Can Patients' Likelihood of Benefiting from Primary Chemotherapy for Breast Cancer Be Predicted Before Commencement of Treatment?

A Phenylacetamide Resveratrol Derivative Exerts Inhibitory Effects on Breast Cancer Cell Growth

Resveratrol (RSV) is a natural compound that displays several pharmacological properties, including anti-cancer actions. However, its clinical application is limited because of its low solubility and bioavailability. Here, the antiproliferative and anti-inflammatory activity of a series of phenylacetamide RSV derivatives has been evaluated in several cancer cell lines. These derivatives contain a monosubstituted aromatic ring that could mimic the RSV phenolic nucleus and a longer flexible chain that could confer a better stability and bioavailability than RSV. Using MTT assay, we demonstrated that most derivatives exerted antiproliferative effects in almost all of the cancer cell lines tested. Among them, derivative 2, that showed greater bioavailability than RSV, was the most active, particularly against estrogen receptor positive (ER+) MCF7 and estrogen receptor negative (ER-) MDA-MB231 breast cancer cell lines. Moreover, we demonstrated that these derivatives, particularly derivative 2, were able to inhibit NO and ROS synthesis and PGE2 secretion in lipopolysaccharide (LPS)-activated U937 human monocytic cells (derived from a histiocytoma). In order to define the molecular mechanisms underlying the antiproliferative effects of derivative 2, we found that it determined cell cycle arrest at the G1 phase, modified the expression of cell cycle regulatory proteins, and ultimately triggered apoptotic cell death in both breast cancer cell lines. Taken together, these results highlight the studied RSV derivatives, particularly derivative 2, as promising tools for the development of new and more bioavailable derivatives useful in the treatment of breast cancer.

Association between Immunohistochemical Expression of Topoisomerase IIα, Her2 and Hormone Receptors and Response to Primary Chemotherapy in Breast Cancer

The aim of this study was to evaluate the association between immunohistochemical expression of topoisomerase IIα, HER2 and hormone receptors and response to primary anthracycline-based chemotherapy in locally advanced breast cancer. We analyzed 109 medical charts of patients treated with primary anthracycline-based chemotherapy in the Women's Integral Health Care Center from 1996 to 2004. The clinical and pathological response to primary chemotherapy was associated with topoisomerase IIα and HER2 expression and hormone receptor negativity. Statistical analysis was performed using chi-squared, Fisher's exact test and Mann-Whitney test. No statistical association between clinical response and expression of topoisomerase IIa, HER2 and hormone receptor negativity was found. However, there was an association between complete pathological response and hormone receptor negativity (P = 0.0289). The present study suggested that these markers should not be considered predictors of response to primary anthracycline-based chemotherapy, and prospective studies must be designed for this purpose.

Prognostic significance of Bcl-2 expression in non-basal triple-negative breast cancer patients treated with anthracycline-based chemotherapy

B cell lymphoma/leukemia-2 (Bcl-2) expression has generally been associated with estrogen receptor positivity and favorable prognosis in breast cancer. We examined immunohistochemical expression of Bcl-2 in 492 triple-negative breast cancers (TNBCs) using tissue microarrays and investigated its correlation with clinicopathologic features and clinical outcome. A total of 47 (9.5 %) TNBCs showed Bcl-2 expression. Bcl-2 expression was not associated with any of the clinicopathologic parameters and did not affect patient survival in TNBCs (Bcl-2-positive vs Bcl-2-negative TNBCs; overall survival (OS), P = 0.258; disease-free survival (DFS), P = 0.436). When TNBCs were divided into basal (cytokeratin 5/6 (CK5/6)+ and/or epidermal growth factor receptor (EGFR)+) and non-basal (CK5/6- and EGFR-) subgroups, Bcl-2 expression showed a significant association with worse OS (P = 0.002) and DFS (P = 0.002) in the non-basal subgroup. Among patients treated with an anthracycline, Bcl-2 expression also showed an association with decreased survival (OS, P = 0.004; DFS, P = 0.003) in the non-basal subgroup. In multivariate analyses, Bcl-2 expression was an independent poor prognostic factor for OS (P = 0.003) and DFS (P = 0.002) in this subgroup of TNBCs. Our results suggest that positive expression of Bcl-2 predicts no benefit from adjuvant anthracycline-based chemotherapy in non-basal TNBC patients. In conclusion, Bcl-2 status showed both prognostic and predictive values in non-basal TNBCs; therefore, assessment of Bcl-2 status and basal phenotype can provide information on prognostic and therapeutic classifications of TNBCs.

