Abstract Book

S246

ESTRO 37

Abstract text The number of cancer survivors grows every year and as they age the attention needs to shift to their long-term health. Cancer and treatment-related symptoms can impact on long-term health and health-related quality of life (HRQOL). Common side-effects following pelvic radiotherapy for prostate cancer include decreased urinary, bowel and sexual function (symptoms include erectile dysfunction or urinary incontinence). Androgen deprivation therapy (ADT), commonly used with radical radiotherapy, can add fatigue, hot flushes or muscle and bone loss to the spectrum of expected side-effects. This impacts on supportive care needs of men. Patients experience groups of symptoms called clusters. This concept can serve as basis for the assessment and management of multiple symptoms. Symptom clusters enable identification of groups of correlated symptoms that are more prevalent and more relevant to patients. Therefore, this allows recognition of symptom clusters specific to the type of cancer and its treatment which is important for appropriate symptom management. We studied synergy of symptoms in clusters and described the effect on HRQOL. PROs data of 843 prostate cancer survivors from the Medical Research Council RT01 radiotherapy with neoadjuvant ADT trial were used. PROs were recorded over 5 years with the University of California, Los Angeles Prostate Cancer Index (UCLA-PCI) and the 36-Item Short-Form Health Survey (SF-36). These data allowed us to observe the late deterioration in symptoms and HRQOL that starts to emerge from year 2 post-radiotherapy. This deterioration possibly due to radiation fibrosis deserves attention and engagement of early management strategies. With the long-term follow- up, we were also able to establish the effect of early outcomes on late PROs. Older age, illness perception at baseline and early (baseline and acute) symptom clusters were associated with decreased long-term function and HRQOL in this population. For example, acute bladder symptoms were a precursor of late symptoms and patients with pre-treatment bladder symptoms were more likely to report bladder symptom at 3 years. This was independent of the radiotherapy dose and added to the evidence towards consequential late effects. These findings are important in identification of patients at risk of long-term symptoms and late radiotherapy-related toxicity and underpin the importance of employing pre- treatment PROs assessment including symptoms, function and HRQOL measurements. Early management of co- morbidities and prehabilitation of physical and functional status should complement treatment planning to aid recovery during and after cancer treatment. This findings can lead to targeted prehabilitation approaches in the form of lifestyle interventions prior to radiotherapy. OC-0480 Patient-reported outcomes in the search for the optimal radiotherapy schedule for prostate cancer E. Rammant 1 , P. Ost 2 , M. Swimberghe 2 , F. Vanpachtenbeke 2 , R. Bultijnck 1 , N. Lumen 3 , K. Decaestecker 3 , V. Fonteyne 2 1 Ghent University, Radiotherapy and experimental cancer research, Ghent, Belgium 2 Ghent University Hospital, Radiotherapy and experimental cancer research, Ghent, Belgium 3 Ghent University Hospital, Urology, Ghent, Belgium Purpose or Objective Although there is a growing interest in hypofractionated radiotherapy as primary treatment for prostate cancer (pca), no consensus is made about which hypofractionated schedule to use. When comparing treatment options with similar success rates, patient- reported outcomes including health-related quality of life (HRQoL) should be considered as an important endpoint for guiding the treatment decision. Therefore, we want

patients in treatment-related decision-making is in line with the increasingly acknowledged patients’ right to autonomy and self-determination. Involving cancer patients’ values may assist in obtaining as often as possible the best achievable care for individual patients. Since their cancer diagnosis will have put most patients in a totally new situation, they most probably will not have pre-existing preferences for the outcomes of care relevant to this treatment decision, as they have never thought about these issues. The more so, that considerable evidence indicates that people do not have well-formed, complete, and stable preferences. 36-38 These newly diagnosed patients facing a treatment decision, will need to think about treatment outcomes, in order to determine for themselves how important these are. Also, they will need to think about trade-offs between benefits and side effects. The need to involve patients is supported by evidence that physicians do not have the ability to adequately judge patients’ values for outcomes of care, nor patients’ treatment preferences. If patient values are to be incorporated in treatment decision- making, this requires patients to participate in the consultation and voice their values. A review of the empirical evidence on patients’ experiences with health care in the Netherlands showed that 26-47% of hospital patients indicate not to be given the opportunity to participate in treatment decision-making. To be able to engage patients in a constructive shared decision making process, a number of topics have to be addressed. Firstly, reliable information on patients’ values and preferences needs to be obtained. We previously showed that clinicians cannot reliably predict patients’ preferences and therefore an appropriate way for obtaining information on patients values needs to be used. Independent of the chosen method, preferences can only be acquired when the clinician has a clear view of the most important benefits and risks of the proposed treatment. This requires that current clinical trials and registries provide us with not only physician-based outcomes, but also with patient reported outcomes. In addition, the patient needs to understand that there is always a choice and possible alternatives should therefore be discussed. To be able to do so, the clinician needs to be trained to communicate about risks and preferences. Possibly even more important, clinicians need a change of how to evaluate the outcomes of clinical trials. Up till now, most clinicians considered a trial to have either a positive or negative outcome, based on the estimated difference in predefined oncological outcomes. However, we now know that different patients will perceive differences in outcomes differently. Some may consider higher risks acceptable when this is accompanied by lower risks of side effects, whilst others do not want to take any risk. With the introduction of organ preservation for several tumour sites, this delicate balance between risks and benefits becomes even more explicit. The impact of patients’ values and preferences will therefore become more and more important, influencing our daily practice of informing patients enormously. SP-0479 Listening to patients: PROs analysis to improve communication and enhance practice. A. Lemanska 1 , D. Dearnaley 2 , R. Jena 3 , M. Sydes 4 , S. Faithfull 1 1 University of Surrey, School of Health Sciences, Guildford, United Kingdom 2 Institute of Cancer Research and Royal Marsden NHS Trust, Institute of Cancer Research and Royal Marsden NHS Trust, London, United Kingdom 3 Addenbrookes Hospital, Cambridge University Hospitals, Cambridge, United Kingdom 4 Institute of Clinical Trials and Methodology, MRC Clinical Trials Unit at UCL, London, United Kingdom