ObjectivesThe widespread use of complementary therapies alongside biomedical treatment by people with cancer is not supported by evidence from clinical trials. We aimed to use combined qualitative and quantitative data to describe and measure individualized experiences and outcomes. Methods In three integrative Cancer Support Centres (two breast cancer only) in the UK, consecutive patients completed the individualised outcome questionnaire Measure Yourself Concerns and Wellbeing (MYCaW) before and after treatment. MYCaW collects quantitative data (7-point scales) and written qualitative data and the qualitative data were analysed using published categories. Results 782 participants, 92% female, mean age 51yrs, nominated a wide range of concerns. Psychological and emotional concerns predominated. At follow-up, the mean change (improvement) in scores (n=588) were: concern 1, 2.06 (95% CI 1.92-2.20); concern 2, 1.74 (95% CI 1.60-1.90); and wellbeing, 0.64 (95% CI 0.52-0.75. The most common responses to 'what has been the most important aspect for you?' were 'receiving complementary therapies on an individual or group basis' (26.2%); 'support and understanding received from therapists' (17.1%) and 'time spent with other patients at the centres' (16.1%). Positive (61.5%) and negative (38.5%) descriptions of 'other things affecting your health' correlated with larger and smaller improvement in concerns and wellbeing respectively Conclusions In a multi-centre evaluation the MYCaW questionnaire provides rich data about patient experience, changes over time and perceptions of what was important to each individual with cancer within that experience. It is unlikely that meaningful evaluations of this complex intervention could be carried out by quantitative methods alone.