Breast Cancer: Achievements in Adjuvant Systemic Therapies in the Pre‐Genomic Era

Targeted therapy of breast tumor by PLGA-based nanostructures: The versatile function in doxorubicin delivery

Breast carcinoma is a molecularly diverse illness, and it is among the most prominent and often reported malignancies in female across the globe. Surgical intervention, chemotherapy, immunotherapy, gene therapy, and endocrine treatment are among the currently viable treatment options for the carcinoma of breast. Chemotherapy is among the most prevalent cancer management strategy. Doxorubicin (DOX) widely employed as a cytostatic medication for the treatment of a variety of malignancies. Despite its widespread acceptance and excellent efficacy against an extensive line up of neoplasia, it has a variety of shortcomings that limit its therapeutic potential in the previously mentioned indications. Employment of nanoparticulate systems has come up as a unique chemo medication delivery strategy and are being considerably explored for the amelioration of breast carcinoma. Polylactic-co-glycolic acid (PLGA)-based nano systems are being utilized in a number of areas within the medical research and medication delivery constitutes one of the primary functions for PLGA given their inherent physiochemical attributes, including their aqueous solubility, biocompatibility, biodegradability, versatility in formulation, and limited toxicity. Herein along with the different application of PLGA-based nano formulations in cancer therapy, the present review intends to describe the various research investigations that have been conducted to enumerate the effectiveness of DOX-encapsulated PLGA nanoparticles (DOX-PLGA NPs) as a feasible treatment option for breast cancer.

Personalized medicine in breast cancer: pharmacogenomics approaches

Abstract: Breast cancer is the fifth cause of cancer death among women worldwide and represents a global health concern due to the lack of effective therapeutic regimens that could be applied to all disease groups. Nowadays, strategies based on pharmacogenomics constitute novel approaches that minimize toxicity while maximizing drug efficacy; this being of high importance in the oncology setting. Besides, genetic profiling of malignant tumors can lead to the development of targeted therapies to be included in effective drug regimens. Advances in molecular diagnostics have revealed that breast cancer is a multifaceted disease, characterized by inter-tumoral and intra-tumoral heterogeneity and, unlike the past, molecular classifications based on the expression of individual biomarkers have led to devising novel therapeutic strategies that improve patient survival. In this review, we report and discuss the molecular classification of breast cancer subtypes, the heterogeneity resource, and the advantages and disadvantages of current drug regimens with consideration of pharmacogenomics in response and resistance to treatment.

Harnessing benefit from targeting tumor associated carbohydrate antigens

Integrating additive or synergistic antitumor effects that focus on distinct elements of tumor biology are the most rational strategies for cancer treatment. Treatments for breast cancer have increased overall survival, but remain limited by lack of efficacy in a subset of breast cancer patients. The real challenge is to define what elements of tumor biology make the most sense to be integrated. An emerging strategy is to consider a systems biology approach to impact multiple interactions in networks as compare with hitting a specific protein-protein interaction target. In this review, we consider how targeting tumor associated carbohydrate antigens (TACA) that are fundamental to signal pathways might be tailored to harness benefit from combination therapy of sustained immunity with chemotherapy. An approach we are developing makes use of a carbohydrate mimetic peptide (CMP) to induce polyspecific antibodies, which by their nature have numerous on and off target effects. Linking multi-target TACA recognition with mechanisms affecting tumor growth in the context of network heterogeneity and concepts of immune surveillance to tumor cells and the type of breast cancer patients that would benefit from such an approach provides a novel integrative treatment.

Use of Systemic Therapy Concurrent With Cranial Radiotherapy for Cerebral Metastases of Solid Tumors

The incidence of brain metastases of solid tumors is increasing. Local treatment of brain metastases is generally straightforward: cranial radiotherapy (e.g., whole-brain radiotherapy or stereotactic radiosurgery) or resection when feasible. However, treatment becomes more complex when brain metastases occur while other metastases, outside of the central nervous system, are being controlled with systemic therapy (chemotherapeutics, molecular targeted agents, or monoclonal antibodies). It is known that some anticancer agents can increase the risk for neurotoxicity when used concurrently with radiotherapy. Increased neurotoxicity decreases quality of life, which is undesirable in this predominantly palliative patient group. Therefore, it is of utmost importance to identify the compounds that should be temporarily discontinued when cranial radiotherapy is needed.This review summarizes the (neuro)toxicity data for combining systemic therapy (chemotherapeutics, molecular targeted agents, or monoclonal antibodies) with concurrent radiotherapy of brain metastases. Because only a limited amount of high-level data has been published, a risk assessment of each agent was done, taking into account the characteristics of each compound (e.g., lipophilicity) and the microenvironment of brain metastasis. The available trials suggest that only gemcitabine, erlotinib, and vemurafenib induce significant neurotoxicity when used concurrently with cranial radiotherapy. We conclude that for most systemic therapies, the currently available literature does not show an increase in neurotoxicity when these therapies are used concurrently with cranial radiotherapy. However, further studies are needed to confirm safety because there is no high-level evidence to permit definitive conclusions. The Oncologist 2017;22:222-235Implications for Practice: The treatment of symptomatic brain metastases diagnosed while patients are receiving systemic therapy continues to pose a dilemma to clinicians. Will concurrent treatment with cranial radiotherapy and systemic therapy (chemotherapeutics, molecular targeted agents, and monoclonal antibodies), used to control intra- and extracranial tumor load, increase the risk for neurotoxicity? This review addresses this clinically relevant question and evaluates the toxicity of combining systemic therapies with cranial radiotherapy, based on currently available literature, in order to determine the need to and interval to interrupt systemic treatment.

