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Biomedical subjects

H O Adami

Publications and source records attributed to H O Adami.

At least 181 records · Page 10Linked to original sources

Organochlorine compounds in relation to breast cancer, endometrial cancer, and endometriosis: an assessment of the biological and epidemiological evidence.

There is an increasing public and scientific concern that certain chlorinated compounds, recognized as environmental pollutants, may cause estrogen-related neoplastic disease in humans. The main hypothesis has been that certain organochlorines, through their estrogenic actions, might cause breast cancer. From experimental studies, both in vitro and in vivo, there is evidence that certain organochlorine compounds may cause estrogenic effects, whereas others may cause antiestrogenic effects. In limited studies, some of these compounds in high doses have also been shown to increase and reduce the frequency of estrogen-related tumors in animals. The epidemiological findings regarding the association between organochlorines and breast cancer are inconclusive. However, the largest and best designed study has been interpreted as negative with respect to DDT and polychlorinated biphenyls (PCB) in relation to breast cancer. Associations between organochlorine exposure and endometrial cancer or endometriosis have even more limited empirical basis. The hypothesis that human exposure to environmental levels or organochlorines would favor an estrogenic overactivity leading to an increase in estrogen-dependent formation of mammary or endometrial tumors is not supported by the existing in vitro, animal and epidemiological evidence. It can, however, not be conclusively rejected on the basis of available data.

Animals↗

The value of prostate specific antigen in early diagnosis of prostate cancer: the study of men born in 1913.

PURPOSE: We attempt to elucidate the performance of serum prostate specific antigen (PSA) as a screening test for prostate cancer. MATERIALS AND METHODS: We analyzed sera stored since 1980 in a nested case-control study. RESULTS: The 36 patients with prostate cancer had a markedly greater mean serum PSA level than did 68 subjects without cancer (22.71 versus 2.67, respectively, p < 0.0001). Among the controls 24% had a serum PSA of greater than 4.0 micrograms/l. A serum PSA value exceeding 4.0 micrograms/l. in 1980 was associated with a 20-fold excess risk of cancer between 1981 and 1986, and an 8-fold risk between 1987 and 1991. CONCLUSIONS: Diagnosis of clinically significant prostate cancer can be advanced substantially by serum PSA testing. However, the large number of high serum PSA values in men who remained free of clinical disease emphasizes the need for a more specific screening test.

Aged↗

Alcohol intake and breast cancer risk: effect of exposure from 15 years of age.

Research regarding the relationship between alcohol intake and breast cancer risk has suggested an association between the two, although the data are inconsistent regarding dose effects and susceptible populations. To clarify these issues, we investigated the association of breast cancer risk with alcohol intake at various ages in a population-based case-control study nested within a screening cohort in Sweden. Subjects were women 40-75 years old who participated in a screening program in central Sweden. Information about personal characteristics, diet, and alcohol intake was obtained by a questionnaire sent out at the invitation to the screening interview and at a supplementary interview conducted among a sample of women who did and did not develop breast cancer. Alcohol intake did not affect breast cancer risk among women under 50 years old. However, among those over 50 years of age, ever-drinking conferred a relative risk of 1.8 (95% confidence interval = 1.2-2.6). Current and former drinkers had similar increases in risk. No particular latent period of alcohol effect was identified, but drinking later in life to have a bigger effect than did drinking earlier in life.

Adolescent↗

Parity, age at first childbirth, and risk of ovarian cancer.

Increasing parity is associated with a reduction in the risk of ovarian cancer, but it is not clear whether this association applies to different histopathological types and to borderline tumours. Moreover, the temporal relations are poorly understood, and the possible role of age at first birth remains unequivocal. We have investigated these issues in a case-control study nested in a nationwide cohort of women born between 1925 and 1960 in Sweden. During follow-up until 1984, 3486 invasive ovarian cancers (2992 epithelial, 330 stromal, 149 germ-cell, 15 not classifiable) and 510 tumours of borderline malignant potential were diagnosed. 5 individually age-matched controls (total 19,980) were selected for each case woman. After simultaneous adjustment for parity and age at first birth, increasing parity was associated with a pronounced consistent decrease in relative risk of all invasive cancers (odds ratio for each additional birth 0.81 [95% Cl 0.77-0.85]), epithelial cancer (0.81 [0.77-0.86]), stromal cancer (0.84 [0.72-0.98]), and germ-cell cancer (0.71 [0.48-1.05]), but a less consistent decrease for borderline tumours (0.92 [0.81-1.04]). The risk of ovarian cancer decreased by about 10% for each 5-year increment in age at first childbirth (odds ratios 0.89 [0.84-0.94] epithelial cancer, 0.92 [0.77-1.10] stromal cancer, 0.92 [0.65-1.32] germ-cell cancer, 0.93 [0.80-1.09] borderline tumours). Because our findings cannot be readily explained by theories involving incessant ovulation or high serum concentrations of gonadotropins, new aetiological hypotheses are needed. Pregnancy-dependent clearance from the ovaries of cells that have undergone malignant transformation could explain the reproductive risk factors for ovarian cancer.

