Breast cancer is the most common type of cancer afflicting women worldwide, and in Korea, it is the second most prevalent form of cancer affecting females. For Western women, the risk of developing breast cancer increases with age, while in Korea, women in their 40s have the highest incidence of breast cancer. Further, patients below the age of 40 account for approximately 15.0% of the overall number of Korean patients with breast cancer, a percentage that is approximately three times greater than in Western society. Meanwhile, in 2012 it was reported that the mortality of breast cancer in Korea was the lowest among Organization for Economic Cooperation and Development member countries and that the five-year survival rate in the country for early-stage breast cancer with no metastasis was over 97.7% [1].

Young breast cancer survivors, those aged 45 or under [2, 3], show more severe levels of physical disability, anxiety, depressive symptoms, and sleep disorders, along with lower satisfaction in terms of their marriage and a greater fear of cancer recurrence, than older survivors [3]. These symptoms persist for over three years after diagnosis and even influence quality of life [3]. Furthermore, young breast cancer survivors have complained of a fear of premature menopause as a result of their treatment and of suffering from psychological distress due to the change their treatment brought to their role in the family [4]. The symptom distress these patients feel is usually quite severe and it should be noted that it persists after the completion of treatment [4, 5]. Another notable finding in this respect is that, after the completion of treatment, young breast cancer survivors require a higher level of social and psychological support to adapt to their health conditions than older breast cancer survivors do [6]. In this context, it is evident that effective coping strategies for addressing the issues faced by young breast cancer survivors at the individual level are required to improve their quality of life [7].

The Transactional Model of Stress and Coping developed by Lazarus & Folkman [8] emphasizes the process of dynamic interaction between individuals' awareness, cognition, and stress-coping strategies. They also state that stress events are not directly associated with maladjustment reactions and are actually adjusted by individuals' awareness of the stress event and the resources available to them to conduct effective coping [8, 9]. These resources affect the coping process and are assumed to be factors that mediate stress. The range of coping resources can be divided into two categories: social and psychological [8].

In regard to social resources, individuals seek social support when they require information or assistance to respond to or cope with a certain danger [8, 9]. In comparison to individuals with other conditions, breast cancer patients receive relatively more information support from medical personnel and emotional support from their family and friends. Further, those with low social support or a weak social network have been found to be less likely to receive proper help and support [10]. However, it is especially difficult for young breast cancer patients to find others experiencing the same situation, and this commonly causes them to feel isolated. By providing such patients with social support, such as informational and emotional support, and wider opportunities for information sharing, this greater level of social interaction, along with improved coping strategies, can enhance their quality of life [11].

Returning to the abovementioned categorization of coping resources, it should be noted that in regard to psychological resources, resilience is important. Resilience is categorized as positive belief, and it concerns one's ability to overcome emotional hardship when faced with challenges and to quickly and efficiently recover from negative experiences [12, 13]. By enhancing resilience, young breast cancer survivors can alleviate the negative impacts of the various physical, psychological, and social issues they experience after the completion of treatment, and it can also help them establish positive coping behaviors. Therefore, it is clearly important to predict the variables associated with coping resources for young breast cancer survivors and to comprehensively examine their influence, as these resources can have an impact on the success of these patients' coping.

To perform this, we reviewed previous literature in an attempt to gain an understanding of the relationship between symptom distress (perceived stress) and coping in young breast cancer survivors, focusing on studies that have applied Lazarus & Folkman's theory [8]. However, many studies merely reported associations between coping resources or their fragmentary effects [14, 15, 16]. Moreover, in a study on the indirect effects of coping resources (social support and optimism) on the relationship between symptom experience and coping in patients with early breast cancer [17], structural correlation between individual variables were identified. However, despite the fact that the severity of symptoms experienced varies in different age groups (young or old) [2, 3] and the level of coping resources required by the subjects also varies [11], the study identified the causal relationships without considering age groups, which presents the limitation of not being able to identify the relationships between perceived stress, coping resources, and coping in young breast cancer survivors.

Considering the above, this study was conducted with the purpose of identifying the structural correlation between factors that influence the coping process of young breast cancer survivors. To achieve this, these influential factors were applied to the stress-coping theory. Consequently, in order to determine the effectiveness and impact of appropriate channels, a model, which could contribute to could contribute to the identification of practical and effective nursing interventions to improve coping strategies for young breast cancer survivors, was established and verified.

1. Theoretical framework and hypothetical model

The theoretical framework of this study is Lazarus and Folkman's stress-coping theory [8] featuring the key concepts of stress, appraisal, and coping. When an individual is diagnosed with breast cancer, their cognitive appraisal of the stress event can generate stress. They then evaluate the stress through primary appraisal, which determines if the event or situation poses a threat to their physical and/or psychological health, and, once stress is initially generated, symptom distress can persist, even after diagnosis and the completion of the overall treatment process [3, 4, 5]. It is for this reason that symptom distress has been established as the primary appraisal in this study.