Azaepothilone B and its derivatives: a patent review

INTRODUCTION

Azaepothilone B, also known as ixabepilone, is a semi synthetic second generation epothilone B analogue. Azaepothilone B, its derivatives, and analogues, are used for treating advance metastatic breast cancer. It has been used as a chemotherapeutic medication for cancer.

AREAS COVERED

This review highlights the patents on different routes for synthesis of azaepothilone B, its derivatives and analogues. The review will also provide the reported pharmacological activity and its polymorphs in the treatment of several cancers, such as breast cancer (metastatic or locally advanced), non-Hodgkin's lymphoma, and pancreatic cancer. In addition, it considers other proliferative diseases such as viral infections, degenerative diseases of the musculoskeletal system, kidney disease, and immune response related diseases. Different databases such as Espacenet, ISI Web of Knowledge, Patbase, and Thomson Innovation have been searched extensively to review the patents. The analysis has been done to indicate the patenting trend across years and the comparison of active assignees.

EXPERT OPINION

Azaepothilone B, along with its derivatives and analogues, can damage cancer cells in very low concentrations and retain its activity when tumor cells are insensitive to paclitaxel. Hence, it is highly potent agent. Azaepothilone B alone, in combination with other chemotherapeutics, or in the form of formulations, led to applications in various types of cancer. Also, antiproliferative activity of azaepothilone B has great potential for the treatment of proliferative diseases, such as skin diseases and infections. Recent progress in synthesizing azaepothilone B has encouraged researchers to develop new methods for the synthesis of azaepothilone B, its derivatives, and analogues, to obtain maximum yield in minimum steps.

Advances in the approach to novel drug clinical development for breast cancer

INTRODUCTION

In the post-genomic era clinical development of new agents to treat breast cancer (BC) can be a real challenge. Different from chemotherapy agents, with a broad but not specific spectrum of activity, novel drugs are being developed as 'targeted' agents, potentially benefiting a subgroup of patients. In BC, different clinically identifiable subtypes are now separately addressed in specific clinical trials.

AREAS COVERED

In this review, the authors discuss the clinical development of targeted drugs that have become part of the current treatment of BC. They also highlight the challenges that in other cases determined the failure of promising compounds. Furthermore, the article reports on how combinations of targeted agents have emerged as valid strategies to overcome acquired resistance. It also provides discussion of how 'old' therapies can be retargeted to certain patient populations or 'reinvented' as safer and more effective with the creation of drug conjugates. They also discuss how novel clinical trial designs are emerging to accelerate the successful matching of targeted drugs to the right patient population.

EXPERT OPINION

It is important not to forget that the development of BC therapeutics is a 'moving target', as its biology evolves in time under the pressure of ongoing treatments. There are currently a finite number of resources available for the development of new therapeutics, which means that resources need to be carefully allocated. There is also a need to prioritize clinical trials that can reduce the number of patients who are candidates for expensive treatments.

Everolimus: a new hope for patients with breast cancer

BACKGROUND

Breast cancer cells can develop resistance to standard hormonal treatment and chemotherapy with the activation of the mTOR pathway; this is supported by results of preclinical and clinical studies. In clinical trials, the addition of everolimus to hormonal treatment or anti-HER2 treatment improved the outcomes of breast cancer patients. The aim of this review is to discuss the efficacy and safety data of everolimus in all categories of breast cancer in recent published studies.

SCOPE

Everolimus showed positive results in clinical studies. A literature search was made from PubMed, ASCO and San Antonio Breast Cancer Symposium Meeting abstracts by using the following search key words: 'everolimus', 'RAD001', 'mTOR inhibitor', 'breast cancer' 'endocrine therapy resistance' and 'HER-2 targeted therapies'. The last search was on June 10, 2013. The most important limitation of our review is that most of the data on everolimus rely on phase I and II trials.

