10-year opportunistic mammographic screening scenario in Brazil and its impact on breast cancer early detection: a nationwide population-based study

Abstract

Background Mammographic screening has been used to reduce breast cancer mortality worldwide and remains the main modality for the early detection of this disease. Women from low- and middle-income countries still lack access to periodic mammograms and efficient health care. This cross-sectional study aimed to explore opportunistic mammographic coverage in Brazil, while considering the privately insured population and its association with early breast cancer (EBC) detection. Methods Data on population, gross domestic product (GDP), number of mammograms performed under the Sistema Único de Saúde (SUS) public health system or private system, and women diagnosed with early-stage breast cancer from 2010 to 2019 were retrieved from publicly available databases. Results A total of 39 555 636 mammograms with an average of 3 955 564 ± 395 704 mammograms were obtained per year from 2010 to 2019 in Brazil. Most examinations (58.6%) were performed in the target population (50-69 years old), while 32% were performed in women aged 40-49, and 9.4% were performed in women <40 years or >70 years of age. The 10-year mammogram coverage was 30.6% in the target population and 24.8% in the population aged 40-49 years, with significant variation across states and municipalities. The overall EBC detection rates in Brazil were 30.6% in populations aged 50-70 and 24.8% in those aged 40-50 years. We observed a positive correlation between coverage and EBC detection rate (r = 0.68; P = 0.0001 (50-70 years) and r = 0.75; P < 0.0001 (40-50 years)). According to the GDP, the municipalities with higher GDP per capita had higher mammogram coverage ( P < 0.0001). Conclusions The coverage of mammographic screening for women under the SUS is far below the international guidelines. Additionally, a significant number of mammograms have been performed in non-target populations. This scenario reflects the problematic screening programs in developing countries and reflects low rates of EBC diagnosis. As Brazil is a continental country with heterogeneous socioeconomic indicators, we observed significant variations in the number of mammograms performed by age groups when separated by states and municipalities. Even when considering supplemental health system coverage, municipalities with higher GDP per capita were associated with higher mammogram coverage.

Differences in breast cancer survival and stage by age in off-target screening groups: a population-based retrospective study

“…A recent study from Brazil found a nationwide prevalence of stage 0 (in situ) or stage I breast cancer of 31% among women aged 50 to 70 years and a prevalence of 36% in the state of São Paulo. 12 In our study based in Campinas, a municipality of the state of São Paulo, tumors staged 0 (in situ) or I accounted for 40% of women aged 50 to 59 years and 44% of women aged 60 to 69 years. There are 2 possible explanations for this higher prevalence.…”

“…Stage was registered according to the American Joint Committee on Cancer. 12 The study's end for censorship was March 31, 2020, which was the first month of the isolation period in Brazil because of the COVID-19 pandemic. The MIS in Campinas is very accurate and gets updated periodically with the MIS of surrounding cities, a well-established linkage in the region.…”

Breast Cancer Screening in Latin America: The Challenge to Move from Opportunistic to Organized-Systematic Screening

“…Organized screening programs can contribute to improved coverage, reduced mortality, and reduced health disparities 11,14,22 . Latin American selected countries in this study do not comply with the key performance indicators defined for organized screening programs.…”

“…Peisl S et al (2019) compared a group of 989 women in Switzerland that received opportunistic or organized screening and observed that women in the organized program presented more frequently with in situ rather than invasive cancer and were less likely to undergo radiation therapy 11 . On the other hand, the existence of an opportunistic screening program in Brazil for the last 10 years has maintained screening rates at about 30% with significantly lower rates and early-stage diagnosis in underserved populations 22 .…”

Breast and gynecologic cancers as a Brazilian health priority

“…However, in Brazil, mammographic screening has been an opportunistic procedure. Despite educational campaigns, mammography coverage is currently around 35% of the target population, well below the 70% recommended worldwide 15 .…”