BackgroundMany people around the world are getting cancer and living longer with the disease. Thanks to improved treatment options in healthcare, patients diagnosed with advanced gastrointestinal cancer can increasingly live for longer. Living with cancer creates existential uncertainty, but what does this situation mean for the individual? The purpose of the study is to interpret meanings of existential uncertainty and certainty for people diagnosed with advanced gastrointestinal cancer and receiving palliative treatment.MethodsThis study is part of a larger project in which 7 men and 7 women aged between 49 and 79 participated in a study of information and communication for people with advanced gastrointestinal cancer. A total of 66 interviews were conducted with participants who were followed up over time. The narrative interviews were transcribed verbatim and the texts were analysed in three steps: naive reading, structural analysis and interpreted whole by utilizing a phenomenological life-world approach.ResultsThis study has identified different spheres in which people diagnosed with advanced gastrointestinal cancer vacillate between existential uncertainty and certainty: bodily changes, everyday situations, companionship with others, healthcare situations and the natural environment. Existing in the move between existential uncertainty and certainty appears to change people’s lives in a decisive manner. The interview transcripts reveal aspects that both create existential certainty and counteract uncertainty. They also reveal that participants appear to start reflecting on how the new and uncertain aspects of their lives will manifest themselves –a new experience that lays the foundation for development of knowledge, personal learning and growth.ConclusionsPeople diagnosed with advanced gastrointestinal cancer and receiving palliative care expressed thoughts about personal learning initiated by the struggle of living with an uncertain future despite their efforts to live in the present. Their personal learning was experienced through a changed life for themselves and having to confront their own pending death and develop self-insight regarding finality of life. Healthcare professionals can try to support people receiving palliative treatment for cancer by diversifying avenues for their personal growth, thus helping them manage their existential uncertainty and gravitate towards greater existential certainty.