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.

Randomized trial of preoperative docetaxel with or without capecitabine after 4 cycles of 5-fluorouracil­ epirubicin­cyclophosphamide (FEC) in early-stage breast cancer: exploratory analyses identify Ki67 as a predictive biomarker for response to neoadjuvant chemotherapy.

This randomized, multicenter study compared the efficacy of docetaxel with or without capecitabine following fluorouracil/epirubicin/cyclophosphamide (FEC) therapy in operable breast cancer and investigated the role of Ki67 as a predictive biomarker. Patients were randomized to 4 cycles of docetaxel/capecitabine (docetaxel: 75 mg/m2 on day 1; capecitabine: 1,650 mg/m2 on days 1­14 every 3 weeks) or docetaxel alone (75 mg/m2 on day 1 every 3 weeks) after completion of 4 cycles of FEC (5-fluorouracil 500 mg/m2, epirubicin 100 mg/m2 and cyclophosphamide 500 mg/m2 on day 1 every 3 weeks). The primary endpoint was the pathological complete response (pCR) rate. Predictive factor analysis was conducted using clinicopathological markers, including hormone receptors and Ki67 labeling index (Ki67LI). A total of 477 patients were randomized; the overall response in the docetaxel/capecitabine and docetaxel groups was 88.3 and 87.4 %, respectively. There were no significant differences in the pCR rate (docetaxel/capecitabine: 23 %; docetaxel: 24 %; p = 0.748), disease-free survival, or overall survival. However, patients with mid-range Ki67LI (10­20 %) showed a trend towards improved pCR rate with docetaxel/capecitabine compared to docetaxel alone. Furthermore, multivariate logistic regression analysis showed pre-treatment Ki67LI (odds ratio 1.031; 95 % CI 1.014­1.048; p = 0.0004) to be a significant predictor of pCR in this neoadjuvant treatment setting. Docetaxel/capecitabine (after 4 cycles of FEC) did not generate significant improvement in pCR compared to docetaxel alone. However, exploratory analyses suggested that assessment of pre-treatment Ki67LI may be a useful tool in the identification of responders to preoperative docetaxel/capecitabine in early-stage breast cancer.

Combination neratinib (HKI-272) and paclitaxel therapy in patients with HER2-positive metastatic breast cancer.

INTRODUCTION: Neratinib is a potent irreversible pan-ErbB tyrosine kinase inhibitor that has demonstrated antitumour activity and an acceptable safety profile in patients with human epidermal growth factor receptor (HER)-2-positive breast cancer and other solid tumours. METHODS: This was a phase I/II, open-label, two-part study. Part 1 was a dose-escalation study to determine the maximum tolerated dose (MTD) of neratinib plus paclitaxel in patients with solid tumours. Part 2 evaluated the safety, efficacy, and pharmacokinetics of the combination at the MTD in patients with HER2-positive breast cancer. RESULTS: Eight patients were included in the dose-escalation study; no dose-limiting toxicities were observed, and an MTD of oral neratinib 240 mg once daily plus intravenous paclitaxel 80 mg m(-2) on days 1, 8, and 15 of each 28-day cycle was determined. A total of 102 patients with HER2-positive breast cancer were enrolled in part 2. The overall median treatment duration was 47.9 weeks (range: 0.1-147.3 weeks). Common treatment-emergent adverse events (all grades/grade ≥3) included diarrhoea (92%/29%; none grade 4), peripheral sensory neuropathy (51%/3%), neutropenia (50%/20%), alopecia (46%/0%), leukopenia (41%/18%), anaemia (37%/8%), and nausea (34%/1%). Three (3%) patients discontinued treatment due to an adverse event (mouth ulceration, left ventricular ejection fraction reduction, and acute renal failure). Among the 99 evaluable patients in part 2 of the study, the overall response rate (ORR) was 73% (95% confidence interval (CI): 62.9-81.2%), including 7 (7%) patients who achieved a complete response; an additional 9 (9%) patients achieved stable disease for at least 24 weeks. ORR was 71% among patients with 0/1 prior chemotherapy regimen for metastatic disease and no prior lapatinib, and 77% among those with 2/3 prior chemotherapy regimens for metastatic disease with prior lapatinib permitted. Kaplan-Meier median progression-free survival was 57.0 weeks (95% CI: 47.7-81.6 weeks). Pharmacokinetic analyses indicated no interaction between neratinib and paclitaxel. CONCLUSION: The combination of neratinib and paclitaxel was associated with higher toxicity than that of neratinib as a single agent, but was manageable with antidiarrhoeal agents and dose reductions in general. The combination therapy also demonstrated a high rate of response in patients with HER2-positive breast cancer. A phase III trial is ongoing to assess the benefit and risk of this combination in the first-line setting.

LMTK3 is implicated in endocrine resistance via multiple signaling pathways.

