Suicides in the Baltic countries, 1968-90

Trends of male and female suicides in the Baltic countries--Estonia, Latvia and Lithuania--in the years 1968-90 were studied. As throughout the former USSR, suicide rates declined sharply from 1986, the year marking the onset of turbulent social change. During the "period of stagnation" from 1968 to 1984, the mean value of male suicide rates per 100,000 males were 55.7 in Estonia, 52.5 in Latvia and 51.7 in Lithuania. The figures for female suicide rates were 14.3, 14.3 and 10.4, respectively. Suicide rates remained consistently high in Estonia and Latvia, while in Lithuania the male suicide rate rose gradually from 33.0 to 61.3 and the female rate from 8.0 to 13.1 during the stagnation period. In conjunction with perestroika in the former USSR (including a restrictive alcohol policy and the first tentative steps towards democracy), annual male suicide rates per 100,000 in the years 1986-90 fell considerably below those in the stagnation period. Mean values of male suicide rates decreased by 26.6% in Estonia, 26.6% in Latvia and 14.4% in Lithuania in the period 1986-90 compared with the mean values for the period 1968-84. Female suicide rates were relatively stable and the male-female ratio was accordingly lower in 1986-90 (Estonia and Latvia 3.1, Lithuania 4.2) than in 1968-84 (Estonia 3.9, Latvia 3.7 and Lithuania 5.0).

Male suicides and alcohol consumption in the former USSR

A significant decline (34.5%) in the suicide rate occurred in 1984-1988 throughout the USSR. The decline was observed shortly after the introduction of strict restrictions on the sale of alcohol. We tested the hypothesis that the restrictive alcohol policy in the first years of perestroika (June 1985) caused the fall in suicide rates in the former USSR. Data on alcohol consumption, violent death caused by external injury and poisoning (n = 916,315), death due to accidental alcohol poisoning (n = 77,837), suicide (n = 192,305) and death undetermined whether accidentally or purposely (n = 54,253) were analyzed for all former Soviet republics for 1984, 1986, 1988 and 1990. Men were chosen for the analysis, since men are more prone to abuse alcohol than women. Regression analysis with alcohol consumption as the independent variable and suicide rates and violent death rates as dependent variables shows that suicide and alcohol consumption were positively correlated as were violet death and alcohol consumption. In the republics with high alcohol consumption (Slavic and Baltic), suicide rates were also high. In the Caucasian republics, low alcohol consumption was associated with low suicide rates. For most republics, alcohol seems to explain more than 50% of suicides. Alcohol also has considerable explanatory value for violent death. Thus, a restrictive alcohol policy might be a way to reduce suicide and violent death.

Epstein-Barr virus infection, salted fish and nasopharyngeal carcinoma. A case-control study in southern China

Two hundred and five histologically confirmed cases of nasopharyngeal carcinoma (NPC) in southern China, and an equal number of matched controls, were investigated for their dietary habits, occupational exposure, use of tobacco and alcohol, history of relatives with NPC, and IgA against Epstein-Barr virus (EBV) capsid antigen (IgA/VCA). Positive IgA/VCA and intake of salted fish were associated with a strong excess risk of NPC. The association persisted after adjustment for other factors. The combination of salted fish and EBV was strongly associated with NPC, and more so than EBV or salted fish per se. Multivariate analyses showed that IgA/VCA was the most important predictor of NPC, and salted fish the second most important. These results suggest that EBV has a strong effect on the development of NPC. The exclusion of EBV and genetic factors in earlier epidemiological studies may have resulted in an overestimation of salted fish as important etiological factor causing NPC.

Nonsmoking, non-alpha 1-antitrypsin deficiency-induced emphysema in nonsmokers with healed spontaneous pneumothorax, identified by computed tomography of the lungs

This case-control study is based on an investigation of 27 nonsmoking patients with radiologically verified spontaneous pneumothorax (SP) and ten healthy never-smoker control subjects. The posteroanterior and lateral radiographs of patients and control subjects were normal. They were all submitted to the same clinical, laboratory, and radiologic examinations, including computed tomography (CT) of the lungs, with the aim of detecting any parenchymatous lung changes. Emphysema-like changes (ELCs) were detected on CT in 22 (81 percent) of the 27 patients, and if the ELC cases detected during interventional surgery are added, the frequency increases to 24/27 (89 percent). In 20 patients with unilateral SP, at least one ELC was found in 13 of the 20 SP-affected lungs, but only in five of the 20 lungs that were not diagnosed as having SP (p < 0.05). ELCs were found more frequently in the upper than in the lower lung regions (p < 0.05) and more frequently in the radiologically peripheral than in central regions (p < 0.001). No ELC was detected in the control group on CT. No alpha 1-antitrypsin deficiency was found in the 27 nonsmoking patients with radiologically verified SP who had ELCs despite the absence of these known promoters of emphysema.

