Purpose <p>Although targeted therapies have prolonged survival in human epidermal growth factor receptor 2 (HER2)–positive metastatic breast cancer, the resulting chronic disease trajectory is frequently accompanied by substantial psychological burden. This study aimed to conduct a preliminary investigation into the feasibility and psychological outcomes of a low-intensity, group-based cognitive-behavioral therapy intervention (CBT-OP-4) among women receiving palliative care.</p> Methods <p>A prospective feasibility study without a control group was undertaken involving 13 female participants (mean age = 63&#xa0;years, SD = 8.05), all diagnosed with HER2-positive metastatic breast cancer. The four-session CBT-based group intervention targeted key psychological domains. Self-reported measures of distress, depression, anxiety, perceived stigma, self-compassion, and locus of control were administered pre- and post-intervention. Feasibility and acceptability were further examined via semi-structured qualitative interviews and standardized patient satisfaction instruments.</p> Results <p>Following the intervention, pre–post improvements were observed in psychological distress, depressive symptoms, and perceived stigma. In parallel, participants demonstrated an increase in self-compassion. Overall, the program was rated as highly acceptable, with participants emphasizing the relevance and applicability of the intervention content within their illness context.</p> Conclusion <p>Findings from this preliminary study suggest that the CBT-OP-4 program is a feasible and acceptable psycho-oncological intervention for women with advanced-stage HER2-positive breast cancer receiving palliative care. The results offer initial empirical support for the incorporation of structured, evidence-based psychological interventions into the routine psychosocial management of this patient population.</p>