A feasibility study of the efficacy and tolerability of the combination of Exemestane with the COX-2 inhibitor Celecoxib in post-menopausal patients with advanced breast cancer

Aspirin potentiates celecoxib-induced growth inhibition and apoptosis in human non-small cell lung cancer by targeting GRP78 activity

Background:

Aspirin has recently emerged as an anticancer drug, but its therapeutic effect on lung cancer has been rarely reported, and the mechanism of action is still unclear. Long-term use of celecoxib in large doses causes serious side effects, and it is necessary to explore better ways to achieve curative effects. In this study, we evaluated the synergistic anticancer effects of celecoxib and aspirin in non-small cell lung cancer (NSCLC) cells.

Methods:

In vitro, we evaluated the combined effects of celecoxib (40 μM) and aspirin (8 mM) on cell apoptosis, cell cycle distribution, cell proliferation, cell migration and signaling pathways. Furthermore, the effect of aspirin (100 mg/kg body weight) and celecoxib (50 mg/kg body weight) on the growth of xenograft tumors was explored in vivo.

Results:

Our data suggest that cancer sensitivity to combined therapy using low concentrations of celecoxib and aspirin was higher than that of celecoxib or aspirin alone. Further research showed that the anti-tumor effect of celecoxib combined with aspirin was mainly produced by activating caspase-9/caspase-3, arresting cell cycle and inhibiting the ERK-MAPK signaling pathway. In addition, celecoxib alone or in combination with aspirin inhibited the migration and invasion of NSCLC cells by inhibiting MMP-9 and MMP-2 activity levels. Moreover, we identified GRP78 as a target protein of aspirin in NSCLC cells. Aspirin induced an endoplasmic reticulum stress response by inhibiting GRP78 activity. Furthermore, combination therapy also exhibited a better inhibitory effect on tumor growth in vivo.

Conclusions:

Our study provides a rationale for further detailed preclinical and potential clinical studies of the combination of celecoxib and aspirin for NSCLC therapy.

Celecoxib in breast cancer prevention and therapy

Breast cancer has a high incidence worldwide. The results of substantial studis reveal that inflammation plays an important role in the initiation, development, and aggressiveness of many malignancies. The use of celecoxib, a novel NSAID, is repetitively associated with the reduced risk of the occurrence and progression of a number of types of cancer, particularly breast cancer. This observation is also substantiated by various meta-analyses. Clinical trials have been implemented on integration treatment of celecoxib and shown encouraging results. Celecoxib could be treated as a potential candidate for antitumor agent. There are, nonetheless, some unaddressed questions concerning the precise mechanism underlying the anticancer effect of celecoxib as well as its activity against different types of cancer. In this review, we discuss different mechanisms of anticancer effect of celecoxib as well as preclinical/clinical results signifying this beneficial effect.

Curcumol potentiates celecoxib-induced growth inhibition and apoptosis in human non-small cell lung cancer

Combinatorial therapies that target multiple signaling pathways may provide improved therapeutic responses over monotherapies. Celecoxib and curcumol are two highly hydrophobic drugs which show bioavailability problems due to their poor aqueous solubility. In the present study, we evaluated the effects of celecoxib and curcumol alone and in combination on cell proliferation, invasion, migration, cell cycle and apoptosis induction in non-small cell lung cancer (NSCLC) cells using in vitro and in vivo experiments. Our data showed that the sensitivity of a combined therapy using low concentration of celecoxib and curcumol was higher than that of celecoxib or curcumol alone. Suppression of NF-κB transcriptional activity, activation of caspase-9/caspase-3, cell cycle G1 arrest, and inhibition of survival MAPK and PI3K/AKT signaling pathway contributed to the synergistic effects of this combination therapy for induction of apoptosis. Additionally, either celecoxib alone or in combination with curcumol inhibited NSCLC cell migration and invasion by suppressing FAK and matrix metalloproteinase-9 activities. Furthermore, the combined treatment reduced tumor volume and weight in xenograft mouse model, and significantly decreased tumor metastasis nodules in lung tissues by tail vein injection. Our results confirm and provide mechanistic insights into the prominent anti-proliferative activities of celecoxib and/or curcumol on NSCLC cells, which provide a rationale for further detailed preclinical and potentially clinical studies of this combination for the therapy of lung cancer.

