Association between smoking and deaths due to colorectal malignant carcinoma: a national population-based case-control study in China.

BACKGROUND: This study explored the association between smoking and colorectal malignant carcinoma (CRC) in the Chinese population at the national level for the first time. METHODS: In the China Nationwide Retrospective Mortality Survey conducted during 1989-1991, 12,942 CRC cases among 1,136,336 all-cause deaths aged ≥30 years were randomly assigned 25,884 control interviews from 325,255 surviving spouses of all-cause deaths across 103 urban and rural areas. RESULTS: Compared with non-smokers, smoking significantly increased the risk of CRC-specific mortality by 9.8% (odds ratio (OR)=1.098, 95% confidence interval (CI)=1.046-1.153) adjusted for sex, age, and residence. There were significant dose-response relationships between smoking and CRC, such as smoking years, cigarettes smoked daily, and age at onset of smoking. Long-term heavy smokers aged ≥50 years with ≥30 smoking years and ≥20 cigarettes daily had an excess risk of CRC deaths of 30.2% (OR=1.302, 95% CI=1.214-1.397). The strongest association between these smoking variables, such as long-term heavy smokers (OR=1.604, 95% CI=1.341-1.919), and CRC was observed among rural men. CONCLUSIONS: Quitting smoking at any time would likely be beneficial to CRC prevention. Long-term heavy smokers and rural men should be viewed as special targets for smoking prevention and cessation programs.

Relationship of hair dye use, benign breast disease, and breast cancer.

An epidemiologic case-control study of 118 breast cancer patients and 233 controls was conducted to test the hypothesis that hair dyes are related to breast cancer. Matched controls were selected by "random digit dialing," and all epidemiologic data were collected by telephone interviews. No overall association was detected. On a prospective basis, the interaction between hair dye exposure and six variables known to be risk factors for breast cancer then were examined: previous benign breast disease (BBD), "ever" versus "never" pregnant, age at first pregnancy, menopause induced by operation, age at menarche, and education. A statistically significant increased risk of breast cancer was found for women with a history of BBD and exposure to hair dyes as compared to women with BBD but no hair dye exposure: The relative risk (RR) was 4.5, and the 95% confidence intervals (C) were 1.20 and 15.78. A total of 24 women (19 patients and 5 controls) reported a history of BBD and hair dye use. Further analysis revealed a significant association between hair dye use and breast cancer among women 40-49 years of age (RR = 3.33; 95% CI: 1.1 and 10.85) and a highly significant (P = 0.0008) dose-response relationship among women who used hair dyes for changing their natural color as opposed to covering gray hair. The numbers of patients and controls included in this study were small and several hypotheses were tested. Additional epidemiologic studies are needed before firm conclusions can be reached concerning the nature of these associations.

Relationship of leukemia risk to radiation dose following cancer of the uterine corpus.

BACKGROUND: Radiotherapy has been linked infrequently to secondary leukemia despite extensive exposure of the active bone marrow to ionizing radiation. Few studies include substantial numbers of elderly patients. PURPOSE: We evaluated women with cancer of the uterine corpus, the majority of whom were treated at older ages, to gain additional information on cancer risk following partial-body radiotherapy and to examine differences in risk between external-beam therapy and brachytherapy. METHODS: A cohort of 110,000 women with invasive cancer of the uterine corpus who survived at least 1 year following their initial cancer was assembled from nine population-based cancer registries. Cancer diagnoses occurred from 1935 through 1985, and most patients were diagnosed during the 1960s and 1970s. Radiation doses were computed to 17 sections of the active bone marrow for 218 women who developed leukemia and for 775 matched control subjects. RESULTS: Radiotherapy did not increase the risk of chronic lymphocytic leukemia (CLL) (relative risk [RR] = 0.90; 95% confidence interval [CI] = 0.4-1.9). However, for all leukemias except CLL, a significant risk was identified (RR = 1.92; 95% CI = 1.3-2.9). Overall, the pattern of risk in relation to dose was erratic and was most consistent with a constant increased risk across the entire dose range. The risk following continuous exposures from brachytherapy at comparatively low doses and low dose rates (RR = 1.80; 95% CI = 1.1-2.8; mean dose = 1.72 Gy) was similar to that after fractionated exposures at much higher doses and higher dose rates from external-beam treatment (RR = 2.29; 95% CI = 1.4-3.7; mean dose = 9.88 Gy), indicating a large difference in the estimated risk per unit dose. Risk did not vary by age at first exposure; increased risks were apparent for irradiated patients aged 65 years or older (RR = 1.77; 95% CI = 0.9-3.5). CONCLUSION: The leukemia risk associated with partial-body radiotherapy for uterine corpus cancer was small; about 14 excess leukemia cases were due to radiation per 10,000 women followed for 10 years. Women aged 65 years or older had a radiation risk comparable with that found in younger women. The relationship of leukemia risk to radiation dose was found to be complex due to the competing processes of cell killing, transformation, and repair. At very high doses delivered at high rates, destruction of cells likely dominates, and the risk per unit dose is low. In the low dose range, where dose was protracted and delivered at relatively low dose rates, the leukemia risk appears lower than that projected from risk estimates derived from the instantaneous whole-body exposures of atomic bomb survivors.

