[Prognostic factors in lung cancer based on Shanghai population]

Life table, Cox model and Cox multivariate model were used to measure the prognostic factors in 1417 new prevalent lung cancer cases in Shanghai population of urban area. There were 3 main prognostic factors in lung cancer as follows: a. histologic type was correlated to prognosis, among which, squamous type was the best, SCLC the worst, the factor influenced to prognosis of various types was stage and therapy. b. the earlier stage the better prognosis, and related to a optimal therapy. c. Combined therapy was good for prognosis, it was optimal for either surgical or nonsurgical therapy. Early detection, extension of combined therapy and make public of knowledge on lung cancer were encouraged.

A population-based case-control study of dietary factors and endometrial cancer in Shanghai, People's Republic of China

The relation between diet and endometrial cancer was examined in a population-based case-control study conducted in Shanghai, People's Republic of China, between 1988 and 1990, involving interviews with 268 cases and 268 controls aged 18-74 years. The subjects' usual dietary intake of 63 major foods during the previous 10 years (disregarding any recent changes) was measured by means of a structured quantitative food questionnaire. Although women in the highest quartile of total caloric intake had a 2.1-fold increased risk of endometrial cancer, risk varied according to the source of calories. The highest quartiles of caloric intake from fat and protein were associated with odds ratios of 3.9 and 3.1, respectively, while calories from carbohydrates, the major contributor of total calories in this population, were not related to risk. The association of fat and protein with endometrial cancer risk was confined to foods of animal origin in the diet. After adjustment for age, body mass index (weight (kg)/height (m)2), and number of pregnancies, odds ratios were 3.5 (95% confidence interval (CI) 2.0-6.0) and 3.0 (95% CI 1.7-5.1) for women in the highest quartiles of intake of animal fat and animal protein, respectively. Food group analyses showed a similar pattern, with high consumption of meat, eggs, and fresh fish being associated with elevated risks. After adjustment for total calories, no significant association of risk was found with intake of vegetables or dark green/yellow vegetables, or with estimated carotene intake, although fruit and allium vegetables were associated with some reduction in risk. These results suggest that diets rich in animal fat and animal protein may play an important role in the etiology of endometrial cancer.

Genotoxicity of heated cooking oil vapors

Epidemiological studies of lung cancer in Chinese women indicated that factors other than cigarette smoking are related to lung cancer risk. A case-control study suggested that indoor air pollution, particularly from cooking oil emissions, may be involved. Condensates of volatile emissions from rapeseed and soybean cooking oils were prepared and found to be genotoxic in short-term tests including the Salmonella mutation assay, SV50 forward-mutation assay, and sister-chromatid exchange assay, as well as the micronucleus assay in mouse bone marrow. In contrast, condensates from rapeseed oil with butylated hydroxyanisole or hydrogenated rapeseed oil were not mutagenic, implicating oxidation products as the cause for mutagenicity. Peanut oil and lard condensates were not mutagenic in any assay. The association of exposure to Chinese rapeseed cooking-oil emissions and lung-cancer risk may be related to the mutagenic component of these condensates.

A population-based case-control study of cancers of the nasal cavity and paranasal sinuses in Shanghai

A population-based case-control study of cancer of the nasal cavity and sinuses, involving interviews of 60 incident cases and 414 controls, was conducted in Shanghai. Cigarette smoking was associated with a mild elevation in risk of squamous-cell carcinoma but not cancers of other cell types. Occupational exposures to wood and silica dusts and to petroleum products, and the use of wood and straw as cooking fuel, were linked to moderate increases in risk, while 4-fold or greater increases were associated with a history of chronic nasal diseases, including those occurring 10 or more years prior to cancer diagnosis. Dietary analyses revealed a significant protective effect of consumption of allium vegetables, oranges and tangerines, with a 50% reduced risk of nasal cancer among individuals in the highest intake group of these foods. Consumption of salt-preserved vegetables, meat and fish was associated with a significantly increased risk of nasal cancer in a dose-response fashion, with a 5-fold excess observed for the heaviest intake of these salted foods. These findings suggest that dietary factors may contribute to the development of nasal cancer.