Bcl-2 expression predicts sensitivity to chemotherapy in breast cancer: a systematic review and meta-analysis

Background

Numerous studies have yielded inconclusive results regarding the relationship between anti-apoptotic protein Bcl-2 expression and the sensitivity to chemotherapy in the patients with breast cancer. The purpose of the current study was therefore to elaborate their relationship.

Methods, findings

A total of 23 previously published eligible studies involving 2,467 cases were identified and included in this meta-analysis. Negative Bcl-2 expression was associated with good chemotherapy response in breast cancer patients (total objective response [OR]: risk ratio [RR] = 1.16, 95% confidence interval [CI] = 1.02-1.32, p = 0.026; total complete response [CR]: RR = 1.67, 95% CI = 1.24-2.24, p = 0.001; pathological CR: RR = 1.92, 95% CI = 1.38-2.69, p < 0.001). In further stratified analyses, this association remained for sub-groups of response in neoadjuvant chemotherapy setting, especially pathological CR. Besides, negative Bcl-2 expression was significantly associated with good OR and pathological CR in anthracycline-based chemotherapy subgroup. Furthermore, there were significant links between negative Bcl-2 expression and taxane-based chemotherapy with pathological CR, but not OR.

Conclusion

The results of the present meta-analysis suggest that Bcl-2 expression is a predictive factor for chemotherapy sensitivity in breast cancer patients. They could also potentially benefit further clinical treatment for breast cancers.

Correlation between the molecular subtype of breast cancer and the in vitro adenosine triphosphate-based chemosensitivity assay

Purpose

The empirical use of a chemotherapy regimen shows different results in individual breast cancer patient treatment. Recent studies showed the effectiveness of the adenosine triphosphate-based chemotherapy response assay (ATP-CRA). However, little is known about the correlation between chemosensitivity and breast cancer molecular subtypes. Therefore, we investigated whether the result of ATP-CRA is associated with a molecular subtype of breast cancer.

Methods

Two hundred eighty-seven patients diagnosed with breast cancer and receiving ATP-CRA at Mokdong Hospital, Ewha Womans University between September 2007 and December 2010 were enrolled in this study. Hormone receptor status, HER2/neu expression, and results of chemosensitivity tests of the patients was analyzed.

Results

In all of four subtypes, the combination of two agents showed significant higher mean cell death rate than a single agent. Within the breast cancer cell lines in this study, the range of chemosensitivity response was very wide and varied for each patient. For this reason, the molecular subtype of breast cancer is inconclusive in choosing an effective chemotherapeutic agent and in vitro chemosensitivity test, prior to therapy, could be a useful method for planning chemotherapy for each patient.

Conclusion

Chemosensitivity response to anticancer agents was found to vary depending on the individual breast cancer patients. The molecular subtype of breast cancer is inconclusive to choose the effective chemotherapeutic agent and the in vitro chemosensitivity test, prior to therapy, could be more useful for planning chemotherapy for each patient.

Assessment of predictive markers of response to neoadjuvant chemotherapy in breast cancer

OBJECTIVE

To identify the predictive markers associated with chemotherapy sensitivity, especially those producing pathological complete response (pCR) following neoadjuvant chemotherapy (NACT) in patients with locally advanced breast cancer.

METHODS

Core needle biopsy of 50 locally advanced breast cancer patients was analysed for histopathology, grade, oestrogen receptor, progesterone receptor, HER2, Ki-67, p53, Bcl-2, and BAX before starting NACT. This was correlated with response to NACT using Response Evaluation Criteria in Solid Tumours criteria.

RESULTS

The mean tumour reduction rate per chemotherapy cycle was significantly higher in BAX-positive (p = 0.01) and Bcl-2-negative (p = 0.04) tumours. BAX expression significantly (p = 0.043) correlated with a response of an at least 30% reduction in tumour size post-NACT on multivariate analysis. A significant relationship was seen between loss of Bcl-2 expression and pCR on univariate (p = 0.048) analysis. Overall, all of the above 12 parameters had 30.4% and 28.5% success in predicting clinical complete response and pCR, respectively, by the Cox and Snell formula.