FINDINGS

Preclinical studies showed that mTOR activation can be the responsible mechanism in all subgroups of breast cancer. Results of both the TAMRAD and BOLERO-2 studies have showed that mTOR inhibition in combination with endocrine therapy can be a new treatment strategy for MBC patients who are resistant to aromatase inhibitors. In the BOLERO-2 study, time to deterioration in health-related quality of life was also significantly higher in the everolimus and exemestane arm compared to the exemestane plus placebo arm. The recently completed BOLERO-3 study showed that mTOR inhibition in combination with trastuzumab plus vinorelbine treatment significantly improved PFS compared to trastuzumab plus vinorelbine alone in trastuzumab-resistant MBC patients.

CONCLUSION

Recent trials have shown that everolimus has produced promising anti-tumor activity in combination with trastuzumab in HER2-positive metastatic breast cancer and in combination with exemestane in patients with hormone-receptor-positive metastatic breast cancer who had recurrence or progression while receiving a nonsteroidal aromatase inhibitor. Results of ongoing studies with everolimus show evidence that using everolimus in earlier stages of the disease, namely in the adjuvant and neoadjuvant settings, could be benefical.

Advances in molecular and clinical subtyping of breast cancer and their implications for therapy

The identification of the intrinsic molecular subtypes of breast cancer has enhanced our understanding of tumor biology, informing therapeutic targets, and clinical trial design. This article reviews the intrinsic classification system and the clinically defined subtypes of breast cancer. We review the molecular drivers of each subtype and discuss implications for prognosis, clinical management, and future directions.

The role of thymidine kinase in cancer diseases

Thymidine kinase 1 (TK 1-fetal) is a cell cycle-dependent marker that increases dramatically during the S-phase of the cell cycle. In this review, the authors discuss serum levels of thymidine kinase in a variety of neoplasias. Determination of thymidine kinase helps to monitor the follow-up of solid tumours and haematological malignancies as well as indicating the efficacy of adjuvant and palliative chemotherapy. Elevated levels of thymidine kinase must always be interpreted together with a detailed knowledge of the patient's condition because nonspecific elevations of serum levels (inflammatory and autoimmune diseases) must be excluded.

A prospective evaluation of a breast cancer prognosis signature in the observational RASTER study

The 70-gene signature (MammaPrint™) has been developed on retrospective series of breast cancer patients to predict the risk of breast cancer distant metastases. The microarRAy-prognoSTics-in-breast-cancER (RASTER) study was the first study designed to prospectively evaluate the performance of the 70-gene signature, which result was available for 427 patients (cT1–3N0M0). Adjuvant systemic treatment decisions were based on the Dutch CBO 2004 guidelines, the 70-gene signature and doctors' and patients' preferences. Five-year distant-recurrence-free-interval (DRFI) probabilities were compared between subgroups based on the 70-gene signature and Adjuvant! Online (AOL) (10-year survival probability <90% was defined as high-risk). Median follow-up was 61.6 months. Fifteen percent (33/219) of the 70-gene signature low-risk patients received adjuvant chemotherapy (ACT) versus 81% (169/208) of the 70-gene signature high-risk patients. The 5-year DRFI probabilities for 70-gene signature low-risk (n = 219) and high-risk (n = 208) patients were 97.0% and 91.7%. The 5-year DRFI probabilities for AOL low-risk (n = 132) and high-risk (n = 295) patients were 96.7% and 93.4%. For 70-gene signature low-risk–AOL high-risk patients (n = 124), of whom 76% (n = 94) had not received ACT, 5-year DRFI was 98.4%. In the AOL high-risk group, 32% (94/295) less patients would be eligible to receive ACT if the 70-gene signature was used. In this prospective community-based observational study, the 5-year DRFI probabilities confirmed the additional prognostic value of the 70-gene signature to clinicopathological risk estimations such as AOL. Omission of adjuvant chemotherapy as judged appropriate by doctors and patients and instigated by a low-risk 70-gene signature result, appeared not to compromise outcome.

Combining mTOR Inhibitors with Chemotherapy and Other Targeted Therapies in Advanced Breast Cancer: Rationale, Clinical Experience, and Future Directions

Improvements in survival of patients with breast cancer have been attributed to the development of agents that target key components of dysregulated pathways involved in oncogenesis and progression of breast cancer. Aberrant mammalian target of rapamycin (mTOR) activation has been implicated in oncogenesis, angiogenesis, and the development of estrogen independence and resistance to chemotherapy in breast tumors. Several mTOR inhibitors (sirolimus, everolimus, temsirolimus, and ridaforolimus) have demonstrated antitumor activity in breast cancer cells. Combining mTOR inhibitors with endocrine therapies has demonstrated clinical antitumor activity in patients with metastatic breast cancer. In addition, mTOR inhibitor combinations with various targeted biologic agents or cytotoxic chemotherapeutic agents are being examined in more than 40 clinical trials with some early promising results. Combination therapies targeting multiple components of these central signaling pathways may be an optimal treatment strategy for patients with advanced breast cancer.