Risk factors for renal-cell cancer in Shanghai, China

A population-based case-control study of 154 histologically verified renal-cell cancer patients and 157 controls was performed in Shanghai, China, an area with low rates for this tumor. Elevated risks were observed for cigarette smoking (odds ratio (OR) = 2.3; 95% confidence interval (CI): 1.1 to 4.9), and for increasing categories of body weight and meat consumption, while reduced risks were seen for increasing categories of fruit and vegetable intake. An increased risk was also observed for regular use of phenacetin-containing analgesics (OR = 2.3; 95% CI:0.7 to 7.0). These findings are consistent with earlier studies in Western countries, and indicate that many of the same etiologic factors for renal-cell cancer operate in low- and high-risk societies.

Occupational risks for nasopharyngeal cancer in Shanghai

To investigate occupational determinants of nasopharyngeal cancer (NPC) in the urban area of Shanghai, occupational information for 996 incident NPC patients diagnosed during 1980 to 1984 was compared with 1982 census data on employment. Standardized incidence ratios for NPC were estimated for broad and detailed occupational classifications. For the broadest level of classification, no excess risk was observed among craftmen and related manufacturing workers, but within this group significant excess risks were observed for specific occupations of textile weavers and knitters; metal smelting, converting, and refining furnacemen; boiler firemen; blacksmiths, hammersmiths, and forging-press operators; bakers, pastry cooks, and confectionery makers; welders and flame-cutters; and metal grinders, polishers, tool sharpeners, and machine-tool operators. Some of these findings are new; others are consistent with previous studies in other areas of the world. This study provides further evidence for the role of occupational factors in NPC.

Risk factors for oral and pharyngeal cancer in Shanghai, with emphasis on diet

A population-based case-control study of oral and pharyngeal cancer was conducted in Shanghai, China, from 1988 to 1990, in which 204 (115 male, 89 female) incident cases and 414 (269 male, 145 female) controls were interviewed. Cigarette smoking and alcohol consumption, as well as occupational exposures to asbestos and to petroleum products and the use of kerosene stoves in cooking, were associated with increased risk of oral and pharyngeal cancer. In addition, more cases than controls reported having chronic oral diseases and false teeth. Dietary intakes of 42 major foods and selected salt-preserved or deep-fried foods during the past 10 years, ignoring any recent changes, were measured by a structured quantitative food questionnaire. After adjusting for known etiological factors, risks decreased with increasing intake of fruits, particularly oranges and tangerines, and some vegetables, including dark yellow vegetables and Chinese white radish. Men in the highest tertile of intake of these fruits and vegetables had about 30-50% the risk of those in the lowest tertile, with a less pronounced effect among women. A new finding was an excess risk associated with high consumption of salt-preserved meat and fish. The findings from this study provide further evidence that dietary factors play an important role in the development of oral and pharyngeal cancer.

Diet and other risk factors for laryngeal cancer in Shanghai, China

A population-based, case-control study of laryngeal cancer was conducted in Shanghai, China, during 1988-1990, in which 201 incident cases (177 males, 24 females) and 414 controls (269 males, 145 females) were interviewed. Cigarette smoking was the major risk factor, accounting for 86% of the male and 54% of the female cases. After adjusting for smoking, there was little increase in risk associated with drinking alcoholic beverages. Among men, cases more often reported occupational exposures to asbestos and coal dust. A protective effect was associated with the intake of fruits (particularly oranges and tangerines), certain dark green/yellow vegetables, and garlic, but there was an increased risk with the intake of salt-preserved meat and fish. The findings suggest that risk factors for laryngeal cancer in Shanghai resemble those in Western countries, and they provide further evidence that dietary factors play an important etiologic role.

Relation of obesity and body fat distribution to endometrial cancer in Shanghai, China

In a case-control study involving 268 cases of endometrial cancer and an equal number of population controls, we assessed the relationship of risk to body weight and fat distribution, examining weight at various ages and current anthropometric measurements. Weight gain during later adulthood and resultant high body masses were important risk predictors, indicating that obesity is an important risk factor, even in an area where the prevalence of obesity and incidence of endometrial cancer are low. Certain fat distribution patterns were related to risk of endometrial cancer independent of general obesity. In particular, fat deposits on the trunk were associated with elevated risks, with the odds ratio for the highest versus lowest quartile of subscapular skinfolds remaining significant even after adjustment for body mass index (odds ratio = 2.9; 95% confidence interval, 1.1-7.3). Central versus peripheral obesity, as measured by the subscapular:triceps ratio, also was related to increased risk, although the association failed to remain significant after adjustment for body mass (highest to lowest quartile, odds ratio = 1.7). In contrast, upper body obesity, as assessed by the waist:thigh ratio, was unrelated to risk. These results support the need for future studies assessing the relationship of hormonal and other biological parameters of fat distribution to assist in identifying causal mechanisms for this tumor.