Secondary appraisal relates to when coping resources available to patients are identified and applied to alleviate the degree of stress. As young breast cancer survivors generally find it extremely difficult to make decisions concerning their health [13], they must make use of resources provided from the outside, such as necessary support, information, and feedback [18]. Considering this, in our study social support was set as one of the coping resources used during secondary appraisal. Furthermore, resilience, which is positive belief and is required to overcome uncertainty about and fear of cancer [8, 12, 13, 18], was also set as one of the coping resources used during the secondary appraisals of young breast cancer survivors.

Based on Lazarus & Folkman's theory [8], a path was established in which symptom distress affected social support [16, 19] and resilience [13, 16], and another path was established in which symptom distress affected coping [16]. In addition, further paths were established in which social support [17] and resilience affected coping [16] (Figure 1).

Figure 1
Lazarus & Folkman's stress-coping theory and hypothetical model.

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Young breast cancer survivors more frequently complain of psychological distress, depressive symptoms, fatigue, and issues relating to attention and sexual function than their older counterparts, and multiple studies have reported that such symptom distress may play a critical role in undermining such patients' health-related quality of life [3]. Thus, efficient use of coping resources (social support and resilience) in stress situations [8], such as when experiencing symptom distress, would strengthen young breast cancer survivors' coping capabilities, and ultimately have beneficial effects on their mental health and psychosocial adjustment. Considering this, this study investigated the direct and indirect effects of influential factors on the coping process of young breast cancer survivors by applying Lazarus & Folkman's stress-coping theory [8].

Our model suitability test showed adequate results, indicating that it was suitable for predicting the coping processes of such survivors. In this study, young breast cancer survivors' symptom distress, social support, and resilience were found to explain 46.4% of the total variance of coping. Symptom distress was found to have no direct effects on coping but was confirmed to have indirect effects through social support and resilience as complete mediating variables, with no difference in the level of indirect effects. As the physical and psychological symptom distress of young breast cancer survivors can only be alleviated through the application of coping resources relating to social support and resilience, our results confirm that mediation of such coping resources can have beneficial effects on the coping of these survivors.

Applying Lazarus & Folkman's stress-coping theory [8], this study established a body of nursing knowledge concerning the coping of young breast-cancer survivors. This was achieved by forming a basis for describing the causal pathway of such cancer survivors' coping processes. According to Lazarus & Folkman [8], coping resources can be considered mediating factors for stress and coping strategies, and they are also especially important for perceiving difficult situations in a positive manner. The results of this study show that the indirect effects of social support (coping resources provided from the outside) and resilience (individuals' psychological coping resources) on symptom distress (perceived stress) and coping are statistically significant; therefore, this study has empirically verified the concept of Lazarus and Folkman's theory [8].

In this study, the direct effects of social support and resilience on the symptom distress of young breast cancer survivors were confirmed and, consistent with the findings of previous studies [13, 16, 19], we substantiated the effects perceived stress has on coping resources [8]. Even after the completion of their cancer treatment, young breast cancer survivors still experience stress events—symptom distress—more frequently than do older survivors [3, 4, 5]. This suggests that, in order to reduce various forms of physical and mental symptom distress, including premature menopause and fear of experiencing various physical symptoms such as sexual dysfunction, poor body image, and cancer relapse [3], and to enhance social support and resilience in young breast cancer survivors, measures such as systematic inspections for symptom distress, development of guidelines for symptom distress management, development and operation of symptom distress alleviation programs, provision of information and education on regularly occurring health issues, and telephone counseling should be implemented.

The symptom distress scores in this study were generally low, which is inconsistent with the findings of a previous study in which young breast cancer survivors showed higher symptom distress than old survivors [3]. This may be attributable to the fact that the subjects of the present study were breast cancer survivors who had completed their treatment over six months previously. Another possible reason for this finding is that the symptom distress instrument used in this study had originally been developed for all cancer patients [23], and not strictly for breast cancer patients, which means that it is possible that some of the symptoms experienced by breast cancer patients were not included. Thus, additional studies should be conducted using instruments that thoroughly reflect the symptoms of young breast cancer survivors.

