Effect of changes in baseline cancer mortality rates and survival functions on the estimated risks of radiation-induced cancer

One of the uncertainty factors in estimating radiation-induced cancer risk is temporal changes in baseline cancer and all-cause mortality rates, which reflect advances in medical and diagnostic technologies, increased diagnostic frequency, and improvements in lifestyle, hygiene standards, and public health. Assessments of radiation-induced cancer risk have generally been performed using constant baseline data and therefore do not consider the effects of temporal changes in these data. To determine the effect of changes in baseline data on risk estimation, we calculated lifetime attributable risks (LARs) for individuals from six countries and different regions under two conditions: using constant baseline data and using baseline data that changed over time . The LARs were calculated for all solid cancers, oesophagus cancer, stomach cancer, colon cancer, lung cancer, and breast cancer. The LARs calculated using changing baseline data were comparable to those calculated using constant baseline data in 2021, and were, on average, approximately 1.7-fold higher (ranging from 0.8-to 4fold) than those calculated using constant baseline data in 1955. Furthermore, comparison of the effects of baseline data changes with that of other uncertainty factors indicated that the effect of baseline changes was greater than that of the minimum latency period but smaller than those of the fitting parameter of the risk models and the dose and dose-rate effectiveness factor.