The aim of this thesis is to understand how the world’s largest digital platforms may enable businesses to sell questionable cancer treatments that exploit cancer patients. The thesis examines the affordances offered by digital platforms to predatory businesses to advertise, reach, and attempt to influence cancer patient treatment decisions; evaluates the effectiveness of digital platform policies to protect cancer patients; investigates how predatory businesses frame their treatment benefits; and formulates normative policy and interventional recommendations. Five analyses are completed. The first research chapter examines how alternative cancer clinics frame questionable cancer treatments across paid ads on Meta-owned social media platforms. The second chapter examines how alternative cancer clinics frame their services on their Google business profile and examines the scoring and content of their reviews. The third chapter examines how Google search results can be manipulated through paid ads to display and promote non-conventional cancer treatments through paid Google search ads. The fourth chapter examines how Google keyword targeting in Google search ads can emulate the sensitive informational search queries of cancer patients. The last research chapter examines how the e-commerce platform Amazon enables sellers to list and sell alleged cancer cure books with questionable treatment success claims. The results of my thesis suggest (1) predatory businesses use digital platform services to strategically curate their reputations and attract patients; (2) digital platforms profit from questionable businesses by facilitating the passive or active exploitation of cancer patients; (3) existing safeguards from digital platforms to curb misuse of their products are absent, limited, or ineffective; (4) digital platforms have little incentive to change the current context; and (5) research into the commercial determinants of health requires renewed focus on the mechanisms of information transfer and not solely the authors of potentially misleading or harmful information.