Interaction of Salicylates and the Other Nonsteroidal Anti-Inflammatory Agents With Breast Cancer Endocrine Treatment: Systematic Review

Despite advances in breast cancer treatment, mortality from breast cancer is still high. Undoubtedly, novel treatment strategies are needed for chemoprevention of high-risk women and for the treatment of receptor-negative breast cancer. An appealing strategy would be the combination of breast endocrine treatment with salicylates and the other nonsteroidal anti-inflammatory agents (NSAIDs). This systematic review aimed to synthesize evidence on the possible synergistic antitumor effect of breast cancer endocrine treatment with salicylates and the other NSAIDs. Electronic databases were searched with the appropriate search terms. Most of the identified studies investigated the possible synergistic effect of exemestane with celecoxib in different clinical settings including metastatic treatment, adjuvant treatment, ductal carcinoma in situ. The possible synergistic effect of tamoxifen with celecoxib was investigated in one experimental study and the possible synergistic effect of exemestane with aspirin was investigated in another experimental study. Synergistic effect was detected in the majority of the studies. In conclusion, existing limited evidence suggests synergistic interaction of salicylates and the other NSAIDs in the treatment of estrogen responsive breast cancer with clinical implications in the reversal of acquired resistance to breast cancer endocrine treatment and in chemoprophylaxis.

Molecular modeling and synthesis of new 1,5-diphenylpyrazoles as breast cancer cell growth inhibitors

New pyrazoles have been synthesized and evaluated as breast cancer cell growth inhibitors. Condensation of the substituted pyrazole-4-carbaldehyde1with acetophenone and chloroacetophenone afforded α, β-unsaturated ketones2and3, respectively. Compounds2and3were subjected to different reactions using hydrazine hydrate, substituted hydrazine hydrate, hydroxylamine,o-phenylenediamine, malononitrile under different conditions affording 4-substituted pyrazole derivatives4–28. Structure elucidation of these compounds was conducted using IR,1H NMR,13C NMR, mass spectral data and elemental analysis. Antitumor activity of target compounds was tested against MCF-7 cell line (human breast cancer). Compounds4,10and20show significant antitumor activity against breast cancer. Docking was performed with protein 1UYK to study the binding mode of the designed compounds.

Synergistic effect between celecoxib and luteolin is dependent on estrogen receptor in human breast cancer cells

The anti-cancer effects of celecoxib and luteolin are well known. Although our previous study demonstrated that the combination of celecoxib and luteolin synergistically inhibits breast tumor growth compared with each of the treatments alone, we did not uncover the molecular mechanisms of these effects. The aims of our present study were to compare the effects of a celecoxib and luteolin combination treatment in four different human breast cell lines and to determine the mechanisms of action in vitro and in vivo. The synergistic effects of a celecoxib and luteolin combination treatment yielded significantly greater cell growth inhibition in all four breast cancer cell lines compared with the single agents alone. In particular, combined celecoxib and luteolin treatment significantly decreased the growth of MDA-MB-231 cancer cells in vivo compared with either agent alone. The celecoxib and luteolin combination treatment induced synergistic effects via Akt inactivation and extracellular signal-regulated kinase (ERK) signaling inhibition in MCF-7 and MCF7/HER18 cells and via Akt inactivation and ERK signaling activation in MDA-MB-231 and SkBr3 cells. These results demonstrate the synergistic anti-tumor effect of the celecoxib and luteolin combination treatment in different four breast cancer cell lines, thus introducing the possibility of this combination as a new treatment modality.

