The common belief in line with early cognitive schemas of human beings is to perceive the world as a safe place. This perception is a cognitive defense mechanism to protect oneself from uncertainties.1,2 However, in real life, each individual faces different levels and types of stressors and adversities, which might enhance traumas. Soon after facing an adversity, event-related thoughts show up and individuals ruminatively start questioning their perceived belief systems.3 The ruminative thinking, which might be considered a type of coping mechanism, involves repeatedly and intrusively thinking about what had been experienced to understand the adversity. This way, voluntarily or involuntarily, individuals try to have a sense of meaning within the event by questioning and thinking about the experienced event over and over again.4 Cann et al.3 defined ruminative thinking as being of two subtypes, namely intrusive and deliberate. While deliberate ruminations are based on voluntarily thinking about the event, intrusive ruminations involuntarily come to mind and disturb the individual. Hence, deliberate ruminations are more associated with coping than intrusive ruminations. Deliberate ruminations are voluntary and based on building a sense of meaning in the event by confronting the experienced negative emotions, so deliberate ruminations become a part of the solution and help individuals restructure their maladaptive beliefs.3 In contrast, intrusive rumination, which occurs shortly after an occurrence and automatically comes to mind, keeps the individual's mind occupied with event-associated thoughts for a long time and promotes unhappiness, fear, and anxiety.3,5

Cancer experience is commonly perceived as a trauma, so it can disrupt individuals’ coping mechanisms and cause questioning of their fundamental beliefs.6,7 During the active treatment (e.g., chemotherapy, radiotherapy, surgery, etc.) periods, individuals often question, “Why am I sick?” and “When will treatment end?”,8,9 whereas aforementioned thoughts replace in remission with “What is the meaning of life?” and “What if a recurrence occurs?”.10,11 Hence, it is obvious that even after remission, cancer experience continues to have impacts on individuals who have been cured from cancer. Recent literature showed that intrusive ruminative thoughts of cancer survivors have a strong association with mental health problems such as posttraumatic stress disorder, anxiety, and depression,12, 13, 14 while deliberate rumination motivates cancer survivors to gain awareness and posttraumatic growth.15,16 Therefore, individuals try to overcome intrusive ruminations using various strategies, such as staying in the moment or avoiding them.17,18 Nonetheless, these strategies might not always be adaptive and effective.

Given the effect of ruminative thoughts on cancer survivors, it is essential to reveal these thoughts. Although there are quantitative studies on ruminative thoughts in the literature, no qualitative study discloses what these thoughts are, how they influence cancer survivors, or what ways they take to cope with ruminations. Therefore, the aim of this study was to explore a deeper understanding of how cancer survivors experience ruminative thoughts and manage these thoughts.