Social support, a coping resource, was confirmed to have direct effects on the coping of young breast cancer survivors. This study supports the result of another study [19], which suggested that a higher coping score means that the respondent receives greater social support. This study confirmed that social support is a useful coping resource that can strengthen individuals' problem-solving abilities and enable them to effectively cope with stress situations; further, it showed that support from family, friends, and significant others are key factors that affect coping in young breast cancer survivors. Considering that the survival rate of young breast cancer patients is higher among those who have heightened social support post-cancer diagnosis than among those who maintain the same amount of contact with friends and family as before breast cancer treatment [11], it is clearly highly important to develop individualized intervention strategies for such patients, who are in more serious need of psychosocial help than are older breast cancer survivors, with the aim of increasing social support. This should be performed with the goal of transforming various difficult situations into more positive ones. Further, appropriate social support should be provided for young breast cancer survivors, who will generally be required to visit outpatient clinics for the foreseeable future in order to receive follow-up care, by investigating the kind of resource network each patient requires. For individuals with good support from family and friends, the emotional support they receive from these areas should be reinforced, and medical professionals should also provide assistance in terms of disease-related information and decision making. Moreover, individuals who perceive themselves to have low support from friends and family should be provided with a comprehensive social support program that comprises systems for both continuous follow-up care from medical personnel and for the acquiring of assistance from community social organizations. In particular, it can be supposed that developing a system that provides young breast cancer survivors with the required social support through their social networks would also provide them with the social resources they require.

However, the results of this study were different from the results of Kim & So [17], which reported that social support does not mediate the relationship between symptom experience and coping in early breast cancer patients. Young breast cancer patients (<50 years old) are more likely than older breast cancer patients (≥50 years old) to want emotional support from professional counselors, while also showing higher demand for appropriate social support services [6, 30]. In the study by Kim & So [17], the study population consisted of a relatively high percentage—approximately 70.0%—of older women aged ≥50 years, and as a result, social support may not have affected coping.

It should also be noted that social support scores were generally high in this study, which is inconsistent with a previous study's finding that young breast cancer survivors have higher demands regarding social support than do old breast cancer survivors [5]; this latter finding is similar to another finding: that young women with breast cancer who actively participate in breast cancer treatment have higher social support [11]. One reason for the difference between these findings and our own may be that the participants of this study were breast cancer survivors who had completed aggressive treatment at least six months previously. Further, the social support instrument used in this study measures individuals' perceived support from family, friends, and significant others, which suggests that South Korea's family-centered culture and breast cancer support group activities may have affected the outcomes. Thus, further studies to clarify this point are required.

Resilience, which is another coping resource, was shown to have direct effects on coping, and this result was consistent with that of a previous study that demonstrated a positive correlation between resilience and coping [17]. Considering this and our own results, we surmise that developing and implementing resilience-enhancing nursing intervention programs for young breast cancer survivors improves their coping capabilities, thereby improving their adaptation to distress and psychosocial problems that would negatively affect them for the foreseeable future.

The present study confirmed the direct, indirect, and total effects of variables, along with identifying the correlations between them, through the application of covariance structure analysis, which was conducted to verify the predictive model created concerning the coping of young breast cancer survivors. Further, the complete mediating effects of social support and resilience were verified by identifying the pathway from symptom distress to coping. It is also recommended that the effect of mediation strategies be maximized, as this can facilitate the development of various programs that can be applied in cancer nursing practice, as well as more effective nursing practices. In particular, a 12-week stress management and resilience training (SMART) program has been reported to significantly improve the resilience, perceived stress, and quality of life of breast cancer patients [31]; moreover, the implementation of a four-module breast cancer e-support program has also been reported to be effective in enhancing individuals' symptom distress, social support, depression and anxiety, and quality of life [32]. Hence, the SMART and breast cancer e-support programs may be effective in relieving symptom distress and enhancing social support and resilience in young breast cancer patients, thereby helping them implement effective coping skills.

Despite the abovementioned findings, this study has the following limitations. First, as we established a structural model based on data collected from participants who satisfied specific criteria, it may not be possible to extend the results of the study to all young breast cancer survivors. In addition, this study has a second limitation that it has not been able to establish a structural model, including all mediating factors that may influence the coping of young breast cancer survivors. Finally, this was only a cross-sectional study. Thus, longitudinal research is recommended to confirm the causal path of this study's findings. Thus, longitudinal research is recommended to confirm the causal path of this study's findings.

In this study, the mediating effect of coping resources on the relationship between perceived stress and coping was identified. Such findings demonstrate that to improve the coping capacity of young breast cancer survivors suffering from severe physical and psychological symptom distress, there is a need for social resources that provide supportive care, helping build health together with family, friends, and health professionals, as well as psychological resources that allow for positive views about the disease. In other words, providing individually customized nursing intervention to young breast cancer survivors through continued assessment of their resilience and social support can contribute to improving coping ability and the health outcomes of the subjects.