BackgroundThe internet is an important source of information for many informal caregivers and patients living with cancer. A better understanding of how individuals use the internet to meet their informational needs is important for guiding intervention development.ObjectiveThe objectives of this study were to develop a theory describing why individuals living with cancer use the internet to find information, characterize the challenges faced with existing web-based content, and provide recommendations for web-based content design.MethodsAdults (≥18 years) with a history of being patients with cancer or informal caregivers were recruited from Alberta, Canada. After providing informed consent, participants were engaged through digitally recorded one-on-one semistructured interviews, focus groups, a web-based discussion board, and emails. Classic grounded theory guided the study procedures.ResultsA total of 21 participants took part in 23 one-on-one interviews and 5 focus groups. The mean age was 53 (SD 15.3) years. Breast, gynecological, and hematological cancers were the most common cancer types (4/21, 19% each). In total, 67% (14/21) of patients, 29% (6/21) of informal caregivers, and 5% (1/21) of individuals reporting both roles participated. Participants experienced many new challenges in their cancer journey and used the internet to become better oriented to them. For each challenge, internet searching attempted to address one or more of 3 key orientation questions: why the challenge was happening, what to expect, and options for managing it. Better orientation resulted in improved physical and psychosocial well-being. Content that was well laid out, concise, free of distractions, and that addressed the key orientation questions was identified as the most helpful in assisting with orientation. Creators of web-based content are encouraged to 1) clearly identify the cancer challenge and population the content is addressing, as well as the presence of any potentially distressing information; 2) provide versions of the content in different formats, including printer-friendly, audio, video, and alternative languages; 3) state who created the content, including the individuals, organizations, and processes involved; 4) place hyperlinks after the key orientation questions have been addressed; and 5) ensure that the content is optimized for discovery by search engines (ie, Google).ConclusionsWeb-based content plays an essential role for many living with cancer. Clinicians are encouraged to take active steps to help patients and informal caregivers find web-based content that meets their informational needs. Content creators also have a responsibility to ensure that the content they create assists and does not hinder those navigating the cancer journey. Research is needed to better understand the many challenges that individuals living with cancer face, including how they are temporally related. In addition, how to optimize web-based content for specific cancer challenges and populations should be considered an important area for future research.