Age-related incidence of cervical cancer supports two aetiological components: a population-based register study.

OBJECTIVE: To assess whether age-related incidence of cervical cancer supports two aetiological components and to assess trends in these components due to risk factors and to organised screening in Finland. DESIGN: Population-based register study. SETTING: Finnish Cancer Registry. POPULATION: Cervical cancer cases and female population in Finland in 1953-2012. METHODS: Cervical cancer incidence was estimated using Poisson regression where age-specific incidence consists of two (early-age and late-age) normally distributed components. MAIN OUTCOME MEASURES: Accumulated net risks (incidences) and numbers of cancer cases attributed to each age-related component by calendar time. RESULTS: The accumulated cervical cancer incidence in 2008-2012 was only 30% of that in 1953-1962, before the screening started. The fit of the observed age-specific rates and the rates based on the two-component model was good. In 1953-62, the accumulated net risk ratio (RR; early-age versus late-age) was 0.42 (95% CI 0.29-0.61). The early-age component disappeared in 1973-77 (RR 0.00; 95% CI 0.00-0.08). Thereafter, the risk for the early-age component increased, whereas the risk for the late-age component decreased, and in 2008-2012 the RR was 0.55 (95% CI 0.24-0.89). CONCLUSIONS: In Finland, cervical cancer incidence has two age-related components which are likely to indicate differences in risk factors of each component. The trend in risk of both components followed the effects of organised screening. Furthermore, the risk related to the early-age component followed changes in risk factors, such as oncogenic HPV infections and other sexually transmitted diseases and smoking habits. TWEETABLE ABSTRACT: Cervical cancer incidence has two age-related components which are likely to have differencies in their aetiology.

Outcomes of medical and surgical treatment for lower urinary tract symptoms (benign prostatic obstruction)--a population-based cohort study.

OBJECTIVE: To compare outcome of lower urinary tract symptoms (LUTS) between men with medical and surgical treatment. MATERIALS AND METHODS: A questionnaire was mailed to men aged 55, 65 and 75 years living in Tampere region, Finland in 1999 and the survey was repeated in 2004. LUTS were evaluated using DAN-PSS-1 questionnaire. A total of 1679 men (68% of the eligible) responded to both questionnaires. Of them, 114 men reported LUTS at baseline and medical treatment in the repeat survey and 47 men with LUTS had received surgical treatment. Seventy-two men with prostate cancer were excluded. Men with no medical treatment or surgery for LUTS in either questionnaire were included to no-treatment group. RESULTS: The men after surgical treatment showed a reduction in all LUTS symptom groups. However, among the medically treated and untreated men, all the symptoms worsened during the follow up. The proportion of symptomatic men after surgery was lower than among the medically treated men. In men with medical treatment, the prevalence of all 12 LUTS increased. Dysuria and postmicturition dribble were the only symptoms that had slightly better results in medical than in surgical treatment group. CONCLUSIONS: In this population-based study, operative treatment seemed to relieve LUTS, whereas medical treatment only slowed down their progression. These findings suggest that men with surgical treatment experience a more favourable outcome in LUTS than those receiving medical treatment.

Effects of annual vs triennial mammography interval on breast cancer incidence and mortality in ages 40-49 in Finland.

BACKGROUND: The aim of this study was to evaluate the effects of mammography screening invitation interval on breast cancer mortality in women aged 40-49 years. METHODS: Since 1987 in Turku, Finland, women aged 40-49 years and born in even calendar years were invited for mammography screening annually and those born in odd years triennially. The female cohorts born during 1945-1955 were followed for up to 10 years for incident breast cancers and thereafter for an additional 3 years for mortality. RESULTS: Among 14,765 women free of breast cancer at age 40, there were 207 incident primary invasive breast cancers diagnosed before the age of 50. Of these, 36 women died of breast cancer. The mean follow-up time for cancer incidence was 9.8 years and for mortality 12.8 years. The incidence of breast cancer was similar in the annual and triennial invitation groups (RR: 0.98, 95% confidence interval (CI): 0.75-1.29). Further, there were no significant differences in overall mortality (RR: 1.20, 95% CI: 0.99-1.46) or in incidence-based breast cancer mortality (RR: 1.14, 95% CI: 0.59-1.27) between the annual and triennial invitation groups. CONCLUSIONS: There were no differences in the incidence of breast cancer or incidence-based breast cancer mortality between the women who were invited for screening annually or triennially.