Multiple births and risk of epithelial ovarian cancer.

BACKGROUND AND METHODS: Prevailing hypotheses about the causes of ovarian carcinogenesis predict that women with a history of multiple births (twins, triplets, etc.) should be at increased risk of epithelial ovarian cancer. However, the scant available evidence suggests that they may actually be at lower risk. To resolve this issue, we pooled data from eight studies involving 2859 parous women with epithelial ovarian cancer (case patients) and 7434 parous women without ovarian cancer (control women). In addition to assessing their history of multiple births (and the sex of the children, where available), we obtained information on age, parity, oral contraceptive use, and other reproductive factors for each woman. Details of tumor histology were available for all case patients. We estimated the relative risks of various histologic types of ovarian cancers associated with multiple births by using multivariable logistic regression analysis, adjusting for matching and confounding variables. RESULTS: Among these parous women, 73 case patients (2. 6%) and 257 control women (3.5%) had a history of multiple births. The adjusted summary odds ratio (OR) for developing all types of epithelial ovarian cancer that are associated with multiple births was 0.81 (95% confidence interval [CI] = 0.61-1.08). We found no evidence that risks associated with multiple births differed among women with borderline or invasive tumors and among women with same-sex and opposite-sex offspring from multiple births. The risk reductions appeared specific for nonmucinous tumors (n = 2453; summary adjusted OR = 0.71 [95% CI = 0.52-0.98]); in contrast, associations with mucinous tumors (n = 406) were heterogeneous across studies. CONCLUSIONS: Parous women with nonmucinous ovarian cancer are no more likely to have a history of multiple births than other parous women, counter to the predictions of current hypotheses for causes of ovarian cancer.

Cancer in United States Jews.

The published studies of cancer of United States Jews are reviewed. Despite the lack of religious designation on death certificates, case reports, and census returns, a number of indirect methods for measuring the problem have been devised, which produce fairly consistent findings. In general, for American Jews, these show deficits in cancer mortality, among males, for the buccal cavity and pharynx and prostate and, among females, for the breast, uterine cervix and corpus, and bladder. Excesses in mortality, noted for both sexes, are esophagus, stomach, colon, pancreas, lymphomas, and leukemia and, in females, the lung and the ovary. The standardized mortality ratios for cancer of selected sites for Russian-born residents of upstate New York, 1969 through 1971, are presented as an indirect measure of the problem in the United States Jews. Statistically significant excesses were found in males for stomach and colon, with a striking deficit in cancer of the buccal cavity and pharynx. Among females, excesses were noted for stomach, pancreas, and lung with a sharp deficit in the uterine cervix. On the basis of the religious affiliation of the cemetery of burial, estimates of the Jewish and non-Jewish components of the 800 deaths in Russian-born residents were determined. Expected deaths in these two subgroups by sex, for each cancer site, were then calculated by use of the site-specific proportionate mortality of upstate New York for these years. This revealed a significant excess among Jewish males for colon cancer, with a deficit in lung cancer, while among the non-Jewish male components stomach cancer mortality was the only site significantly in excess. Among Jewish females, stomach and lung cancers were in excess, with a deficit in cancers of the breast and cervix uteri. In non-Jewish Russian-born females, the only site significantly in excess was stomach, with breast cancer showing a deficit.

An epidemiologic case-control study of breast cancer and exposure to hair dyes.

An epidemiologic case-control study of 1617 patients with a primary breast cancer and 1617 control subjects was conducted to test the hypothesis that use of hair dyes is related to breast cancer. No overall association was observed between breast cancer risk and "ever use" of hair dyes (odds ratio, 1.04; 95% confidence interval, 0.90 to 1.21), age when hair dye use started and age when it stopped, duration of hair dye use (years), types of hair dyes used, and estimated lifetime number of individual applications. The current data set also failed to show an increased risk for breast cancer in women who had been diagnosed with benign breast disease and were exposed to hair dyes.