Use of disease-modifying antirheumatic drugs during pregnancy and risk of preeclampsia

OBJECTIVE

To describe patterns of disease-modifying antirheumatic drug (DMARD) use during pregnancy in a population-based cohort, and to evaluate the association between autoimmune disease, DMARDs, corticosteroids, and nonsteroidal antiinflammatory drugs (NSAIDs) and preeclampsia.

METHODS

Using health care utilization databases from British Columbia (1997-2006), we compared the risk for preeclampsia among 44,786 women with and without autoimmune disease with study drug dispensings before pregnancy (past users) and before and during the first 20 gestational weeks (continuous users). Relative risks (RRs) and 95% confidence intervals (95% CIs) were estimated.

RESULTS

Only 414 women (0.1%) had a DMARD dispensing during pregnancy. The incidence of preeclampsia was 2.3% for past DMARD users, 2.7% for past corticosteroid users, and 2.9% for past NSAID users. Compared to past users, the continuous DMARD user RR was 2.29 (95% CI 0.81-6.44), and was 0.89 (95% CI 0.51-1.56) for corticosteroid and 0.84 (95% CI 0.63-1.10) for NSAID users. Compared to women without autoimmune disease, the delivery year-adjusted RR was 2.02 (95% CI 1.11-3.64) for women with systemic lupus erythematosus (SLE). The DMARD results were attenuated when antimalarials were excluded, and the delivery year-adjusted RR was 0.95 (95% CI 0.25-3.55) when the DMARD analysis was restricted to women with autoimmune disease.

CONCLUSION

Few women were exposed to DMARDs during pregnancy. We observed a 2-fold increased risk of preeclampsia among women with SLE and a nonsignificant increase in risk in DMARD users. The DMARD and preeclampsia association was attenuated when antimalarials were excluded and null when restricted to women with autoimmune disease, which suggests the association is likely due to greater autoimmune disease severity in DMARD users.

Long-term biomonitoring of breast cancer patients under adjuvant chemotherapy: the comet assay as a possible predictive factor

Most chemotherapy treatments induce DNA damage in the exposed patients. Using the comet assay and peripheral blood mononuclear cells (PBMC), we have quantified this induced DNA damage and studied its relationship with GSTM1 and GSTT1 polymorphisms, and clinical parameters. For this purpose, 29 Caucasian women, breast cancer patients under CMF or CEF adjuvant chemotherapy were included in the study. The clinical parameters considered were (i) therapies side effects, like haematological and biochemical toxicities, (ii) prognostic and predictive factors, like hormonal receptor expression, tumour differentiation degree, sickness stage, and nodal status, and (iii) the effectiveness of the chemotherapy measured as five years relapse probability. The results were also related to the confounding factor age. Comet assay results indicate that 13 patients were characterised by absence of induced DNA strand breaks, and 16 patients presented induced DNA strand breaks along the treatment. Relationships between comet variables and clinical parameters, found with principal component analysis, correlations, one-way ANOVA and multivariate logistic regression analyses revealed that: (1) baseline levels of DNA damage are related to GSTM1 genotype and to hormonal receptor expression; (2) GSTM1 genotype also influences comet results after chemotherapy, as it does the AST level; (3) the tail moment values of the cycle 6.1 and the sickness stage might predict cancer relapse at five years: for the Stage, OR = 13.8 (IIB versus I+IIA), 95% CI 0.80-238.97, and for 6.1 cycle TM, OR = 1.3, 95%, CI 0.97-1.79, with a potential model (10* Stage (I-IIA = 0, IIB = 1) + 6.1 cycle), that has a good predictive capacity, with an area under ROC curve of 0.872 (CI 0.62-1.00). To our knowledge, this is the first time such a predictive value is found for the comet assay. Nevertheless, before the comet assay could be used as a tool for oncologists, this relationship should be confirmed in more patients, and problems of standardisation and data interpretation should be solved.

Long-term toxic effects of adjuvant chemotherapy in breast cancer

Breast cancer is the most common malignant tumor affecting women. Adjuvant systemic therapies have been shown to have a significant impact on reducing the risk for breast cancer recurrence and overall mortality. Chemotherapy remains an important and frequently used treatment option in the adjuvant setting, and the associated short-term adverse events are very well described. However, there is insufficient information regarding the long-term sequelae of most chemotherapeutic agents. In this review, we describe different potential long-term adverse events associated with adjuvant chemotherapy in breast cancer, with a particular focus on long-term cardiac toxicity, secondary leukemia, cognitive function, and neurotoxicity. In addition, we discuss the effect of adjuvant chemotherapy on fertility and sexual function of young breast cancer patients. These adverse events are frequently overshadowed by the well-demonstrated clinical efficacy and/or reassuring short-term safety profiles of the different chemotherapy regimens commonly used today. We believe that a proper understanding and appreciation of these adverse events will enable us to refine our strategies for managing breast cancer. The fact that adjuvant chemotherapy is often given to patients who might not really need it urges us to consider the whole spectrum of chemotherapy risks versus benefits to maximize benefit without compromising quality of life.