Knowledge transfer as a tool towards improvement of cancer care in low- and middle-income countries. 6th European Roundtable Meeting (ERTM), June 14th, 2019, Berlin, Germany.

PURPOSE: To identify key factors for the best practice of knowledge transfer from high-income settings to low- and middle-income settings. RESULTS: Interactive sessions led to the identification of European learnings that can and should be shared beyond Europe. Furthermore, methods were characterised which may lead to successful knowledge transfer with subsequent quality improvement. CONCLUSION: To ensure successful implementation of knowledge and new methods, political support is extremely important. A strong focus should be an improvement of collaboration and network development. Rehabilitation, early and late pallative care, cost effectiveness and long-term follow-up are priorities. Limitations are budget constraints which limit the execution of NCCPs.

The risk of congestive heart failure is increased in persons with varicose veins.

AIM: Varicose veins are a common condition but their etiology and relationship with other cardiovascular diseases are not well established. The aim of the study was to find out if persons with varicose veins have a higher risk of congestive heart failure (CHF) than persons without varicose veins. METHODS: The prevalence of CHF at entry and the incidence of CHF during a five-year follow-up period were studied in persons with and without varicose veins. A study was conducted with a questionnaire in a population of 4903 middle-aged residents in Tampere, Finland. RESULTS: Marginally higher prevalence of CHF was found in persons with varicose veins than in those without (2.9% vs. 1.9%) with OR 1.6 (1.0-2.3) and sex and age adjusted OR 1.2 (0.8-1.9). The incidence of CHF was higher in subjects with varicose veins than in others (4.9 vs. 2.6 per 1000 person-years) with IDR 1.9 (1.1-2.9) and sex and age adjusted IOR 2.5 (1.4-4.6). The result was further adjusted for body mass index, arterial disease and hypertension; multi-adjusted IOR for the incidence of CHF by varicose veins was 2.1 (1.1-4.0). CONCLUSIONS: Our longitudinal observation is consistent with the hypothesis that persons with varicose veins have a higher risk of CHF which is not mediated through sex, age, overweight, arterial disease or hypertension.

The sense of coherence and risk of injuries: role of alcohol consumption and occupation.

STUDY OBJECTIVE: To test the hypothesis that individuals with a strong sense of coherence (SOC) have a decreased incidence of external cause injuries and to study the role of alcohol consumption and occupational category in that association. DESIGN: Participants of the Helsinki Heart Study were followed up for injuries for eight years through the national hospital discharge register and cause of death statistics. Cox proportional hazards models were used to calculate the relative risks. SETTING: The Helsinki Heart Study, a clinical trial to prevent coronary heart disease. PARTICIPANTS: 4405 Finnish middle-aged employed men. MAIN RESULTS: The SOC was inversely associated with the risk of injuries, with a significant 25% lower incidence in the highest tertile of SOC (7.6 per 1000 person-years) compared with the lowest (10.2 per 1000 person-years). The association remained significant if adjusted for age, but not if adjusted additionally for alcohol consumption or occupation. When considered jointly with occupational category, the injury risk showed a decreasing trend (p = 0.02) with increasing SOC among blue collar but not among white collar workers. The use of alcohol had a great impact on injury risk among those with weak SOC, with incidences of 7.7, 10.2, and 14.9 per 1000 person-years in the non/light, medium, and heavy categories of consumption (p for trend 0.01). No such trend was seen in other SOC tertiles. CONCLUSIONS: There was an effect of SOC on the incidence of injury especially among blue collar workers. A substantial part of the effect was mediated by alcohol consumption.