CONCLUSION

Of all parameters examined, only the apoptosis-related genes (Bcl-2 and BAX) seemed to exert some influence on the response to NACT, and neither by itself was sufficient to predict pCR; however, 50 patients is not sufficient to simultaneously analyse several predictive markers.

Gene expression profiles for predicting the efficacy of the anticancer drug 5-fluorouracil in breast cancer

Chemotherapy is an important postsurgery adjuvant therapy in the treatment of breast cancer. However, because of the individual genotype differences of patients, the drug efficacy differs from person to person, even when the same chemotherapy drug is administered. The purpose of this research was to probe the gene expression profiles to predict the efficacy of 5-fluorouracil (5-FU), the common drug used in chemotherapy for various type of cancers, in Taiwanese breast cancer patients. Microarray analysis was conducted on the cancer cell line ZR-75-1 with and without 5-FU stimulation to identify the differentially expressed genes. The significant overexpressed gene groups were selected after bioinformatics software analysis to explore the molecular mechanism of 5-FU. Six strains of breast cancer cell line purchased from American Type Culture Collection were used to analyze the expression profiles of the above target gene groups. IL18, CCL28, CXCL2, SOD1, HRAS, FDXR, and CHI3L1 genes were significantly differentially expressed in 5-FU responder and nonresponder cell lines. The selected gene groups were validated with 20 strains of breast cancer primary cultures established previously in our laboratory. The experimental results demonstrated that FAM46A, IL18, CCL28, TNF, CXCL2, PLEKHA8, HRAS, FDXR, and CHI3L1 genes showed statistically significant differential expression between primary breast cancer culture cells that respond and nonrespond to 5-FU. Six genes, IL18, CCL28, CXCL2, HRAS, FDXR, and CHI3L1, showed significant differential expression pattern in both American Type Culture Collection and primary breast cancer cultured cells. The findings of this study may serve as basis for predicting the effectiveness of 5-FU on breast cancer.

Combinatorial biomarker expression in breast cancer

Current clinical management of breast cancer relies on the availability of robust clinicopathological variables and few well-defined biological markers. Recent microarray-based expression profiling studies have emphasised the importance of the molecular portraits of breast cancer and the possibility of classifying breast cancer into biologically and molecularly distinct groups. Subsequent large scale immunohistochemical studies have demonstrated that the added value of studying the molecular biomarker expression in combination rather than individually. Oestrogen (ER) and progesterone (PR) receptors and HER2 are currently used in routine pathological assessment of breast cancer. Additional biomarkers such as proliferation markers and 'basal' markers are likely to be included in the future. A better understanding of the prognostic and predictive value of combinatorial assessment of biomarker expression could lead to improved breast cancer management in routine clinical practice and would add to our knowledge concerning the variation in behaviour and response to therapy. Here, we review the evidence on the value of assessing biomarker expression in breast cancer individually and in combination and its relation to the recent molecular classification of breast cancer.

A literature review of molecular markers predictive of clinical response to cytotoxic chemotherapy in patients with breast cancer

BACKGROUND

We aimed to identify, through a review of the literature, candidate genes for a prospective predictive chemosensitivity test in patients with breast cancer.

METHODS

Papers demonstrating an association between gene alterations in tumor tissue and clinical chemosensitivity in breast cancer patients were selected by Medline searches. We calculated odds ratios (ORs) and their 95% confidence intervals (CIs) of response rates for patients who had tumors with or without gene alteration. Combined ORs and CIs were estimated using the DerSimonian-Laird method.

RESULTS

A total of 18 genes were evaluated for association with clinical chemosensitivity in 6378 patients registered in 69 studies. The median (range) number of patients in each study was 73 (29-319). Overexpression of ABCB1 (P-glycoprotein) was associated with poor responses to first-line chemotherapy (combined OR [CI], 0.16 [0.05-0.59]; n = 322). Overexpression and amplification of TOP2A (topoisomerase II-alfa) were more frequently observed in patients who responded to first-line chemotherapy (combined OR [CI], 2.73 [1.02-7.27]; n = 323). Overexpression of ERBB2 (c-erbB2) was associated with favorable responses in patients treated with both first-line anthracycline-based chemotherapy and second-line taxane-based chemotherapy (combined ORs [CIs], 1.60 [1.19-2.17]; n = 1807 and 2.24 [1.06-4.74]; n = 259, respectively). BCL2 overexpression was associated with resistance to first-line chemotherapy (combined OR [CI], 0.44 [0.21-0.91]; n = 816).