Optimal sequence of implied modalities in the adjuvant setting of breast cancer treatment: an update on issues to consider

The adjuvant setting of early breast cancer treatment is an evolving field where different modalities must be combined to improve outcomes; moreover, quality of life of breast cancer survivors emerges as a new important parameter to consider, thus implying a better understanding of toxicities of these modalities. We have conducted a review focusing on the latest literature of the past 3 years, trying to evaluate the existing data on the maximum acceptable delay of radiotherapy when given as sole adjuvant treatment after surgery and the optimal sequence of all these modalities with respect to each other. It becomes evident radiotherapy should be given as soon as possible and within a time frame of 6-20 weeks. Chemotherapy is given before radiotherapy and hormone therapy. However, radiotherapy should be started within 7 months after surgery in these cases. Hormone therapy with tamoxifen might be given safely concomitantly or sequentially with radiotherapy although solid data are still lacking. The concurrent administration of letrozole and radiotherapy seems to be safe, whereas data on trastuzumab can imply only that it is safe to use concurrently with radiotherapy. Randomized comparisons of hormone therapy and trastuzumab administration with radiotherapy need to be performed.

Gene expression profile predicts outcome after anthracycline-based adjuvant chemotherapy in early breast cancer

Prognosis of early beast cancer is heterogeneous. Today, no histoclinical or biological factor predictive for clinical outcome after adjuvant anthracycline-based chemotherapy (CT) has been validated and introduced in routine use. Using DNA microarrays, we searched for a gene expression signature associated with metastatic relapse after adjuvant anthracycline-based CT without taxane. We profiled a multicentric series of 595 breast cancers including 498 treated with such adjuvant CT. The identification of the prognostic signature was done using a metagene-based supervised approach in a learning set of 323 patients. The signature was then tested on an independent validation set comprising 175 similarly treated patients, 128 of them from the PACS01 prospective clinical trial. We identified a 3-metagene predictor of metastatic relapse in the learning set, and confirmed its independent prognostic impact in the validation set. In multivariate analysis, the predictor outperformed the individual current prognostic factors, as well as the Nottingham Prognostic Index-based classifier, both in the learning and the validation sets, and added independent prognostic information. Among the patients treated with adjuvant anthracycline-based CT, with a median follow-up of 68 months, the 5-year metastasis-free survival was 82% in the "good-prognosis" group and 56% in the "poor-prognosis" group. Our predictor refines the prediction of metastasis-free survival after adjuvant anthracycline-based CT and might help tailoring adjuvant CT regimens.

Hormonal therapy for oestrogen receptor-negative breast cancer is associated with higher disease-specific mortality

BACKGROUND

Tamoxifen has a remarkable impact on the outcome of oestrogen receptor (ER)-positive breast cancer. Without proven benefits, tamoxifen is occasionally prescribed for women with ER-negative disease. This population-based study aims to estimate the impact of tamoxifen on the outcome of ER-negative disease.

METHODS

We identified all women (n = 528) diagnosed with ER-negative invasive breast cancer between 1995 and 2005. With Cox regression analysis, we calculated breast cancer mortality risks of patients treated with tamoxifen compared with those treated without tamoxifen. We adjusted these risks for the individual probabilities (propensity scores) of having received tamoxifen.

RESULTS

Sixty-nine patients (13%) with ER-negative disease were treated with tamoxifen. Five-year disease-specific survival for women treated with versus without tamoxifen were 62% [95% confidence interval (CI) 48% to 76%] and 79% (95% CI 75% to 83%), respectively (P(Log-rank) < 0.001). For ER-negative patients, risk of death from breast cancer was significantly increased in those treated with tamoxifen compared with patients treated without tamoxifen (adjusted hazard ratio = 1.7, 95% CI 1.1-2.9, P = 0.031).

CONCLUSION

Our results show that patients with ER-negative breast cancer treated with tamoxifen have an increased risk of death from their disease. Tamoxifen use should be avoided for these patients.

Improving decision-making in early breast cancer: who to treat and how?

