Beyond breast cancer: addressing long-term local side effects and enhancing quality of life
Authors:   , Mink van der Molen Dieuwke Rosalie 
Published: October 2023

Breast cancer patients and survivors may experience local side effects during and after breast cancer treatment involving breast surgery and adjuvant radiotherapy. The first part of this thesis focuses on the occurrence of local side effects and its impact on quality of life during and after breast cancer treatment using real-world data from the large, prospective UMBRELLA breast cancer cohort. The effectiveness of hyperbaric oxygen therapy was studied as potential treatment for late local side effects in irradiated breast cancer patients. In the second part of this thesis, the impact of the COVID-19 pandemic on quality of life and perceived health care among breast cancer patients and survivors was evaluated. Chapter 2 shows that patient-reported late local side effects, i.e., pain, edema, movement restriction, impaired cosmetic outcome, and firmness of the breast, axilla and/or chest wall, are relatively common after adjuvant radiotherapy for early-stage breast cancer and are associated with reduced physical, role, and social functioning. A limited number of studies, mostly small and single-arm, have shown that hyperbaric oxygen therapy might be useful for the reduction of late local side effects in irradiated breast cancer patients, but evidence still remains scarce (chapter 3). In chapter 4, we present the results of a randomized clinical trial within the prospective multicenter UMBRELLA cohort to assess the effectiveness of hyperbaric oxygen therapy for late local side effects in irradiated breast cancer patients. Offering hyperbaric oxygen therapy to breast cancer patients with late local side effects was significantly associated with a reduction in patient-reported fibrosis. Undergoing hyperbaric oxygen therapy was associated with a significant reduction in pain and fibrosis. In chapter 5, we compared clinician-reported acute local side effects and patient-reported outcomes of the adjuvant hypofractionated radiotherapy schedule of 26 Gy in 5 fractions over 1 week to the conventional schedule of 40 Gy in 15 fractions over 3 weeks after breast-conserving surgery for early-stage breast cancer in a routine clinical setting. Acute local side effects, i.e., dermatitis, breast pain, and fatigue, were comparable between both groups or in favor of the 5-fraction schedule during and up to four weeks after completion of treatment. The 5-fraction schedule also seems safe in terms of acute local side effects for patients who underwent oncoplastic breast-conserving surgery. In chapter 6, we evaluated oncological and short and long-term patient-reported outcomes after oncoplastic breast-conserving surgery compared to conventional breast-conserving surgery. Clinical outcomes after oncoplastic and conventional breast-conserving surgery were comparable. Shortly after surgery, oncoplastic surgery was associated with worse physical functioning and body image and more pain and breast symptoms than conventional breast conserving surgery. From six months onwards, functioning and symptoms were comparable between both groups, although body image remained significantly lower after oncoplastic breast-conserving surgery when compared to conventional breast-conserving surgery up to 24 months after surgery. In chapter 7, we found that perceived access to health care among breast cancer patients recovered substantially between the first and second wave of the COVID-19 pandemic. Digital health was well received during the COVID-19 pandemic, especially by patients receiving active breast cancer treatment. During the COVID-19 pandemic, breast cancer patients and survivors with symptoms of anxiety and/or depression experienced higher barriers in seeking health care (chapter 8). Quality of life, physical functioning, and psychosocial well-being of breast cancer patients and survivors remained stable or improved between the first and second COVID-19 wave (chapter 9).