Lena Damber

Residential Radon Exposure and Lung Cancer in Sweden

BACKGROUND Residential radon is the principal source of exposure to ionizing radiation in most countries. To determine the implications for the risk of lung cancer, we performed a nationwide case-control study in Sweden. METHODS The study included 586 women and 774 men 35 to 74 years of age with lung cancer that was diagnosed between 1980 and 1984. For comparison, 1380 female and 1467 male controls were studied. Radon was measured in 8992 dwellings occupied by the study subjects at some time since 1947. Information on smoking habits and other risk factors for lung cancer was obtained from questionnaires. RESULTS Radon levels followed a log-normal distribution, with geometric and arithmetic means of 1.6 and 2.9 pCi per liter (60.5 and 106.5 Bq per cubic meter), respectively. The risk of lung cancer increased in relation to both estimated cumulative and time-weighted exposure to radon. In comparison with time-weighted average radon concentrations up to 1.4 pCi per liter (50 Bq per cubic meter), the relative risk was 1.3 (95 percent confidence interval, 1.1 to 1.6) for average radon concentrations of 3.8 to 10.8 pCi per liter (140 to 400 Bq per cubic meter), and it was 1.8 (95 percent confidence interval, 1.1 to 2.9) at concentrations exceeding 10.8 pCi per liter. The estimates of risk were in the same range as those projected from data in miners. The interaction between radon exposure and smoking with regard to lung cancer exceeded additivity and was closer to a multiplicative effect. CONCLUSIONS Residential exposure to radon is an important cause of lung cancer in the general population. The risks appear consistent with earlier estimates based on data in miners.

The Swedish rectal cancer registry

An audit of all patients with rectal cancer in Sweden was launched in 1995. This is the first report from the Swedish Rectal Cancer Registry (SRCR).

Familial prostate cancer in sweden: A nationwide register cohort study

Although prostate carcinoma is not widely recognized as a familial cancer, familial aggregation of this disease has been shown in some retrospective case–control studies. To study familial prostate cancer in Sweden, a population‐based cohort study was performed, that attempted to avoid possible bias connected with some earlier studies of familial prostate cancer.

Studies of genetic factors in prostate cancer in a twin population

It has been suggested that positive family history constitutes a risk factor for the development of prostate cancer. Familial clustering of prostate cancer might suggest that genetic factors are of importance in the etiology of this disease. To elucidate further the relative importance of genetic factors, we studied prostate cancer among an unselected Swedish twin population. Information from the Swedish Twin Registry and the Swedish Cancer Registry was used. In 4,840 male twin pairs 458 prostate cancers were identified between 1959 and 1989. Among these 16 monozygotic and 6 dizygotic twin pairs were concordant for prostate cancer. Proband concordance rates of 0.192 and 0.043, and a correlation of liability of 0.40 and -0.05 were found for monozygotic and dizygotic pairs, respectively. These differences in proband concordance rates and correlations of liability for monozygotic pairs compared to dizygotic pairs are pronounced. The results indicate that genetic factors might be of importance for the development of prostate cancer. The results of this study indicate the need for further investigations of genetic factors in prostate cancer, including large scale epidemiological studies and investigations of molecular genetics of risk families.

Total Food Consumption and Body Mass Index in Relation to Prostate Cancer Risk: A Case-Control Study in Sweden with Prospectively Collected Exposure Data

PURPOSE Prostate cancer is the most common cancer among men and accounts for most cancer related deaths in Sweden today. To find or confirm exogenous risk factors for prostate cancer a population based case-control study was performed. MATERIALS AND METHODS By linking the Swedish Cancer Registry with the Swedish Twin Registry 406 cases of prostate cancer were selected from the twin register. As controls 1,218 men without prostate cancer were randomly selected from the same register. The selection procedure ensured that no cases or controls were related to each other. Questionnaire concerning height, weight, dietary habits, and alcohol and tobacco consumption were mailed in 1967 and 1970 to members in the twin register and the collected information was used in this study. RESULTS There was a positive trend for prostate cancer risk seen for total food consumption to (p < 0.001) with an odds ratio of 2.22 (95% confidence interval 1.23 to 3.99) for those who consumed somewhat more and 3.89 (1.09 to 13.96) for those who consumed much more than people in general. An increased trend was also seen for body mass index (BMI) (p = 0.015), with an odds ratio of 1.44 (0.98 to 2.11) for 26 to 29 kg./m.2 and 1.80 (1.07 to 3.04) for BMI greater than 29 kg./m.2 compared with BMI less than 23 kg./m.2. Total food consumption and BMI remained independent risk factors in a multivariate analysis. All specific food items studied, as well as tobacco and alcohol consumption, were unrelated to prostate cancer risk. CONCLUSIONS This study suggests that high BMI and total food consumption are independent risk factors for prostate cancer and that dietary habits are important in the development of this tumor. It is also unlikely that neither tobacco nor alcohol use substantially changes the risk of prostate cancer.

