Toxicity profile differences of adjuvant docetaxel/cyclophosphamide (TC) between Asian and Caucasian breast cancer patients.

AIM: For early-stage breast cancer, four cycles of docetaxel and cyclophosphamide (TC) was proven superior to doxorubicin plus cyclophosphamide in the US Oncology 9375 trial. Given primary prophylactic antibiotics, 5% febrile neutropenia was recorded in a population comprising 75.5% Caucasians. Smaller trials and retrospective studies reviewing TC use in Asian patients did not produce similar incidence rates. This study aims to discover the variable hematological toxicities with TC use in Caucasian and Asian patients. METHODS: Breast cancer data was retrospectively reviewed for patients receiving adjuvant docetaxel 60-75 mg/m2 plus cyclophosphamide 600 mg/m2 from six countries (China, Hong Kong, Japan, Taiwan, Italy, and United States). Similar number of patients with relatively balanced baseline characteristics were chosen for analysis of hematological and nonhematological toxicities and survival data. RESULTS: From March 2004 to July 2013, data of 227 patients (127 Asians and 100 Caucasian) patients were analyzed for treatment-related toxicities. During the four cycles of TC, Asians had a significantly higher rate of grade ≥2 neutropenia than Caucasians (45.7% vs 6.0%; P <0.001) and significantly more grade ≥3 neutropenia events were documented (respectively 30.7% vs 4.0%, P <0.001). The prophylactic use of G-CSF was similar; 26.0% in Asians and 28.0% in Caucasian (P = 0.764). There were no differences in nonhematological toxicities. No significant difference in disease-free survival was observed between Asians and Caucasians (log-rank P = 0.910). CONCLUSIONS: Ethnic differences in toxicity profile exist between Asian and Caucasian patients given adjuvant TC. Over 30% Asians but less than 5% Caucasians experienced grade ≥3 neutropenia.

The future perspectives of breast cancer therapy.

Adjuvant therapy after surgery for breast cancer has provided significant benefits to patients at risk of relapse. However, the success of therapy for each individual patient will often take years to reveal. Preoperative therapy has brought about significant advances in the treatment of breast cancer. More breast conservation therapy can be performed and it becomes clear that pathologic complete response (pCR) is a good prognostic marker. Moreover, patients can be segregated into different clinical phenotypes after preoperative therapy: the responder non-recurrent, the responder recurrent, the non-responder non-recurrent and the non-responder recurrent. While conventional therapy and surgery is adequate for the responder non-recurrent and the non-responder non-recurrent cases, modification of conventional therapy, the adoption of a new approach or the incorporation of novel therapeutics may be necessary to improve the pCR and reduce recurrence for the later two groups of patients. Preoperative therapy has also made possible the development of biomarkers to predict response and resistance to treatment. With this translational approach, the therapy for each patient can be more targeted and individualized. A higher rate of success is expected.

A new predictive and prognostic marker (ATP bioluminescence and positron emission tomography) in vivo and in vitro for delivering adjuvant treatment plan to invasive breast tumor patients.

The cell proliferation rate has been used to assess the biological aggressiveness and the metastatic potential of breast carcinoma. Different methods (flow cytometric S phase and proliferation associated antigens) have been used to assess the rate of proliferation previously. In this preliminary study, the cell proliferation rate of normal (N=45), benign (N=29) and invasive breast tumor tissue (N=70) has been quantified in vitro by ATP bioluminescence assay. Next, individual prognostic factor (tumor grades, lymph node involvement, estrogen and progesterone receptor and HER-2 status) has been correlated with the level of metabolic rate (ATP). The results showed that invasive tumor had the highest level of ATP bioluminescence compared with that of benign tumor (mean difference=1.97) and the normal breast tissue (mean difference=2.75). In addition, ATP level positively correlated with the number of axillary lymph node involvement (r(spearman)=0.433, P=0.021). These findings suggested that the measurement of ATP level may serve as a mean for the detection of cell proliferation and hence a surrogate marker for disease prognosis.

Aberrant methylation of cyclooxygenase-2 in breast cancer patients.