The 15-Country Collaborative Study of Cancer Risk Among Radiation Workers in the Nuclear Industry: design, epidemiological methods and descriptive results.

Radiation protection standards are based mainly on risk estimates from studies of atomic bomb survivors in Japan. The validity of extrapolations from the relatively high-dose acute exposures in this population to the low-dose, protracted or fractionated environmental and occupational exposures of primary public health concern has long been the subject of controversy. A collaborative retrospective cohort study was conducted to provide direct estimates of cancer risk after low-dose protracted exposures. The study included nearly 600,000 workers employed in 154 facilities in 15 countries. This paper describes the design, methods and results of descriptive analyses of the study. The main analyses included 407,391 nuclear industry workers employed for at least 1 year in a participating facility who were monitored individually for external radiation exposure and whose doses resulted predominantly from exposure to higher-energy photon radiation. The total duration of follow-up was 5,192,710 person-years. There were 24,158 deaths from all causes, including 6,734 deaths from cancer. The total collective dose was 7,892 Sv. The overall average cumulative recorded dose was 19.4 mSv. A strong healthy worker effect was observed in most countries. This study provides the largest body of direct evidence to date on the effects of low-dose protracted exposures to external photon radiation.

The 15-Country Collaborative Study of Cancer Risk among Radiation Workers in the Nuclear Industry: estimates of radiation-related cancer risks.

A 15-Country collaborative cohort study was conducted to provide direct estimates of cancer risk following protracted low doses of ionizing radiation. Analyses included 407,391 nuclear industry workers monitored individually for external radiation and 5.2 million person-years of follow-up. A significant association was seen between radiation dose and all-cause mortality [excess relative risk (ERR) 0.42 per Sv, 90% CI 0.07, 0.79; 18,993 deaths]. This was mainly attributable to a dose-related increase in all cancer mortality (ERR/Sv 0.97, 90% CI 0.28, 1.77; 5233 deaths). Among 31 specific types of malignancies studied, a significant association was found for lung cancer (ERR/Sv 1.86, 90% CI 0.49, 3.63; 1457 deaths) and a borderline significant (P = 0.06) association for multiple myeloma (ERR/Sv 6.15, 90% CI <0, 20.6; 83 deaths) and ill-defined and secondary cancers (ERR/Sv 1.96, 90% CI -0.26, 5.90; 328 deaths). Stratification on duration of employment had a large effect on the ERR/Sv, reflecting a strong healthy worker survivor effect in these cohorts. This is the largest analytical epidemiological study of the effects of low-dose protracted exposures to ionizing radiation to date. Further studies will be important to better assess the role of tobacco and other occupational exposures in our risk estimates.

Cardiovascular drug use and the incidence of erectile dysfunction.

It is unclear whether high blood pressure per se or antihypertensive drug use causes erectile dysfunction (ED). The aim of this study was to investigate the effect of cardiovascular diseases and their concomitant medications use on the incidence of ED. The target population consisted of men aged 55, 65 or 75 years old residing in the study area in Finland in 1999. Questionnaires were mailed to 2837 men in 1999 and to 2510 of them 5 years later. The follow-up sample consisted of 1665 men (66% of those eligible) who responded to both baseline and follow-up questionnaires. Men free of moderate or severe ED at baseline (N=1000) were included in the study. ED was assessed by two questions on subject ability to achieve or maintain an erection sufficient for intercourse. Poisson regression model was used in the multivariable analyses. The risk of ED was higher in men suffering from treated hypertension or heart disease than in those with the untreated condition. The risk of ED was higher in men using calcium channel inhibitor (adjusted relative risk (RR)=1.6, 95% confidence interval (CI) 1.0-2.4), angiotensin II antagonist (RR=2.2, 95% CI 1.0-4.7), non-selective beta-blocker (RR=1.7, 95% CI 0.9-3.2) or diuretic (RR=1.3, CI 0.7-2.4) compared with non-users. ED was not associated with using organic nitrates, angiotensin-converting enzyme inhibitors, selective beta-blockers and serum lipid-lowering agents. In summary, calcium channel inhibitors, angiotensin II antagonists, non-selective beta-blockers and diuretics may increase the risk of ED.