CONCLUSION

ABCB1, TOP2A, ERBB2, and BCL2 were good candidates for future clinical trials of predictive chemosensitivity tests in patients with breast cancer.

Plumbagin-induced apoptosis of human breast cancer cells is mediated by inactivation of NF-kappaB and Bcl-2

Breast cancer remains the major cause of cancer-related deaths in women world-wide. The heterogeneity of breast cancer has further complicated the progress of target-based therapies. Triple negative breast cancers, lacking estrogen receptor, progesterone receptor and the Her-2/neu (ErbB2), represent a highly aggressive breast cancer subtype, that are difficult to treat. Pleiotropic agents, such as those found in nature, can target receptor-positive as well as receptor-negative cancer cells, suggesting that such agents could have significant impact in breast cancer prevention and/or therapy. Plumbagin (5-hydroxy-2-methyl-1, 4-naphthoquinone) is one such agent which has anti-tumor activity against several cancers. However, its mechanism of action against breast cancer is not clearly understood. We hypothesized that plumbagin may act as an effective agent against breast cancer especially triple negative breast cancer. We tested our hypothesis using ER-positive MCF-7 and ER-negative MDA-MB-231 (triple negative) breast cancer cells, and we found that plumbagin significantly inhibits the growth of breast cancer cells with no effect on normal breast epithelial cells. We also found that plumbagin induces apoptosis with concomitant inactivation of Bcl-2 and the DNA binding activity of NF-kappaB. Bcl-2 over-expression resulted in attenuation of plumbagin-induced effects, suggesting that the inhibition of cell growth and induction of apoptosis by plumbagin is in part due to inactivation of NF-kappaB/Bcl-2 pathway. To our knowledge, this is the first report, showing mechanistic and cancer cell specific apoptosis-inducing effects of plumbagin in breast cancer cells, suggesting the potential role of plumbagin in the prevention and/or treatment of breast cancer.

Estrogen Receptors: Role in Breast Cancer

The estrogen receptor (ER) exists in two forms known as ERalpha and ERbeta. Currently, a clinical role has only been established for ERalpha. The primary use of ERalpha in breast cancer is for predicting likely response to hormone treatment. Patients with breast cancers expressing ERalpha are approximately seven to eight times more likely to benefit from endocrine therapy than ERalpha-negative patients. For the initial three to five years after primary diagnosis, ERalpha-positive patients generally have a better outcome than ERalpha-negative patients. Overall, however, the prognostic value of ERalpha is relatively weak and only of limited value in the clinically important subgroup of patients with lymph node-negative disease. Further work is required to establish if ERbeta has a clinical role in breast cancer.

Prognostic value of Bcl-2 in breast cancer patients treated with neoadjuvant anthracycline based chemotherapy

We have analyzed the predictive/prognostic value of Bcl-2 protein in breast cancer patients treated with neoadjuvant chemotherapy. One hundred and ten patients were submitted to two different chemotherapeutic regimens: a) 5-fluorouracil, adriamycin or epirubicin, and cyclophosphamide (FAC/FEC) during 2-6 cycles before surgery and 3 or 4 additional cycles of FAC/FEC after surgery (n=40) and b) doxorubicin (D) 75 mg/m(2) or epirubicin (E) 120 mg/m(2) during 4 cycles before surgery, and 6 cycles of cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) after surgery (n=70). Bcl-2 expression, evaluated by immunohistochemistry, did not change significantly after chemotherapy and was not related to clinical/pathological response. In FAC/FEC group, Bcl-2 positive expression after chemotherapy correlated with better disease free survival (DFS) and overall survival (OS) (P=0.008 and P=0.001). In D/E group, Bcl-2 also correlated with better DFS and OS (P=0.03 and P=0.054) in the post-chemotherapy biopsies. An unusual nuclear localization of Bax was observed in some biopsies, but this localization did not correlate with the tumor response or outcome of the patients. We found that a high Bcl-2 expression had no predictive value but had prognostic value in breast cancer patients treated with neoadjuvant anthracycline based chemotherapy.