Diet and the risk of vulvar cancer.

In this case-control study, 201 case patients with vulvar cancer and 342 community control subjects responded to a 61-item food frequency questionnaire. Risk was unrelated to intake of dark green vegetables, citrus fruits, legumes, and vitamins A and C and folate. Risk increased modestly with decreased intake of dark yellow-orange vegetables; the relative risk for the lowest versus the highest quartile was 1.6. Analyses using preliminary determinations of the major carotenoids in common fruits and vegetables suggested that alpha carotene might be the protective constituent in dark yellow-orange vegetables. Intake of beta carotene and provitamin A carotenoids was unrelated to risk. Multivitamin users were at lower risk, compared to nonusers, but no trend was observed with increasing years of use, suggesting that this association was due to unmeasured differences in life-style factors. Risk increased irregularly with the number of cups of coffee consumed per week whereas consumption of alcohol was unrelated to risk.

Cigarette smoking and breast cancer.

An epidemiological case-control study was conducted in New York State, with 1617 primary breast cancer patients and an equal number of controls, to examine the relationship between cigarette smoking and breast cancer. Results showed no overall association between ever smokers versus never smokers and breast cancer risk (odds ratio [OR] = 1.03, 95% confidence interval [CI]: 0.90-1.19), nor was there any dose response trend observed with increased levels of smoking. In addition, no association was found with risk and age started smoking, age stopped smoking, amount smoked or total years smoked. Controlling for previously identified risk factors for breast cancer in the analysis did not significantly alter these relationships. Previous studies have found a difference in menopausal age among smokers compared to nonsmokers. The mean menopausal age was only slightly lower in smokers than in never smokers for both cases and controls. Breast cancer risk was observed to be close to unity for premenopausal women (OR = 0.97, 95% CI: 0.74-1.34) and postmenopausal women (OR = 1.06, 95% CI: 0.91-1.26). A recent study suggested breast cancer risk was more strongly related to starting smoking at a young age among women who smoked at least 25 or more cigarettes per day in the most recent year of smoking. This hypothesis was not supported by these data.

Investigation of a testicular cancer cluster using a case-control approach.

A case-control methodology was developed and utilized to investigate a reported cluster of testicular cancer among leather workers in New York. Eighteen cases of testicular cancer, including the three index cases, diagnosed from 1974 to 1986 among residents of two counties with substantial leather tanning and finishing establishments made up the case group. Controls (n = 259) consisted of men of similar age who had been diagnosed with cancers of all other sites during the same time period. Reports of usual occupation for cases and controls, obtained from cancer registry reports and death certificates, indicated that cases were much more likely to be leather workers (28%) than controls (7%). After adjustment for age, the relative risk estimate for occupation and testicular cancer was 7.2 (95% Cl: 1.9-27.7). The association was further supported by occupational histories showing similar work environments within the leather industry for five out of six cases known to have been leather workers. Case-control analysis of a reported cluster does not provide independent confirmation of an association between occupational factors and testicular cancer. The methodology, however, can provide a timely way to evaluate the significance of occupational cancer clusters.

Population density and cancer mortality differentials in New York State, 1978-1982.

Patterns of cancer mortality within five population density quintiles in Upstate New York (New York State, exclusive of New York City), were investigated between 1978 and 1982. Sex-specific standardized mortality ratios (SMRs) were calculated within each population density quintile for all cancer deaths combined and for site-specific cancer deaths based on cancer mortality patterns exhibited by the general population of New York State, exclusive of New York City. Areas with the highest population density demonstrated a 12% excess of cancer deaths among males and a 6% excess among females. In contrast, areas with the lowest population density exhibited lower cancer mortality, among both males (9% less) and females (7% less). Males demonstrated a significant linear relationship between increasing population density and deaths for all cancer sites combined and for cancers of the oral cavity and pharynx, oesophagus, stomach, colon, gallbladder, pancreas, lung, prostate, and kidney. Among females, a significant linear relationship was observed between increasing population density and deaths for all cancer sites combined and for deaths due to cancers of the stomach, colon, liver and breast. Deaths due to cancers of the rectum, malignant melanomas of the skin, and cervix also exhibited unusual patterns of mortality across the population density quintiles. These data are most useful in generating hypotheses for further studies to define specific aetiological factors operating within population density groupings. Population density, as measured in this investigation, may represent a surrogate measure for other factors which are related to cancer morbidity and cancer mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Oestrogen replacement therapy and breast cancer risk: a case-control study.

