Over 60% of cancers occur in older persons, and the number of older cancer patients is expected to grow as the population ages. Older cancer patients are at increased risk of treatment complications, and there is no standard approach for reducing chemotherapy toxicity. Several studies, including a Cancer and Aging Research Group (CARG) study in 500 patients, have demonstrated that 50% of older patients have severe toxicity from chemotherapy within 3 months of treatment initiation and that measures within a geriatric assessment (GA), a validated approach to assessing health status in older persons, can predict severe chemotherapy toxicities. Although geriatric assessment has great potential to improve adverse outcomes of older adults with cancer, the majority of oncologists have not adopted GA, largely because of lack of knowledge on how to best incorporate GA into clinical care. The overall hypothesis of this proposed research is that providing oncologists with information from geriatric assessment with and targeted interventions guided by GA for older patients can reduce the risk of chemotherapy toxicity. The principal investigator, a geriatric oncologist, and the research team assembled through CARG are well positioned to successfully complete this high-impact research. The study will be conducted in 2 phases. In Phase 1, patients aged 70 and over (n=240) with metastatic solid tumor malignancies who are planning to receive first-line chemotherapy at University of Rochester Community Clinical Oncology Program (CCOP) sites will be recruited over the course of 1 year. "Usual-care" practices including physician characteristics, prescribing patterns, patient and physician decision-making for chemotherapy initiation, and chemotherapy toxicity will be captured. In Phase 2, we will conduct a 2-armed cluster randomized study utilizing CCOP sites. Prior to chemotherapy initiation, patients aged 70 and over (n=688) with metastatic solid tumor malignancies will complete a GA. The oncologists at sites randomized to Arm 1 will receive a summary of GA results plus targeted interventions to consider for implementation. In Arm 2, oncologists will only receive information from GA regarding severe depression or cognitive impairment. The primary outcome will be a comparison of the proportion of patients who have severe chemotherapy toxicity at 3 months after chemotherapy initiation. Secondary outcomes will include comparisons of survival, the number of interventions implemented in both groups, and decision-making for chemotherapy. An exploratory aim will evaluate whether or not GA plus targeted interventions can slow functional and physical decline in older patients with advanced cancer. With regard to expected outcomes, this proposal will fill vital gaps in knowledge regarding whether GA can improve outcomes of older cancer patients and the mechanisms of how GA can improve quality of life (decisions, GA-driven interventions). These data will have a positive impact by providing a pragmatic mechanism for incorporating GA into routine clinical oncology care to improve outcomes of older adults with metastatic cancer.