Obstetric medication versus residential area as perinatal risk factors for subsequent adult drug addiction in offspring

In an attempt to explain pronounced uneven distributions of births of subsequent amphetamine and opiate addicts at seven hospitals in Stockholm, two possible mechanisms for adult drug addiction were weighed against each other: (1) risk factors associated with the obstetric care at the hospitals of birth of the addicts and (2) risk factors associated with the phenomenon of 'contagious' transmission of drug addiction in certain residential areas during adolescence. The subjects comprised 200 amphetamine addicts and 200 opiate addicts born between 1945 and 1966. By loglinear analysis the relative risk for future addiction was determined for eight residential areas as well as for the seven hospitals and four periods of birth. For the opiate addicts only one weak association was found for the residential area, which could not explain fully a clustering of births at any particular hospital. For the amphetamine addicts, hospital of birth was found to be an important risk factor even after controlling for residential area. Hence, the variable residential area has not been able to explain the uneven distribution of births of drug abusers among the studied hospitals.

Socio-economic versus obstetric risk factors for drug addiction in offspring

Two possible risk factors for drug addiction were weighed against each other: (1) perinatal factors associated with obstetric medication at time of birth; and (2) factors associated with familial socio-economic conditions at time of birth. The subjects comprised 200 amphetamine addicts and 200 opiate addicts born in Stockholm 1945-1966. In a matched case control study, addicts were compared to their siblings with regard to possible obstetric risk factors by means of conditional logistic regression controlling for socio-economic level and civil status. Administration of opiates, barbiturates and nitrous oxide to mothers during labour was associated with drug addiction in offspring, hence confirming results from earlier studies. In a cohort study the risk associated with birth at a given hospital and familial socio-economic level was analysed by means of log-linear analysis using 7100 controls from the general population. For amphetamine addicts, a low socio-economic level at time of birth might be of importance for the infant subsequently becoming an addict. This could not be demonstrated for the opiate addicts. An uneven distribution of births among the hospitals, most pronounced for the amphetamine addicts, is in agreement with the hypothesis that obstetric practices may be risk factors for adult drug addiction.

Bilateral bronchial anomaly. A pathogenetic factor in spontaneous pneumothorax

Flexible fiberoptic bronchoscopy (FFB) was performed in 26 never-smokers with healed spontaneous pneumothorax (SP) with the aim of detecting and localizing any bronchial obstruction, including congenital anomaly. In a case-control study these patients were compared with a consecutive, randomly sampled, control group of 41 patients who were undergoing FFB for respiratory symptoms but who had not had a SP. In both groups the endobronchial anatomy with respect to such anomalies, which could be classified as disproportionate bronchial anatomy, an accessory bronchus, and/or a missing bronchus, was compared with normal anatomy. All except one of the 26 patients with SP but only four of the 41 control patients without SP had such bronchial anomalies bilaterally. This corresponds to an odds ratio of 231 (95% confidence interval, 24 to 880; p < 0.001). The significantly higher frequency of bilateral bronchial anomalies in never-smokers with SP suggests that a virtual prerequisite for the occurrence of SP has been found. However causal links between the probably congenital bronchial anomalies and SP have not yet been identified.

Response bias in a case-control study: analysis utilizing comparative data concerning legal abortions from two independent Swedish studies

Independent reports of legal abortions in two Swedish epidemiologic studies of breast cancer in young women, covering the same women and overlapping the same time period, have been compared in order to estimate a putative response bias. One study used case-control methods and obtained data by retrospective interviews from 317 cases and 512 controls. The other study was based on objectively documented information froma nationwide registry covering legally induced abortions. Analysis demonstrated a ratio between the odds ratios from the two studies of 1.5 (95 percent confidence interval 1.1-2.1) and an observed ratio of 22.4 (p less than 0.007) between underreporting of previous induced abortions among controls relative to overreporting among cases. This response bias may explain the tendency toward increased risk of breast cancer which, according to several case-control studies, appears to be associated with induced abortion.

