Helicobacter pylori IgA and IgG antibodies, serum pepsinogen I and the risk of gastric cancer: changes in the risk with extended follow-up period.

The prediction of Helicobacter pylori antibodies immunoglobulin A (IgA) and immunoglobulin G (IgG) and serum pepsinogen I (PG I) on gastric cancer occurrence was studied in a nested case-control study, based on 225 incident cancer cases and 435 matched controls from a Finnish cohort followed from 1966-1991. The odds ratio of noncardia gastric cancer between infected and noninfected persons was 3.12 (95% confidence interval (CI)=1.97-4.95) for elevated IgA and 2.88 (CI: 1.63-5.07) for elevated IgG antibodies. The odds ratio between low and high PG I was 2.24 (CI: 1.43-3.49). The strength of association was significant for IgA antibodies during the total follow-up, but for IgG antibodies this was only true for follow-up periods of 15 years or more. IgA antibodies were significantly associated with all registered histological subtypes apart from intestinal type adenocarcinoma. The highest gastric cancer risk was found among individuals with simultaneously elevated IgA and IgG antibodies and low PG I with an odds ratio of 10.9 (CI: 4.31-27.7) in comparison with those who were negative for both antibodies and had normal PG I. Elevated IgA and IgG antibodies and low PG I were not associated with cancers of the gastric cardia. The findings support the hypothesis that H. pylori infection is a cause of noncardia gastric cancer. Although elevated H. pylori IgA and IgG antibodies and low PG I independently could predict the occurrence of noncardia gastric cancer, their power to do so varied with the stage and length of the follow-up period and it increased when they were applied in combination.

A feasibility study of magnetic resonance imaging of silicone breast implants in Finland.

Cosmetic breast implants have become increasingly popular throughout the world. However, there is insufficient knowledge about the frequency and severity of local complications such as rupture and capsular contracture. A pilot study of 25 Finnish women with 50 cosmetic breast implants was organized to determine the feasibility of conducting a magnetic resonance imaging (MRI)-based study of rupture incidence. The pilot investigation included a clinical examination by a plastic surgeon, MRI scan, and self-administered questionnaire. The participation rate was 100%. Implants in our study represented a cross-section of the different generations of implants in Finland, with implant ages varying from 4 months to 20 years. The average implant size was 215 mL, typical in Finnish cosmetic surgery. MR images were evaluated by two independent readers. The first reader diagnosed six implants with intracapsular rupture, while the other diagnosed all implants as intact. The procedures of the feasibility study proved successful, and the results demonstrate the importance of a rigid image evaluation protocol with employment of well-defined rupture criteria, as well as the benefits of several image readers.

Blood biochemistry and the risk of cancer.

A longitudinal study based on a serum sample bank was carried out in Finland to find out the association between biochemical substances and the subsequent risk of cancer. The objective was to evaluate the consistency between means of individually estimated levels of these compounds and levels based on pooling. Levels of alpha-tocopherol, beta-carotene, retinol, retinol-binding protein, and ceruloplasmin were estimated by primary site and sex and partly by age and morphology. The concentrations in pooled samples were consistently lower than the averages of the individual samples. On the basis of individual samples, all the five biochemical compounds had a rather consistent protective effect on the risk of cancers at most primary sites. This protective effect disappeared in the pool analyses, and more than half of exposure contrasts showed an opposite sign. For ceruloplasmin, the effect of pooling was smaller but not negligible. The results of this study emphasize the demand to standardize the collecting, handling, and analysing of samples in serum banks. They are, furthermore, consistent with the hypothesis that pooling of biochemical samples affects the levels of the substances and may affect the conclusions of epidemiological studies on causes of diseases.

No improvement in the overall survival of 194 patients with chondrosarcoma in Finland in 1971-1990.