Adolescent↗

Testicular cancer in nine northern European countries.

The incidence of testicular cancer was examined in the Nordic and Baltic countries, Poland and Germany by collaboration among 10 cancer registries. Population-based registers were used to analyze a total of 34,309 cases, diagnosed from the start of registration (varying from 1943 in Denmark to 1980 in Latvia and Lithuania) through 1989. An approximately 10-fold geographical variation was found in 1980, with the highest age-standardized incidence rate (7.8 per 10(5); world standard population) in Denmark and the lowest (0.9) in Lithuania. During the entire period of registration, incidence increased rapidly in all countries, by 2.3 to 3.4 per cent annually in the Nordic countries and by about 5 per cent in Poland and Germany; there was some evidence of a slower increase in Denmark and Poland after 1975. The rising trend was more pronounced for ages below 30. The age-specific incidence peaked in all countries at ages 25 to 34, but the geographical variation was considerable. Our data indicate that environmental influences on testicular cancer are strong. Exposure to causal factors mostly takes place early in life, shows substantial geographical variation, and increases over time, so that the age-standardized incidence doubles every 15 to 25 years. New aetiological hypotheses are needed to accommodate these salient features of the descriptive epidemiology, since risk factors considered so far cannot explain the observed pattern.

Adolescent↗

Diet and breast cancer risk. Results from a population-based, case-control study in Sweden.

BACKGROUND: We describe an epidemiologic analytical study of the relationship between current diet and breast cancer risk. METHOD: The study design is a case-control analysis. Cases were recruited from a mammography screening program used within the national health care system; the control subjects were selected from subjects free of breast cancer in the same population. A total of 380 cases and 525 control subjects, frequency-matched for age, month of mammography, and county of residence, were identified. Of these, 265 cases and 432 control subjects were included in this analysis. Odds ratios for breast cancer in relation to food and nutrient intake were the main outcome measures. RESULTS: Exposure in the highest quartile of beta-carotene intake gave an odds ratio of 0.6 (95% confidence interval, 0.4 to 1.0). No increased risk was noted with high fat intake. Breast cancer risk was associated with alcohol intake only when alcohol was analyzed in quartiles: odds ratio, 1.6 (95% confidence interval, 1.0 to 2.4) for the highest quartile of intake vs the lowest. Stratified analyses showed that a high fat intake might decrease the protective effect of beta-carotene intake. Risks did not change appreciably with adjustment for total energy intake or known breast cancer risk factors. CONCLUSIONS: As in most other studies, no strong risk factors for breast cancer have been identified in the current diet. The negative association between breast cancer risk and beta-carotene intake may be supported by a plausible mechanism, but our finding concerning alcohol should be interpreted cautiously since there was no dose-response relationship and the biological mechanism for a threshold effect at very low levels of consumption is unclear.

Adult↗

Perinatal measles infection and subsequent Crohn's disease.

Although the aetiology of Crohn's disease is unknown, morphological and epidemiological studies have implicated measles virus as a potential component cause, particularly when exposure occurs in utero or early in life. An increased incidence of Crohn's disease among people born during measles epidemics would support this hypothesis. We identified all individuals born in four counties in central Sweden in 1945-54 who had had Crohn's disease diagnosed before the age of 30 years. Yearly reports compiled in these counties revealed that five measles epidemics had affected all four counties during the trial period. After adjusting for monthly differences in the number of livebirths in the four counties, we calculated the expected number of patients with Crohn's disease and ulcerative colitis born during the 3-month period after the peaks of the epidemics. The number of people with Crohn's disease significantly exceeded that expected: 57 versus 39.0 (standardised incidence ratio 1.46, 95% CI 1.11-1.89). For patients with ulcerative colitis, the observed number (42) was close to that expected (46.8). Our results strengthen the hypothesis that measles is related to Crohn's disease and that the perinatal period is a time of vulnerability.

Adult↗

Transient increase in the risk of breast cancer after giving birth.