Condylomata acuminata and risk of cancer: an epidemiological study

OBJECTIVE

To determine whether patients with condylomata acuminata have an increased risk of developing cancer.

DESIGN

Prospective cohort study on patients diagnosed as having condylomata acuminata. The number of malignant tumours in the cohort was compared with national incidences obtained from the Swedish Cancer Registry.

SETTING

Dermatology department of the Karolinska Hospital, Stockholm, Sweden.

SUBJECTS

3260 patients (2549 males and 711 females, median (range) age 23 (1-80) years) seen during 1969-84, with a mean follow up of 7.8 years.

MAIN OUTCOME MEASURES

Number of malignant tumours observed in the cohort during the study period and expected number from national incidence.

RESULTS

There were 27 malignancies in the study group. There was no significant increase genital cancer in females compared with the national incidence. Only one patient had invasive cervical cancer (relative risk = 1.8; 95% confidence interval 0 to 10.1). Seventeen women had cervical carcinoma in situ (1.5; 0.9 to 2.5) compared with an expected number of 11.5; this increase was not significant. For males 22 cancers were observed at all sites (1.6; 1.0 to 2.5). The number of genitourinary cancers observed in males was almost three times higher than expected (2.6; 1.2 to 5.0).

CONCLUSION

The results indicate that the risk of developing cervical carcinoma in situ or invasive cervical cancer after a genital human papillomavirus infection is less than previously thought. The implications of increase in the genitourinary malignancies in males are uncertain.

Acute leukemia in professional drivers exposed to gasoline and diesel

The environmental exposure to the petroleum products gasoline, diesel, and their motor exhausts was studied in a case-control interview of 125 patients with acute leukemia and 1 matched control per patient. Odds ratios were calculated by comparing discordant matched patient-control pairs. An excess risk for developing acute leukemia was found for the professional drivers, and odds ratio was determined to be 3.0 (95% CI: 1.1-9.2/p less than or equal to 0.02). For those who were exposed for more than 5 years in their life-time, or more than 1 yr during the 5-20 yr period prior to diagnosis, the odds ratio was 5.0 (p less than 0.05). This finding remains after consideration is given to exposures to organic solvents, smoking and therapeutic x-ray treatment. No excess risk was observed for persons professionally exposed to motor oil and machine oil without exposure to fuels and exhausts. No preferential type of acute leukemia was found to be associated with exposure to fuels and their exhausts. The results indicate an etiological relationship between the development of acute leukemia and exposure to petroleum products as fuels and exhaust.

Occurrence of other malignancies in 1973 patients with basal cell carcinoma

To evaluate the possible association of other malignancies with basal cell carcinoma, we reviewed 1973 consecutive patients with basal cell carcinoma. We searched the Swedish Cancer Registry for records reporting malignancies in the study population (1958-1984) and the expected number of malignancies was calculated on the basis of age- and sex-standardized incidence data. In 452 patients with basal cell carcinoma another malignancy was diagnosed. The expected number was 323 (relative risk = 1.4; 95% confidence interval = 1.3 to 1.5). A significant association with basal cell carcinoma was found in four cancer types for men and in three for women. For skin malignancies other than malignant melanoma there was more than a sixfold increased risk for men (relative risk = 6.8; 95% confidence interval = 4.8 to 9.4) and more than a threefold increased risk for women (relative risk = 3.1; 95% confidence interval = 1.4 to 5.9) during the period after the diagnosis of basal cell carcinoma. During the period before the diagnosis of basal cell carcinoma, there were also increased risks (men: relative risk = 5.0; 95% confidence interval = 3.1 to 7.5; women: relative risk = 4.0; 95% confidence interval = 1.9 to 7.4). This was in contrast to the risks of malignant melanoma. Before the diagnosis of basal cell carcinoma there was no significant increased risk of malignant melanoma but after the diagnosis there was more than a sixfold increased risk for men (relative risk = 6.8; 95% confidence interval = 4.8 to 9.4) and more than a fourfold increased risk for women (relative risk = 4.2; 95% confidence interval = 1.5 to 9.2).(ABSTRACT TRUNCATED AT 250 WORDS)

Randomized study of mammography screening--preliminary report on mortality in the Stockholm trial