Erectile dysfunction influences the subsequent incidence of lower urinary tract symptoms and bother.

It is unclear whether lower urinary tract symptoms (LUTS) cause erectile dysfunction (ED) independently or through common underlying pathophysiology and shared risk factors. The aim of this study was to investigate the effect of ED on the incidence of frequency and bother of LUTS. Target population consisted of men aged 50, 60 or 70 years residing in the study area in Finland in 1994. Questionnaires were mailed to 3143 men in 1994 and to 2837 of them 5 years later. The follow-up sample comprised 1683 men who responded to both baseline and follow-up surveys. ED was assessed by two questions on subject's ability to achieve or maintain an erection sufficient for intercourse and LUTS by the Danish Prostatic Symptom Score questionnaire. A dose-response relation was found between the severity of ED at baseline and the incidence of LUTS or bother during follow-up. After adjustment for the confounders, the incidence rate ratio (RR) of LUTS was higher in men with moderate (RR 1.5, 95% confidence interval (CI) 1.0-2.3) or severe ED (RR 2.3, 95% CI 1.4-3.8) than in those free of ED at entry. Compared with men free of ED at baseline, the RRs of urinary bother were 1.6 (95% CI 1.1-2.4), 1.9 (95% CI 1.1-3.2) and 2.2 (95% CI 1.1-4.3) for minimal, moderate or severe ED, respectively. In summary, ED is associated with an increased incidence of LUTS and bother. ED and LUTS may have a common underlying pathophysiology or shared risk factors.

Indoor radon exposure and risk of lung cancer: a nested case-control study in Finland.

BACKGROUND: Inhaled radon has been shown to cause lung cancer among underground miners exposed to very high radon concentrations, but the results regarding the effects of residential radon have been conflicting. PURPOSE: Our aim was to assess the effect of indoor radon exposure on the risk of lung cancer. METHODS: To investigate this effect, a nested case-control study was conducted in Finland. The subjects of the study were the 1973 lung cancer case patients (excluding patients with cancers of the pleura) diagnosed from January 1, 1986, until March 31, 1992, within a cohort of Finns residing in the same one-family house from January 1, 1967, or earlier, until the end of 1985 and 2885 control subjects identified from the same cohort and matched by age and sex. In September 1992, a letter was sent to all study subjects or proxy respondents explaining the purpose and methods of the study. After giving informed consent, the study participants were asked to fill out a questionnaire on smoking habits, occupational exposures, and other determinants of lung cancer risk and radon exposure. The odds ratio (OR) of lung cancer was estimated from matched and unmatched logistic regression analyses relative to indoor radon concentration assessed by use of a 12-month measurement with a passive alpha track detector. RESULTS. Five hundred seventeen case-control pairs were used in the matched analysis, and 1055 case subjects and 1544 control subjects were used in the unmatched analysis. The OR of lung cancer for indoor radon exposure obtained from matched analysis was 1.01 (95% confidence interval [CI] = 0.94-1.08) per 2.7 pCi/L (100 Bq m-3) after adjustment for the cigarette smoking status, intensity, duration, and age at commencement of smoking by subjects. For indoor radon concentrations 1.4-2.6, 2.7-5.3, 5.4-10.7, and 10.8-34.5 pCi/L (50-99, 100-199, 200-399, and 400-1277 Bq m-3, respectively), the matched ORs were 1.03 (95% CI = 0.84-1.26), 1.00 (95% CI = 0.78-1.29), 0.91 (95% CI = 0.61-1.35), and 1.15 (95% CI = 0.69-1.93), respectively, relative to the concentration below 1.4 pCi/L (0-49 Bq m-3). The unmatched analysis yielded similar results with somewhat smaller CIs. In the analyses stratified by age, sex, smoking status, or histologic type of lung cancer, no statistically significant indications of increased risk of lung cancer related to indoor radon concentration were observed for any of the subgroups. CONCLUSIONS: Our results do not indicate increased risk of lung cancer from indoor radon exposure. IMPLICATION: Indoor radon exposure does not appear to be an important cause of lung cancer.