Recent advances in primary and adjuvant treatment for early-stage breast cancer have reduced mortality rates, and improved the overall prognosis. Many patients can be cured, while others may survive for 10 years or more beyond diagnosis, thanks to a combination of preoperative therapy, surgery, radiotherapy, and systemic adjuvant therapy. Minimally invasive procedures, more effective drugs, and improved treatment regimens are helping to reduce breast cancer recurrences and deaths, while minimizing side effects and maintaining quality of life. Despite such improvements, a significant number of patients with early disease will relapse, including those who are clinically disease-free after primary and adjuvant therapy. Advances in breast tumor biology have led to the discovery of many different tumor types, and a uniform approach to treatment is no longer appropriate. Potential markers have been identified for the risk of relapse and responsiveness to a given therapy, thus treatment decisions and clinical guidelines, previously based on data from large patient populations, are changing to reflect a movement towards individually tailored treatment. Refinements in clinical practice will help physicians to identify the patients who will benefit the most from a particular approach, reducing overtreatment, and sparing patients unnecessary therapy. Genetic studies are helping to increase our understanding of the metastatic potential of tumors, leading to the development of adjuvant therapies for the prevention of metastases in selected patients. This article reviews the latest advances in treatment for early breast cancer, and explores how research and clinical practice are evolving to improve therapies and treatment decision-making, allowing physicians to optimize patient care.

Maurocalcine as a non toxic drug carrier overcomes doxorubicin resistance in the cancer cell line MDA-MB 231

PURPOSE

The aim of this study is to overcome tumour cell resistance that generally develops after administration of commonly used anti-cancer drugs, such as doxorubicin.

METHODS

Recently, cell penetrating peptides have been used for their ability to deliver non-permeant compounds into cells. One such cell penetrating peptide, maurocalcine, has been isolated from the venom of a Tunisian scorpion. Herein, we report the effects of doxorubicin covalently coupled to an analogue of maurocalcine on drug-sensitive or drug-resistant cell lines MCF7 and MDA-MB 231.

RESULTS

We demonstrated the in vitro anti-tumoral efficacy of the doxorubicin maurocalcine conjugate. On a doxorubicin-sensitive cancer cell line, the maurocalcine-conjugated form appears slightly less efficient than doxorubicin itself. On the contrary, on a doxorubicin-resistant cancer cell line, doxorubicin coupling allows to overcome the drug resistance. This strategy can be generalized to other cell penetrating peptides since Tat and penetratin show similar effects.

CONCLUSION

We conclude that coupling anti-tumoral drugs to cell penetrating peptides represent a valuable strategy to overcome drug resistance.

National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for Use of Tumor Markers in Testicular, Prostate, Colorectal, Breast, and Ovarian Cancers

Background: Updated National Academy of Clinical Biochemistry (NACB) Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed.

Methods: Published reports relevant to use of tumor markers for 5 cancer sites—testicular, prostate, colorectal, breast, and ovarian—were critically reviewed.

Results: For testicular cancer, α-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase are recommended for diagnosis/case finding, staging, prognosis determination, recurrence detection, and therapy monitoring. α-Fetoprotein is also recommended for differential diagnosis of nonseminomatous and seminomatous germ cell tumors. Prostate-specific antigen (PSA) is not recommended for prostate cancer screening, but may be used for detecting disease recurrence and monitoring therapy. Free PSA measurement data are useful for distinguishing malignant from benign prostatic disease when total PSA is &lt;10 μg/L. In colorectal cancer, carcinoembryonic antigen is recommended (with some caveats) for prognosis determination, postoperative surveillance, and therapy monitoring in advanced disease. Fecal occult blood testing may be used for screening asymptomatic adults 50 years or older. For breast cancer, estrogen and progesterone receptors are mandatory for predicting response to hormone therapy, human epidermal growth factor receptor-2 measurement is mandatory for predicting response to trastuzumab, and urokinase plasminogen activator/plasminogen activator inhibitor 1 may be used for determining prognosis in lymph node–negative patients. CA15-3/BR27–29 or carcinoembryonic antigen may be used for therapy monitoring in advanced disease. CA125 is recommended (with transvaginal ultrasound) for early detection of ovarian cancer in women at high risk for this disease. CA125 is also recommended for differential diagnosis of suspicious pelvic masses in postmenopausal women, as well as for detection of recurrence, monitoring of therapy, and determination of prognosis in women with ovarian cancer.

Conclusions: Implementation of these recommendations should encourage optimal use of tumor markers.

[Adjuvant endocrine therapy in postmenopausal hormone-sensitive breast cancer: to start, to switch or to extend?]

From the big randomized clinical trials there are evidences that adjuvant endocrine therapy for hormone-sensitive early breast cancer in postmenopausal women should include an aromatase inhibitor (AI). Anastrozole or letrozole should be used upfront for 5 years (ATAC and BIG 1-98), the sequential approach of tamoxifen for 2-3 years, followed by anastrozole or exemestane for 2-3 years is a reasonable alternative (ABCSG8, ARNO 95, IES, ITA), and mostly in patients with node-positive disease completing 5 years of tamoxifen should be offered letrozole up to 4-5 years (MA-17). In each of these trials incorporation of an AI resulted in significant improvement in study endpoints. Further results will be needed to establish the optimal beneficial effect, use, duration and safety of adjuvant AI therapies.