Resistance to endocrine therapy in breast cancer is common. With the aim of discovering new molecular targets for breast cancer therapy, we have recently identified LMTK3 as a regulator of the estrogen receptor-alpha (ERα) and wished to understand its role in endocrine resistance. We find that inhibition of LMTK3 in a xenograft tamoxifen (Tam)-resistant (BT474) breast cancer mouse model results in re-sensitization to Tam as demonstrated by a reduction in tumor volume. A whole genome microarray analysis, using a BT474 cell line, reveals genes significantly modulated (positively or negatively) after LMTK3 silencing, including some that are known to be implicated in Tam resistance, notably c-MYC, HSPB8 and SIAH2. We show that LMTK3 is able to increase the levels of HSPB8 at a transcriptional and translational level thereby protecting MCF7 cells from Tam-induced cell death, by reducing autophagy. Finally, high LMTK3 levels at baseline in tumors are predictive for endocrine resistance; therapy does not lead to alteration in levels, whereas in patient's plasma samples, acquired LMTK3 gene amplification (copy number variation) was associated with relapse while receiving Tam. In aggregate, these data support a role for LMTK3 in both innate (intrinsic) and acquired (adaptive) endocrine resistance in breast cancer.

Predictions of the pathological response to neoadjuvant chemotherapy in patients with primary breast cancer using a data mining technique.

Nomogram, a standard technique that utilizes multiple characteristics to predict efficacy of treatment and likelihood of a specific status of an individual patient, has been used for prediction of response to neoadjuvant chemotherapy (NAC) in breast cancer patients. The aim of this study was to develop a novel computational technique to predict the pathological complete response (pCR) to NAC in primary breast cancer patients. A mathematical model using alternating decision trees, an epigone of decision tree, was developed using 28 clinicopathological variables that were retrospectively collected from patients treated with NAC (n = 150), and validated using an independent dataset from a randomized controlled trial (n = 173). The model selected 15 variables to predict the pCR with yielding area under the receiver operating characteristics curve (AUC) values of 0.766 [95 % confidence interval (CI)], 0.671-0.861, P value < 0.0001) in cross-validation using training dataset and 0.787 (95 % CI 0.716-0.858, P value < 0.0001) in the validation dataset. Among three subtypes of breast cancer, the luminal subgroup showed the best discrimination (AUC = 0.779, 95 % CI 0.641-0.917, P value = 0.0059). The developed model (AUC = 0.805, 95 % CI 0.716-0.894, P value < 0.0001) outperformed multivariate logistic regression (AUC = 0.754, 95 % CI 0.651-0.858, P value = 0.00019) of validation datasets without missing values (n = 127). Several analyses, e.g. bootstrap analysis, revealed that the developed model was insensitive to missing values and also tolerant to distribution bias among the datasets. Our model based on clinicopathological variables showed high predictive ability for pCR. This model might improve the prediction of the response to NAC in primary breast cancer patients.

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.

Prognostic contribution of the HER-2 oncogene overexpression to the Nottingham Prognostic Index in breast cancer.

The Nottingham prognostic index (NPI) is a widely adopted prognostic tool in breast cancer. The HER-2 oncogene overexpression is also associated with higher risk. The aim of our study is to investigate the correlation between the NPI and HER-2 in breast cancer. Two hundred and five patients with breast cancer managed in the Department of Surgery, University of Hong Kong Medical Centre, at Queen Mary Hospital between January 1995 and December 1997 were studied. This is a retrospective analysis of prospectively collected database. Variables evaluated for the analysis of prognostic significance included tumor size, axillary lymph node status, histological grade, estrogen and progesterone receptor status and HER-2 oncogene expression. NPI was calculated from tumor size, lymph node status and histological grade. In univariate analysis, tumor size, axillary lymph node status, distant metastasis status, HER-2 oncogene overexpression and NPI score were found to be significant variables. Significant poorer overall survival was also observed with higher NPI category and positive HER-2. Only tumor size and NPI category with subdivision by HER-2 status were independent factors in multivariate analysis . The combination of the HER-2 oncogene expression status with the widely adopted NPI provides a reliable way to predict prognosis in breast cancer patients.

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.

Increases in circulating VEGF levels during COX-2 inhibitor treatment in breast cancer patients.

Cyclooxygenase-2 (COX-2) inhibitors are being tried in clinics for cancer treatment. One of the mechanism by which COX-2 inhibitors suppress cancer progression is suggested to be inhibition of angiogenesis. To investigate how COX-2 inhibitors affect regulation of angiogenic factors, we studied alterations in VEGF levels in sera and plasma during COX-2 inhibitor treatment in breast cancer patients. Serum and plasma VEGF levels were monitored in 48 patients treated with the COX-2 inhibitor celecoxib together with 5-FU, epirubicine, cyclophosphamide (FEC). Serum VEGF levels showed decreases on day 3 of the first cycle (P<0.0001), followed by increases after 3 weeks (P<0.0001). Plasma VEGF levels did not show decreases on day 3 but showed increases after 3 weeks (P<0.05). The increases of VEGF levels in sera and plasma continued until the next cycle of the treatment. In patients treated with FEC alone (without celecoxib) did not show increases in serum VEGF levels during the treatment. Our data showed that treatment with COX-2 inhibitors decreased serum VEGF levels at an early time and increased VEGF levels in serum and plasma at a late time in breast cancer patients. Further studies are necessary to elucidate how COX-2 inhibitors regulate production of VEGF in different cells and different tissues in cancer patients.

