Objective When cancer hits a family, the entire family members start to adapt to the new status. This study aimed to investigate the main issue of the family with cancer patient and their way of solving it. Methods In‐depth interviews were conducted as a qualitative research. Thirty‐three participants described their experience either as cancer patients or as family caregivers. Results Guided by the grounded theory, we identified the main concern of the families being primary caregiver selection. The primary caregiver was determined by the conditions of the patient and the family, but the primary caregiver accepted his/her role believing no alternative was plausible in the family. The processes of the entire family have change since cancer showed their “adapting living,” which was identified as the core variable. Conclusions On the basis of the current study's limitations, suggestions were made for future studies in which cultural attributes are distinguished from the medical system attributes.