To the best of our knowledge, this is the first study to incorporate both psychological and physiological symptoms into the symptom network of breast cancer patients. Our study results showed that depression, anxiety and eight symptoms of the EORTC-QLQ-C30 questionnaire were highly intercorrelated and could be represented as a symptom network. In this study, we found that FA, Anx, AP, PA, Dep and DY were central symptoms both in total and after adjusting for covariates network and they remained central in patients with all subgroups. We also find three major symptom clusters in breast cancer patients: emotional symptoms (Dep, Anx, and SL), gastrointestinal symptoms (NV, DI, and AP), and somatic symptoms (FA, PA, and DY). Therefore, FA, Anx, AP, PA, Dep and DY may play a crucial role in symptom network in breast cancer patients, which might be important targets for clinical intervention to improve overall symptom burden.
Our findings indicate that fatigue is the most prevalent symptom, affecting 71% of patients, and plays a central role in the overall network, except for those with a disease duration of less than one year. Furthermore, the results of DAG show that fatigue is at the upstream of the DAG and activate other symptoms in the network to varying degrees. Previous studies consistently show that fatigue is the most common and distressing symptom experienced by breast cancer patients [25, 26]. Moreover, fatigue has a more severe negative impact on quality of life compared to other symptoms [27]. Consistent with these findings, Rooij et al. [10] identified fatigue as the most central symptom in the symptom network of all cancer types, including breast cancer, and highlighted its strong associations with other symptoms. Similarly, Berger et al. [28] found that fatigue is the central symptom in breast cancer patients one month after completing chemotherapy. Fatigue exhibits a multidimensional nature within the context of cancer-related symptomatology. Numerous studies have established links between fatigue and mental well-being [29], often proposing psychological interventions as potential remedies. Rha and Lee's findings suggest that fatigue's central position in symptom networks may be attributed to chemotherapy usage and the duration of cancer survivorship [30]. In contrast, Zhu et al. observed a diminished centrality of fatigue in populations with over five years of survivorship [9]. This underscores that cancer therapies, encompassing chemotherapy, radiation therapy, immunotherapy, and surgical interventions, could significantly influence fatigue's prominence within symptom networks. It is important to note that fatigue in breast cancer patients not only leads to physical sleepiness but also contributes to cognitive impairments, such as attention and memory deficits, as well as emotional disturbances, such as depression and anxiety [31, 32]. Therefore, addressing fatigue should be prioritized as a key intervention target to reduce the overall symptom burden and improve the quality of life of breast cancer patients. Long-term symptom management strategies should be implemented to ensure comprehensive care.
In this study, depression and anxiety were identified as central symptoms in breast cancer patients. Notably, anxiety emerged as the central symptom within the subset of patients diagnosed within one year. These findings underscore the imperative of early detection and intervention to effectively address emotional disorders in breast cancer patients. Moreover, the prevalence of depression and anxiety within this demographic is conspicuously elevated, often ranging from 13–54%. [33]. These affective disorders exhibit a strong correlation with clinical manifestations of pain and fatigue, exerting a profound detrimental impact on the overall well-being of patients [34, 35], and concomitantly elevating the susceptibility to suicidal ideation [36]. Jing et al. [11] and Rooij et al. [10] similarly observed the centrality of emotional symptoms among breast cancer patients. Nonetheless, there is a prevalent tendency among healthcare professionals to inadequately acknowledge the gravity of these emotional disorders, resulting in the frequent underestimation of depression and anxiety concerns in individuals diagnosed with breast cancer [37]. To facilitate comprehensive care and bolster support for breast cancer patients throughout their survivorship journey, heightened awareness regarding the significance of emotional disorders is imperative among healthcare providers, patients, and their families. Regular psychological evaluations are advocated for the timely identification and assessment of symptoms, thus enabling early intervention and management.
This study identified three primary symptom clusters prevalent among breast cancer patients: emotional manifestations encompassing depression, anxiety, and insomnia; gastrointestinal disturbances including nausea/vomiting, diarrhea, and appetite loss; and somatic complaints comprising fatigue, pain, and dyspnea. Prior investigations frequently underscored the association between fatigue and emotional disorders, particularly insomnia [10] [28]. Research posits that cancer and its therapeutic interventions may trigger peripheral pro-inflammatory cytokine networks, eliciting symptoms such as fatigue, pain, insomnia, anxiety, and depression via cytokine-mediated signaling pathways within the central nervous system [38, 39]. A systematic review elucidated a strong correlation between nausea/vomiting and loss of appetite among breast cancer patients, a finding corroborated by our study as well [40]. Nevertheless, constipation did not coalesce into a symptom cluster with gastrointestinal manifestations in our investigation, potentially attributable to the predominance of chemotherapy recipients among our study cohort (89.83%). Catherine et al. [41] noted chemotherapy-induced autonomic dysfunction as a contributor to delayed gastric motility, thereby precipitating constipation in affected patients. Given the likelihood of distinct symptom profiles across varying cancer types and the potential influence of diverse symptom assessment instruments on cluster identification [40], forthcoming research endeavors ought to incorporate cancer-specific assessment tools to enhance the precision of symptom quantification.