In the past couple of decades, there has been significant interest in the research literature and patient narratives that focus on describing the cancer journey as involving existential and spiritual transformative experiences. The purpose of this article is to contribute with a new and deepened understanding of the existing literature by offering a philosophical informed analytic conceptualization that highlights the ‘liminal’, transformative and ‘generative’ dimension of the cancer journey. For that purpose, qualitative data drawn from a qualitative study investigating existential experiences of a group of Danish patients in rehabilitation were analysed employing the American phenomenologist Anthony J. Steinbock’s interpretation of the Husserlian concepts homeworld/alienworld (Heimwelt/Fremdwelt). Data used in this article derived from qualitative interviews (11 individual interviews and 9 focus group interviews) with cancer patients participating in rehabilitation week courses at a Danish rehabilitation centre. The analysis led to the development of three themes: ‘The heavy break with the homeworld’, ‘Realizing a new homefellowship’ and ‘Transformation of the homeworld’. Findings suggest that journeying with cancer involves a ‘liminal’ experiencing of having to navigate in a borderless and unfamiliar territory between a homeworld and an alienworld before ultimately arriving at a sense of transformation in which meaning is derived from both lifeworlds. It is argued that such an understanding of the intersubjectivity between lifeworlds highlights the need for health care professionals communicating with patients throughout their cancer journey about whether and how the illness experiences have been integrated into their lifeworld and whether help is needed in order to achieve existential rehabilitation.