Studies have shown that age, family income and education level are key factors that influence the fear of cancer recurrence, but these factors are expressed differently in different populations. Vachon [19] found a significant negative correlation between age and fear of cancer recurrence when studying the relationship between fear of cancer recurrence and health care behavior in breast cancer survivors. Zhang Yang [20] showed that the younger the age of cancer patients, the higher the fear of cancer recurrence. Niu [21] conducted a survey on 342 patients after breast cancer surgery and found that family income was negatively correlated with patients’ fear of cancer recurrence. According to the study of Wu Qiyun [22] , family income is one of the factors affecting the fear of cancer recurrence. Another study conducted by Hu Zewei [23] , through a survey of 124 patients after breast cancer surgery, found that patients with higher education levels experienced lower fear of cancer recurrence. In addition, the fear of cancer recurrence is influenced by other demographic factors. Pang [24] found in the meta-analysis that because women are better at expressing vulnerability and fear, the overall level of cancer recurrence fear in women is higher than that in men. Anderson [25] analyzed 19 literatures from European and American countries and found significant differences in the average level of fear of cancer recurrence between ethnic minorities and major ethnic groups. At the same time, the study of Ashing [26] surveyed Asian Americans, and the results showed that women from China reported lower levels of fear of cancer recurrence than women from other Asian countries (such as South Korea, the Philippines and Vietnam), which may be related to the cultural background of different ethnic groups.

Multiple studies have found that while various cancer types can cause varying levels of fear of recurrence, breast cancer patients report the most significant levels of fear [27] [28] . In a population-based cohort study in Germany, patients experienced greater fear of recurrence when their cancer recurred or metastasized [29] . A study conducted by Xing Jiwei [30] on 300 breast cancer patients also found that the severity of the disease was positively correlated with the fear of recurrence. Regarding the surgical treatment of breast cancer, studies have shown that patients with breast-conserving surgery often experience a higher level of fear of recurrence compared with patients who receive modified radical surgery [31] . In addition, studies [32] have shown that different treatments for breast cancer have an impact on the level of fear of recurrence, with patients receiving radiotherapy generally having a lower level of fear of recurrence than those receiving chemotherapy.

Depression and anxiety have a significant impact on the fear of cancer recurrence in breast cancer patients. Chirico [12] found that breast cancer patients with high anxiety and depression have higher sensitivity to stressful events, which not only increases psychological pressure, but also may lead to higher fear of recurrence. KOCH [33] also observed a positive correlation between the degree of anxiety and depression and the fear of cancer recurrence in a survey of 2671 breast cancer patients. In addition, Lebel [34] also showed that breast cancer patients with symptoms of depression and anxiety tended to experience more severe fear of recurrence. The research of Niu Yaling [15] , a domestic scholar, revealed that the recurrence fear of patients with breast cancer after surgery is negatively correlated with the level of psychosocial adaptation, indicating that psychological maladaptation may exacerbate the recurrence fear. Ye Chunli [17] also found in a survey of 180 patients after breast cancer surgery that the more uncertain patients were about the disease, the more serious their fear of cancer recurrence.

Social support plays a crucial role in how individuals cope with stressful events. It is not only an effective external resource that can be used, but also an important reason for individual psychological adjustment in the face of stressful events. It can relieve stress and improve physical and mental condition through emotional interaction, information exchange, tool support and re-evaluation [35] . Studies [17] [20] have shown that the fear of recurrence in breast cancer patients is negatively correlated with social support. Based on the social cognitive processing model that validated breast cancer patients and their spouses, Soriano [13] analyzed the impact of social environment on the recurrence fear of breast cancer patients, and pointed out that patients with fewer social resources and their spouses may suffer greater psychological pressure, resulting in a higher recurrence fear level. On the other hand, Huang Jialian [36] randomly divided 180 breast cancer patients into intervention group and control group. The intervention group received information support, while the control group received routine nursing education. The results showed that information support significantly reduced patients’ fear of recurrence and feelings of uncertainty about their disease, while increasing their confidence and determination to cope with their cancer.

Self-disclosure is a core concept in the field of psychology, originally proposed by American psychologist Jourard, who describes self-disclosure as the process of revealing information about oneself to others and sharing one’s private thoughts and emotions [37] . Self-disclosure is a positive and effective way of communication, which has a direct negative predictive effect on the fear of cancer recurrence. It not only helps individuals gain understanding and support from others through expressing bad emotions, and enhances the function of social support system, but also promotes the adjustment of cognitive structure, enhances positive perception, and improves their social relations through revealing extreme thinking. Thus reducing the fear of cancer recurrence [38] . In the study of Chen Jiao [39] , 88 postoperative breast cancer patients who received chemotherapy were randomly assigned to the control group and the intervention group. The control group received standard chemotherapy care, while the intervention group added self-disclosure intervention measures on the basis of routine care. This helps reduce the fear of cancer recurrence. In addition, Xu [40] also showed that through effective communication with others, patients can change their wrong understanding of the fear of cancer recurrence, establish a correct disease concept, and then reduce the fear of cancer recurrence.

Coping style is a coping strategy that involves cognitive and behavioral measures taken by individuals in response to frustration and stress. Adopting positive coping strategies can help individuals proactively deal with stressors and increase confidence in treatment [41] . Simard [42] found that patients who adopted religion as a coping strategy showed a lower level of fear of cancer recurrence, which may be because they believed that they could gain more power to fight cancer through faith. Chinese scholar Ren Jialei’s research shows [43] that when breast cancer patients adopt active coping methods, their reported fear level of cancer recurrence is lower.