The use of an in vitro adenosine triphosphate-based chemotherapy response assay to predict chemotherapeutic response in breast cancer

The adenosine triphosphate-based chemotherapy response assay (ATP-CRA) has the advantages of standardization, evaluability, reproducibility, and accuracy, and can be performed on relatively small numbers of tumor cells. A total of 43 patients were enrolled in the present study, and chemosensitivity tests were successfully performed in 40 (93.0%) of these patients. Twenty of the 40 received neoadjuvant chemotherapy or chemotherapy for metastatic breast cancer. The chemotherapy regimens used were doxorubicin plus docetaxel (n=9, 45.0%) or doxorubicin plus paclitaxel (n=11, 55.0%). Mean cell death rate, as determined by ATP-CRA, was lower in non-responders than in responders to therapy (P=0.012). Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for ATP-CRA were 78.6%, 100%, 100%, 66.7%, and 85.0%, respectively. Diagnostic accuracy achieved by immunohistochemistry using estrogen receptor or progesterone receptor was lower than that achieved using ATP-CRA. Expression of p53, erb-B2, Ki67, Bcl-2, Bcl-xL, and annexin I was not significantly associated with response to chemotherapy. Our results show that ATP-CRA has high specificity and positive predictive value for predicting response to chemotherapy.

Primary systemic chemotherapy of invasive lobular carcinoma of the breast

Invasive lobular carcinoma is the second most frequent histological type of breast cancer and its incidence is increasing. It has unique clinical, biological, and molecular features. Invasive lobular carcinoma is almost invariably positive for the oestrogen receptor and, when compared with invasive ductal carcinoma, it is typically of a lower grade. Even though invasive lobular carcinoma represents a distinct clinical entity, the same criteria used for invasive ductal carcinoma are currently applied to establish the need for primary or adjuvant systemic chemotherapy. We reviewed randomised trials of neoadjuvant and adjuvant chemotherapy and noted that insufficient evidence is available to support or withhold use of chemotherapy in patients with invasive lobular carcinoma. Thus, the benefit from systemic chemotherapy for individuals with this form of breast disease is unclear. Invasive lobular carcinoma deserves to be investigated separately in prospective clinical trials to define the best treatment and prevention strategies.

Synergistic effects of meloxicam and conventional cytotoxic drugs in human MG-63 osteosarcoma cells

Cyclooxygenase-2 (COX-2) inhibitors have been shown to exert inhibitory effects on many types of malignant tumors and several groups have suggested that COX-2 inhibitors enhance the cytotoxic effects of other anti-cancer agents. We previously reported that meloxicam has an anti-tumorigenic effect on COX-2-expressing osteosarcoma cells. In the current study, we evaluated the synergy between meloxicam and cisplatin (CDDP), doxorubicin (DXR) and 4-hydroperoxy ifosfamide (4OOH-IFM), using the human osteosarcoma cell line, MG-63. Cytotoxicity was determined using 3-(4,5'-dimethylthiazol-2-yl)-2,5'-diphenyltetrazolium bromide (MTT) assays, and isobolographic analysis was used to evaluate any synergy. Apoptotic activity was determined by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL), and by evaluating Bax and Bcl-2 expression levels using real-time RT-PCR and western blotting analysis. Cell cycling was evaluated by flow cytometry. The cytotoxic effects of CDDP and DXR were enhanced synergistically in the presence of meloxicam and were partially due to an increase in apoptosis. By contrast, meloxicam enhanced neither the cytotoxic nor the apoptotic activity of 4OOH-IFM. Combining meloxicam with DXR significantly up-regulated Bax expression, whereas it down-regulated Bcl-2 expression in combination with CDDP. Furthermore, the number of cells in the G2/M phase was significantly increased in DXR-treated samples by the addition of meloxicam, but not in CDDP-treated or 4OOH-IFM-treated samples. These results suggest a potential clinical application of meloxicam in combination with cytotoxic drugs in patients with COX-2-positive osteosarcoma.

