Juozas Kurtinaitis

The 15-country collaborative study of cancer risk among radiation workers in the nuclear industry: Estimates of radiation-related cancer risks

Abstract Cardis, E., Vrijheid, M., Blettner, M., Gilbert, E., Hakama, M., Hill, C., Howe, G., Kaldor, J., Muirhead, C. R., Schubauer-Berigan, M., Yoshimura, T., Bermann, F., Cowper, G., Fix, J., Hacker, C., Heinmiller, B., Marshall, M., Thierry-Chef, I., Utterback, D., Ahn, Y-O., Amoros, E., Ashmore, P., Auvinen, A., Bae, J-M., Bernar, J. S., Biau, A., Combalot, E., Deboodt, P., Diez Sacristan, A., Eklöf, M., Engels, H., Engholm, G., Gulis, G., Habib, R. R., Holan, K., Hyvonen, H., Kerekes, A., Kurtinaitis, J., Malker, H., Martuzzi, M., Mastauskas, A., Monnet, A., Moser, M., Pearce, M. S., Richardson, D. B., Rodriguez-Artalejo, F., Rogel, A., Tardy, H., Telle-Lamberton, M., Turai, I., Usel, M. and Veress, K. The 15-Country Collaborative Study of Cancer Risk among Radiation Workers in the Nuclear Industry: Estimates of Radiation-Related Cancer Risks. Radiat. Res. 167, 396– 416 (2007). 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.

Risk of cancer after low doses of ionising radiation: retrospective cohort study in 15 countries

Abstract Objectives To provide direct estimates of risk of cancer after protracted low doses of ionising radiation and to strengthen the scientific basis of radiation protection standards for environmental, occupational, and medical diagnostic exposures. Design Multinational retrospective cohort study of cancer mortality. Setting Cohorts of workers in the nuclear industry in 15 countries. Participants 407 391 workers individually monitored for external radiation with a total follow-up of 5.2 million person years. Main outcome measurements Estimates of excess relative risks per sievert (Sv) of radiation dose for mortality from cancers other than leukaemia and from leukaemia excluding chronic lymphocytic leukaemia, the main causes of death considered by radiation protection authorities. Results The excess relative risk for cancers other than leukaemia was 0.97 per Sv, 95% confidence interval 0.14 to 1.97. Analyses of causes of death related or unrelated to smoking indicate that, although confounding by smoking may be present, it is unlikely to explain all of this increased risk. The excess relative risk for leukaemia excluding chronic lymphocytic leukaemia was 1.93 per Sv (< 0 to 8.47). On the basis of these estimates, 1-2% of deaths from cancer among workers in this cohort may be attributable to radiation. Conclusions These estimates, from the largest study of nuclear workers ever conducted, are higher than, but statistically compatible with, the risk estimates used for current radiation protection standards. The results suggest that there is a small excess risk of cancer, even at the low doses and dose rates typically received by nuclear workers in this study.

The 15-country collaborative study of cancer risk among radiation workers in the nuclear industry: Design, epidemiological methods and descriptive results

Abstract Vrijheid, M., Cardis, E., Blettner, M., Gilbert, E., Hakama, M., Hill, C., Howe, G., Kaldor, J., Muirhead, C. R., Schubauer-Berigan, M., Yoshimura, T., Ahn, Y-O., Ashmore, P., Auvinen, A., Bae, J-M., Engels, H., Gulis, G., Habib, R., Hosoda, Y., Kurtinaitis, J., Malker H., Moser, M., Rodriguez-Artalejo, F., Rogel, A., Tardy, H., Telle-Lamberton, M., Turai, I., Usel, M. and Veress, K. The 15-Country Collaborative Study of Cancer Risk among Radiation Workers in the Nuclear Industry: Design, Epidemiological Methods and Descriptive Results. Radiat. Res. 167, 361–379 (2007). 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.

Recent trends in cancer survival across Europe between 2000 and 2004: A model-based period analysis from 12 cancer registries

BACKGROUND Monitoring population-based cancer survival is an essential component in the evaluation of cancer control, but subject to an inherent delay in the reporting of the most recent survival estimates with traditional techniques of analysis. METHODS We examined survival trends between the years 2000 and 2004 for 20 common cancers based on follow-up data from 12 cancer registries from diverse areas of Europe using model-based period analysis techniques. RESULTS Between 2000 and 2004, marked rises were seen in 5-year relative survival amongst patients with prostate, breast and colorectal cancer, which were statistically significant in 10, 8 and 7 of the 12 participating cancer registries, respectively. For cancer sites amenable to effective early detection and treatment, major geographical differences in patient prognosis still persisted, with a lower survival generally observed in Eastern European countries. CONCLUSION Model-based period analysis enables the timely monitoring of recent trends in population-based cancer survival. For colorectal and breast cancers, the identified rises in survival are probably (at least partly) explained by the improvements in clinical care and the management of the disease. Nevertheless, persisting geographic differences do point to the potential for a further reduction in the burden of cancer throughout Europe, towards which improvements in diverse areas of care, including secondary prevention, access to advances in treatment as well as subspecialisation and regionalisation of oncologic care may all contribute.

