Adherence to a breast cancer screening program and its predictors in underserved women in southern Brazil.

BACKGROUND: Adherence to breast cancer screening is a key element to ensure effectiveness of programs aiming at downstaging of breast cancer. In this study, we evaluated adherence to a screening program and its predictors in underserved women in southern Brazil. METHODS: Attendance to the program, which is based on yearly mammogram and clinical examination, was evaluated prospectively. Mean time frames between visits were calculated. Possible predictors of adherence (defined as mean intervals ≤18 mo), such as socioeconomic indicators and health/lifestyle behaviors, were investigated. RESULTS: A total of 3,749 women (age 51 ± 8 y, illiteracy rate of 6.8%, 57.4% with parity ≥3) were analyzed. Median time between screening rounds was 16.5 months (interquartile range, 13.1-25.7), and median number of rounds attended was 3 (interquartile range, 2-4); 57.6% had mean intervals ≤18, and 71% ≤24 months. The most important independent predictors of adherence were high genetic risk [relative risk (RR), 1.25; 95% confidence interval (95% CI), 1.11-1.40], illiteracy (RR, 0.77; 95% CI, 0.67-0.90), parity ≥5 (RR, 0.89; 95% CI, 0.83-0.96), and smoking (RR, 0.82; 95% CI, 0.77-0.88). CONCLUSIONS: Although the proposed screening interval was 1 year, compliance to biannual screening (accepted in several international programs) was high, especially when considering the low socioeconomic level of the sample. IMPACT: This project aims to test a breast cancer screening model for underserved populations in limited-resource countries where adherence is an issue. The identification of worst adherence predictors can point to interventions to improve outcomes of similar public health screening strategies.

A model to optimize public health care and downstage breast cancer in limited-resource populations in southern Brazil. (Porto Alegre Breast Health Intervention Cohort).

BACKGROUND: Breast cancer (BC) is a major public health problem, with rising incidence in many regions of the globe. Although mortality has recently dropped in developed countries, death rates are still increasing in some developing countries, as seen in Brazil. Among the reasons for this phenomenon are the lack of structured screening programs, a long waiting period between diagnosis and treatment, and lack of access to health services for a large proportion of the Brazilian population. METHODS AND DESIGN: Since 2004, an intervention study in a cohort of women in Southern Brazil, denominated Porto Alegre Breast Health Intervention Cohort, is being conducted in order to test the effectiveness and cost-effectiveness of a model for BC early detection and treatment. In this study, over 4,000 women from underserved communities aged 40 to 69 years are being screened annually with mammography and clinical breast examination performed by a multidisciplinary team, which also involves nutritional counseling and genetic cancer risk assessment. Risk factors for BC development are also being evaluated. Active search of participants by lay community health workers is one of the major features of our program. The accrual of new participants was concluded in 2006 and the study will last for 10 years. The main goal of the study is to demonstrate significant downstaging of BC in an underserved population through proper screening, attaining a higher rate of early-stage BC diagnoses than usually seen in women diagnosed in the Brazilian Public Health System. Preliminary results show a very high BC incidence in this population (117 cases per 100,000 women per year), despite a low prevalence of classical risk factors. DISCUSSION: This study will allow us to test a model of BC early diagnosis and treatment and evaluate its cost-effectiveness in a developing country where the mortality associated with this disease is very high. Also, it might contribute to the evaluation of risk factors in a population with a different ethnic background from that studied in developed countries. If our model is proven effective, it may be replicated in other parts of the globe where BC is also a major public health problem.