Background: Several studies from other countries have reported that patients with screen-detected breast cancer have better survival than those with symptomatic breast cancer. However, no such comparison has been performed in Japan. Therefore, we aimed to compare the clinicopathological characteristics and survival rates between symptomatic and screen-detected breast cancer in Japanese women.
Methods: From January 2000 to December 2004, 977 and 182 women with symptomatic or screen-detected breast cancer, respectively, underwent surgery at a single Japanese hospital. We retrospectively reviewed these patients' clinicopathological data. Likelihood of death was estimated using the Kaplan-Meier method and the log-rank test. Multivariate analysis including mode of detection, tumor size, lymph node status, hormone receptor status, and adjuvant therapy administration was performed using the Cox proportional hazards model.
Results: Screen-detected breast cancer was associated with increased rate of breast-conserving surgery, non-invasive carcinoma, smaller tumor size, decreased lymph node involvement, increased hormone receptor positivity, and decreased adjuvant chemotherapy administration. Compared to women with symptomatic tumors, those with screen-detected tumors had improved overall and breast cancer-specific survival rates. Factors associated with survival in univariate analysis were screen detection, tumor size, lymph node status, progesterone receptor status, and adjuvant chemotherapy administration.
Conclusions: Breast cancer screening in Japanese women has led to increases in the rates of breast-conserving surgery, hormone receptor positivity, and survival rates along with reductions in axillary lymph node dissection and adjuvant chemotherapy administration.
Keywords: Breast cancer; Clinicopathological characteristics; Mode of detection; Screening; Survival.