In March 1981, 40,318 women in Stockholm, aged 40-64, entered a randomized trial of breast cancer screening by single-view mammography alone versus no intervention in a control group of 20,000 women. The attendance rate during the first screening round was 81 per cent and the cancer detection rate was 4.0 per 1000 women. The detection the rate fell to 3.1 per 1000 in the second round, which was completed in October 1985. During 1986 the controlled design of the study was broken and the control women were invited once to screening which was completed the same year. A total of 428 cases of breast cancer were thus diagnosed in the study group and 439 in the adjusted control group. After a mean follow-up of 7.4 years the number of breast cancer deaths in the study and control groups was 39 and 30 respectively. The relative risk of breast cancer death (screening versus control) was 0.71 (95 per cent confidence interval: 0.4-1.2). Among women older than 50 years at entry the relative risk was 0.57 (95 percent confidence interval: 0.3-1.1). Cancer deaths among women under 50 were few and perhaps because of this no mortality reduction was seen in this age group. The estimate of mortality reduction lies between the results from two earlier Swedish randomized controlled trials.

Mortality among Swedish reindeer breeding Lapps in 1961-85

We analyzed the mortality pattern among Swedish reindeer breeding Lapps, a unique group with a carefully preserved culture and a lifestyle that differs considerably from that of the rest of the population. The cohort consisted of 2,034 Lapps who were recorded in the 1960 Population and Housing census as members of a household where someone were occupied in reindeer breeding. The cohort was followed-up in the Swedish Cause-of-Death Register from January 1, 1961 until death or December 31, 1985. The total mortality was similar to that of the entire population. Four hundred and twenty eight deaths occurred and the standardized mortality ratio (SMR) was 0.95. Ischemic heart disease was the most frequent cause-of-death and the mortality was the same as in the general population (SMR = 0.95). Significantly lower mortality than expected was observed for malignant tumors (SMR = 0.70), diseases of the circulatory system (SMR = 0.68 and for diseases of the digestive system (SMR = 0.42). Significantly increased SMR was found for external causes of injury (SMR = 1.83) and among female Lapps for cerebrovascular diseases (SMR = 1.70). Female Lapps had a significantly higher mortality of diseases of the circulatory system (SMR = 1.19) in relation to males (SMR = 0.48).

Cancer risks in Swedish Lapps who breed reindeer

Cancer risks during the period 1961-1984 were studied in a cohort of 2,034 Swedish reindeer-breeding Lapps, a unique group whose culture and life-style differ considerably from those in the rest of the Swedish population. A total of 100 cases of cancer were observed versus 163 expected. Statistically significantly decreased risks were found for cancers of the colon, respiratory organs, female breast, male genital organs, and kidneys, and for malignant lymphomas. The stomach was the only site with a significantly increased risk. Reindeer-breeding Lapps have ingested fallout products via the lichen-reindeer-man food chain since the 1950s. However, no increased risk was found for the cancer sites considered to be most sensitive to radiation.

Opiate addiction in adult offspring through possible imprinting after obstetric treatment

OBJECTIVE

To test the hypothesis that opiate addiction in adults might stem partly from an imprinting process during birth when certain drugs are given to the mother.

DESIGN

Retrospective study by logistic regression of opiate addicts with siblings as controls.

SETTING

Stockholm, Sweden.

SUBJECTS

200 Opiate addicts born in Stockholm during 1945-66, comprising 41 identified during interviews of probands for an earlier study; 75 patients whose death from opiate addiction had been confirmed during 1978-88; and 84 accepted for the methadone programme. 262 Siblings (controls) born in Stockholm during the same period, 24 of whom were excluded for drug addiction or being brought up outside the family. Birth records were unavailable for eight, leaving 230 siblings and 139 corresponding probands.

MAIN OUTCOME MEASURES

Administration of opiates, barbiturates, and nitrous oxide (for greater than 1 h) to mothers of all subjects during labour within 10 hours before birth as a risk factor for adult opiate addiction.

RESULTS

In subjects who had subsequently become addicts a significant proportion of mothers had received opiates or barbiturates, or both, compared with unmatched siblings (25% v 16%, chi 2 = 5.83, df = 1, p = 0.02), and these mothers had received nitrous oxide for longer and more often. After controlling for hospital of birth, order of birth, duration of labour, presentation other than vertex, surgical intervention, asphyxia, meconium stained amniotic fluid, and birth weight the relative risk for offspring subsequently becoming an adult opiate addict increased with the number of administrations of any of the three drugs. When the addicts were matched with their own siblings the estimated relative risk was 4.7 (95% confidence interval 1.8 to 12.4, p for trend = 0.002) for three administrations compared with when no drug was given.

