Cancer has been defined by the World Health Organization as "a disease caused by abnormal cells growing uncontrollably in the body, going beyond their usual boundaries, invading adjoining parts of the body and spreading to other organs". Being diagnosed with cancer has been described as an experience with diverse emotional reactions and difficulties in adaptation, having psychological consequences, being most common depression, anxiety and psychological distress; but also, some patients present positive consequences after having a cancer diagnosis, such as post traumatic growth, which includes positive changes presented after the disease experience. Subjective appraisal about cancer has been defined as a mediating variable for the emotional response presented after a stressor, such as cancer diagnosis, treatment, or important changes during disease process (initiating and finalizing treatment, presenting relapse or remission, as well as when having control studies). The subjective appraisal can be presented with different thought content and styles. Thought style is referred as the way thoughts about the stressor are presented, it has been classified as rumination (thoughts that are intrusive and repetitive that also increase psychological distress), cognitive engagement (thoughts associated with problem solving and meaning finding) or avoidance (aiming to stop thinking about stressor or feeling associated with it). Depending on the thought style presented at a stressor, could be the emotional response (anxiety, depression, distress, post-traumatic growth). The aim of the present study was to describe the thoughts (style, content, valence and temporality) related to cancer diagnosis in a group of ten oncologic patients. To identify if differences between thought style, valence and temporality were presented. The study design is qualitative from a phenomenological point of view. Ten oncologic (different cancer type, clinical stage and treatment) patients were asked to write the five more frequent thoughts since their cancer diagnosis. Each thought was classified by: thought style, valence, and temporality (top-down, classifying the thoughts according to theory). The same thoughts were also classified in semantic units (bottom-up, classifying the thoughts according to their own contents), generating concerns from the content. Cross tabs were made to identify contents and temporality for thought style and valence, which were analyzed by chi square to identify differences between thought style, temporality and valence. The most common thought style was cognitive engagement, followed by rumination (almost same frequency). On what respects to thought style and temporality, rumination was more focused on past (causes and attributions of cancer) and future (uncertainty about death and treatment effectiveness); meanwhile, cognitive engagement was focused on present (to enjoy present moment and focus on daily actions). Chi square was made to identify if this difference was significant, showing temporality was significantly different in cognitive engagement and rumination. The concerns identified in study participants were uncertainty about future and disease, family (communication and wellness of the family), finances (due to expensive treatments), causes and guilt about having cancer. Thoughts that were more centered in present, were more likely to be associated with cognitive engagement. Cognitive engagement has been described previously as an important variable associated with post traumatic growth. Thoughts centered in the past and present were more associated with rumination. Rumination has been associated with depression and post-traumatic stress disorder. Because of mediating role of thought style in disease adaptation, emotional response to the disease, and the relation of this adaptation with the perception of quality of life in cancer patients, the design of psychological interventions aiming on promoting cognitive engagement by problem solving skills, meaning finding, and focusing on present could be a research line derived from present studies results. [ABSTRACT FROM AUTHOR]