COX2 expression in high-grade breast cancer: evidence for prognostic significance in the subset of triple-negative breast cancer patients

COX2 expression correlates with high-grade breast cancer, but the clinical significance and possible prognostic influence in these patients have not been studied in depth. Our goal was to evaluate the significance of COX2 expression in a group of patients with high-grade breast cancer. Three hundred and three patients (median age 55; age range 25-95 years) with high-grade breast cancer entered this retrospective study. Mean follow-up was 65.2 months (4-179 months). COX2 expression was studied by immunohistochemistry. The distribution of patients with high-grade tumors according to staining for COX2 was as follows: score 0-28/303 (9.3 %); score 1-101/303 (33.3 %); score 2-114/303 (37.6 %); score 3-60/303 (19.8 %). Patients with score 2 and 3 were classified as COX2 positive (174 of 303 patients (57.4 %). There was no correlation between any clinicopathological pattern, ER, PR, Her2 status and COX2 expression. In the group of patients with triple-negative breast cancer, the 5-year disease-free survival rate was 58.3 % for patients with COX2 expression compared with 83.9 % for patients without COX2 expression (P = 0.042). COX2 expression did not provide any prognostic significance for the other biological subtypes of breast cancer with high-grade histological features.

COX2 overexpression is a prognostic marker for Stage III breast cancer

To determine the significance of (Cyclooxygenase 2) COX2 for clinical outcome in breast cancer, we analyzed the correlation between COX2 overexpression and survival in 687 patients with invasive breast cancer. Cytoplasmic immunoreactivity of COX2 was determined as positive in 325 of 687 (47.3%) invasive breast cancers. COX2 positivity was significantly correlated with high histologic grade, negative estrogen receptor (ER), high Ki67, luminal B and triple-negative tumors, Bcl2 negativity, and p53 overexpression. In univariate analysis, COX2 overexpression resulted in significantly shorter relapse-free survival (RFS) [hazard ratio (HR) 1.487, 95% CI 1.035-2.110, P = 0.032]. Multivariate analysis revealed no significant association between COX2 overexpression and either overall survival (OS) or RFS. Kaplan-Meier analysis of the whole patient group showed significantly reduced RFS in patients with high COX2 expression, compared to those that did not overexpress COX2 (91 vs. 162 months, P = 0.031). Stratified subgroup analysis by TNM stage disclosed marked differences in OS and RFS rates in Stage III patients. We observed a significant association of COX2 overexpression with shorter RFS in the ER-negative subgroup of Stage III patients. The results show that COX2 overexpression is a significant unfavorable prognostic factor in Stage III breast cancer, and provide selective criteria for COX2 inhibitor combinations for invasive breast cancer therapy.

Celecoxib and acetylbritannilactone interact synergistically to suppress breast cancer cell growth via COX-2-dependent and -independent mechanisms

The use of celecoxib is associated with a significant decrease in breast cancer risk. However, the long-term use of high-dose celecoxib might be limited owing to cardiovascular side effects. In this study, we found that acetylbritannilactone (ABL), extract from a Chinese medicinal herb, could reduce celecoxib dose and potentiate the growth-inhibitory effect in breast cancer cells. ABL enhanced the apoptotic effect of celecoxib in COX-2-expressing cells, but had little effect in COX-2-negative cells. The apoptosis induced by the combination treatment disappeared when COX-2 was knocked down, whereas the lack of apoptotic effects in COX-2-negative cells was reversed after COX-2 transfection. However, the combination treatment induced a G(0)/G(1) phase arrest independent of whether or not the cells expressed COX-2. The G(0)/G(1) arrest was attributed to a decreased expression of cyclinD1, cyclinE, CDK2 and CDK6, especially the upregulation of p21. In addition, inhibition of Akt and p38 signaling pathways was required by the synergism, as the constitutively active Akt and p38 protected cells against apoptosis and cell cycle arrest induced by the combination treatment. In vivo, administration of celecoxib and ABL were more effective than the individual agents against xenograft tumor growth. Thus, our data suggested that the combinatorial approach of celecoxib and ABL might be helpful for breast cancer treatment.