Smoking and survival after breast cancer diagnosis

We examined whether a history of smoking is associated with an increased risk of death from any cause or from breast cancer, among women diagnosed with breast cancer. This was a prospective observational study among 5,056 women from the Nurses' Health Study with Stages I-III invasive breast cancer diagnosed between 1978 and 2002 and for whom we had information on smoking, and who were followed until January 2002 or death, whichever came first. Subjects were classified as current, former or never smokers based upon smoking status at the biennial questionnaire immediately preceding the breast cancer diagnosis. In multivariate-adjusted analyses, compared with never smokers, women who were current smokers had a 43% increased adjusted relative risk (RR) [95% confidence interval (95% CI): 1.24-1.65] of death from any cause. A strong linear gradient was observed with the number of cigarettes per day smoked, p-trend <0.0001; the RR (95% CI) for 1-14, 15-24 and 25 or more cigarettes per day was 1.27 (1.01-1.61), 1.30 (1.08-1.57) and 1.79 (1.47-2.19). In contrast, there was no association with current smoking and breast cancer death; the RR (95% CI) was 1.00 (0.83-1.19). Current and past smokers were more likely than never smokers to die from primary lung cancer, chronic obstructive pulmonary disease and other lung diseases. We conclude that a history of smoking increased mortality following diagnosis with breast cancer, but did not increase mortality from breast cancer.

Evaluation of ER, PR, MIB-1, pS2, and nuclear grade in FNA specimens of cT1 breast carcinomas: clinicopathological correlation

Objectives were to determine oestrogen (ER), progesterone receptors (PR), and antigen related to ER (pS2) and to characterize their relationship with the cellular proliferation marker MIB-1 and the nuclear grade (NG) of the cancer cells, using fine-needle aspirates (FNA), as well as the evaluation of their clinical usefulness. The expression of ER, PR, pS2, and MIB-1 was preoperatively detected by immunocytochemistry in FNAs of 70 patients with breast adenocarcinoma and clinical tumor size up to 2 cm. The NG of the tumor cells was also assessed in these samples. We analyzed whether there was any correlation between these biocytologic markers and the invasion of ipsillateral axillary lymph nodes (LN), which were histologically identified after standard surgical treatment in each case. Of the 70 patients 50, 42.85, 50, and 41.42% were positive for ER, PR, pS2, and MIB-1, respectively. Only NG alone was strongly related to the invasion of the LN (P < 0.001). All the patients with NG1 (100%) tumors presented free LN, whereas the majority of those with NG3 (72.72%) had invaded LN (P < 0.001). Patients (14.28%) with NG1 expressed MIB-1, 85.71% ER or PR, and 71.42% pS2. Among the MIB-1-positive tumors a high proportion of NG3 (65.51%) was observed. This finding underlined a relationship between MIB-1 and NG (P < 0.05), identifying an aggressive cancer type. Remarkably 93.33% of the patients with positive MIB-1 and invaded axilla had NG3, whereas 66.66% of them expressed ER or PR and 40% pS2. The findings of the present prospective, multivariate study indicate that NG of the tumor cells, obtained from the preoperative FNAs of breast cancer patients, is a strong predictive marker for the axillary status and in parallel with MIB-1 expression can with sufficient accuracy be of clinical utility. ER, PR, or pS2 on the other hand did not show any relation to the LN status and were not dependent to NG or MIB-1.

CA 15-3 is predictive of response and disease recurrence following treatment in locally advanced breast cancer

BACKGROUND

Primary chemotherapy (PC) is used for down-staging locally advanced breast cancer (LABC). CA 15-3 measures the protein product of the MUC1 gene and is the most widely used serum marker in breast cancer.

METHODS

We retrospectively investigated the role of CA 15-3 in conjunction with other clinico-pathological variables as a predictor of response and time to disease recurrence following treatment in LABC. Pre and post primary chemotherapy serum concentrations of CA 15-3 together with other variables were reviewed and related to four outcomes following primary chemotherapy (clinical response, pathological response, time to recurrence and time to progression). Persistently elevated CA 15-3 after PC was considered as consecutively high levels above the cut off point during and after PC.

