Intercontinental comparison of women with breast cancer treated by oncologists in Europe, Asia, and Latin America: a retrospective study of 99,571 patients.

Purpose: The aim of the study was to evaluate the baseline data of women with breast cancer (BC) undergoing treatment in an intercontinental comparison.

Methods: This study included 99,571 women with BC from Europe (70,834), Asia (18,208), and Latin America (10,529) enrolled between 2017 and 2021, based on data from IQVIA's Oncology Dynamics database. This source is supplied with information by means of a cross-sectional partially retrospective survey collecting anonymized data on inpatients and outpatients treated by a representative panel of oncologists. A multivariable logistic regression model was used to investigate the probability of metastases.

Results: The data available in Asia (98%) and Latin America (100%) were hospital data, while in Europe, patients were treated both in hospitals and in office-based practices (62%, 38%). The mean age in Asia and Latin America (57 ± 13) was lower than in Europe (61 ± 13; p < 0.001). Lobular BC was diagnosed twice as often in Europe compared to Asia and Latin America (15.2%, 9.8%, 8.0%). The number of patients with metastasized hormone receptor-positive (HR +) BC was significantly higher in Europe and Latin America than in Asia (76%, 68%; p < 0.001). The highest number of women with metastasized BC was reported in Europe (26% compared to 14% and 20%, respectively, in Asia and Latin America). Across the continents, the percentage of women with BC who experienced metastases was 51-61% for bone, 30-39% for lung and 25-32% for liver, followed by 3-6% for skin and 3% for brain.

Conclusion: Women with BC treated in Europe tend to be significantly older and more likely to develop metastases than women in Asia and Latin America, except for lung metastases.