Urinary aflatoxin biomarkers and risk of hepatocellular carcinoma

Aflatoxins have long been suspected to be human hepatic carcinogens but no direct study was feasible until assays to measure individual aflatoxin exposure became available. We have used assays for urinary aflatoxin B1, its metabolites AFP1 and AFM1, and DNA-adducts (AFB1-N7-Gua) to assess the relation between aflatoxin exposure and liver cancer, as part of an ongoing prospective study of 18,244 middle-aged men in Shanghai, People's Republic of China. After 35,299 person-years of follow-up, 22 cases of liver cancer had been identified. For each case, 5 or 10 controls were randomly selected from cohort members without liver cancer on the date the disorder was diagnosed in the case and matched to within 1 year for age, within 1 month for sample collection, and for neighbourhood of residence. Subjects with liver cancer were more likely than were controls to have detectable concentrations of any of the aflatoxin metabolites (relative risk 2.4, 95% confidence interval 1.0-5.9). The highest relative risk was for aflatoxin P1 (6.2, 1.8-21.5). In an analysis adjusting for the effects of hepatitis B surface antigen seropositivity, level of education, cigarette smoking, and alcohol consumption, the relative risk for the presence of aflatoxin metabolites was 3.8 (1.2-12.2). There was a strong interaction between serological markers of chronic hepatitis B infection and aflatoxin exposure in liver-cancer risk. Reduction of aflatoxin exposure may be a useful intermediate goal in prevention of liver cancer, since the benefits of wide-scale hepatitis B vaccination will not be apparent for many years.

Bladder cancer and occupation in Shanghai, 1980-1984

To investigate occupational determinants of bladder cancer in the urban area of Shanghai, occupation and industry information for 1,219 incident bladder cancer cases diagnosed during the period 1980 to 1984 were compared with 1982 census data on employment. Standardized incidence ratios (SIR) for bladder cancer were estimated for occupation and industry classifications. Significant excess risks were observed for plastic products workers (male: SIR = 432; female: SIR = 368); textile bleachers, dyers, and finishers (male: SIR = 169); metal refining and processing workers (male: SIR = 139; female: SIR = 197); petroleum refining workers (male: SIR = 2152); railway engine drivers and firemen (male: SIR = 683); and workers employed in industries of apparel and other textile products manufacturing (female: SIR = 204); paper processing (male: SIR = 146; female: SIR = 226); organic chemical manufacturing (male: SIR = 186); plastic product manufacturing (male: SIR = 218; female: SIR = 272); and metallurgy (male: SIR = 107; female: SIR = 561). This study indicates that many of the industries and occupations that are responsible for increased risk throughout the world are also associated with occupational bladder cancer in Shanghai.

A population-based case-control study of endometrial cancer in Shanghai, China

A case-control study of 268 patients with endometrial cancer and 268 population controls was conducted during 1988-1990 in Shanghai, China, to evaluate etiologic factors in a population whose risk had not been substantially altered by the use of exogenous estrogens. In spite of this, the major risk factors resembled those found in other studies. The risk of endometrial cancer was significantly elevated among nulligravidas (OR = 5.4, 95% CI = 2.0-14.6) and decreased with number of pregnancies (p less than 0.01). Late age at menopause was associated with increased risk, while early age at menarche was unrelated. Use of oral contraceptives for more than 2 years was associated with a reduction in endometrial cancer risk (OR = 0.4, 95% CI = 0.1-1.2), while short-term use of oral contraceptives and other methods of contraception were unrelated. Obesity was a strong predictor of risk, with women in the highest quartile of weight having 2.5 times the risk of those in the lowest quartile. In contrast to many other studies, cigarette smokers were at elevated risk (OR = 1.7, 95% CI = 0.9-3.0). Risk was also elevated among women reporting a history of gall-bladder disease, polycystic ovaries, menstrual symptoms, and non-estrogen hormone use.

