This systematic review and meta-analysis examines the psychological outcomes of patients with rare cancers, defined as cancers with an incidence of less than six per 100,000 per year. The study, conducted by researchers from the National University of Singapore, National Cancer Centre Singapore, and other institutions, aimed to determine the prevalence, incidence, and risk of depression, anxiety, suicide, and post-traumatic stress disorder (PTSD) in these patients. The review included 32 studies with a total of 57,470 patients with rare cancers. Key findings include: - A statistically significant increased risk of depression (RR = 2.61, 95% CI: 1.43–4.77) and anxiety (RR = 2.66, 95% CI: 1.27–5.55) compared to healthy controls. - A high incidence of suicide (315 per 100,000 person-years) and prevalence of depression (17%), anxiety (20%), and PTSD (18%). - Advanced disease stage, chemotherapy treatment, lower income, and social status were identified as significant risk factors for negative psychological outcomes. The study highlights the need for early identification and intervention for psychological maladjustment in patients with rare cancers, emphasizing the importance of comprehensive care strategies to address the unique challenges they face.This systematic review and meta-analysis examines the psychological outcomes of patients with rare cancers, defined as cancers with an incidence of less than six per 100,000 per year. The study, conducted by researchers from the National University of Singapore, National Cancer Centre Singapore, and other institutions, aimed to determine the prevalence, incidence, and risk of depression, anxiety, suicide, and post-traumatic stress disorder (PTSD) in these patients. The review included 32 studies with a total of 57,470 patients with rare cancers. Key findings include: - A statistically significant increased risk of depression (RR = 2.61, 95% CI: 1.43–4.77) and anxiety (RR = 2.66, 95% CI: 1.27–5.55) compared to healthy controls. - A high incidence of suicide (315 per 100,000 person-years) and prevalence of depression (17%), anxiety (20%), and PTSD (18%). - Advanced disease stage, chemotherapy treatment, lower income, and social status were identified as significant risk factors for negative psychological outcomes. The study highlights the need for early identification and intervention for psychological maladjustment in patients with rare cancers, emphasizing the importance of comprehensive care strategies to address the unique challenges they face.