The relationship between oestrogen replacement therapy and breast cancer risk was examined based on data obtained from a population-based case-control study of breast cancer on Long Island, New York, USA. Cases were defined as female residents of two Long Island counties, aged 20-79, who were diagnosed with breast cancer between 1 January 1984 and 31 December 1986. Age- and county-matched controls were selected from driver's licence files. Among all postmenopausal women, there was no significant association between ever-use of hormones to treat menopausal symptoms and breast cancer risk. There was also no significant positive association in any subgroup defined by type of menopause (natural, hysterectomy with at least one ovary intact, bilateral oophorectomy) or age at menopause. Additionally, there was no increasing trend in risk with duration of use either overall or in any subgroup, nor was there an effect at any interval since last use. A significant elevation in risk was observed in women with 10-19 years since first exposure, which was concentrated in women with a natural menopause or hysterectomy with at least one ovary remaining, and women aged > 45 at menopause. Results of logistic regression analysis revealed no important confounding by any of several established breast cancer risk factors. However, a significant interaction was observed between body mass index (BMI) and oestrogen use, with an effect of oestrogen use being seen only in the thinnest tercile. Although biologically plausible explanations for this finding exist, the effect of chance cannot be ruled out.

Cholesterol and cancer in a population of male civil service workers.

Cancer incidence and mortality were ascertained in a cohort of 1910 male participants of the Albany Cardiovascular Health Center (CVHC). The New York State Cancer Registry, vital records files, CVHC follow-up records, New York State Retirement System files, and New York State Department of Motor Vehicles driver's license files were used. Serum cholesterol measurements as well as values for other exposure variables were obtained from records of medical examinations which began in 1953-1954. The study cohort was divided into two groups, based on initial serum cholesterol measurement (less than or equal to 190 mg/100 ml and less than or equal to 190 mg/100 ml). For total cancers, both incidence and mortality were similar in these groups. For digestive cancer, both incidence and mortality were slightly lower in the less than or equal to 190 mg/100 ml group. The deficit was not statistically significant. For respiratory cancer, relative risk and rate ratio estimates were in the range of 1.4-1.7 for incidence and mortality. The excess risk in the less than or equal to 190 mg/100 ml group was of borderline statistical significance. The association was concentrated in the lowest cholesterol quintile rather than suggesting a strong dose-response relationship. The estimates were not found to be confounded by cigarette smoking, body mass index, education or age. A reduction in the crude rate ratio estimate from 1.5 to 1.2 was observed when early cases were excluded, suggesting that part of the observed excess may be due to preclinical cancer.

An epidemiological case-control study of breast cancer and alcohol consumption.

A case-control study of breast cancer and alcohol consumption was conducted with 1617 patients diagnosed with a primary cancer of the breast between 1982 and 1984 in 18 New York State counties. For each case, one control, matched for year of birth and county of residence, was selected from the driver's license files of the New York State Department of Motor Vehicles. Breast cancer risk was shown to increase as daily consumption of alcohol increased, with a risk of 1.37 (95% Cl = 1.07, 1.75) observed among women who consumed 15 or more grams of alcohol per day. Breast cancer risk did not appear to be related to the total number of years a woman drank or to be restricted to specific types of alcoholic beverages. The data suggest that this may be higher in women who began drinking at a later age. The increased risk associated with alcohol consumption, observed in the current study, persisted within strata of various breast cancer risk factors.

Timing of prenatal care and risk of sudden infant death syndrome.

Sudden infant death syndrome (SIDS) is the leading cause of death during post-neonatal life. Mothers whose infants succumb to SIDS are reported to initiate prenatal care later than control mothers. Previous studies have not always controlled for socioeconomic status (SES) of mothers or other potential confounders such as gestational age or birthweight of infants. The purpose of this study was to assess whether timing of prenatal care adjusted for these potential confounders was an independent risk factor for SIDS. SIDS cases (N = 148) were identified from the Upstate New York livebirth cohort for 1974 (N = 132,948) and compared to randomly selected controls (N = 355) who were frequency-matched on maternal age, race, parity and residence and infant's birth date. Data were abstracted from matched vital certificates (97% response), hospital delivery records (89% response) and selected sample of autopsy reports (100% response). Odds ratios (OR) and 95% confidence intervals (CI) were obtained using unconditional logistic regression. A significant inverse relationship was observed for number of prenatal visits and risk of SIDS; a significant direct relationship was observed between trimester prenatal care initiated and risk of SIDS. The results suggest that timing of prenatal care is important in assessing SIDS risk even after adjusting for potential confounders of early prenatal care utilization.