Phase II trial of neoadjuvant exemestane in combination with celecoxib in postmenopausal women who have breast cancer

PURPOSE

Within breast tissue, aromatase expression and activity is increased by prostaglandin E2, providing a rationale for combining the COX-2 inhibitor celecoxib with an aromatase inhibitor. To evaluate the effect of these drugs on aromatase and other biomarkers, a phase II trial of neoadjuvant exemestane followed sequentially by celecoxib plus exemestane was performed.

METHODS

Postmenopausal women with estrogen receptor (ER) and/or progesterone (PR) positive stages II-III breast cancers received 8 weeks of exemestane 25 mg daily, followed by 8 weeks of exemestane 25 mg daily and celecoxib 400 mg twice daily. Core biopsies were collected pretreatment, after 8 weeks of exemestane, and at definitive breast cancer surgery. A tissue microarray was constructed and immunohistochemistry (IHC) for aromatase, ER, PR, HER-2, Ki-67, and COX-2 was performed.

RESULTS

Twenty-two women were enrolled. Celecoxib was discontinued in 4 (18%) women for toxicity (all grade 1 and 2) and 2 (9%) developed serious cardiac events occurring at 1 and 4 months after completing treatment. By US, there were 8 (36%)-partial responses and 12 (55%)-stable disease. There were no pathological complete responses (pCR). There were statistically significant decreases in ER (P = .003), PR (P = .002), Ki-67 (P < .001), and COX-2 (P = .004) expression. No significant differences in aromatase or HER-2 expression were observed (P = .13 and P = .39, respectively).

CONCLUSION

The addition of celecoxib to exemestane was tolerated by the majority of women and anti-tumor response was observed. Additional studies, including gene expression, are required to more fully understand the basis for the decreased expression of ER, PR, Ki-67, and COX-2.

Bone metabolism and quality-of-life of postmenopausal women with invasive breast cancer receiving neoadjuvant hormonal therapy: sub-analyses from celecoxib anti-aromatase neoadjuvant (CAAN) trial

OBJECTIVE

Anti-aromatase therapy is important in the treatment of breast cancer in postmenopausal women but they have effects on the bone mineral density (BMD) and osteoporosis. Cyclooxygenase-2 (COX-2) inhibitors have been shown to be effective in chemoprevention in animal and clinical studies. A proof of principle study was performed to investigate the efficacy of combing anti-aromatase therapy (exemestane) and COX-2 inhibitors neoadjuvantly. The changes in the BMD, bone turnover proteins and quality-of-life (QoL) were analyzed and presented here.

METHOD

82 postmenopausal patients with histologically confirmed invasive hormone-sensitive breast cancers were included for the neoadjuvant therapy (NHT). 30 patients received exemestane (EXE) 25 mg daily and celecoxib (CXB) 400 mg twice daily (group A), 24 patients received EXE 25 mg daily (group B) and 28 patients received letrozole (LET) 2.5 mg daily (group C). The same assigned treatment was intended to continue for 2 years to study the changes in the bone metabolism. BMD of 48 patients were analyzed; 23 belongs to group A, 10 to group B and 15 to group C. The serum bone turnover proteins bone-specific alkaline phosphatase (BAP) and carboxyterminal crosslinked telopeptide of type I collagen (ICTP), were measured with commercially available test kits before treatment, 3 months and 15 months after treatment. Functional Assessment of Cancer Therapy core questionnaire (FACT-G) with its additional breast cancer subscale were performed at baseline, 4, 8, and 12 weeks after NHT.

RESULT

Difference between groups (p=0.007) for BMD at femur was significant. The changes of BMD in group B patients were significantly greater than patients in group A (p=0.011, CI=0.063-0.437), and group C (p=0.003, CI=0.146-0.620). The mean BAP increased from baseline in group B patients but decreased from baseline in group C patients at 3 months and 15 months. No statistical significance was found in the FACT-G scores and FACT-B scores among different groups at baseline, week 4, week 8 and week 12 after NHT. The Breast Cancer Subscale scores in group A patients were significantly higher than that of group C patients (p=0.021). After 4 weeks of NHT, negative changes of FACT-B and FACT-G scores were found in group B and C patients, but there were positive changes in group A patients. Significant differences of FACT-B score (p=0.008) and FACT-G score (p=0.019) were observed at that time point. Article from the Special issue on Targeted Inhibitors.