RESULTS

73 patients were included in this study. Patients received PC (AC or AC-T regimen) for locally advanced breast cancer. 54 patients underwent surgery. The median follow up was 790 days. Patients with high concentrations of CA 15-3 before PC treatment had a poor clinical (p = 0.013) and pathological (p = 0.044) response. Together with Her-2/neu expression (p = 0.009) and tumour lympho-vascular space invasion (LVI) (p = 0.001), a persistently elevated CA 15-3 post PC (p = 0.007) was an independent predictive factor of recurrence following treatment in LABC.

CONCLUSION

Elevated CA 15-3 level is predictive of a poor response to chemotherapy. In addition, persistently elevated CA 15-3 levels post chemotherapy in conjunction with lympho-vascular invasion and HER2 status predict a reduced disease free survival following treatment in locally advanced breast cancer.

A Phase II Trial of Pemetrexed in Advanced Breast Cancer: Clinical Response and Association with Molecular Target Expression

PURPOSE

This phase II trial of pemetrexed explored potential correlations between treatment outcome (antitumor activity) and molecular target expression.

EXPERIMENTAL DESIGN

Chemonaïve patients with advanced breast cancer received up to three cycles of pemetrexed 500 mg/m2 (10-minute i.v. infusion) on day 1 of a 21-day cycle, with folic acid and vitamin B12 supplementation. Tumors were surgically removed after the last cycle of pemetrexed as clinically indicated. Biopsies were taken at baseline, 24 hours after infusion in cycle 1, and after cycle 3.

RESULTS

Sixty-one women (median age, 46 years; range, 32-72 years) were treated and were evaluable for response. Objective response rate was 31%. Simple logistic regression suggested a potential relationship between mRNA expression of thymidylate synthase (TS) and pemetrexed response (P = 0.103). Based on threshold analysis, patients with "low" baseline TS (< or = 71) were more likely to respond to pemetrexed than patients with "high" baseline TS (>71). Expression of baseline dihydrofolate reductase and glycinamide ribonucleotide formyl transferase tended to be higher in responders but this association was not significant (P > 0.311). TS expression increased significantly between baseline and biopsy 2 (P = 0.004) and dropped to near baseline levels at biopsy 3. Conversely, dihydrofolate reductase and glycinamide ribonucleotide formyl transferase decreased after pemetrexed chemotherapy.

CONCLUSIONS

Our results suggest a potential association between "low" pretreatment TS expression levels and response to pemetrexed chemotherapy. Future trials examining expression levels of other genes important to the folate pathway and/or breast cancer may identify a more robust multigene profile that can better predict response to this novel antifolate.

The Nuclear Transcription Factor κB/bcl-2 Pathway Correlates with Pathologic Complete Response to Doxorubicin-Based Neoadjuvant Chemotherapy in Human Breast Cancer

PURPOSE

Molecular factors involved in apoptosis may affect breast cancer response to chemotherapy. Herein, we studied the nuclear factor kappaB (NF-kappaB)/bcl-2 pathway to determine whether or not activation of this antiapoptotic pathway was associated with a poor response of human breast cancer to anthracycline-based neoadjuvant chemotherapy.

EXPERIMENTAL DESIGN

We studied 82 human breast cancer samples from patients treated with neoadjuvant doxorubicin-based chemotherapy and studied whether or not nuclear location of the transcription factor NF-kappaB was associated with expression of bcl-2 and bax and whether or not expression of these proteins correlated with chemotherapy response. Protein expression was measured with immunohistochemical staining. A dedicated breast cancer pathologist who was unaware of the clinical outcome data dichotomized the slides as positive or negative based on the presence or absence of cytoplasmic staining for bcl-2 and bax or nuclear staining for NF-kappaB.

RESULTS

Sixty-one percent of the tumors were positive for bcl-2, 85% were positive for bax, and 16% were positive for NF-kappaB. All bcl-2-positive tumors were also bax positive (P < 0.0001) and all NF-kappaB-positive tumors were both bcl-2 positive (P = 0.001) and bax positive (P = 0.113). Eleven of the 82 patients (13%) had a pathologic complete response (pCR) to chemotherapy. Patients with positive staining tumors for any of the markers less commonly achieved a pCR to chemotherapy than those with negative tumor staining. The pCR rates were NF-kappaB positive 0% (0 of 13) versus NF-kappaB negative 13% (11 of 69; P = 0.130); bcl-2 positive 4% (2 of 49) versus bcl-2 negative 27% (9 of 33; P = 0.004); and bax positive 6% (4 of 69) versus bax negative 58% (7 of 12; P < 0.001).

