Application of Survival Analysis on Analysing the Association Between Chromosomal Aberrations and Carcinoma

Abstract

This paper focuses on the analysis of data that come from 219 radon-mine workers who underwent cytogenetic analysis (or analyses) of peripheral blood lymphocytes. The main focus lies on the connection between the results of the analysis (the occurrence of various types of chromosomal aberrations—chromatid and chromosome changes and breaks) and the incidence of carcinoma, but we also analyzed the association with other explanatory variables, such as age, smoking, and the level of exposure to radon. The Cox analysis was performed separately for the incidence of any type of cancer and for the incidence of lung cancer only as dependent variables. In the first case, we found two suitable models. Both models utilise age, smoking status, the level of exposure and the frequency of chromatid changes. In addition to these variables, the first model contains the frequency of chromatid breaks and the second model contains overall frequency of chromosomal aberrations. As for the lung cancer incidence, we found only two significant factors, the level of exposure to radon and the fact whether or not the subject ever smoked. The other purpose of the paper was to compare our results with the results of the study of Šmerhovský et al. [8], as our study was an expansion to this study. For the overall incidence of cancer, the results were not markedly different from the aforementioned study. Regarding the lung cancer incidence, a significant association of chromosomal aberration frequency and chromatid breaks frequency had been found in the original study, while our findings showed that none of the aberrations were significant for the lung cancer incidence.