How do Psychological Factors Interact With the Oncological Outcomes of Women With Triple-negative Breast Cancer?

Triple negative breast cancer (TNBC) is a highly heterogeneous subtype, which exhibits aggressive clinical behavior and generally carries a poor prognosis. As it lacks hormone receptors expression (estrogen and progesterone receptors) and amplification of the Human epidermal growth factor receptor 2 (HER2), targeted therapies are lacking. Thus, the identification of any modifiable factors which may influence the course of the disease is critical both in improving the quality of care and the patient's quality of life. In addition to lifestyle factors, such as diet and exercise habits, psychological factors, such as cumulative lifetime stress, coping response, perceived social support, and overall psychological well-being may also influence cancer progression.

While it is known that stress can directly upregulate certain immune mechanisms, it is suspected that a patient's coping response, perceived social support, and general psychological well-being may have an indirect influence on cancer progression via altered health-related behaviors. For example, during stressful periods, alcohol consumption may rise, sleep quality may be diminished, nutritional needs may not be properly met, and exercise may be avoided. As a group, TNBC patients face additional challenges not experienced by other BC patients. Due to the disease's poor prognosis, its relatively new status as a BC subtype (first mention in 2005), and the lack of targeted treatments; patients may experience an increased stress-response following their diagnosis. For instance, it is known that an event induces a stress response when it involves novelty and unpredictability, a lack of sense of control, and threats to the sense of self; elements that are clearly emphasized in TNBC.

To promote the development of psycho oncological strategies tailored towards women in this particular patient group, this study aims to explore any trends which might be indicative of an interaction between psychological aspects and the oncological outcomes of patients treated for TNBC between 01.01.2015-31.12.2019, at Pius Hospital, in Oldenburg, Germany. Because we intend to evaluate a retrospective cohort of patients, the psychological instruments were chosen and slightly adapted to target past events (stress across life span and social support) and stable traits (psychological well-being, coping).

As there is an existing body of evidence supporting the relationship between stress and the immune system, we expect to see the poorest oncological outcomes in patients who 1) have had more adverse life events, and 2) those who present inadequate/inappropriate coping skills. Additionally, we intend to explore if other psychological variables mentioned in the literature, including perceived social support and psychological well-being, are also related to the oncological outcomes in our cohort of patients.

This study combines prospective and retrospective approaches since the psychosociological data is to be collected prospectively from a single retrospective cohort of patients. Patients could not be randomized into groups, due to the retrospective nature of the study. Considering that all data derived from this study will be numerical, this will be a quantitative analysis. This research is comparative since the patients' clinical outcomes will be analyzed in terms of psychological measures. Lastly, the present study is exploratory as it aims to shed light on the interplay between psychological and clinical aspects in TNBC, as psycho-oncological studies are lacking for this BC subtype.