COX-2 activation is associated with Akt phosphorylation and poor survival in ER-negative, HER2-positive breast cancer

Background

Inducible cyclooxgenase-2 (COX-2) is commonly overexpressed in breast tumors and is a target for cancer therapy. Here, we studied the association of COX-2 with breast cancer survival and how this association is influenced by tumor estrogen and HER2 receptor status and Akt pathway activation.

Methods

Tumor COX-2, HER2 and estrogen receptor α (ER) expression and phosphorylation of Akt, BAD, and caspase-9 were analyzed immunohistochemically in 248 cases of breast cancer. Spearman's correlation and multivariable logistic regression analyses were used to examine the relationship between COX-2 and tumor characteristics. Kaplan-Meier survival and multivariable Cox proportional hazards regression analyses were used to examine the relationship between COX-2 and disease-specific survival.

Results

COX-2 was significantly associated with breast cancer outcome in ER-negative [Hazard ratio (HR) = 2.72; 95% confidence interval (CI), 1.36-5.41; comparing high versus low COX-2] and HER2 overexpressing breast cancer (HR = 2.84; 95% CI, 1.07-7.52). However, the hazard of poor survival associated with increased COX-2 was highest among patients who were both ER-negative and HER2-positive (HR = 5.95; 95% CI, 1.01-34.9). Notably, COX-2 expression in the ER-negative and HER2-positive tumors correlated significantly with increased phosphorylation of Akt and of the two Akt targets, BAD at Ser136 and caspase-9 at Ser196.

Conclusions

Up-regulation of COX-2 in ER-negative and HER2-positive breast tumors is associated with Akt pathway activation and is a marker of poor outcome. The findings suggest that COX-2-specific inhibitors and inhibitors of the Akt pathway may act synergistically as anticancer drugs in the ER-negative and HER2-positive breast cancer subtype.

Aldo-keto reductase 1C3 expression in MCF-7 cells reveals roles in steroid hormone and prostaglandin metabolism that may explain its over-expression in breast cancer

Aldo-keto reductase (AKR) 1C3 (type 5 17beta-hydroxysteroid dehydrogenase and prostaglandin F synthase), may stimulate proliferation via steroid hormone and prostaglandin (PG) metabolism in the breast. Purified recombinant AKR1C3 reduces PGD(2) to 9alpha,11beta-PGF(2), Delta(4)-androstenedione to testosterone, progesterone to 20alpha-hydroxyprogesterone, and to a lesser extent, estrone to 17beta-estradiol. We established MCF-7 cells that stably express AKR1C3 (MCF-7-AKR1C3 cells) to model its over-expression in breast cancer. AKR1C3 expression increased steroid conversion by MCF-7 cells, leading to a pro-estrogenic state. Unexpectedly, estrone was reduced fastest by MCF-7-AKR1C3 cells when compared to other substrates at 0.1muM. MCF-7-AKR1C3 cells proliferated three times faster than parental cells in response to estrone and 17beta-estradiol. AKR1C3 therefore represents a potential target for attenuating estrogen receptor alpha induced proliferation. MCF-7-AKR1C3 cells also reduced PGD(2), limiting its dehydration to form PGJ(2) products. The AKR1C3 product was confirmed as 9alpha,11beta-PGF(2) and quantified with a stereospecific stable isotope dilution liquid chromatography-mass spectrometry method. This method will allow the examination of the role of AKR1C3 in endogenous prostaglandin formation in response to inflammatory stimuli. Expression of AKR1C3 reduced the anti-proliferative effects of PGD(2) on MCF-7 cells, suggesting that AKR1C3 limits peroxisome proliferator activated receptor gamma (PPARgamma) signaling by reducing formation of 15-deoxy-Delta(12,14)-PGJ(2) (15dPGJ(2)).