Serum selenium and subsequent risk of cancer among Finnish men and women.

The association between the serum selenium level and the subsequent incidence of cancer was investigated in a longitudinal study of 39,268 men and women participating in the Social Insurance Institution's Mobile Clinic Health Examination Survey in Finland. The baseline examinations, including the collection of blood samples, were performed in 1968-1972. During a median follow-up of 10 years, 1,096 new cancer cases were identified from the files of the Finnish Cancer Registry. Selenium concentrations were measured from the stored serum samples collected from these cancer cases and from two controls per case, matched for sex, municipality, and age. The mean serum selenium level was 59.1 micrograms/L among all male cancer cases and 62.5 micrograms/L among controls. The difference was statistically significant (P less than .001). Corresponding values among women were 63.6 and 63.9 micrograms/L, respectively. Low serum selenium levels were associated with an increased risk of developing cancer at several sites, especially cancers of the stomach and lung among men. The relative risk of lung cancer between the highest and lowest decile of serum selenium was 0.11, and it differed significantly from unity (P less than .001). These findings are in agreement with the hypothesis that low selenium intake may increase the risk of some cancers among men.

Prospective seroepidemiologic study of human papillomavirus infection as a risk factor for invasive cervical cancer.

BACKGROUND: Major risk factors for invasive cervical cancer include infection with human papillomavirus (HPV), infection with other sexually transmitted pathogens (e.g., Chlamydia trachomatis), and smoking. Since exposures to these risk factors can be related, the contribution of any single factor to cervical carcinogenesis has been difficult to assess. We conducted a prospective study to define the role of HPV infection in cervical carcinogenesis, with invasive cancer as an end point. METHODS: A nested case-control study within a joint cohort of 700,000 Nordic subjects was performed. The 182 women who developed invasive cervical cancer during a mean follow-up of 5 years were matched with 538 control women on the basis of age and time of enrollment. Serum samples taken at enrollment were analyzed for evidence of tobacco use (i.e., cotinine levels); for antibodies against HPV types 16, 18, and 33; and for antibodies against C. trachomatis. Relative risks (RRs) were estimated by use of conditional logistic regression. RESULTS: Presence of antibodies against HPV in serum (seropositivity) was associated with an increased risk of cervical cancer, and adjustment for smoking and for C. trachomatis seropositivity did not affect this finding (RR = 2.4; 95% confidence interval [CI] = 1.6-3.7). HPV16 seropositivity was associated primarily with an increased risk of squamous cell carcinoma (RR = 3.2; 95% CI = 1.7-6.2). In contrast, risk associated with HPV18 seropositivity tended to be higher for cervical adenocarcinoma (RR = 3.4; 95% CI = 0.8-14.9). In populations with a low prevalence of antibodies against C. trachomatis, the HPV16-associated risk of cervical cancer was very high (RR = 11.8; 95% CI = 3.7-37.0); in contrast, in populations with a high prevalence of antibodies against C. trachomatis, no excess risk was found. CONCLUSION: Past infection with HPV16 increases the risk of invasive cervical squamous cell carcinoma, most clearly seen in populations with a low prevalence of sexually transmitted diseases.

Relationship between smoking and erectile dysfunction.