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.

Serum lipid profiles in patients receiving endocrine treatment for breast cancer--the results from the Celecoxib Anti-Aromatase Neoadjuvant (CAAN) Trial.

BACKGROUND: Anti-aromatase therapy is important in the treatment of breast cancer. Cyclooxygenase-2 (COX-2) inhibitors may be effective in chemoprevention. A proof of principle study was performed to investigate the efficacy and side effects including changes in lipid profiles of combining anti-aromatase therapy and COX-2 inhibitor preoperatively in hormone sensitive postmenopausal breast cancers. METHODS: From February 2002 to April 2003, 41 postmenopausal women with histologically proven LABC were recruited. The patients were randomly assigned to receive exemestane 25 mg daily and celecoxib 400 mg twice-daily (group A), exemestane 25 mg daily (group B) and letrozole 2.5 mg daily (group C. RESULTS: Observed clinical response rates were 61.5%, 60% and 54.5% for Groups A-C, respectively, with no pathologic complete response. Cholesterol levels for Group A dropped progressively and a statistical difference was observed between fifth week after operation and preoperative level (P = 0.026). In addition, Group A has significantly lowered cholesterol and LDL levels than Groups B and C after 18 weeks of treatment. CONCLUSION: The initial results show that different neoadjuvant anti-aromatase therapies has similar efficacy but the combination with celecoxib may have an advantageous effects on the serum lipid profiles.

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.

Patient effective dose from sentinel lymph node lymphoscintigraphy in breast cancer: a study using a female humanoid phantom and thermoluminescent dosemeters.

The aim of this study was to measure the dose delivered to patients undergoing sentinel lymph node lymphoscintigraphy by taking into account both the transmission scan dose using a (57)Co flood source and the (99)Tc(m) internal emission dose. An adult female humanoid phantom and a set of thermoluminescent dosimeters were used in the measurements. The choice of measurement organs in the humanoid was guided by the recommendations described in the International Commission on Radiological Protection report number 60. A (57)Co flood source was used in external transmission to irradiate the humanoid at posterior, left lateral, left posterior oblique, right lateral and right posterior oblique positions. Four (99)Tc(m) deposits as internal emission sources were used to simulate patient peritumoural injection. The individual effective doses for external transmission and internal emission, normalized to the cumulated activity and expressed in micro Sv(MBq x h)(-1) were then calculated. The effective dose for a transmission scan was on average 0.061 micro Sv(MBq x h)(-1) for each (57)Co flood source position and for internal emission 0.312 micro Sv(MBq x h)(-1) and 0.291 micro Sv(MBq x h)(-1) for left and right breast injection, respectively. Using these results, the effective dose from both transmission and emission sources can be calculated according to the nuclear medicine scanning protocol and surgical procedure of the individual institution. For our protocols, the patient receives a maximum effective dose of 52 micro Sv for the 1 day protocol (18 MBq injection) and 204 micro Sv for the 2 day protocol (74 MBq injection) if only the sentinel lymph node is excised. If other tissues containing radioactivity are removed, the patient effective dose will be reduced by about 50% and 6%, respectively, for the 1 day protocol and 2 day protocol. Although the doses are low compared with other radiological examinations, the results are informative for patients concerned about radiation exposure for this new imaging technique.

Immunomagnetic tumor cell enrichment is promising in detecting circulating breast cancer cells.

OBJECTIVE: Magnetic-activated cell separation (MACS) for the enrichment of tumor cells was evaluated with immunocytochemistry (ICC) and flow cytometry (FCM). METHODS: Blood (20 ml) was sampled in 36 affected patients before surgery. Nucleated blood cells were obtained with the removal of red blood cells in the buffy coat. Nucleated blood cells (2 x 10(6)) from breast cancer patients were aliquoted before enrichment for direct immunostaining (ICC group), while all remaining cells were enriched and then immunostained (MACS/ICC group). Breast cancer cell lines were spiked serially in normal nucleated blood cells for FCM evaluation of the enrichment efficiency of MACS. RESULTS: The enrichment rate of spiked tumor cells was 37- to 2,300-fold and was negatively correlated with the ratio of tumor cells to normal nucleated cells (p < 0.05). The positive rate was only 5.6% (2/36) in the ICC group and was as high as 38.9% (14/36) in the MACS/ICC group (p < 0.001). The positivity in the enriched fraction was 0% (0/4), 33.3% (8/24), 60% (3/5) and 100% (3/3) for tumors at stages I, II, III and IV, respectively (p < 0.05). CONCLUSION: MACS can enrich circulating tumor cells, and the presence of circulating breast cancer cells correlates with clinical staging.