A liquid chromatography-tandem mass spectrometry method for the simultaneous determination of exemestane and its metabolite 17-dihydroexemestane in human plasma

A simple and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the quantitation of exemestane (Exe) and its main metabolite 17-dihydroexemestane (DhExe) in human plasma. The analytes were extracted by protein precipitation with acetonitrile, containing stable 13C-labelled Exe (13C3-Exe) as internal standard, and measured by LC-MS/MS. The best chromatographic separation of the analytes from the interferences was achieved by using a Phenyl column operating under isocratic regime conditions. The total chromatographic runtime was 5.0 min and the elution of Exe and DhExe occurred at 2.5 min and 2.9 min, respectively. Quantitation was performed by employing the positive electrospray ionization (ESI) technique and multiple reaction monitoring mode (MRM). The monitored precursor to product-ion transitions for Exe, DhExe and 13C3-Exe internal standard were m/z 297.0 --> 120.8, m/z 299.1 --> 134.9 and m/z 300.0 --> 123.2, respectively. The lower limit of quantitation (LLOQ) was 0.1 ng/ml for DhExe and 0.2 ng/ml for Exe. The method was linear up to 36-51 ng/ml with r2 > or = 0.998. The intra- and inter-assay precision were < or = 7.7% and 5.1% for Exe and < or = 8.1 and 4.9% for DhExe while deviations from nominal values were in the 1.5-13.2% and - 9.0-5.8% ranges for Exe and DhExe, respectively. The analytical method resulted robust and suitable for pharmacokinetic monitoring of Exe and its main metabolite during adjuvant therapy in patients with breast cancer.

Effects of celecoxib and ly117018 combination on human breast cancer cells in vitro

Activation and signalling of estrogen receptor (ER) and COX-2 represent two important pathways in breast cancer cell regulation. Activation of either pathway is associated with breast cancer cell proliferation and eventually malignant progression. Raloxifene analogue, Ly117018, a selective estrogen receptor modulator and celecoxib, a specific COX-2 inhibitor have been shown to inhibit breast cancer cell proliferation when used alone in vitro and in vivo. In this study, the combined drug effects on hormone-dependent MCF-7 and hormone-independent MDA-MB-435 cells in vitro were evaluated. Cell proliferation assays excluded drug antagonism and revealed a moderate synergistic growth inhibitory activity of Ly117018 and celecoxib on both cell lines when combined in specific concentrations. Growth inhibition of either compound was not associated with cell cycle arrest. In MCF-7 cells, western blot analysis revealed a decreased phosphorylation of the AKT protein by either agent alone or in combination. In MDA-MB-435 cells, celecoxib alone induced an increase in AKT phosphorylation relative to total AKT protein; this effect was decreased in the presence of Ly117018. These results indicate that these two drugs are non-antagonistic; and when combined in specific concentrations, moderate synergistic antiproliferative activity of celecoxib and Ly117018 were observed in hormone-dependent MCF-7 and hormone-independent MDA-MB-435 cells associated with changes in cell cycle distribution and regulation of AKT protein and phosphorylation. These findings further support a central role of the ER- and COX-2 pathways in human breast cancer cells.

Celecoxib anti-aromatase neoadjuvant (CAAN) trial for locally advanced breast cancer

OBJECTIVES

To evaluate the efficacy and safety of combing aromatase inhibitor (AI) and cyclooxygenase-2 (COX-2) inhibitor neoadjuvantly in postmenopausal patients with invasive hormone-sensitive breast cancer.

METHODS

Eighty-two patients were randomly assigned to receive exemestane 25mg daily and celecoxib 400mg twice daily (group A, n=30), exemestane 25mg daily (group B, n=24) and letrozole 2.5mg daily (group C, n=28).

RESULTS

All groups showed clinical responses (58.6% for group A, 54.5% for group B and 62.0% for group C) and decrease in tumor area (61.8% for group A, 58.1% for group B and 55.7% for group C). 3 out of 5 patients with complete clinical response were observed from group A and 2 out of 69 patients operated with pathologic complete response were observed in group C. The mean microscopic tumor size was 2.53 cm for group A, 3.05 cm for group B and 2.10 cm for group C. The differences were only statistically significant when group C was compared with group B (P=0.025). The toxicity profiles among groups were satisfactory.