Comparative epidemiology of cancers of the colon, rectum, prostate and breast in Shanghai, China versus the United States

Incidence rates of cancers of the colon, rectum, female breast, and prostate were compared among native Chinese (Shanghai), Chinese-American, and American populations. Americans had fourfold higher age-adjusted rates of colon cancer, and twofold higher rates of rectal cancer than Chinese, which is consistent with elevated per capita intake of fat and lower intake of cereals and vegetables in the US. Incidence rates of colon and rectal cancers in Chinese-Americans were nearly equal to the American rates, suggesting that the risk for tumour development in the lower intestinal tract is rapidly increased with transition to the US diet. Rates of prostate cancer and postmenopausal breast cancer were 26-fold and tenfold higher in Americans than in Chinese, whereas the rates for Chinese-Americans were intermediate. Environmental factors such as dietary fat apparently had a more gradual effect in promoting cancers of the breast and prostate relative to their influence on neoplasms of the lower intestinal tract.

Exposure of nonsmoking women to environmental tobacco smoke: a 10-country collaborative study

The interpretation and interpretability of epidemiologic studies of environmental tobacco smoke (ETS) depend largely on the validity of self-reported exposure. To investigate to what extent questionnaires can indicate exposure levels to ETS, an international study was conducted in 13 centers located in 10 countries, and 1,369 nonsmoking women were interviewed. The present paper describes the results of the analysis of self-reported recent exposure to ETS from any source in relation to urinary concentrations of cotinine. Of the total, 19.7 percent of the subjects had nondetectable cotinine levels, the median value was 6 ng/mg, and the cut-point of the highest decile was 24 ng/mg. The proportion of subjects misreporting their active smoking habit was estimated at between 1.9 and 3.4 percent, depending on whether cut-points of 50 or 100 ng/mg creatinine were used. Large and statistically significant differences were observed between centers, with the lowest values in Honolulu, Shanghai, and Chandigarh, and the highest in Trieste, Los Angeles, and Athens. Mean cotinine/creatinine levels showed a clear linear increase from the group of women not exposed either at home or at work, to the group of those exposed both at home and at work. Values were significantly higher for women exposed to ETS from the husband but not at work, than for those exposed at work but not from the husband. The results of linear regression analysis indicated that duration of exposure and number of cigarettes to which the subject reported being exposed were strongly related to urinary cotinine. ETS exposure from the husband was best measured by the number of cigarettes, while exposure at work was more strongly related to duration of exposure. After adjustment of number of cigarettes for volume of indoor places, a similar increase in cotinine (5 ng/mg) was predicted by the exposure to 7.2 cigarettes/8 h/40 m3 from the husband and 17.9 cigarettes/8 h/40 m3 at work. The results indicate that, when appropriately questioned, nonsmoking women can provide a reasonably accurate description of ETS exposure. Assessment of individual exposure to ETS should focus on daily duration and volume of indoor places where exposure occurred.

Serum hormone levels in pre-menopausal Chinese women in Shanghai and white women in Los Angeles: results from two breast cancer case-control studies

To assess whether risk of breast cancer in young women is associated with differences in luteal-phase hormone production and to attempt to explain differences in risk of breast cancer of young Shanghai Chinese and Los Angeles white women, two concurrent case-control studies of serum hormone concentrations were conducted. Both studies were carefully controlled for the possible confounding effects of age, weight, height, pregnancy history, and day of the menstrual cycle, by individually matching cases and controls on these factors. Case eligibility was limited to women with localized breast cancer. Sixteen of 39 Shanghai breast-cancer cases were sampled prior to the histologic diagnosis of their disease. The remaining 23 Shanghai cases and all 42 Los Angeles cases were diagnosed, and treated by surgery only, at least six months prior to hormonal evaluation. All subjects were sampled on day 22 of the menstrual cycle. Overall, cases had 13.5% higher serum estradiol concentrations (p = 0.038) with a case-to-control excess of 16.6% in Shanghai subjects (p = 0.089) and 10.8% in Los Angeles subjects (p = 0.23). There were no appreciable differences in amounts of sex-hormone binding globulin between cases and controls. Cases had lower progesterone levels than controls, but the situation was reversed when the analysis was restricted to subjects with evidence of ovulation. Los Angeles controls had 20.6% greater estradiol concentrations than Shanghai controls (p = 0.036); adjustment for body weight accounted for only 25.7% of this difference.(ABSTRACT TRUNCATED AT 250 WORDS)