Residential Radon and Lung Cancer among Never-Smokers in Sweden

In this study, we attempted to reduce existing uncertainty about the relative risk of lung cancer from residential radon exposure among never-smokers. Comprehensive measurements of domestic radon were performed for 258 never-smoking lung cancer cases and 487 never-smoking controls from five Swedish case-control studies. With additional never-smokers from a previous case-control study of lung cancer and residential radon exposure in Sweden, a total of 436 never-smoking lung cancer cases diagnosed in Sweden between 1980 and 1995 and 1,649 never-smoking controls were included. The relative risks (with 95% confidence intervals in parentheses) of lung cancer in relation to categories of time-weighted average domestic radon concentration during three decades, delimited by cutpoints at 50, 80, and 140 Bq m−3, were 1.08 (0.8–1.5), 1.18 (0.9–1.6), and 1.44 (1.0–2.1), respectively, with average radon concentrations below 50 Bq m−3 used as reference category and with adjustment for other risk factors. The data suggested that among never-smokers residential radon exposure may be more harmful for those exposed to environmental tobacco smoke. Overall, an excess relative risk of 10% per 100 Bq m−3 average radon concentration was estimated, which is similar to the summary effect estimate for all subjects in the main residential radon studies to date.

Residential radon and lung cancer in Sweden: risk analysis accounting for random error in the exposure assessment.

A large epidemiologic study on residential radon exposure and lung cancer has been conducted in Sweden. An attempt is now made to quantify the impact of random error in the exposure assessment on the risk estimate for lung cancer in this study. The study included 1,360 lung cancer cases, diagnosed from 1980 to 1984, and 2,847 population controls. Radon measurements were performed in 8,992 dwellings occupied by the study subjects some time since 1947. Questionnaires provided information on smoking and other risk factors. Imprecision in the retrospective exposure assessment for radon was estimated from a Monte Carlo technique modeling Swedish conditions. Adjusted risk estimates were obtained from regression analyses based on expected values for true time-weighted average residential radon concentration (TWA), conditional on observed TWA. Without adjustment for random error in the TWA estimates, the linear excess relative risk coefficient was 0.10 per 100 Bq m(-3), but an excess relative risk of about 0.15 to 0.20 per 100 Bq m(-3) was suggested following adjustment. The potentially significant consequences of errors in the retrospective radon exposure assessment should be taken into consideration in the risk estimation as well as in comparisons of results of different studies and in future pooled analyses.

Parenteral Estrogen versus Combined Androgen Deprivation in the Treatment of Metastatic Prostatic Cancer - Scandinavian Prostatic Cancer Group (SPCG) Study No. 5

Objective : In the mid-1980s, interest in parenteral estrogen therapy for prostate cancer was renewed when it was found that it influenced liver metabolism only marginally and had very few cardiovascular side-effects. In this study high-dose polyestradiol phosphate (PEP; Estradurin ® ) was compared to combined androgen deprivation (CAD) for the treatment of patients with metastatic prostate cancer. The aim of the study was to compare anticancer efficacy and adverse events, especially cardiovascular side-effects. Material and Methods : A total of 917 patients with T0-4, NX, M1, G1-3 prostate cancer and an Eastern Cooperative Oncology Group performance status of 0-2 were randomized to treatment with either PEP 240 mg i.m. twice a month for 2 months and thereafter once a month or flutamide (Eulexin ® ) 250 mg t.i.d. per os in combination with either triptorelin (Decapeptyl ® ) 3.75 mg per month i.m. or, on an optional basis, bilateral orchidectomy. A total of 556 patients had died at the time of this analysis. Results : There was no difference between the treatment arms in terms of time to biochemical or clinical progression and overall or disease-specific survival. There was no increase in cardiovascular mortality in the PEP arm. The PEP group had a higher prevalence of cardiovascular disease prior to the study and a significantly higher incidence of non-fatal ischemic heart events and heart decompensation during the study. Conclusions : PEP has an equal anticancer efficacy to CAD and does not increase cardiovascular mortality. Final evaluation of cardiovascular morbidity is awaiting further analysis and follow-up. PEP is considerably cheaper than CAD.

A Pooled Analysis of Thyroid Cancer Incidence Following Radiotherapy for Childhood Cancer

Childhood cancer five-year survival now exceeds 70–80%. Childhood exposure to radiation is a known thyroid carcinogen; however, data are limited for the evaluation of radiation dose-response at high doses, modifiers of the dose-response relationship and joint effects of radiotherapy and chemotherapy. To address these issues, we pooled two cohort and two nested case-control studies of childhood cancer survivors including 16,757 patients, with 187 developing primary thyroid cancer. Relative risks (RR) with 95% confidence intervals (CI) for thyroid cancer by treatment with alkylating agents, anthracyclines or bleomycin were 3.25 (0.9–14.9), 4.5 (1.4–17.8) and 3.2 (0.8–10.4), respectively, in patients without radiotherapy, and declined with greater radiation dose (RR trends, P = 0.02, 0.12 and 0.01, respectively). Radiation dose-related RRs increased approximately linearly for <10 Gy, leveled off at 10–15-fold for 10–30 Gy and then declined, but remained elevated for doses >50 Gy. The fitted RR at 10 Gy was 13.7 (95% CI: 8.0–24.0). Dose-related excess RRs increased with decreasing age at exposure (P < 0.01), but did not vary with attained age or time-since-exposure, remaining elevated 25+ years after exposure. Gender and number of treatments did not modify radiation effects. Thyroid cancer risks remained elevated many decades following radiotherapy, highlighting the need for continued follow up of childhood cancer survivors.

Risk factors of rectal cancer local recurrence: population-based survey and validation of the Swedish rectal cancer registry

Aim  Despite advances in rectal cancer treatment, local recurrence (LR) remains a significant problem. To select high‐risk patients for different treatment options aimed at reducing LR, it is essential to identify LR risk factors.