CONCLUSION

AI is effective in treating breast cancer and may be safely used preoperatively. The addition of COX-2 inhibitor may provide additional benefit.

Perspectives on microbes as oncogenic infectious agents and implications for breast cancer

Cancer management is partly based on weighing risk factors attributed to noninfectious agents, human genes and epigenetic factors. Infectious disease causation has largely been restricted to genes directly responsible for causing cancer after sustaining damage i.e. oncogenes. Lately, evidence has emerged linking infectious agents to a number of chronic diseases. These studies have recognized the influence that acute, atypical, latent and chronic infections may play in tricking the immune system and affecting disease etiology. Similar evidence is emerging in model systems with respect to the role of infectious agents in gastrointestinal, liver and lung cancers. Although viruses have been found in association with breast cancer, skepticism remains about a role for other infectious agents, notably microbes in the disease etiology. Improved experimental designs employed in different cancer studies and a less rigid definition of infectious causation may aid in confirming or refuting a microbe-breast cancer connection. Cancer recurrence could potentially be minimized and treatment options further tailored on a case by case basis if microbes/microbial components/strain variants associated with breast cancer are identified; probiotics are employed to reduce treatment side-effects and if microbes could effectively be harnessed in immunotherapy.

Treatment of advanced hormone-sensitive breast cancer in postmenopausal women with exemestane alone or in combination with celecoxib

PURPOSE

Preclinical data showed that the combination of exemestane and celecoxib has synergistic effects. Therefore, a study was undertaken to explore the efficacy and tolerability of this combination in postmenopausal patients with advanced, hormone-sensitive breast cancer.

PATIENTS AND METHODS

A randomized phase II study was conducted in postmenopausal patients with hormone-sensitive breast cancer and measurable disease who had progressive disease after treatment with tamoxifen. Patients were randomly assigned to either exemestane 25 mg daily or the combination of exemestane 25 mg daily with celecoxib 400 mg twice daily. Response Evaluation Criteria in Solid Tumors Group criteria were used to determine antitumor efficacy. Primary end point was the rate of clinical benefit. Secondary end points were tolerability, objective response rate, time to progression (TTP), and duration of clinical benefit. A pharmacodynamic and a pharmacokinetic study were conducted in parallel.

RESULTS

One hundred eleven patients (exemestane, n = 55; combination, n = 56) were enrolled in 2002. The demographic characteristics and prognostic factors were similar in both arms. In the assessable population, 24 of 51 patients in the combination arm and 24 of 49 patients in the exemestane arm achieved clinical benefit. TTP was similar in both groups. Duration of clinical benefit was longer in the combination group (median, 96.6 v 49.1 weeks). The addition of celecoxib did not change the tolerability profile of exemestane alone.

CONCLUSION

Similar rates of clinical benefit were achieved in both groups.

NSAIDs and breast cancer: a possible prevention and treatment strategy

CONTEXT

Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase (COX) and thereby reduce prostaglandin synthesis. Abnormally upregulated COX and prostaglandins are features of breast cancer so NSAIDs might have a role in treatment and prevention of the disease.

OBJECTIVE

To review the available epidemiological data on the relation between NSAIDs and risk of breast cancer together with interventional studies in established disease.

RESULTS

Both case-control and cohort studies indicate a moderate reduction in risk of breast cancer among women taking NSAID particularly aspirin. There may be a reduction in oestrogen receptor positive tumours in aspirin users but results are heterogeneous. It is not possible to estimate the dose-response effect for duration of use. In patients with breast cancer, aspirin increased levels of serum nitric oxide (NO) and maspin both of which inhibit growth of breast cancer cells in vitro. Furthermore, a reduced breast cancer and all-cause mortality has been reported in those taking NSAIDs after diagnosis. The cyclooxygenase 2 (COX-2) inhibitor celecoxib showed promising preliminary efficacy and acceptability in combination with exemestane in advanced breast cancer although cardiotoxicity led to discontinuation of celecoxib in a prevention trial for individuals with colonic polyps.