Occupational risk factors for gastric cancer in Shanghai, China

Occupational data for over 13,000 incident stomach cancer cases reported to the Shanghai Cancer Registry between 1980 and 1984 were compared with 1982 census employment information to calculate standardized incidence ratios for stomach cancer in the Shanghai urban area. Several occupations were found to have statistically significantly increased risks for stomach cancer, most notably grain farming and several jobs involving potential for exposure to metal, wood, and other dusts and to fossil fuel combustion products. Because of the large numbers involved and consistency of associations, the findings raise hypotheses regarding occupational exposures that warrant further investigation.

Safety comparison of insecticide microencapsulation and investigation of its mechanism

Four kinds of microencapsulated insecticides were prepared with fenthion, mevinphos, acetofenate and methylparathion. From observations made after the experiment it was found that type II microcapsules with polyurea capsule walls formed by interfacial polymerization had a special advantage: they had greatly enhanced safety in mice when administered via mouth, respiratory tract and skin. Type I microcapsules, with capsular walls of gelatin and Arabic gum formed through complex condensation, had no safety protection with oral administration. The mechanism of safety enhancement associated with type II microcapsules depends mainly on maintenance of microcapsule integrity within the digestive tract; type II microcapsules rarely disintegrated in the gastrointestinal tract and only about 5 per cent were ruptured. Of the small quantity of insecticide that leaked through the ruptured capsule walls, the amount absorbed by the digestive tract was not sufficient to kill the mice before the microcapsules were discharged in faeces--The amount of discharge within 48 hours exceeded 80 per cent. Administration of large numbers of microcapsules was necessary before sufficient insecticide could be absorbed by the digestive tract to cause lethal dosage; on post-mortem examination some microcapsules were found intact in the stomach and small intestine. Type I microcapsules, however, were totally disintegrated in the digestive tract and no traces could be found in the faeces; therefore their drug safety could not be increased.

Population-based case-control study of ovarian cancer in Shanghai

A case-control study of 229 ovarian cancer cases (including 172 epithelial tumors) and an equal number of population-based controls was conducted during 1984 to 1986 in Shanghai, China, a low-risk area for ovarian cancer. Similar to studies in high-risk areas, the risk of epithelial tumors was high for nulliparous women (odds ratio, 1.6; 95% confidence interval, 0.8 to 3.2) and decreased with increasing number of livebirths (P less than 0.01). Early menarche and late menopause were associated with increased risk, with the trend in risk for age at menarche being statistically significant. In contrast to other studies, oral contraceptive use was not associated with reduced risk, although there was some reduction in risk for those with a prior tubosterilization or intrauterine device use. Risk was also elevated among those reporting a prior ovarian cyst, medroxyprogesterone use, a first degree family history of cancer, and occupational exposure to paint. Risk factors for the nonepithelial tumors were similar to the other cancers, although the power to detect differences was limited.

Dietary factors and epithelial ovarian cancer

Dietary data from a population-based case-control study of 172 epithelial ovarian cancer cases and 172 controls were analysed. A significant (P less than 0.01) dose-response relationship was found between intake of fat from animal sources and risk of ovarian cancer, but plant fat was not associated. Although the effect of animal fat was confounded by education, an adjusted odds ratio of 1.8 persisted for those in the upper quartile compared to the lower quartile of consumption (P for trend = 0.03). After adjustment for animal fat intake, calorific and protein intake had minimal effects on risk. Total vegetables were found to be somewhat protective, but the mechanism of action was unclear. Weight, height and relative weight (weight/height2) were not related to risk of ovarian cancer.

