Background: Cancer impacts on patients and their families across a range of different domains. For that reason, optimal cancer care has moved away from a disease-centric focus to a more holistic approach in order to proactively support people with their individual needs and concerns. While international policy clearly advocates this agenda, implementation into routine care is limited. Therefore, relevant interventions that measurably improve patient outcomes are essential to understand if this ideal is to become routine multidisciplinary practice. The aim of this study was to analyse the impact of a proactive, holistic, community-based intervention on health-related quality of life in a cohort of people diagnosed with cancer. Secondary aim was to explore the relationship between changes in health status and: cancer type, cancer stage, number of concerns expressed and change in severity of concerns pre and post intervention. Method: Prospective observational cohort study. A convenience sample of 437 individuals were referred to the service 'Improving the Cancer Journey (ICJ) in the UK. Each completed the Euroqol EQ-5D-3 L and visual analogue scale (VAS) and a Holistic Needs Assessment (HNA) during initial visit to the service and again at follow-up review, median 84 days later. Change between scores was tested with paired t-tests and relationships between variables with multiple regression models with heteroscedasticity-consistent standard errors. Results: Participants were White British with median age between 50 and 64 years. Cancer type and stage were varied. EQ-5D utility scores improved at follow-up by 0.121 [0.0891-0.153], p < .001, and VAS scores improved by 7.81 [5.88-9.74], p < .001. The strongest predictor of change was a decrease in severity of concerns. Cancer stage 'palliative care' contributed to a reduction in health status. Conclusion: This study is the first to show that a holistic community intervention dedicated to supporting the individual concerns of participants had both a statistically significant and clinically meaningful impact on participants' health-related quality of life. The mean change in EQ-5D scores was more than the 'minimally important clinical difference' described in the literature. This is important because while quality of life has multiple determinants, this study has shown for the first time that it is possible to capture a clinically meaningful improvement as a function of reducing someone's personally identified concerns.