Abstract
We will discuss the issue of surveillance bias, which arises when differences in the frequency of cancer are due to changes in screening and detection strategies rather than to differences in the true occurrence of cancer (2). This bias hampers the surveillance of scrutiny-dependent cancers, such as thyroid and prostate cancers and melanoma, leading to misinterpretations of cancer trends. Moreover, it can lead to the misinterpretation of potential risk factors for cancer occurrence, such as socioeconomic status.