A population-based case-control study of childhood leukemia in Shanghai

A population-based case-control interview study of 309 childhood leukemia cases and 618 healthy population control children was conducted in urban Shanghai, China. Like some studies in other countries, excess risks for both acute lymphocytic leukemia (ALL) and acute nonlymphocytic leukemia (ANLL) were associated with intrauterine and paternal preconception diagnostic x-ray exposure, and with maternal employment in the chemical and agricultural industries during pregnancy. ANLL was linked to maternal occupational exposure to benzene during pregnancy, whereas both ALL and ANLL were significantly associated with maternal exposure to gasoline and the patient's prior use of chloramphenicol. New findings, previously unsuspected, included an association of ANLL with younger maternal age at menarche (odds ratio [OR] = 4.3; 95% confidence interval (CI) = 1.3-13.9); a protective effect for long-term (greater than 1 year) use of cod liver oil containing vitamins A and D for both ALL (OR = 0.4; 95% CI = 0.2-0.9) and ANLL (OR = 0.3; 95% CI = 0.1-1.0); and excess risks of ANLL among children whose mothers were employed in metal refining and processing (OR = 4.6; 95% CI = 1.3-17.2) and of ALL associated with maternal occupational exposure to pesticides (OR = 3.5; 95% CI = 1.1-11.2). No relationships were found with late maternal age, certain congenital disorders, or familial occurrence, which have been related to childhood leukemia in other studies. In contrast with other reports, an excess of leukemia, primarily ANLL, occurred among second or later-born rather than firstborn children.

Occupation and lung cancer in Shanghai: a case-control study

Occupation was evaluated as a potential risk factor for lung cancer as part of a large population based case-control study conducted in the ten urban districts of Shanghai. A total of 733 newly diagnosed cases of male lung cancer and 760 controls selected from the general population was interviewed to obtain lifetime occupational histories and information on smoking and other factors. Of the approximately 25 major industrial titles examined, significantly raised risks, adjusted for smoking, were found for employment in agricultural production (odds ratio (OR) = 1.6, 95% confidence interval (CI) = 1.0-2.6). A concomitant increase was detected for farmers (OR = 1.6, 95% CI = 1.0-2.5) when 35 major occupational titles were examined. There was a 70% excess among workers in the chemical industry (OR = 1.7, 95% CI = 0.9-3.1) and a significant decrease among textile industry workers (OR = 0.7, 95% CI = 0.5-1.0). Raised risks of 30% to 80% were associated with reported job exposures to wood and coal dusts, smoke from burning fuels, and chemical fumes. Employment categories were also examined for 672 cases and 735 controls among women, but small numbers in many of the industrial and occupational categories precluded detailed analyses. The largest excess risk among women (OR = 5.1, 95% CI 1.3-23.5) was among glass products workers. Although cigarette smoking was the dominant cause of lung cancer among men and a significant risk factor among women in Shanghai, these findings suggest the importance of certain workplace exposures and offer leads to occupational carcinogens.

Lung cancer and smoking in Shanghai

A case-control study involving interviews with 733 male and 672 female incident lung cancer patients and 1495 population-based controls revealed that cigarette smoking is the dominant cause of lung cancer among men in urban Shanghai. All of the principal cell types were affected, with clear trends of rising risk with increasing intensity and duration of smoking. Far fewer women smoked cigarettes, but the overall risk patterns resembled those among males. Among women, however, smoking accounted for only about one-quarter of all lung cancers and less than 10% of lung adenocarcinomas. The findings lay to rest any doubts about the health hazards of smoking Chinese cigarettes, although smoking is not responsible for the high rates of adenocarcinoma reported among Chinese women.

Risk factors for breast cancer in Chinese women in Shanghai

Five hundred thirty-four histologically confirmed incident cases of breast cancer in Chinese women of Shanghai and an equal number of age and sex-matched population controls were interviewed as part of an epidemiological study of breast cancer risk factors. Early age at menarche was positively associated with breast cancer risk whereas early age at first full term pregnancy, high parity, and long duration of nursing were each negatively associated. We found high average body weight to be a risk factor, especially among women over age 60. Use of oral contraceptives after age 45 also was a risk factor, but use in general was not. Personal history of benign breast disease and history of breast cancer in first degree female relatives both increased risk. Multivariate analysis showed that each of these risk (or protective) factors was independently related to breast cancer. In addition to confirming most of the breast cancer risk factors of Western populations in a low risk developing Asian country, this study demonstrates a clear beneficial effect on breast cancer risk of lactation in a population characterized by a long cumulative duration of nursing in the majority of women. Finally, this study supports several other recent reports of a residual and beneficial effect of parity on breast cancer risk after controlling for age at first full term pregnancy.