Psychometric Properties of the Breast Cancer Awareness Measure (Breast-CAM): A Systematic Review and Meta-Analysis

<b>Background/Objectives</b>: Breast cancer awareness is essential for early detection and timely help-seeking among women and represents a key component of multidisciplinary breast cancer prevention. The Breast Cancer Awareness Measure (Breast-CAM) is widely used to assess awareness of breast cancer symptoms, risk factors, and screening behaviors. Its measurement quality across populations has not yet been comprehensively evaluated. As Breast-CAM is a population-reported measurement instrument, evaluation using a standardized framework for measurement properties is required. This systematic review and meta-analysis aimed to assess the psychometric properties of the Breast-CAM across diverse populations and cultural adaptations, in accordance with COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) methodological standards. <b>Methods:</b> Major bibliographic databases and trial registries were systematically searched for peer-reviewed English-language studies published between 2010 and 2025 that evaluated at least one psychometric property of the Breast-CAM in adult women. Methodological quality was assessed using the COSMIN Risk of Bias checklist. Measurement properties were evaluated according to COSMIN criteria, and the certainty of evidence was graded using a modified GRADE approach. Meta-analysis was performed when data were sufficiently comparable. <b>Results:</b> Seventeen studies met the inclusion criteria for narrative synthesis, of which eleven were included in a meta-analysis, representing fourteen cultural adaptations of the instrument. A descriptive random-effects meta-analysis of reported Cronbach's α yielded a pooled estimate of 0.89 (95% confidence interval 0.85-0.92). This value should be interpreted cautiously, as structural validity was frequently insufficient across cultural adaptations, limiting interpretation of internal consistency according to COSMIN guidance. Other measurement properties, including reliability and measurement error, were frequently inadequately assessed or unreported. The certainty of evidence ranged from very low to moderate. <b>Conclusions</b>: Content validity was generally rated as sufficient, although certainty of evidence was low. Despite the high pooled α estimate, the reliability of Breast-CAM cannot be firmly established because structural validity was frequently insufficient across cultural adaptations. In accordance with the COSMIN ceiling rule, internal consistency was not considered sufficient in the absence of adequate structural validity. Key measurement properties, including test-retest reliability, measurement error, and responsiveness, were rarely evaluated. Further high-quality psychometric studies, particularly in culturally diverse populations, are needed to address these gaps and support appropriate use of the instrument in research and public health practice.