BACKGROUND: The effect of pregnancy on the risk of breast cancer is not clear. We tested the hypothesis that the risk of breast cancer increases transiently after pregnancy but then falls to a level below that of age-matched nulliparous women. METHODS: We conducted a case-control study of a nationwide cohort in Sweden, using a computerized record linkage between the Cancer Registry and the Fertility Registry. The study subjects were women born from 1925 through 1960 who were resident citizens of Sweden at the time of the 1960 census. A total of 12,666 patients with breast cancer were compared with 62,121 age-matched control subjects. We used conditional logistic regression to estimate odds ratios for the development of breast cancer at different ages, according to maternal age at first delivery (in uniparous as compared with nulliparous women) and age at second delivery (in biparous as compared with uniparous women). RESULTS: Uniparous women were at higher risk of breast cancer than nulliparous women for up to 15 years after childbirth and at lower risk thereafter. The excess risk was most pronounced among women who were older at the time of their first delivery (odds ratio 5 years after delivery among women 35 years old at first delivery, 1.26; 95 percent confidence interval, 1.10 to 1.44). Women who had two pregnancies had a less striking increase in risk. CONCLUSIONS: Pregnancy has a dual effect on the risk of breast cancer: it transiently increases the risk after childbirth but reduces the risk in later years. In women with two pregnancies, the short-term adverse effect is masked by the long-term protection imparted by the first pregnancy. A plausible biologic interpretation is that pregnancy increases the short-term risk of breast cancer by stimulating the growth of cells that have undergone the early stages of malignant transformation but that it confers long-term protection by inducing the differentiation of normal mammary stem cells that have the potential for neoplastic change.

Adult↗

Nutrients and gastric cancer risk. A population-based case-control study in Sweden.

A population-based case-control study of gastric cancer was conducted in areas with contrasting incidence rates in Sweden. Face-to-face interviews were carried out with 338 (74.1%) of all eligible cases and 679 (77.3%) of the selected controls. Consumption of selected nutrients during adolescence and 20 years prior to interview was estimated, together with life-time intake of vitamin supplements. Ascorbic acid and beta-carotene had an unequivocal protective effect, but alpha-tocopherol and nitrate were also negatively associated with gastric-cancer risk. In a multivariate analysis including all of these factors, only ascorbic acid remained a significant protective factor. The only macronutrient positively associated with the risk of gastric cancer was fat: intake 20 years prior to interview, but not during adolescence, was found to have a significant impact. Supplementation with vitamins almost halved the risk after adjustment for dietary intake of the corresponding vitamins. While the protective effect of vitamin C and beta-carotene could conceivably be ascribed to other agents in the diet, the strong negative association between supplementation with vitamin C and risk of gastric cancer supports the hypothesis of a protective role of this anti-oxidant.

Age Factors↗

Clinical and histopathologic predictors of survival in patients with malignant melanoma: a population-based study in Sweden.

BACKGROUND: Previous malignant melanoma studies regarding prognostic factors have often selected their patients from hospitals. Unfortunately, most of these studies have had small numbers of patients, consisted of short-term data sets, omitted important factors, did not optimize histopathologic classification, had too short or inadequate follow-up, and did not test their predictive models. PURPOSE: Our study goals were to identify independent clinical and histopathologic determinants of survival in malignant melanoma, to analyze changes in prognostic value over follow-up time, and, finally to construct a prognostic index. METHODS: A random sample from the Swedish Cancer Registry of the records of 498 (246 men and 252 women) patients defined by gender, five 5-year time periods of diagnosis from 1960 through 1984, and five anatomic sites formed the cohort on whom data were analyzed by univariate analyses. Multivariate analyses were based on data on 476 patients with complete information about all variables. All patients in the cohort had complete follow-up through December 31, 1989. Clinical information was abstracted and recorded as: date of diagnosis, stage at diagnosis, sex, age, anatomic site of primary tumor, date of death, and cause of death. Histopathologic slides were re-examined and classified with regard to histogenetic type, level of invasion, tumor thickness, ulceration, vascular invasion, regression, lymphocytic reaction, pre-existing nevus, and cell type. RESULTS: All variables, except pre-existing nevus and cell type, were significant predictors of survival. In the multivariate analyses including all variables, women still had a significant, 33% lower relative hazard than men. The prognosis was poor in the youngest age group. Patients with external ear, scalp-neck, and trunk-located melanoma had increasing relative hazard when all variables were included. Regional metastases and tumor thickness remained independent prognostic factors. No significant association between histogenetic type or level of invasion persisted. Patients whose tumors showed ulceration or vascular invasion had lower relative hazard when all variables were included. Level of invasion, tumor thickness, ulceration, and vascular invasion were significantly associated with the prognosis during both short- and long-term follow-up. The patients were subgrouped according to percentage fractions of their score on the prognostic index. Survival curves for these groups of patients were well separated, thus identifying patients with a low or high risk of death from malignant melanoma. CONCLUSION: The present population-based study identifies independent clinical and histopathologic predictors of survival in cutaneous malignant melanoma and emphasizes the role of histopathologic characteristics such as tumor thickness, ulceration, and vascular invasion besides anatomic site.