CONCLUSIONS

NSAIDs may reduce breast cancer risk by 20% but the optimal type, dose and duration is still undetermined together with the feasibility of such an intervention in an at risk population. There may be a role for NSAIDs in combination with endocrine therapies as either an adjuvant or palliative treatment for women with established breast cancer.

Estrogen-dependent prognostic significance of cyclooxygenase-2 expression in early-stage invasive breast cancers treated with breast-conserving surgery and radiation

PURPOSE

To evaluate the prognostic significance of cyclooxygenase-2 (COX-2) in breast cancer patients treated with conservative surgery and radiation therapy (CS+RT).

METHODS AND MATERIALS

Between 1975 and 2003, we retrieved specimens from 504 breast cancer patients treated with CS+RT. The specimens were constructed into tissue microarrays processed and stained for estrogen receptor (ER), progesterone receptor, Her2/neu, and COX-2. Each core was scored as positive or negative. All data including demographics, clinical, pathologic, staging, and outcome variables were entered into a computerized database.

RESULTS

Expression of COX-2 was positive in 58% of cases and correlated with younger age (p = 0.01) and larger tumor size (p = 0.001). Expression of COX-2 was predictive of local relapse (relative risk[RR], 3.248; 95% confidence interval [CI], 1.340-7.871; p = 0.0091), distant metastasis (RR, 2.21; 95% CI, 1.259-3.896; p = 0.0058), and decreased survival (RR, 2.321; 95% CI, 1.324-4.071; p = 0.0033). Among ER-positive patients, COX-2 expression was predictive of worse local control (85% vs. 93%, p = 0.04), distant metastasis (75% vs. 95%, p = 0.002) and worse survival (65% vs. 94%, p = 0.002). Among ER-negative tumors COX-2 expression was not significantly correlated with local control (87 vs. 95%, p = 0.12), distant metastasis (73% vs. 78%, p = 0.39), or survival (77% vs. 87%, p = 0.15).

CONCLUSIONS

In breast cancer patients treated with CS+RT, COX-2 expression is associated with younger age, larger tumor size, worse local control, distant metastasis, and worse overall survival. The significance is limited to hormone receptor-positive tumors, consistent with the known effect of COX-2/PGE2 on aromatase activity. Use of COX-2 inhibitors in estrogen-dependent breast cancers warrants further investigation.

Novel therapeutic strategies combining antihormonal and biological targeted therapies in breast cancer: focus on clinical trials and perspectives

Several models have been proposed to explain the mechanisms of endocrine resistance including aberrant growth-signaling pathways, and have led to the rational design of studies combining hormonotherapy with signal transduction inhibitors (STI) in advanced breast cancer. This article reviews the current status of these clinical trials. Preliminary results from the randomized controlled trials are rather disappointing. The mTOR inhibitor temsirolimus and the farnesyl transferase inhibitor tipifarnib combined with letrozole did not show any benefit compared to letrozole alone. As neoadjuvant therapy, gefinitib did not enhance the response rate induced by anastrozole. Interesting results were obtained with exemestane combined to celecoxib but should be further explored with adequate cardiac monitoring. Trastuzumab combined with anastrozole was more effective than anastrozole in terms of response rate and progression-free survival but not survival. Several controlled trials as first- or second-line therapy have started recently and over the next few years we should learn whether this approach will provide significant gains in efficacy.

Insights from transgenic mouse models of ERBB2-induced breast cancer

One-third of patients with breast cancer overexpress the ERBB2 receptor tyrosine kinase, which is associated not only with a more aggressive phenotype but also reduced responsiveness to hormonal therapies. Over the past two decades, many ERBB2 mouse models for breast cancer have conclusively shown that this receptor has a causal role in breast cancer development. These mouse models have also enabled the mechanisms controlling tumour growth, angiogenesis, metastasis, dormancy and recurrence in ERBB2-positive breast cancer to be elucidated. In addition, a mouse model has recently been described that accurately recapitulates many of the hallmarks associated with the early stages of the human disease.