Google allows advertisers to target the sensitive informational queries of cancer patients

Alternative cancer treatments are associated with earlier time to death when used without evidence-based treatments. Our study suggests alternative cancer clinics providing scientifically unsupported cancer treatments spent an estimated $15,839,504 on Google ads from 2012 to 2023 targeting users in the United States. The ads led to an estimated 6,717,663 website visits. Paid traffic constituted 44.4% of all website traffic. Advertisers targeted cancer patients using Google’s keyword matching feature which matches ad keywords to the searches of Google users. Keywords selected by advertisers mimicked the sensitive informational search queries of cancer patients. In 2023, 20,035 unique keywords emulated searches on cancer prognosis, alternative treatments, accessing treatment, treatment options, diagnosis, specific cancers, and late-stage cancer.