We describe the clinicopathologic profile and survival of 306 patients with chondrosarcoma reported to the Finnish Cancer Registry in 1971-1990. 218 cases were available for reevaluation. Owing to their various clinicopathologic characteristics, we excluded the histologic variants of chondrosarcoma. Therefore, the final study population included 194 patients. The minimum follow-up was 9 years. The study population included 69 grade 1 tumors, 114 grade 2 tumors, and 11 grade 3 tumors. The commonest tumor sites were the chest, pelvis and femur. A local recurrence developed in 25% of the patients and metastatic lesions in 18%. The patients were treated in 31 hospitals (in 22 hospitals during the 1970s and in 26 in the 1980s), and the number of patients biopsied before the referral remained about the same from the 1970s (15%) to the 1980s (18%). The 5-and 10-year disease-specific survival rates were 70% and 57%, respectively. Multivariate analysis showed that the most important independent predictors of shortened survival were high histologic grade, age 50 years or older, and a diagnosis in the 1980s, as compared to the 1970s. Most findings accorded with reports from specialist treatment centers, but to our surprise, the survival rate declined among patients diagnosed in the 1980s versus the 1970s. The failure to improve patient survival is probably due to treatment of the patients in 31 hospitals rather than in a few centers dealing with treatment of cancer.

Stressful life events and risk of breast cancer in 10,808 women: a cohort study.

The authors prospectively investigated the relation between stressful life events and risk of breast cancer among 10,808 women from the Finnish Twin Cohort. Life events and breast cancer risk factors were assessed by self-administered questionnaire in 1981. A national modification of a standardized life event inventory was used, examining accumulation of life events and individual life events and placing emphasis on the 5 years preceding completion of the questionnaire. Through record linkage with the Finnish Cancer Registry, 180 incident cases of breast cancer were identified in the cohort between 1982 and 1996. The multivariable adjusted hazard ratio for breast cancer per one-event increase in the total number of life events was 1.07 (95% confidence interval (CI): 1.00, 1.15). This risk estimate rose to 1.35 (95% CI: 1.09, 1.67) when only major life events were taken into account. Independently of total life events, divorce/separation (hazard ratio (HR) = 2.26, 95% CI: 1.25, 4.07), death of a husband (HR = 2.00, 95% CI: 1.03, 3.88), and death of a close relative or friend (HR = 1.36, 95% CI: 1.00, 1.86) were all associated with increased risk of breast cancer. The findings suggest a role for life events in breast cancer etiology through hormonal or other mechanisms.

The Finnish Cancer Registry as follow-up source of a large trial cohort--accuracy and delay.

We evaluated the accuracy and time to reporting of cancer diagnoses obtained through the Finnish Cancer Registry (FCR) for the Alpha-Tocopherol Beta-Carotene Cancer Prevention (ATBC) Study in 1985-1997. In the ATBC Study suspect neoplasms were centrally reviewed through medical records and pathology specimens. The FCR data were compared against the reviewed data for 3600 cancers of eight sites. For most sites, 95% of the cases were reported to the FCR within 0.9 years with longer delays for lung and pancreatic cancers. Ninety-six percent of all FCR cases received the same primary site diagnosis in the ATBC review, and in 1.4% no malignancy was found. Conversely, 97% of cancers ascertained in the ATBC review had the same primary site in the FCR and 0.8% were unknown to the Registry. The accuracy of the FCR data is high but the delay in case notification should be considered in epidemiological studies.

Cancer incidence among patients using antiepileptic drugs: a long-term follow-up of 28,000 patients.

OBJECTIVES: The purpose of the study was to find out whether there is an association between use of enzyme-inducing antiepileptic medicines and cancer. METHODS: : A cohort of 14,487 male and 13,932 female patients who received reimbursement for antiepileptic drugs (AEDs) in 1979-1981 in Finland was followed for subsequent cancers up to 1997 through the Finnish Cancer Registry. RESULTS: During the follow-up, 2242 cancer cases were observed, while the expected number based on national incidence rates was 1743. Over 40% of the excess was attributable to cancer of the brain and nervous system [standardised incidence ratio (SIR) 4.30, 95% confidence interval (CI) 3.81, 4.82]. The relative risk of meningiomas was very high (SIR 46.6, 95% CI 22.3, 85.6) only during the first year of reimbursement, while the risk of gliomas remained tenfold or higher for 7 years and was significantly increased for 19 years in patients taking AEDs. Also cancers of the larynx (SIR 1.77), liver (1.71), pancreas (1.35), colon (1.32), stomach (1.30) and lung (1.29) showed statistically increased risks. CONCLUSION: As epilepsy can be a symptom of cancers of the nervous system, the role of AEDs in their occurrence is speculative albeit possible. The excess of some cancers might be attributable to enzyme-inducing antiepileptic drugs, but the excess is not very high compared with the benefits obtained with these drugs.

A prospective study of life satisfaction, neuroticism and breast cancer risk (Finland).