First-line treatment options for patients with HER-2 negative metastatic breast cancer: the impact of modern adjuvant chemotherapy

The management of early breast cancer has evolved rapidly in recent years. Consequently, the range of first-line treatment options for metastatic breast cancer (MBC) is becoming increasingly complicated and therapy depends on a complex interaction of tumor, patient, and physician variables. Arguably one of the most important factors determining choice of first-line chemotherapy is prior adjuvant therapy. We have reviewed data from large, randomized clinical trials to identify the most effective regimens and help clinicians to select first-line treatment based on previous adjuvant therapy. In this review we provide recommendations on the most appropriate first-line therapy according to the type of previous adjuvant therapy. With such a wide array of treatment options available, none is likely to become the gold-standard first-line treatment for MBC. Furthermore, as increasing emphasis is placed on the quality as well as the duration of survival after development of MBC, treatment decisions should take into account tumor characteristics, toxicity, convenience, potential impact on quality of life, and patient preference, in addition to robust efficacy data.

GnRH and LHR gene variants predict adverse outcome in premenopausal breast cancer patients

BACKGROUND

Breast cancer development and progression are dependent on estrogen activity. In premenopausal women, estrogen production is mainly regulated through the hypothalamic-pituitary-gonadal (HPG) axis.

METHODS

We have investigated the prognostic significance of two variants of genes involved in the HPG-axis, the GnRH (encoding gonadotropin-releasing hormone) 16Trp/Ser genotype and the LHR (encoding the luteinizing hormone receptor) insLQ variant, in retrospectively collected premenopausal breast cancer patients with a long follow-up (median follow-up of 11 years for living patients).

RESULTS

Carriership was not related with breast cancer risk (the case control study encompassed 278 premenopausal cases and 1,758 premenopausal controls). A significant adverse relationship of the LHR insLQ and GnRH 16Ser genotype with disease free survival (DFS) was observed in premenopausal (hormone receptor positive) breast cancer patients. In particular, those patients carrying both the GnRH 16Ser and LHR insLQ allele (approximately 25%) showed a significant increased risk of relapse, which was independent of traditional prognostic factors (hazard ratio 2.14; 95% confidence interval 1.32 to 3.45; P = 0.002).

CONCLUSION

We conclude that the LHR insLQ and GnRH 16Ser alleles are independently associated with shorter DFS in premenopausal patients. When validated, these findings may provide a lead in the development of tailored treatment for breast cancer patients carrying both polymorphisms.

Effects of folate and folylpolyglutamyl synthase modulation on chemosensitivity of breast cancer cells

Folylpolyglutamyl synthase (FPGS) converts intracellular folates and antifolates to polyglutamates. Polyglutamylated folates and antifolates are retained in cells longer and are better substrates than their monoglutamate counterparts for enzymes involved in one-carbon transfer. FPGS modulation affects the chemosensitivity of cancer cells to antifolates, such as methotrexate, and 5-fluorouracil (5FU) by altering polyglutamylation of antifolates and specific target intracellular folate cofactors. However, this effect may be counterbalanced by FPGS modulation-induced changes in polyglutamylation of other intracellular folate cofactors and total intracellular folate pools. We generated an in vitro model of FPGS overexpression and inhibition in breast cancer cells by stably transfecting human MDA-MB-435 breast cancer cells with the sense FPGS cDNA or FPGS-targeted small interfering RNA, respectively, and investigated the effects of FPGS modulation on chemosensitivity to 5FU and methotrexate. FPGS modulation-induced changes in polyglutamylation of both antifolates and folate cofactors and in intracellular folate pools affected chemosensitivity of breast cancer cells to pemetrexed and trimetrexate whose cytotoxic effects do or do not depend on polyglutamylation, respectively, in a predictable manner. However, the effects of FPGS modulation on the chemosensitivity of breast cancer cells to 5FU and methotrexate seem to be highly complex and depend not only on polyglutamylation of a specific target intracellular folate cofactor or methotrexate, respectively, but also on total intracellular folate pools and polyglutamylation of other intracellular folate cofactors. Whether or not FPGS modulation may be an important clinical determinant of chemosensitivity of breast cancer cells to 5FU and methotrexate-based chemotherapy needs further exploration.