Breast cancer mortality patterns and time trends in 10 new EU member states: Mortality declining in young women, but still increasing in the elderly

Breast cancer is the cancer diagnosed most frequently in women worldwide. In Europe it is the most common cancer in the female population, with approximately 350,000 new cases diagnosed each year including 130,000 deaths. Incidence rates are increasing in the majority of European countries, whereas a decline in mortality rates has been observed in many West European countries since the late 1980s and early 1990s. Our study examines breast cancer mortality patterns and time trends in the new European Union (EU) member states and compares them with the situation in current EU member states. A Joinpoint regression analysis was used to assess temporal changes in mortality rates and the trends examined in the light of known risk factors, screening programs and advances in treatment. In the majority of the countries analyzed, a deceleration in the increase of mortality rates appeared, followed by a decrease of mortality in many of them in the second half of the 1990s. The declining tendency was visible primarily in young women, and to a lesser extent in middle‐aged women, whereas in elderly women a continuing increase of mortality was observed. Analysis of mortality data, information from previous publications, as well as analysis of known factors influencing breast cancer risk suggest that changes observed are due mainly to recent advances in treatment rather than changes in lifestyle risk factors or the result of screening programs. Early detection and a shift toward more favorable stage distribution could have played the leading role for mortality decline in younger patients.

Risk of hematological malignancies among Chernobyl liquidators

Abstract Kesminiene, A., Evrard, A-S., Ivanov, V. K., Malakhova, I. V., Kurtinaitis, J., Stengrevics, A., Tekkel, M., Anspaugh, L. R., Bouville, A., Chekin, S., Chumak, V. V., Drozdovitch, V., Gapanovich, V., Golovanov, I., Hubert, P., Illichev, S. V., Khait, S. E., Kryuchkov, V. P., Maceika, E., Maksyoutov, M., Mirkhaidarov, A. K., Polyakov, S., Shchukina, N., Tenet, V., Tserakhovich, T. I., Tsykalo, A., Tukov, A. R. and Cardis, E. Risk of Hematological Malignancies among Chernobyl Liquidators. Radiat. Res. 170, 721–735 (2008). A case-control study of hematological malignancies was conducted among Chernobyl liquidators (accident recovery workers) from Belarus, Russia and Baltic countries to assess the effect of low- to medium-dose protracted radiation exposures on the relative risk of these diseases. The study was nested within cohorts of liquidators who had worked around the Chernobyl plant in 1986–1987. A total of 117 cases [69 leukemia, 34 non-Hodgkin lymphoma (NHL) and 14 other malignancies of lymphoid and hematopoietic tissue] and 481 matched controls were included in the study. Individual dose to the bone marrow and uncertainties were estimated for each subject. The main analyses were restricted to 70 cases (40 leukemia, 20 NHL and 10 other) and their 287 matched controls with reliable information on work in the Chernobyl area. Most subjects received very low doses (median 13 mGy). For all diagnoses combined, a significantly elevated OR was seen at doses of 200 mGy and above. The excess relative risk (ERR) per 100 mGy was 0.60 [90% confidence interval (CI) −0.02, 2.35]. The corresponding estimate for leukemia excluding chronic lymphoid leukemia (CLL) was 0.50 (90% CI −0.38, 5.7). It is slightly higher than but statistically compatible with those estimated from A-bomb survivors and recent low-dose-rate studies. Although sensitivity analyses showed generally similar results, we cannot rule out the possibility that biases and uncertainties could have led to over- or underestimation of the risk in this study.

Increasing thyroid cancer incidence in Lithuania in 1978–2003

BackgroundThe aim of this paper is to analyze changes in thyroid cancer incidence trends in Lithuania during the period 1978–2003 using joinpoint regression models, with special attention to the period 1993–2003.MethodsThe study was based on all cases of thyroid cancer reported to the Lithuanian Cancer Registry between 1978 and 2003. Age group-specific rates and standardized rates were calculated for each gender, using the direct method (world standard population). The joinpoint regression model was used to provide estimated annual percentage change and to detect points in time where significant changes in the trends occur.ResultsDuring the study period the age-standardized incidence rates increased in males from 0.7 to 2.5 cases per 100 000 and in females from 1.5 to 11.4 per 100 000. Annual percentage changes during this period in the age-standardized rates were 4.6% and 7.1% for males and females, respectively. Joinpoint analysis showed two time periods with joinpoint in the year 2000. A change in the trend occurred in which a significant increase changed to a dramatic increase in thyroid cancer incidence rates. Papillary carcinoma and stage I thyroid cancer increases over this period were mainly responsible for the pattern of changes in trend in recent years.ConclusionA moderate increase in thyroid cancer incidence has been observed in Lithuania between the years 1978 and 2000. An accelerated increase in thyroid cancer incidence rates took place in the period 2000–2003. It seems that the increase in thyroid cancer incidence can be attributed mainly to the changes in the management of non palpable thyroid nodules with growing applications of ultrasound-guided fine needle aspiration biopsy in clinical practice.

