To understand the underlying psychosocial reactions against the unfolding of medical events that announce the disease progression, the objective of this analysis was to identify the patterns of online discussion group message themes in relation to the medical timeline of one woman's breast cancer trajectory. 202 messages posted by Darlene (our studied case) were analyzed by 2 independent coders using a grounded theory approach. The findings suggest that the pattern of messages was clearly correlated with distress-inducing events. The most frequent interaction theme was about building friendship with peers through communication of encouragement, validation, appreciation, and life sharing. Narratives of medical progression were constantly updated to identify similarities with peers. Family issues were increasingly raised at the end of life.