BACKGROUND: Although aberrant CpG island methylation and subsequent silencing of the cyclooxygenase-2 (COX-2) promoter has been observed in colorectal and gastric tumors recently, little is known about that in breast cancers. The aim of this study was to identify the methylation status of COX-2 as well as to determine the association between clinical characteristics and COX-2 methylation in breast cancer patients. METHODS: Using bisulfite modification and a methylation-specific PCR, we examined the methylation status of the COX-2 promoter in primary tumors from 110 breast cancer patients. Meanwhile, the expression of COX-2 protein was determined by immunohistochemistry (IHC). RESULTS: Twenty out of 110 (18.2%) primary breast cancers showed aberrant methylation of the 5' region of COX-2. Loss of expression of COX-2 protein was found in all tumors with COX-2 methylation. Methylation of COX-2 was strongly correlated with tumor size (P = 0.026), presence of axillary lymph node metastasis (P = 0.001) and lymphovascular permeation (P = 0.034). CONCLUSION: Our data suggest that COX-2 methylation is associated with good prognostic factors in breast cancer patients. COX-2 promoter methylation may be one of the mechanisms by which tumor cells regulate COX-2 expression.

Current directions for COX-2 inhibition in breast cancer.

Chemotherapy is effective against breast cancer. COX-2 has been implicated in the progression and angiogenesis of cancers. Celecoxib, a cyclooxygenase type 2 (COX-2) inhibitor, has both apoptotic and antiangiogenic activities, and may be of use in treatment of breast tumors which overexpress the COX-2 enzyme. Preliminary clinical trials have shown that the combination of chemotherapy with celecoxib has minimal additional toxicity and it may enhance the effects of the chemotherapy. Beside chemotherapy, celecoxib may promulgate the effect of aromatase inhibitor in breast cancer cells. Animal studies have shown that there are fewer and smaller tumors treated by combining exemestane and celecoxib. Larger clinical trials should be initiated to study the potential anti-cancer effects of celecoxib in breast cancer.

Study of COX-2, Ki67, and p53 expression to predict effectiveness of 5-flurouracil, epirubicin and cyclophosphamide with celecoxib treatment in breast cancer patients.

BACKGROUND: Cyclooxygenase-2 (COX-2) affects cell proliferation, apoptosis, and metastasis of breast cancer, and may also be involved in tumor angiogenesis through vascular endothelial growth factor. Ki67 and p53 are common markers of proliferation and apoptosis in tumor cells. This study investigated the change in expression of COX-2, Ki67, and p53 in solid tumors after the administration of chemotherapeutic drugs. MATERIALS AND METHODS: Fifty patients were eligible to be treated with preoperative 5-fluorouracil, epirubicin, and cyclophosphamide, with celecoxib (FECC). Tumor tissue samples from 10 patients who, diagnosed with invasive ductal carcinoma, completed chemotherapy were examined immunohistochemically for COX-2, Ki67, and p53. RESULTS: From the 60% of patients who expressed COX-2 and 90% who expressed Ki67 and p53 before treatment, 90% of patients revealed a lower intensity staining for each marker after FECC treatment. However, changes in expression of the three markers did not significantly correlate with tumor size, grade, axillary lymph node status. Immunostained slides clearly showed that the diaminobenzidine intensity was markedly reduced after the three-cycle FECC treatment, which implied the combined regimens be effective to the cancer patients. CONCLUSIONS: This study demonstrates a novel relationship between COX-2, Ki67, and p53 expression of human breast invasive ductal carcinomas. This functional relationship provides support for a potential therapeutic role of COX-2 inhibitors in human breast cancer.

The efficacy of Paclitaxel on solid tumour analysed by ATP bioluminescence assay and VEGF expression: a translational research study.

BACKGROUND: Paclitaxel (Taxol), is known to induce mitotic arrest and apoptosis by inhibiting the depolymerisation of microtubules. Tumour growth and metastasis are affected by the metabolic rate and angiogenesis. We investigated the effect of Paclitaxel on tumour metabolism and markers of angiogenesis, vascular endothelial growth factor (VEGF). MATERIALS AND METHODS: Tissue samples of 39 patients diagnosed with invasive carcinoma were obtained. The solid tumours were cultured with Paclitaxel at a concentration of 4.27 ug/ml for 24 h. The metabolic rate of the samples was measured by ATP Bioluminescence assay and the levels of VEGF in culture medium were measured by ELISA. RESULT: The mean ATP concentration of control and test groups were 7.169 and 5.004 rlu/ml, respectively, suggesting that the metabolic rate was inhibited by Paclitaxel. The mean VEGF levels in the control and test groups were 5.335 and 4.567 pg/ml, respectively. All data analysed were statistically significant (P < 0.005). The finding of the study showed that Paclitaxel could inhibit metabolic rate in solid tumour. It could also downregulate VEGF. CONCLUSION: Our result suggested that Paclitaxel is an effective cytotoxic possibly with anti-angiogenic effects.

