Patient-centered approaches to improve outcomes for breast cancer patients

This thesis explores how outcomes for women with breast cancer can be improved by strengthening shared decision-making between patients and healthcare professionals. Over recent decades, survival rates have improved substantially, shifting the focus of breast cancer care toward quality of life and long-term consequences of treatment. Because breast cancer treatment often involves multiple locoregional and systemic options, each with different benefits and side effects, it is essential that treatment decisions align with patients’ personal values, preferences, and life circumstances.

The first part of the thesis focuses on surgical strategies aimed at improving outcomes without compromising oncological safety. A novel technique using indocyanine green (ICG) fluorescence is explored for the localization of non-palpable breast tumors. The findings suggest that ICG is a safe and accurate alternative to existing localization techniques and may help reduce the risk of positive surgical margins. Long-term population-based data show a gradual shift toward less extensive surgery in patients with locally advanced breast cancer. Importantly, this de-escalation of surgical treatment did not negatively affect survival outcomes in selected patient groups. Another surgical focus was breast reconstruction following mastectomy. For women choosing autologous reconstruction with a DIEP flap who also require post-mastectomy radiotherapy, the timing of reconstruction remains a complex decision. This thesis demonstrates that both immediate and delayed DIEP flap reconstruction lead to comparable long-term quality-of-life outcomes, despite differences in short-term side effects. These findings allow clinicians and patients to consider multiple treatment pathways and to tailor decisions to individual priorities.

The second part of the thesis examines non-surgical approaches to support patient-centered care. Patient-reported outcomes (PROs) were used to capture patients’ experiences and to better understand the real-world impact of treatment on daily functioning and well-being. Establishing minimal clinically important differences (MCIDs) for commonly used PRO measures helps distinguish clinically meaningful changes from statistically significant but less relevant differences. In addition, the effectiveness of an online patient decision aid for post-mastectomy breast reconstruction was evaluated. In a setting with high-quality, multidisciplinary counseling, the decision aid did not further reduce decisional conflict, suggesting that the added value of such tools depends strongly on the clinical context. In contrast, one-to-one peer support proved valuable in addressing emotional needs and providing experiential knowledge, highlighting the importance of psychosocial support alongside medical care.

Overall, this thesis demonstrates that optimal breast cancer care extends beyond medical effectiveness alone. Improving information provision, integrating patient-reported outcomes into routine care, and strengthening collaboration and data integration at a national level can further enhance shared decision-making. By actively involving patients in treatment decisions and translating innovations into clinical practice more rapidly, breast cancer care can become more personalized and better aligned with what matters most to patients.