We estimated the effects of smoking on the risk and prognosis of erectile dysfunction (ED), and of ED on smoking behavior. The follow-up sample consisted of the 1442 men aged 50-75 y, who responded to both baseline and follow-up questionnaires. We estimated the effect of smoking on the incidence of ED among the 1130 men free from ED, ED on risk to start smoking in the 502 nonsmokers, smoking on the prognosis of ED among the 312 with ED and ED on quitting smoking among the 292 current smokers at baseline. Risk of ED increased nonsignificantly with smoking (odds ratio (OR)=1.4), while ED recovery reduced (OR=0.6). Therefore, there was the ratio of 2.3 (1.4/0.6) describing the total effect of smoking on the risk of ED. Both quitting (OR=1.7) and starting (OR=1.9) smoking were rare and nonsignificantly higher in men with ED. Most of the OR estimates on smoking-ED relationships were not statistically significant, probably due to small numbers. There are two bidirectional relations between ED and smoking. Those who smoked had a higher risk of ED than nonsmokers. The men with ED were more likely to start smoking than those free from ED. The estimates of effects were not statistically significant, but they were consistent with each other and with the hypothesis that smoking causes ED and ED causes smoking. The recovery from ED was less in smokers than among nonsmokers, and current smokers with ED were more likely to stop smoking than men free from ED. Numbers were few and estimates of effects were not significant, but consistent with the hypothesis of smoking preventing recovery from ED and ED improving the success of smoking cessation. Such transitions in four directions explain indirectly the known positive association between the prevalence of smoking and the prevalence of ED.

Are questions on both achieving and maintaining an erection needed to define erectile dysfunction?

Our aim was to ascertain if the assessment of erectile dysfunction (ED) should include questions on difficulty in both achieving and maintaining erection. A population-based study of 3143 men in Tampere region in Finland was conducted by mailed questionnaire. The 1983 men who responded questions on erectile function were included in the analysis. Different levels in the severity of ED were used to examine the agreement between the two questions. Consistency was measured by kappa coefficient. Consistency was fairly high (kappa=0.71) when the severity of ED was examined in four groups. In those cases where alternative responses were categorized into three groups, consistency was best (kappa=0.86) when the alternatives 'never' and 'sometimes' were combined. Consistency was almost perfect (kappa=0.97) when ED dichotomized into two groups and the cutoff was set between the alternatives 'quite often' and 'intercourse does succeed'. The kappa index was 0.86 with the cutoff level between 'sometimes' and 'quite often' and 0.67 with the cutoff between 'never' and 'sometimes'. When ED was examined in different age groups, the consistency was the highest among the oldest respondents. Responses on both symptoms are needed to distinguish between normal erectile function and minimal ED, and also between minimal and moderate ED, especially in young men. When the aim is to distinguish between complete ED and a milder form, the information from one question is the same as that from two questions.

Validity of process indicators of screening for breast cancer to predict mortality reduction.

The aim of the study was to empirically assess the acceptable levels of process indicators as described in the European Community Guidelines using materials from the mammography service screening programmes. The Finnish programme was evaluated for effectiveness with a prior estimate of 0.74 for RR in Finland and 0.81 in Helsinki. Hence, the Finnish programme was likely to be somewhat less effective in terms of reduction in mortality than implied on the basis of early randomized trials, but probably approaching the same level of effectiveness. Finland therefore provides background data on the applicability of the process indicators that are indicators of performance and surrogates for effectiveness. The performance data on 10 Finnish screening centres at subsequent screens were used. These centres invited 687,000 women aged 50-64 years in 1991-2000. The mean compliance was 93% and the corresponding recall rate was 2.3%. The benign to malignant biopsy ratio was 0.43:1. The average breast cancer detection rate was 0.36%, 2.1 compared with the background incidence. The proportion of screen-detected stage II+ cancers was 26%. Most, but not all, of these process indicators met the desirable reference values of the European Community. The specific criteria of the European Community on stage distribution, rates of screen-detected cancers by stage and detection rate to background incidence may need reconsideration.

