Background: CGA is internationally recommended in the care for older patients with cancer (e.g. ASCO). Only a few recent RCTs have examined the impact on patient’s QoL. Aim of this study is to evaluate the effectiveness of CGA coordinated by a geriatric team combined with intensive patient coaching ( = intervention group (IG)) versus standard of care, which is CGA coordinated by an oncology team ( = control group (CG)) on QoL in older patients with solid tumors receiving systemic therapy. Methods: The G-oncoCOACH study was a multicenter RCT in two academic Belgian hospitals (NCT04069962). Eligibility criteria were 70+ years, solid tumor, systemic therapy with curative or non-curative intent (first/second-line), and physician-estimated life expectancy > 6 months. IG patients received CGA coordinated by the geriatric team in close collaboration with the oncology team, increasing multidisciplinary care and in combination with intensive patient coaching to increase patient compliance. This supports patient empowerment by improving self-efficacy and supporting self-management of age-related problems. It included an individual counselling session at start of systemic therapy to discuss CGA results and recommendations with the patient and to determine their priorities, followed by individual counselling organized at 2, 4.5, 8 and 10 months. Primary endpoint was global health status (GHS) of the European Organisation for Research and Therapy of Cancer (EORTC) QOL questionnaire measured at 6 months after start of systemic therapy. Sample size calculation required > 195 included patients for primary endpoint (≥10 points QoL change at 6 months) for 80% power at 2-sided 5% significance level. After exclusion of multicollinearity, the change in QoL GHS between baseline and 6 months follow-up was analyzed with a mixed model. Results: From 10/2019 to 9/2021, 212 participants were enrolled (CG (n = 107); IG (n = 105)). Mean age was 76.8 years; 52.4% were female (n = 111). The 3 most common tumor types were digestive (n = 65; 30.7%), thorax (n = 44; 20.8%), and urogenital (n = 33; 15.6%). Cancer therapy was started mostly with non-curative intent. After 6 months, the difference between CG and IG in change of adjusted QoL GHS versus baseline amounted 12.8 points in favor of the IG (95%CL 6.7-18.8; p < 0.0001). This difference consisted of an improvement of 4.5 point versus baseline in the IG and decline of 8.2 points in the CG. Secondary endpoints (e.g. QoL at 3 and 12 months, patient satisfaction, severe systemic therapy-related adverse events, survival) will be presented at the meeting. Conclusions: CGA coordinated by a geriatric team combined with extensive patient coaching improves QoL GHS in older patients with cancer compared to CGA coordinated by an oncology team. Clinical trial information: NCT04069962.