Incidence and mortality rates of tumors of the hematopoietic and lymphoid tissues in a cohort of workers chronically exposed to ionizing radiation

   Introduction. Individuals acutely exposed to ionizing radiation demonstrated an increased risk of incidence of malignant neoplasms of the hematopoietic and lymphoid tissues (HLTT). Meanwhile papers describing the impact of chronic radiation exposure on the hematopoietic system are sparse.
Aim — to assess incidence and mortality rates for HLTT in a cohort of workers exposed to chronic, occupational ionizing radiation.
   Materials and methods. Incidence and mortality rates of HLTT were assessed for workers of a nuclear industrial enterprise who had been hired at the facility from 1948–1982 and followed up until the end of 2018 (22,377 workers). All workers of the study cohort were externally and/or internally exposed to ionizing radiation during occupational industrial activities. In the studied cohort of workers, 186 cases and 123 deaths (as a main cause) from HLTT were registered throughout the entire follow-up period (1948–2018).
   Results. Crude incidence and mortality rates of HLTT in workers of the study cohort were associated with sex, attained age of workers and calendar follow-up period. Standardized incidence and mortality rates for males were significantly higher compared to females. The standardized HLTT incidence rates (per 1000 person-years of observation) were 0.36 ± 0.03 in males and 0.23 ± 0.04 in females while the standardized HLTT mortality rates were 0.16 ± 0.02 in males and 0.09 ± 0.02 in females.
   Conclusions. The study revealed significant increasing trends for incidence rates of chronic leukemia and lymphoma by the end of the follow-up period (31. 12. 2018).

1. World Health Organization Global Health Observatory Data Repository, Mortality and Global Health Estimates 2012. URL: https://apps.who.int/gho/data.

2. Clement C.H., Stewart F.A., Akleyev A.V., et al. ICRP publication 118: ICRP statement on tissue reactions and early and late effects of radiation in normal tissues and organs — threshold doses for tissue reactions in a radiation protection context. Ann ICRP. 2012; 41(1–2): 1–322. DOI: 10.1016/j.icrp.2012.02.001.

3. Akleyev A.V., Kossenko M.M., Startsev N.V. Techa River population: Long term medical follow-up. Br J Radiol. 2002; (Suppl. 26): 32–40.

4. Gidali J. Effects of protracted and chronic irradiation on the haemopoetic system in mouse. Exp Eye Res. 2002; (69): 219–35.

5. Guskova A.K., Gusev L.A., Okladnikova N.D. Russian concept of chronic radiation disease in man. Br J Radiol. 2002; (Suppl. 26): 19–23.

6. Okladnikova N.D., Kudryavtseva T.I., Belyaeva Z.D. Plutonium pneumosclerosis, conclusions of the continuous medical studies. Voprosy radiatsionnoy bezopasnosti. 2000; (1): 42–9. (In Russian).

7. Seed T.M., Fritz T.E., Tolle D.V, Jackson W.E. 3rd. Hematopoietic responses under protracted exposures to low daily dose gamma irradiation. Adv Sp Res. 2002; 30(4): 945–55. DOI: 10.1016/s0273-1177(02)00159-x.

8. Azizova T.V., Day R.D., Wald N., et al. The “clinic” medical-dosimetric database of Mayak Production Association workers: Structure, characteristics and prospects of utilization. Health Phys. 2008; 94(5): 449–58. DOI: 10.1097/01.HP.0000300757.00912.a2.

9. Zar J.H. Biostatistical Analysis. New Jersey: Prentice Hall; 1999.

10. Organization of oncological service in Russia (guidelines, manuals for physicians). Part 2. Ed. Chissov V.I., Starinsky V.V., Kovalev B.N. Moscow: FGU MNIOI im. P.A. Herzen Rosmedtekhnologii; 2007. (In Russian).

11. Merkov A.M., Polyakov L.E. Sanitary statistics (a manual for doctors). Moscow: Atomizdat; 1975. (In Russian).

12. Joinpoint Trend Analysis Software. URL: https://surveillance.cancer.gov/joinpoint/.

13. Kim H.J., Fay M.P., Feuer E.J., Midthune D.N. Permutation tests for joinpoint regression with applications to cancer rates. Stat Med. 2000; 19(3): 335–51. DOI: 10.1002/(sici)1097-0258(20000215)19:3<335::aid-sim336>3.0.co;2-z.

14. Lerman P.M. Fitting segmented regression models by grid search. Applied Statistics. 1980; 29(1): 77–84.

15. ICD-9. Guidelines for coding diseases, injuries and causes of death. Revision 1975. Geneva: WHO; 1980. (In Russian).

16. Bondarenko I.A., Martirosov A.R., Zingerman B.V. Hemoblastosis in Russia: Prevalence and mortality (1999–2007). Vestnik gematologii. 2010; 6(2): 18–9. (In Russian).

17. Zhiguleva L.Y., Abdulkadyrov K.M. Primary incidence of hematological malignancies in Saint Petersburg in 1990–2011 and prognosis till 2021. Klinicheskaya onkogematologiya. 2015; 8(4): 362–7. (In Russian).

18. Bakirov B.A., Varshavskiy A.V., Bessmeltsev S.S. The dynamics of hemoblastosis morbidity in the Republic of Bashkortostan (1962–2008). Rossiyskiy biomeditsinskiy zhurnal. 2011; 12: 511–21. (In Russian).

19. Davydov M.I., Aksel’ E.M. The incidence of malignant neoplasms in the population of Russia and CIS countries in 2007. Vestnik RONC im. N.N. Blohina RAMN. 2009; 20(3 Suppl. 1): 52–90. (In Russian)

20. Radiation safety standards (NRB-99/2009): Sanitary and epidemiological rules and regulations. Moscow: Federal’nyy tsentr gigieny i epidemiologii Rospotrebnadzora; 2009. (In Russian).