The risk of cancer among Lithuanian medical radiation workers in 1978–2004

Vitalija Samerdokienė, Vydmantas Atkočius, Konstantinas Povilas Valuckas

Institute of Oncology, Vilnius University, Lithuania

Key words: cancer incidence; medical workers; ionizing radiation.

Summary. Objectives. To describe the cohort of Lithuanian medical radiation workers and to estimate the risk of cancer during 1978–2004.

Methods. Analysis of cancer risk evaluation was done using the retrospective cohort method, an indirect standardization. The observed numbers of cancer cases were obtained from the National Cancer Registry. The expected numbers were based on the age- and gender-specific incidence rates for the general Lithuanian population in 5-year periods. The standardized incidence ratios and 95% confidence intervals (assuming that the incidence of cancer follows the Poisson distribution) were calculated.

Results. During the follow-up of 1978–2004, 159 cases of cancer were observed. There was no increased overall cancer risk in men (SIR=0.92, 95% CI=0.62–1.33, based on 29 cases) and women (SIR=0.97, 95% CI=0.81–1.15, based on 130 cases). The risk of leukemia among men and women was insignificantly increased.

Conclusions. During the follow-up period, the overall cancer risk among medical radiation workers was the same as in the general population of Lithuania.

Correspondence to V. Samerdokienė, Institute of Oncology, Vilnius University, P. Baublio 3B, 08406 Vilnius, Lithuania. E-mail: vitalija.samerdokiene@gmail.com

Received 11 June 2007, accepted 5 May 2009