Comparison of pathological characteristics between self-detected and screen-detected invasive breast cancers in Chinese women: a retrospective study

Abstract

Background In China, there is insufficient evidence to support that screening programs can detect breast cancer earlier and improve outcomes compared with patient self-reporting. Therefore, we compared the pathological characteristics at diagnosis between self-detected and screen-detected cases of invasive breast cancer at our institution and determined whether these characteristics were different after the program’s introduction (vs. prior to). Methods Three databases were selected (breast cancer diagnosed in 1995–2000, 2010, and 2015), which provided a total of 3,014 female patients with invasive breast cancer. The cases were divided into self-detected and screen-detected groups. The pathological characteristics were compared between the two groups and multiple imputation and complete randomized imputation were used to deal with missing data. Results Compared with patient self-reporting, screening was associated with the following factors: a higher percentage of stage T1 tumors (75.0% vs 17.1%, P = 0.109 in 1995–2000; 66.7% vs 40.4%, P < 0.001 in 2010; 67.8% vs 35.7%, P < 0.001 in 2015); a higher percentage of tumors with stage N0 lymph node status (67.3% vs. 48.4%, P = 0.007 in 2010); and a higher percentage of histologic grade I tumors (22.9% vs 13.9%, P = 0.017 in 2010). Conclusion Screen-detected breast cancer was associated with a greater number of favorable pathological characteristics. However, although screening had a beneficial role in early detection in China, we found fewer patients were detected by screening in this study compared with those in Western and Asian developed countries.