Abstract Introduction A minority of women with breast cancer in Mexico are diagnosed through a screening program with a low rate of national coverage of about 20%, which translates into late diagnosis and worse outcomes. The detection of high-risk groups through easy-access interventions is essential to increase the screening rate. OBJECTIVE To identify and analyze patients at high risk of breast cancer, through a web app specially designed for this purpose. MATERIAL AND METHODS The web app stratified respondents according to breast cancer risk into 4 categories: very high risk (symptomatic), high lifetime risk, average risk (usual screening recommendations), or low risk. The app was programmed to guide patients to a risk-based information page or urge them to seek medical advice if indicated (https://cuccuanl.com/tamiz_mama/). The web app also provided the contact information of our center, or an appointment could also be scheduled within the app. Distribution was made via social media. An upgrade of the app was launched, which expanded the functionality with the inclusion of the Gail model to identify women with a high lifetime risk for developing breast cancer and the option for a simple interpretation of mammographic results. In version 2.0, the patients were divided into 2 populations, the first one which already had a breast imaging test but wished to know what the BIRADS score obtained meant and the other group were those who answered a simple survey similar to the one available on version 1.0, with added questions to calculate the Gail model risk. RESULTS The web app was originally released in October 2021 with a total number of 1,012 women answering the survey. The update was released in June 2022 with 406 new subjects. 281 patients wished for a risk calculation with no prior breast imaging tests and 124 patients already had a breast image diagnosis test that wanted a simple interpretation. Table1 depicts the answers given between both versions. Among the group of patients that had a mammography but had doubts about the result 12.9% (n=16) reported a BIRADS 0, 12.1% (n=15) BIRADS 1, 46% (n=57) BIRADS 2, 14.5% (n=18) BIRADS 3, and 14.4% (n=18) BIRADS 4 or 5. To date 41 patients have booked an appointment at the cancer prevention clinic directly within the webapp for further evaluation. DISCUSSION AND CONCLUSION The changes in the criteria of high risk did not translate into changes in the proportion of patients considered at high lifetime risk of breast cancer, but these changes made might be more specific for subsequent screening and chemoprevention strategies. The app persisted with a high proportion of symptomatic patients. The results of integration of the simple mammography interpretation were surprising, with a high proportion of subjects with indication for a biopsy founded. In the Mexican population there is a significant gap between the screening mammography and the first consultation with a specialist, averaging 113 days from an abnormal screening test to a diagnosis of breast cancer (1), which delays treatment initiation resulting on a worst outcome. These kinds of apps may empower patients to seek earlier consultation if warranted or educate patients on their personal risk for developing cancer so they may have a closer adherence to early detection programs. These results and subsequent updates might help evolve the app into something more akin to a digital navigator for patients. Bibliography 1)Unger-Saldaña K, Cedano Guadiamos M. Delays to diagnosis and barriers to care for breast cancer in Mexico and Peru: a cross sectional study. The Lancet Global Health. 2020 Apr 1;8:S16. Table 1 Results stratified by risk groups between version 1.0 and 2.0 Citation Format: Jose F. Muñoz Lozano, Omar Zayas Villanueva, Estefania Abundis Marquez, Fernando Alcorta Nuñez, Maria Fernanda Noriega, Carlos Salazar Mejia, Celia B. Gonzalez Alcorta, Diana Cristina Pérez Ibave, Victor Oyervides Juarez, Larisa M. Renteria Garcia, Adelina Alcorta Garza, Juan Francisco Gonzalez Guerrero, David Hernandez, Rafael Piñeiro Retif, Oscar Vidal Gutiérrez. Analysis of an update to a novel breast cancer screening web-app [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-04-09.