CONCLUSIONS

The results are compatible with the imprinting hypothesis. Therefore, for obstetric pain relief methods are preferable that do not permit substantial passage of drugs through the placenta.

Chronic urticaria and cancer: an epidemiological study of 1155 patients

To evaluate the possible association of malignant disease with chronic urticaria 1155 consecutive cases with chronic urticaria were reviewed. The Swedish Cancer Registry, Stockholm, was searched for records reporting malignancies in the study population (1958-84), and the expected number of malignancies was calculated on the basis of age- and sex-standardized incidence data. A malignancy was diagnosed in 36 patients with urticaria and the expected number of malignancies was 41. In 23 patients the malignancy appeared during the same year as the onset of urticaria or later. The expected number was 25.6. We conclude that chronic urticaria is not statistically associated with malignancy in general.

The prevalence of malignant tumors in patients with psoriasis

A possible association between psoriasis and cancer was investigated by linking the Swedish Psoriasis Association's membership registry to the Swedish Cancer Registry. The population studied was 20,328 living persons. Since 1958 a cancer was recorded in 520 of them. The expected number, based on the prevalence of cancer in Sweden, was 540. Among 43 cancer sites for men and 46 for women selected primarily for analysis, a significant association with psoriasis was found only in two types of cancer. For male breast cancer the observed number was 4 and the expected number was 0.58, and for female kidney cancers the observed number was 17 and the expected number was 6.1. The statistically significant excess risk found for these two forms of cancer may be the result of multiple statistical testing rather than a phenomenon of true biologic significance. Thus psoriasis patients seem not to deviate from the general population with regard to cancer prevalence.

Prospective evaluation of serum CA 125 levels in a normal population, phase I: the specificities of single and serial determinations in testing for ovarian cancer

To determine the potential efficacy of the CA 125 assay as one component of a strategy for early detection of ovarian malignancy, serum CA 125 levels were determined in 1082 women 40 years of age or older in Stockholm. Initial serum CA 125 levels exceeded 35 U/ml in 36 women (3.3%) and 65 U/ml in 11 women (1.0%), placing the exact 95% upper confidence limits on false positive rates for a single screen at 4.3 and 1.7%, respectively. Follow-up CA 125 levels were obtained for those women with initially elevated levels and a group of age-matched controls. Mean CA 125 levels declined significantly for women with initially elevated levels (P = 0.0014). Interindividual variation and variation within individual subjects over the entire follow-up period were 52 and 35%, respectively. Of the 36 subjects with initially elevated serum CA 125 levels, only 2 showed a doubling of these levels; in only 1 of these 2 was this increase sustained. Intensive clinical follow-up with pelvic examination and ultrasonography, with investigators blinded to CA 125 results, led to the diagnosis of Stage III ovarian cancer in the latter individual. Diagnosis was made 21 months after the initially elevated serum CA 125 measurement and 15 months after the first measured doubling of that level. Because no other malignancies were identified at entry or during the follow-up period (median 560 days) in the women with elevated CA 125 levels, the specificity of the assay over that time period would have been 99.9% using the doubling of an initially elevated value as the criterion for determining positivity and 100% using as the criterion a sustained increase in level for those with initially elevated levels that doubled. These results support the continued investigation of longitudinally collected CA 125 levels to identify individuals at high risk for ovarian malignancy.

Pemphigoid and cancer

To evaluate the significance of the association of malignant disease with bullous pemphigoid, we reviewed 497 consecutive cases with positive immunofluorescence tests for circulating antibodies to basement membrane. We searched the Swedish Cancer Registry, Stockholm, Sweden, for records reporting malignancies in the study population (1958 to 1985), and the expected number of malignancies was calculated on the basis of age- and sex-standardized incidence data. In 61 patients, a total of 69 malignancies were diagnosed. The expected number of malignancies was 82.6. In 25 patients, a total of 27 malignancies appeared during the same year as the onset of pemphigoid, or later. The expected number was 35.8. The median titer of circulating antibodies in the 497 patients, in the 61 patients with malignancy, and in the 25 patients with malignancy preceded by the pemphigoid, were not significantly different. We conclude that pemphigoid is not statistically associated with malignancy, and that the former hypothesis of such an association was based on age only.