Adult↗

Sector resection with or without postoperative radiotherapy for stage I breast cancer: five-year results of a randomized trial. Uppsala-Orebro Breast Cancer Study Group.

BACKGROUND: The effectiveness of routine postoperative irradiation following breast-conserving treatment of breast cancer has not previously been assessed in randomized clinical trials that have taken place in settings where mammography has been a major pathway to diagnosis or that have followed patients treated surgically by sector resection. PURPOSE: The aim of this study was to determine if treatment of stage I breast cancer by strictly standardized surgical technique with meticulous confirmation of a complete excision can reduce the local recurrence rate to an acceptable level without routine adjuvant radiotherapy. METHODS: In this trial conducted in Sweden, 381 women with stage I breast cancer were surgically treated by sector resection plus axillary dissection; then 184 women were randomly selected to receive postoperative radiotherapy to the breast (XRT group), and 197 women received no further treatment (non-XRT group). Patient accrual started in October 1981 and ended in September 1988. Criteria for eligibility were a unifocal cancer 20 mm or less in diameter (visible on mammogram) and radical excision and no histopathologic signs of axillary metastases. RESULTS: After median follow-up times of 65 and 63 months, the 5-year local recurrence rate was 2.3% (95% confidence interval [CI] = 0.1%-4.3%) in the XRT group and 18.4% (95% CI = 12.5%-24.2%) in the non-XRT group, respectively. The life-table curves were significantly different (P = .0001). The two treatment groups did not differ in overall survival: For the XRT group, the value was 91.0% (95% CI = 86.4%-95.4%); for the non-XRT group, it was 90.3% (95% CI = 85.8%-94.8%). The same was true for survival free from regional and distant recurrence: XRT group, 90.0% (95% CI = 85.3%-94.5%); non-XRT group, 87.1% (95% CI = 82.3%-92.0%). The rate of local recurrences was significantly higher in patients treated more recently (P. = 003). CONCLUSIONS: Sector resection plus radiotherapy to the breast very effectively achieves local tumor control. Surgery alone results in similar survival prospects, but the probability of local recurrence approaches 20% at 5 years. IMPLICATIONS: The increase in recurrence rate observed over time suggests that surgical technique and patient selection should be improved. The benefits of reduced cost and patient inconvenience that would result from the elimination of postoperative radiotherapy must be carefully weighed against the disadvantages of local recurrence. Longer term follow-up must be done to estimate the risk of cancer recurrence in these women 10 and 15 years later, and methods must be developed to identify those women who have a higher risk of recurrence. Finally, economic analyses of this and similar trials are needed to give empirical underpinnings for optimal use of radiotherapy.

Adult↗

Pancreatitis and pancreatic cancer: a population-based study.

BACKGROUND: Little is known about the etiology of cancer of the exocrine portion of the pancreas, which produces a variety of digestive enzymes. Smoking, certain dietary factors, and diabetes mellitus are considered to be risk factors, although the risk estimates are modest in most instances. A recent cohort study of patients with chronic pancreatitis indicated a ninefold to 16-fold increased risk for pancreatic cancer. PURPOSE: Our purpose was to evaluate the relationship between various clinical types of pancreatitis and pancreatic cancer. METHODS: Data for this study were collected from all inpatient medical institutions in Sweden from 1965 until 1983 by the Swedish National Board of Health and Welfare. Data were recorded on individual hospital admissions and discharges in the Inpatient Register. All patients with records in the Inpatient Register coded for acute, chronic, or unspecified pancreatitis were considered for inclusion in the study. A population-based cohort of 7956 patients with at least one discharge diagnosis of pancreatitis was monitored (up to 19 years of follow-up) for the occurrence of pancreatic cancer by record linkages to the Swedish Cancer Registry and Registry of Causes of Death. RESULTS: A total of 46 pancreatic cancers were diagnosed during follow-up compared with 21 expected (standardized incidence ratio [SIR] of 2.2; 95% confidence interval [CI] 1.6-2.9) for the Uppsala Health Care Region. The excess risk for women and men was similar--most pronounced during the first period of follow-up (2-4 years) after discharge and close to unity after more than 10 years of follow-up. Patients with chronic pancreatitis and patients with more than one discharge diagnosis of either acute or unspecified pancreatitis were at higher risk (SIR = 3.8; 95% CI 1.4-8.2 and SIR = 4.8; 95% CI 1.9-9.9, respectively) compared with those with only one discharge of acute (SIR = 1.6; 95% CI 0.9-2.7) or unspecified (SIR = 2.1; 95% CI 1.2-3.2) pancreatitis. CONCLUSIONS: Our finding of a moderate excess of pancreatic cancer among patients with pancreatitis, especially the chronic or recurrent forms, supports some earlier clinical and case-control studies, but it is not consistent with the ninefold to 16-fold risk reported in a recent cohort study. The absence of an increased risk 10 years or more after first discharge for pancreatitis argues against a straight-forward causal relationship. Because of the relatively short interval between diagnosis of pancreatitis and pancreatic cancer, it is possible that some forms of pancreatitis are a precursor to pancreatic cancer or that shared risk factors for both diseases (e.g., cigarette smoking) may also be involved.