Effectiveness of screening for colorectal cancer with a faecal occult-blood test, in Finland.

BACKGROUND: Screening for colorectal cancer (CRC) with guaiac-based faecal occult-blood test (FOBT) has been reported to reduce CRC mortality in randomised trials in the 1990s, but not in routine screening, so far. In Finland, a large randomised study on biennial FOB screening for CRC was gradually nested as part of the routine health services from 2004. We evaluate the effectiveness of screening as a public health policy in the largest population so far reported. METHODS: We randomly allocated (1:1) men and women aged 60-69 years to those invited for screening and those not invited (controls), between 2004 and 2012. This resulted in 180 210 subjects in the screening arm and 180 282 in the control arm. In 2012, the programme covered 43% of the target age population in Finland. RESULTS: The median follow-up time was 4.5 years (maximum 8.3 years), with a total of 1.6 million person-years. The CRC incidence rate ratio between the screening and control arm was 1.11 (95% CI 1.01 to 1.23). The mortality rate ratio from CRC between the screening and control arm was 1.04 (0.84 to 1.28), respectively. The CRC mortality risk ratio was 0.88 (0.66 to 1.16) and 1.33 (0.94 to 1.87) in males and females, respectively. CONCLUSIONS: We did not find any effect in a randomised health services study of FOBT screening on CRC mortality. The substantial effect difference between males and females is inconsistent with the evidence from randomised clinical trials and with the recommendations of several international organisations. Even if our findings are still inconclusive, they highlight the importance of randomised evaluation when new health policies are implemented. TRIAL REGISTRATION: 002_2010_august.

Insulin-like growth factor I is not a useful marker of prostate cancer in men with elevated levels of prostate-specific antigen.

High serum levels of insulin-like growth factor I (IGF-I) and low levels of IGF-binding protein-3 (IGFBP-3) have been shown to correlate with increased prostate cancer risk. To evaluate this, IGF-I, IGFBP-3, and prostate-specific antigen (PSA) were measured in serum from 665 consecutive men (179 with prostate cancer), aged 55-67 yr, with elevated serum prostate-specific antigen (PSA; > or = 4 microg/L) in a screening trial. Men in the highest quartile of IGF-I levels had an odds ratio (OR) for prostate cancer of 0.50 [95% confidence interval (CI) 0.26-0.97] when adjusting for serum IGFBP-3. IGFBP-3 itself was not significantly associated with prostate cancer risk (OR, 1.24; 95% CI, 0.68-2.24). Prostate volume was larger in men without than in those with prostate cancer (P < 0.001), and after adjustment for prostate volume, the negative association between serum IGF-I and prostate cancer risk was no longer significant (OR, 0.57; 95% CI, 0.28-1.16). In screen-positive men with elevated serum PSA, serum IGF-I is not a useful diagnostic test for prostate cancer, but it may be associated with benign prostatic hyperplasia and enlargement.

Vitamin E and cancer prevention.

Some animal experiments and human studies suggest that vitamin E may protect against cancer. Serum alpha-tocopherol concentration was studied for its prediction of cancer in a cohort of 36,265 adults in Finland. During a mean follow-up of 8 y, cancer was diagnosed in 766 persons. The levels of serum alpha-tocopherol were determined from stored serum samples (at -20 degrees C) taken from these cancer patients and from 1419 matched control subjects. Individuals with a low level of alpha-tocopherol had about a 1.5-fold risk of cancer compared with those with a higher level. The strength of the association between serum alpha-tocopherol level and cancer risk varied for different cancer sites and was strongest for some gastrointestinal cancers and for the combined group of cancers unrelated to smoking. The association was strongest among nonsmoking men and among women with low levels of serum selenium. The findings agree with the hypothesis that dietary vitamin E in some circumstances protects against cancer.