https://doi.org/10.1177/1359105320919893 Journal of Health Psychology 1–14 © The Author(s) 2020 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/1359105320919893 journals.sagepub.com/home/hpq Breast cancer is the most common cancer among women in the United States (Centers for Disease Control and Prevention, 2019). Despite its prevalence, breast cancer represents a high survival rate: if diagnosed at an early stage, 99 percent of patients survive after 5 years (American Cancer Society, 2002). Its diagnosis and subsequent treatments are undoubtfully a painful and traumatic experience (Ganz, 2001). Research showed that receiving the treatments can be very arduous and suffering, which often accompanies the loss of energy, threats of dis- figurement, and declined life quality (Spiegel, 1997). These difficulties and sufferings can last for years, even decades. The frequency and the prolonged duration of the disease make it an important issue to focus on the survivors’ dis- ease adjustment and psychosocial well-being. A large amount of research looking into breast cancer survivors’ coping and well-being found that diagnostic and treatment phases often engender a range of emotional distress and mood disturbances, including fear, shock, anxiety, and feelings of isolation (Mitchell et al., 2017). Most previous studies primarily rely on retrospective self-reported data, which are prone to social desirability concerns and recall biases, especially in highly emotional contexts. One goal of the current study is to pre- sent a more objective picture of breast cancer survivors’ psychosocial state through the lens of their language use in an online support group (OSG). Furthermore, previous psychological Mapping breast cancer survivors’ psychosocial coping along disease trajectory: A language approach Meng Chen 1 and Liang Zhao 2 Abstract This article reports a language analysis of breast cancer patients’ posts in an online support group. Adopting web-scraping techniques, the study analyzed 27,078 online posts contributed by 1443 users along multiple linguistic dimensions to investigate the trajectory of the patients’ psychosocial adaptation of the disease. The findings suggested that breast cancer patients’ emotional experiences and adjustment in the course of illness vary from one stage to another. They reached the peak of emotional expression, struggle and despair, and self-focus at Stage III, whereas wiped out negative emotions and signaled a desire for connections with others at Stage IV. Keywords breast cancer, linguistic analysis, psychological adaptation, social support 1 Webster Vienna Private University, Austria 2 Amazon.com Inc., USA Corresponding author: Meng Chen, Department of Media Communications, Webster Vienna Private University, Palais Wenkheim, Praterstr. 23, 1020 Vienna, Austria. Emails: meng.chen@webster.ac.at; mengchen40@ webster.edu 919893HPQ 0 0 10.1177/1359105320919893Journal of Health PsychologyChen and Zhao research-article 2020 Article