There has been considerable evidence recently demonstrating the anti-tumour effects of flavonols. Quercetin, an ubiquitous bioactive flavonol, inhibits cells proliferation, induces cell cycle arrest and apoptosis in different cancer cell types. The precise molecular mechanism of quercetin-induced apoptosis in human breast cancer cells is unclear. The purpose of this study was to investigate effects of quercetin on cell viability and to determine its underlying mechanism in human breast cancer MDA-MB-231 cells. Quercetin decreased the percentage of viable cells in a dose- and time-dependent manner, which was associated with cell cycle arrest and apoptosis. Quercetin did not increase reactive oxygen species generation but increased cytosolic Ca2+ levels and reduced the mitochondrial membrane potential (ΔΨm). Quercetin treatment promoted activation of caspase-3, -8 and -9 in MDA-MB-231 cells. Caspase inhibitors prevented the quercetin-induced loss of cell viability. Quercetin increased abundance of the pro-apoptotic protein Bax and decreased the levels of anti-apoptotic protein Bcl-2. Confocal laser microscope examination indicated that quercetin promoted apoptosis-inducing factor (AIF) release from mitochondria and stimulated translocation to the nucleus. Taken together, these findings suggest that quercetin results in human breast cancer MDA-MB-231 cell death through mitochondrial- and caspase-3-dependent pathways.

BackgroundCurrently, there is a debate as to whether triple negative breast carcinoma (TNBC) has a worse prognosis than non-TNBC. Our aim was to determine whether TNBC is a prognostic factor for survival.MethodsWe identified 1,048 Taiwanese breast carcinoma patients, of whom 167 (15.9%) had TNBC. Data used for analysis were derived from our cancer registry database for women with breast cancer who were diagnosed between 2002 January and 2006 December.ResultsIn the Kaplan-Meier analysis, tumor subgroup (TNBC vs. non-TNBC) was a prognosis factor related to 5-year overall survival. In the univariate analysis, tumor subgroup (TNBC vs. non-TNBC) was a significant factor related to 5-year overall survival, in addition to age, tumor size, lymph node, metastasis, grade, stage, estrogen receptor status, progesterone receptor status, and HER2 overexpression status. In the multivariate analysis, tumor subgroup was not a significant factor related to 5-year disease-free survival (DFS). In node-positive patients, tumor subgroup was a significant factor related to 5-year overall survival, in addition to age, tumor size, metastasis, and grade. In node-negative patients, tumor subgroup was not a significant factor related to 5-year disease-free survival and 5-year overall survival.ConclusionOur results indicated that TNBC patients in Taiwan have worse 5-year overall survival than non-TNBC patients. Notably, in node-positive patients, TNBC played a prognostic role in 5-year overall survival.

Tumor size is an independent prognostic factor in resected small HCC and the prognostic significance of tumor size may vary according to different cut-off points.

Objective: This study aimed to investigate whether triple-negative breast cancer has a worse prognosis; here, we present the 10-year follow-up results of triple-negative breast cancer patients in Taiwan. Methods: We identified 2858 breast cancer patients in Taiwan, of whom 416 (14.6%) had triple-negative breast cancer. Data used for analysis were derived from those breast cancer patients who were diagnosed between January 1996 and December 2006. Results: In the Kaplan -Meier analysis, tumor subgroup (triple-negative breast cancer vs. non-triple-negative breast cancer) was a prognostic factor related to 10-year breast cancer death-specific survival and disease-free survival. The results of univariate analysis showed that tumor subgroup was a significant factor related to 10-year disease-free survival and breast cancer death-specific survival, as well as menopausal status, tumor size, lymph node, metastasis, grade, stage, estrogen receptor status, progesterone receptor status and her2/ neu gene expression status. Similarly, the multivariate analysis also revealed that tumor subgroup was a significant factor related to 10-year breast cancer death-specific survival and disease-free survival, in addition to tumor size, lymph node, metastasis and grade. Conclusions: It was suggested that triple-negative breast cancer patients in Taiwan have worse 10-year survival. Notably, in node-positive patients, triple-negative breast cancer played a prognostic role in 10-year breast cancer death-specific survival.