Acute Disease↗

Tobacco, alcohol and the risk of gastric cancer. A population-based case-control study in Sweden.

Previous studies have provided conflicting information on the role of tobacco and alcohol in gastric carcinogenesis. A population-based case-control study with 338 histologically confirmed gastric-cancer cases and 679 control subjects was conducted. Information relating to life-time tobacco consumption, alcohol intake and diet during adolescence and 20 years before interview, and to socio-economic conditions was obtained through face-to-face interviews. Current cigarette smokers were found to have a greater risk than non-users of tobacco. The duration of cigarette or pipe smoking was positively associated with gastric-cancer risk. There was significant interaction between tobacco use and fruit consumption. High fruit intake was more protective among users of tobacco than among non-users, and the risk estimates associated with cigarette smoking were higher among those with low fruit consumption than among frequent fruit-eaters. Likewise, though to a lesser extent, vegetable intake interacted with tobacco use. Snuff dipping and alcohol intake was not associated with gastric-cancer risk. However, high alcohol intake tended to increase the risk associated with tobacco use. This study adds further support to the role of tobacco smoking in gastric carcinogenesis, and demonstrates that high intake of fruits and vegetables may be particularly beneficial in smokers.

Adult↗

Early-life risk indicators of gastric cancer. A population-based case-control study in Sweden.

Exposures early in life seem to play an important role in the development of gastric cancer, but their nature is not well understood. In a population-based case-control study, we examined weight, height and body-mass index (BMI) at the age of 20 as well as indices of socioeconomic conditions. Face-to-face interviews were conducted with 338 of 456 eligible histologically confirmed gastric cancer patients and 679 of 880 eligible control subjects, sampled from population registers and frequency matched by age and gender. Gastric cancer risk was negatively associated with height. Risk was positively, associated with weight at age 20 in both sexes. The highest BMI-quartile was associated with an increased risk. This association between BMI and risk was confined to BMI at age 20, and disappeared for BMI 20 years prior to interview. High socioeconomic status (SES) as well as long education carried a decreased risk of gastric cancer. Number of siblings was positively associated with risk. Factors related to short stature and high adolescent body weight are associated with an increased risk of gastric cancer, as is a high number of siblings. These factors may reflect influences of dietary patterns early in life.

Adolescent↗

Risk factors for oesophageal cancer in northeast China.

A hospital-based case-control study of oesophageal cancer was carried out in the Heilongjiang Province, a low-risk area for oesophageal cancer in China. From May 1985 to May 1989, 196 histologically confirmed cases and 392 controls with other (non-neoplastic) diseases were personally interviewed in the wards of 5 major hospitals. Information was obtained about usual consumption in the early 1980s of 32 major contributors to the diet in the province, socio-demographic status, smoking and alcohol consumption. Odds ratios (OR) were obtained from logistic regression models, and confounding was controlled by means of multivariate models. Smoking and alcohol consumption were major risk factors for oesophageal cancer in this population. Smokers of handmade cigarettes exhibited a particularly high risk. A near multiplicative synergism was found between smoking and alcohol consumption. There was a significant inverse dose-risk trend for combined consumption of vegetables and fruits; a 300-g increase per day lowered risk by 35%. Vitamin C intake was negatively associated with risk; a 100-mg increase per day lowered risk by 39%. Our data suggest a modifying effect of vitamin C and beta-carotene on risk associated with smoking, but the power of analyses was low. Salt, salt-preserved foods and pickled vegetables were not associated with increased risk. High temperature of meals and drinks was a strong risk indicator in this population. The strength of tea and overall tea consumption were independent determinants of the risk.

Adult↗