Circulating tumor cells in patients with breast cancer: possible predictor of micro-metastasis in bone marrow but not in sentinel lymph nodes.

BACKGROUND: Blood and lymphatic circulation are the major routes during metastatic spread of breast cancer cells. Despite the predictive and prognostic value of bone marrow (BM) micro-metastasis, repeated and frequent BM aspirations may not be easily accepted by patients. We try to establish the role of circulating tumor cells as a predictor for micro-metastasis in BM and sentinel lymph node (SLN) as well as to identify the association between micro-metastasis in blood and lymphatic circulation. We prospectively studied 47 breast cancer patients without overt metastasis. Bilateral BM samples and blood samples were obtained before surgery and subsequently handled using magnetic-activated cell separation (MACS) followed by immunocytochemistry (ICC). SLN was examined by hematoxylin and eosin (H and E) staining and ICC. RESULTS: Blood and BM micro-metastasis were detected in 16 (35%) and 25 (54%) of 47 patients. SLN micro-metastasis were detected in 13 (27.7%) and 22 (46.8%) patients using H and E and ICC, respectively. All the patients with circulating tumor cells had micro-metastasis in BM, whereas 9 of 25 (36%) patients with micro-metastasis in BM had no circulating tumor cells (P < 0.001). On the other hand, there is no correlation between circulating tumor cells and micro-metastasis in SLNs detected by either H and E (P = 0.52) or ICC (P = 0.36). We found that the presence of circulating tumor cells might predict BM micro-metastasis but not SLN micro-metastasis. It is also interesting to find that the presence of SLN micro-metastasis does not necessarily correlate with the presence of micro-metastasis in BM and blood.

DNA hypermethylation of TIMP3 gene in invasive breast ductal carcinoma.

BACKGROUND: Neoplastic cells often display aberrant methylation and silencing of multiple genes, including tumor suppressor genes (TSGs) that regulate critical processes such as cell cycle control, DNA repair and angiogenesis. Tissue inhibitor of metalloproteinase-3 (TIMP3) is an extracellular matrix-bound protein which regulates matrix composition and affects tumor growth, invasion and angiogenesis. It mediates vascular endothelial growth factor (VEGF) by blocking the binding of VEGF to VEGF receptor-2 and inhibits downstream signaling. This study focused on the hypermethylation status of the TIMP3 gene with clinical parameters in invasive breast ductal carcinoma (IDC) samples. MATERIALS AND METHODS: DNA extraction and methylation specific PCR (MSP) was performed on 173 patients with invasive breast carcinoma. Both specific methylated and unmethylated primers for each gene were used for PCR and the products were visualized on agarose gel. The methylation status of TIMP3 was then compared with corresponding patients' clinicopathologic characteristics. RESULTS: Methylation frequencies of TIMP3 in the breast cancer samples were 20.81 %. Among the hypermethylated cancers, 50% were tumor grade II-III, 44.44% were positive in lymph node involvement (LN), 36.11% were positive in lymphovascular permeation (LVP); 44.44%, 22.22% and 47.22% for the overexpressions in estrogen receptor (ER), progesterone receptor(PR) and c-erbB2, respectively. CONCLUSION: The result demonstrated that hypermethylation of TIMP3 in IDC might be associated with high tumor grading and lymph nodes metastasis, and overexpression of ER, PR and c-erbB2, respectively.

The value of bone marrow aspirates culture for the detection of bone marrow micrometastasis in breast cancer.

BACKGROUND: Detection of micrometastasis is an important problem of clinical significance for a better understanding and control of tumor progression, which will improve patients' survival time. Tumor cells in bone marrow (BM) aspirates are indicative of the general disseminative metastasis in patients with early breast cancer and characterization of breast cancers by various tumor markers which are appropriate for the identification of high risk groups. MATERIALS AND METHODS: Bone marrow aspirates were obtained from 44 breast cancer patients at the time of surgery. To identify micrometastases in bone marrow, an immunocytochemical assay for epithelial cytokeratin (CK) was performed at the second passage after selective culture. Cytokeratin-positive bone marrow disseminated cancer cells were observed in more than 90% of the patients. This high incidence needs further investigation with bigger sample size to confirm. However, these results indicate that this technique can be used as an early diagnostic technique of bone marrow micrometastases in the patient with breast cancer thereby promoting the development of therapeutic strategy. High incidences need further investigation with bigger samples to confirm.