Mortality and cancer incidence among Lithuanian cement producing workers

Aims: To investigate mortality and cancer incidence of cement producing workers. Methods: A total of 2498 cement workers who have been employed at Portland cement producing departments for at least one year from 1956 to 2000 were followed up from 1 January 1978 to 31 December 2000. The cohort contributed 43 490 person-years to the study. Standardised incidence ratios (SIR) and standardised mortality ratios (SMR) were calculated as ratios between observed and expected numbers of cancers and deaths. The expected numbers were based on sex specific incidence and mortality rates for the total Lithuanian population. Results: Significantly increased SMRs were found for all malignant neoplasms (SMR 1.3, 95% CI 1.0 to 1.5) and for lung cancer (SMR 1.4, 95% CI 1.0 to 1.9) among male cement workers. SIR for all cancer sites was 1.2 (95% CI 1.0 to 1.4). Excess risk was found for cancer of the lung (SIR 1.5, 95% CI 1.1 to 2.1). The SIR for urinary bladder cancer was also increased (SIR 1.8, 95% CI 0.9 to 3.5). The overall cancer incidence was not increased among females (SIR 0.8, 95% CI 0.6 to 1.1). With increasing cumulated exposure to cement dust, there were indications of an increasing risk of lung and stomach cancers among males. Conclusions: This study supported the hypothesis that exposure to cement dust may increase the lung and bladder cancer risk. A dose related risk was found for stomach cancer, but no support was found for an increased risk of colorectal cancer.

Lung cancer mortality patterns in selected Central, Eastern and Southern European countries

Significant changes in the prevalence of tobacco smoking have been observed in many European countries. EU candidate countries have also experienced major changes with respect to tobacco smoking, which have resulted in changes in the frequency of lung cancer. In men in the majority of these countries, a reduction of mortality rates has been observed recently, while in Hungary and Poland a deceleration of mortality increase was observed in the 1990s. The situation is much less favorable in females, where in the majority of countries a continuous increase of mortality rates has been observed, the only exceptions being Latvia, Lithuania and, to a lesser extent, Estonia. In Hungarian women, an acceleration of the increase rate was observed in the 1980s and 1990s (compared with the 1970s). Patterns of lung cancer mortality in analyzed countries are somewhat similar to those observed in EU member states. Recent analyses of time trends of lung cancer in EU countries showed, in general, a decreasing risk in the majority of male populations and an increase in several countries in women. If the decrease of mortality is to be achieved and maintained in the longer term, efforts have to be focused on young generations (entering adulthood now or in the near future). Despite all the difficulties present in reducing tobacco smoking in youth, it seems that one of the most important ways to reduce the future lung cancer burden in current and new EU member states is to strengthen efforts toward changing smoking attitudes in young generations.

Process performance of cervical screening programmes in Europe

Standardised tables of aggregated data were collected from 15 European national or regional cervical screening programmes and key performance indicators computed as reported in European Union (EU) Guidelines, 2nd edition. Cytological results varied widely between countries both for the total proportion of abnormal tests (from 1.2% in Germany (Mecklenburg-Vorpommern) to 11.7% in Ireland-Midwest Region) and for their distribution by grade. Referral rates for repeat cytology (ranging from 2.9% of screened women in the Netherlands to 16.6% in Slovenia) or for colposcopy (ranging from 0.8% in Finland to 4.4% in Romania-Cluj) and the Positive Predictive Value (PPV) of colposcopic attendance (ranging from 8% in Romania-Cluj to 52% in Lithuania) were strongly influenced by management protocols, in particular for atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesion (LSIL) cytology. However, cytology-specific PPV also showed remarkable variability. The detection rate of CIN2+ histology ranged from <0.1% of screened women in Poland to >1% in England and Denmark. Low attendance for colposcopy after referral was observed in some east-European countries. These comparisons may be useful for improving the performance of cervical screening in general and more so if new screening technologies and vaccination for Human Papillomavirus are introduced. Overall, quality was better in countries that have operated organised programmes for a longer time, plausibly as a result of long-lasting monitoring and quality assurance activities. Therefore, the availability of these data, the first comparing European countries, and the increased number of countries that can provide such data (only five in 2004) represent progress. Nevertheless, there is a clear need to standardise the cytological and histological classifications used in screening, as well as data registration systems across Europe.