Previous Malignancy as a Risk Factor for the Second Solid Cancer in a Cohort of Nuclear Workers

Mikhail Osipov,Mikhail Sokolnikov

doi:10.28991/scimedj-2021-0301-2

Abstract

This paper describes the results of epidemiological analysis of a cohort of nuclear workers hired at the main facilities of “Mayak” Production Association located in the city of Ozyorsk in Southern Urals of the Russian Federation. Previous malignancy as a risk factor for second cancer in a cohort of 22,373 workers occupationally exposed to ionizing radiation has been analyzed in a retrospective study with more than 60 years of follow-up. Information on main radiation and non-radiation risk factors (attained age, sex, tobacco smoking), as well as the dose of exposure to occupational ionizing radiation has been obtained for the analysis using the data from cancer register as well as other main population registries created in Epidemiological Laboratory of Southern Urals Biophysics Institute. Poisson’s regression realized in the “Amfit” module of “Epicure” statistical package has been applied for risk analysis. Excess relative risk per 1 Gy of absorbed dose of external gamma radiation and internal alpha radiation has been calculated using linear model. Among the 2,471 cancer cases accumulated in the study cohort to the end of follow-up 6.4% of second cancer cases have been diagnosed among workers occupationally exposed to protracted external gamma- and internal alpha radiation. The relative risk of second cancer (except for non-melanoma skin cancer) among nuclear workers with previously diagnosed cancer was about 4 times higher after a decade compared with those cancer patients who had single cancer only. The results showed that previous malignancy along with main non-radiation factors is statistically significant carcinogenic risk factor among nuclear workers exposed to protracted occupational radiation. Doi: 10.28991/SciMedJ-2021-0301-2 Full Text: PDF

Highlights

Malignant Neoplasms (MN) is one of the major problems in a global health care system today, as one of the most potentially life-threatening conditions
The impact of other non-radiation factors such as birth cohort (p
This assumption is consistent with the latest studies on the risk assessment of prostate cancer after radiation therapy [13]. 51% of the first cancers followed by prostate cancer during the decade of follow-up study [14] that might suggest that this localization is more sensitive to the influence of factors associated with the presence of a previous cancer, including diagnostic and therapeutic exposure, what is the point of interest for further research

Summary

Introduction

Malignant Neoplasms (MN) is one of the major problems in a global health care system today, as one of the most potentially life-threatening conditions. On the other hand, growing healthcare quality resulted in the increase in survival of cancer patients. According to the National Cancer Institute of the United States, the 5-year survival for all malignancies in the last decade increased from 50 to 66% in adults and the 10-year survival rate has reached 59%. Those survival advances have been offset by the long-term effects of cancer and its treatment, second MN. The probability of subsequent malignant tumors development among the patients already diagnosed with cancer is 1.14 times higher than in the general population [2], among those patients who had received anti-cancer therapy [3]

Objectives

Methods

Results

Discussion

Conclusion