CONCLUSION

We conclude that nuclear localization of NF-kappaB correlates with bcl-2 and bax expression and that the NF-kappaB/bcl-2 pathway may be associated with a poor response to neoadjuvant doxorubicin-based chemotherapy.

Predictors of primary breast cancers responsiveness to preoperative epirubicin/cyclophosphamide-based chemotherapy: translation of microarray data into clinically useful predictive signatures

Background

Our goal was to identify gene signatures predictive of response to preoperative systemic chemotherapy (PST) with epirubicin/cyclophosphamide (EC) in patients with primary breast cancer.

Methods

Needle biopsies were obtained pre-treatment from 83 patients with breast cancer and mRNA was profiled on Affymetrix HG-U133A arrays. Response ranged from pathologically confirmed complete remission (pCR), to partial remission (PR), to stable or progressive disease, "No Change" (NC). A primary analysis was performed in breast tissue samples from 56 patients and 5 normal healthy individuals as a training cohort for predictive marker identification. Gene signatures identifying individuals most likely to respond completely to PST-EC were extracted by combining several statistical methods and filtering criteria. In order to optimize prediction of non responding tumors Student's t-test and Wilcoxon test were also applied. An independent cohort of 27 patients was used to challenge the predictive signatures. A k-Nearest neighbor algorithm as well as two independent linear partial least squares determinant analysis (PLS-DA) models based on the training cohort were selected for classification of the test samples. The average specificity of these predictions was greater than 74% for pCR, 100% for PR and greater than 62% for NC. All three classification models could identify all pCR cases.

Results

The differential expression of 59 genes in the training and the test cohort demonstrated capability to predict response to PST-EC treatment. Based on the training cohort a classifier was constructed following a decision tree.

First, a transcriptional profile capable to distinguish cancerous from normal tissue was identified. Then, a "favorable outcome signature" (31 genes) and a "poor outcome signature" (26 genes) were extracted from the cancer specific signatures. This stepwise implementation could predict pCR and distinguish between NC and PR in a subsequent set of patients. Both PLS-DA models were implemented to discriminate all three response classes in one step.

Conclusion

In this study signatures were identified capable to predict clinical outcome in an independent set of primary breast cancer patients undergoing PST-EC.

Alterations of β‐tubulin isotypes in breast cancer cells resistant to docetaxel

Docetaxel is one of the most active drugs used to treat breast cancer. The cellular target of docetaxel is the microtubule, specifically the beta-tubulin subunit, that comprises a series of isotypes and that can modulate function. This study has examined the role of alteration in beta-tubulin isotypes in vitro and has sequenced the beta-tubulin gene to determine if there were mutations, both of which may represent important mechanisms of acquired resistance to docetaxel. Breast cancer cells, MCF-7 (oestrogen-receptor positive) and MDA-MB-231, (oestrogen-receptor negative) were made resistant to docetaxel in vitro. Expression of beta-tubulin isotypes (class I, II, III, IVa, IVb, and VI) was determined at the RNA and protein level using RT-PCR and western analysis, respectively. DNA sequencing evaluated the beta-tubulin gene. At the mRNA level, class I, II, III, and IVa beta-tubulin mRNA isotypes were over-expressed in docetaxel-resistant MCF-7 cells when compared with the docetaxel-sensitive parental cells. However, class VI beta-tubulin mRNA isotype expression was decreased in resistant cells. In MDA-MB-231 cells, there was a decrease in expression of the class I and class IVa beta-tubulin mRNA. However, there were increased expressions in class II, IVb, and VI beta-tubulin mRNA isotypes in resistant cells. Western analysis has confirmed corresponding increases in beta-tubulin protein levels in MCF-7 cells. However, in MDA-MB-231 cells, there were decreased protein levels for class II and class III beta-tubulin. This study demonstrates that altered expression of mRNA beta-tubulin isotypes and modulation of beta-tubulin protein levels are associated with acquired docetaxel resistance in breast cancer cells. This allows further understanding and elucidation of mechanisms involved in resistance to docetaxel.