased risk for several major cancers as well as a number of uncommon malignancies, a pattern generally similar for white and black men. Due to the increasing prevalence of obesity and overweight worldwide, it is important to clarify the impact of excess body weight on cancer and to elucidate the mechanisms involved.     

Vasectomy and the risk of prostate cancer in a cohort of multiphasic health-checkup examinees: second report

The relationship of vasectomy to prostate cancer was studied in 5,119 men with a self-reported history of vasectomy, identified at multiphasic health checkups undergone during 1977–82 while members of the Northern California Kaiser Permanente Medical Care Program. Three unvasectomized comparison subjects were identified for each vasectomized man, matched for age, race, marital status, and date and location of the examination. Follow-up for incident prostate cancer was conducted for a mean length of 6.8 years. The relative risk of prostate cancer associated with vasectomy was 1.0 (95% confidence interval = 0.7–1.6); the relative risk was approximately one, regardless of length of interval (less than 10 years, 10–20 years, more than 20 years) between vasectomy and multiphasic health checkup or the age at vasectomy (less than 40 years vs more than 40 years). These data support earlier findings reported in this study group of the lack of an association of vasectomy with subsequent risk of prostate cancer.Supported by a grant from Merck Sharp and Dobme Research Laboratories.