Screen-detected breast cancer is associated with better prognosis and survival compared to self-detected/symptomatic cases in a Chilean cohort of female patients

Purpose The implementation of national breast cancer (BC) screening programs in Latin America has been rather inconsistent. Instead, most countries have opted for opportunistic mammogram screenings on the population at risk. Our study assessed and compared epidemiological, clinical factors, and survival rates associated with BC detected by screening (SDBC) or self-detected/symptomatic (non-SDBC) in Chilean female patients. Methods Registry-based cohort study that included non-metastatic BC (stage I/II/III) patients diagnosed between 1993 and 2020, from a public hospital (PH) and a private university cancer center (PC). Epidemiological and clinical data were obtained from medical records. Results A total of 4559 patients were included. Most patients (55%; n = 2507) came from PH and were diagnosed by signs/symptoms (non-SDBC; n = 3132, 68.6%); these patients displayed poorer overall (OS) and invasive disease-free survival (iDFS) compared to SDBC. Importantly, the proportion of stage I and luminal BC (HR + /HER2 -) were significantly higher in SDBC vs. non-SDBC. Finally, using a stage/subset-stratified age/insurance-adjusted model, we found that non-SDBC cases are at a higher risk of death (HR:1.75; p < 0.001). In contrast, patients with PC health insurance have a lower risk of death (HR: 0.60; p < 0.001). Conclusion We confirm previous studies that report better prognosis/survival on SDBC patients. This is probably due to a higher proportion of stage I and luminal-A cases versus non-SDBC. In turn, the survival benefit observed in patients with PC health insurance might be attributed to a larger proportion of SDBC. Our data support the implementation of a systematic BC screening program in Chile to improve patient prognosis and survival rates

Automated summary

The implementation of national breast cancer screening programs in Latin America is inconsistent, with most countries opting for opportunistic mammogram screenings. A study in Chile found that breast cancer patients detected by screening have better survival rates and prognosis, likely due to a higher proportion of early-stage and hormone receptor-positive cases. Implementing systematic breast cancer screening programs in Chile may improve patient outcomes and survival rates.