OBJECTIVE: To prospectively investigate whether life satisfaction and neuroticism, two measures reflecting aspects of anxiety/depression, are related to risk of breast cancer. METHODS: The study population comprised 12,032 women from the population-based Finnish Twin Cohort. Life satisfaction and neuroticism were assessed in health questionnaires in 1975 and 1981. During 21 years of follow-up, 238 cases of breast cancer were documented in the study cohort through record linkage to the Finnish Cancer Registry. RESULTS: After adjustment for age and other important covariates, the hazard ratios were 1.0 (reference), 0.9 (95% confidence interval 0.6-1.3) and 1.0 (0.7-1.6) by decreasing level of life satisfaction (satisfied, intermediate, dissatisfied), and 1.0 (reference), 1.0 (0.7-1.4) and 0.8 (0.6-1.2) by increasing level of neuroticism (low, intermediate, high). These results did not change after accounting for possible changes in the levels of life satisfaction and neuroticism between 1975 and 1981. The null results were also confirmed with the use of a nested case-control study within twin pairs that became discordant for breast cancer during the follow-up. CONCLUSIONS: Our data indicate that life satisfaction and neuroticism are not substantially associated with breast cancer risk. These findings provide epidemiological evidence against the doubts that breast cancer would be more likely to occur in unhappy, dissatisfied, and worrying women.

Circulating enterolactone and prostate cancer risk: a Nordic nested case-control study.

Enterolactone, a phytoestrogen belonging to the class of lignans, is produced by the intestinal microflora from precursors in plant foods and has been implicated in protection against cancer. We study the effect of enterolactone on the risk of a subsequent diagnosis of prostate cancer. We conducted a longitudinal, nested case-control study by linkage of 3 biobanks to the cancer registries in Finland, Norway and Sweden, respectively. Enterolactone concentrations were measured by time-resolved fluoroimmunoassay in serum from 794 men who had a diagnosis of prostate cancer at a mean follow-up time of 14.2 years after blood collection and among 2,550 control men matched within each cohort for age (+/-2 years), date of blood collection (+/-2 months) and county. The median enterolactone concentrations did not differ between case and control subjects in the full study group (8.4 nmol/L [25th-75th percentile = 4.5-15.0] vs. 8.5 nmol/L [25th-75th percentile = 4.3-15.9]), nor in the national groups. Odds ratios of prostate cancer risk estimated by conditional logistic regression for increasing concentrations of enterolactone in quartiles in the full study group were 1.00 (referent), 1.21 (95% confidence interval [CI] = 0.96-1.52), 1.16 (95% CI = 0.91-1.47) and 1.08 (95% CI = 0.83-1.39). The OR estimate for the highest vs. the lowest quartile of enterolactone in separate analyses of the Norwegian, Finnish and Swedish cohort was 1.21 (95% CI = 0.91-1.60), 1.02 (95% CI = 0.59-1.76) and 0.87 (95% CI = 0.45-1.67), respectively. No support for the hypothesis that high circulating enterolactone is protective against prostate cancer was found.

Incidence of breast and other cancers among Finnish women with cosmetic breast implants, 1970-1999.

Epidemiologic evidence does not point to a carcinogenic effect of silicone implants on the breast, and evidence for or against a carcinogenic effect at sites other than the breast is limited. To examine subsequent cancer risk among women with cosmetic breast implants, we conducted a cohort study of 2171 women in Finland identified from operation diaries of major hospitals and private clinics, 1970-1999. The nationwide population and health outcome registries in Finland were used to trace these women for cancer incidence through 1999. Standard statistical techniques were used to compute expected values based on general population rates. The measure of risk was taken as the ratio of observed to expected cancers, that is, the standardized incidence ratio (SIR) and its 95% confidence interval (CI). Among the 2171 women with cosmetic breast implants, 30 developed cancer against 33.7 expected (SIR = 0.9,95% CI = 0.6-1.3). There was no evidence for an increase in breast cancer risk (SIR 0.5, 95% CI, 0.2-1.0), even among those followed for more than 10 years (2 observed, 4.6 expected). Stage at breast cancer diagnosis did not differ from that expected nor did incidence of any other cancer. Although hindered by small numbers, the consistency of our results with those of other Nordic studies leads us to conclude that cosmetic breast implants are not a cause of cancer and that they do not appear to delay the detection of breast cancers.