Case-control study of cancer of the vulva.

A case-control study of 209 vulvar cancer patients and 348 community controls allowed assessment of risk factors for this rare tumor. As with cervical cancer, risk increased with the number of reported lifetime sexual partners, with five or more partners associated with two- to threefold increases in risk compared with zero to one partner. This factor largely explained the associations of risk with early age at first intercourse and low socioeconomic status. An independent association, however, was noted between vulvar cancer and a history of genital warts (relative risk 15.2; 95% confidence interval 5.5-42.1). Women who reported a previous abnormal Papanicolaou smear were at excess risk (relative risk 1.8), as were current smokers (relative risk 2.0). A significant interaction was noted between smoking and genital warts, with women reporting both having 35 times the risk of those with neither factor. Menstrual, reproductive, and hygiene factors were generally unrelated to risk. The relationships with sexual factors and genital warts support a common etiology for cervical and vulvar cancers. Future studies should focus on the etiologic agents for genital warts--the human papillomaviruses--and their enhancement by other factors, especially smoking and/or immune deficiencies.

Cancer incidence following exposure to drinking water with asbestos leachate.

In November 1985, the New York State Department of Health was altered to extraordinary concentrations of asbestos leachate in the drinking water in the Town of Woodstock. Concentrations of 3.2 million fibers per liter (MFL) to 304.5 MFL were found, depending on location. An investigation of cancer incidence in the area was conducted for the period 1973-83 using the State Cancer Registry to compute standardized incidence ratios. No evidence was found of elevated cancer incidence at sites associated with asbestos exposure. A statistically non-significant excess of kidney cancer was seen among men, but not women. Colon cancer among men was significantly low, but incidence among women was similar to that expected. Lung cancer incidence was lower than expected for both sexes. Ovarian cancer rates were not different from expected rates. At sites not previously related to asbestos exposure, cancer of the oral cavity was significantly high, with most affected persons having a history of cigarette smoking. Surveillance of the community is continuing because of an insufficient latent period for some exposed groups.

Cancer control planning and establishment of priorities for intervention by a state health department.

A number of data sources routinely available to State health departments were analyzed as part of a State health department cancer control planning effort. This planning effort consisted of seven steps; the most challenging one was the establishment of priorities for cancer control interventions. Using data from available sources, however, a framework for prioritizing potential cancer control interventions as well as choosing a geographic area in which to implement selected interventions was developed. Factors considered in this framework for setting intervention priorities included the magnitude of the problem; the existence of scientific consensus regarding the efficacy of intervention techniques; the availability of data needed to plan, implement, and evaluate an intervention; the availability of resources within communities to implement an intervention; and the existence of public demand for the intervention. The development and use of this cancer control planning model and framework for setting cancer control intervention priorities in New York State are described in this paper. In using this planning model and framework for setting priorities, quantitative elements were found to be most necessary to define problems, but qualitative elements were most crucial for decision making.

Smoking and risk of death due to pulmonary tuberculosis: a case-control comparison in 103 population centers in China.

OBJECTIVE: To examine the relationship between smoking and the risk of tuberculosis (TB) mortality in a large population-based case-control study in China using an alternative control group selection design. METHODS: During 1989-1991, a nationwide mortality survey was conducted of deaths among adults from 1986 to 1988. Surviving spouses or other informants provided detailed information about their own as well as the deceased person's smoking history. For the present study, all persons who died of TB at age > or =40 were used as cases, whereas all surviving spouses of deceased persons who died from causes other than those attributed to smoking were used as controls. RESULTS: It was estimated that for 22.5% of men and 6.6% of women, smoking was a contributing factor for TB deaths. Although variations in TB death rates by smoking status were not obvious before the age of 60, these differences increased substantially with age thereafter. This trend occurred in both urban and rural areas, although rural TB death rates were double those observed in urban areas. CONCLUSIONS: Tobacco smoking was associated with a large number of deaths from TB in China. The current study confirms results from previous studies about the relationship between smoking and TB mortality.