Anti-tumor activity of capecitabine and vinorelbine in patients with anthracycline- and taxane-pretreated metastatic breast cancer: findings from the EORTC 10001 randomized phase II trial

The aim of this randomized phase II study was to evaluate the anti-tumor activity and safety of capecitabine and vinorelbine in patients with metastatic breast cancer pretreated with taxanes and anthracyclines. We planned to randomize 72 patients to capecitabine 1250 mg/m(2) orally bid days 1-14 or vinorelbine 30 mg/m(2) i.v. days 1 and 8, both given every 3 weeks. The study was stopped due to poor accrual with 47 patients enrolled. Responses were seen in 2/23 patients treated with capecitabine (8.7%; 95% CI 1.1-29.0) and 3/24 patients treated with vinorelbine (12.5%; 95% CI 2.7-32.4). Median progression-free survival was 2.8 and 2.6 months, and median overall survival was 9.3 and 11.0 months, in the capecitabine and vinorelbine arms, respectively. There was more hematologic toxicity, neurotoxicity, and nausea/vomiting with vinorelbine and more diarrhea and hand-foot syndrome with capecitabine. The anti-tumor activity of capecitabine and vinorelbine seems to be comparable, but the toxicity profiles are different.

Taking gene-expression profiling to the clinic: when will molecular signatures become relevant to patient care?

The advent of microarray technology has enabled scientists to simultaneously investigate the expression of thousands of genes. Gene-expression profiling studies have provided a molecular classification of breast cancer into clinically relevant subtypes, new tools to predict disease recurrence and response to different treatments, and new insights into various oncogenic pathways and the process of metastatic progression. Here we describe the state of the art of gene-expression studies in breast cancer, and consider both their current limitations and future promises. We also discuss the potential of molecular signatures to have an impact on individual breast cancer patient management, and ultimately to accelerate the transition between empirical and tailored medicine.

The discovery of highly selective erbB2 (Her2) inhibitors for the treatment of cancer

The synthesis and biological evaluation of potent and selective inhibitors of the erbB2 kinase is presented. Based on the 4-anilinoquinazoline chemotype, the syntheses of several new series of erbB2 inhibitors are described with quinazoline and pyrido[4,3-d]pyrimidine cores. The vast majority of these compounds are found to be >100x selective over the closely related EGFR kinase. Two lead compounds are further shown to have low clearance and moderate bioavailability in rat.

The Rationale for Adjuvant Chemotherapy in Stage I Non-small Cell Lung Cancer

The past decade has witnessed renewed interest in studies exploring the benefits of adjuvant (postoperative) chemotherapy (+/- radiation therapy) in patients with resected non-small cell lung cancer (NSCLC). Recently completed adjuvant trials have included a heterogeneous group of patients with resected stages I to IIIA NSCLC. With rare exception, the published results of these studies indicate adjuvant chemotherapy imparts a significant overall survival advantage. Subset analyses suggest survival benefit occurs primarily in patients with resected stage II or IIIA and is less likely to occur in stage I patients. This apparent lack of survival benefit in stage I patients was seemingly validated in a prospective trial conducted by the Cancer and Leukemia Group B in which stage IB patients were randomized to observation or adjuvant carboplatin and paclitaxel. Survival at 5 -years was identical in the two arms of this trial. By contrast, two contemporary postoperative chemotherapy trials also conducted exclusively in stage I NSCLC patients yielded positive survival results. The divergent outcome of the prospective trials along with the negative subset analyses has created uncertainty as to the utility of postoperative adjuvant chemotherapy in stage I NSCLC. Herein we review the data underlying this controversy and offer a proposed algorithm to aid the clinician in selecting patients whom we believe may benefit from adjuvant chemotherapy. The treatment algorithm is based on currently available tumor- and host-related factors that affect prognosis.

Advances in hormonal therapy for breast cancer

OBJECTIVES

To describe recent developments in hormonal therapy for breast cancer, focusing on SERMs and AIs.

DATA SOURCES

Published journal articles and texts, research reports and monographs, government publications, and professional organization guidelines.

CONCLUSION

Research continues to identify the effectiveness of hormonal therapy in breast cancer, including adjuvant treatment in early and advanced stages as well as a chemopreventive measure. The individual drug profile must be evaluated for safety and efficacy, and the impact on QOL must be considered.

IMPLICATIONS FOR NURSING PRACTICE

It is imperative that oncology nurses understand the physiology, application, risks, and benefits of hormonal therapies.

Differential effects of tamoxifen and anastrozole on optic cup size in breast cancer survivors

Introduction

The main purpose of this study was to determine whether the optic cups of tamoxifen users and anastrozole users differ in size, with the cups of the tamoxifen users being smaller.

Methods

Optic nerve head (ONH) topography was measured using a commercially available, confocal scanning laser ophthalmoscope for three populations of amenorrheic women ages 40–69 years: subjects using (1) tamoxifen (20 mg/day) or (2) anastrozole (1 mg/day) for ≤ 2 years as adjuvant therapy after successful primary treatment for breast cancer, and (3) control subjects with no breast cancer histories and not using any hormonal medication. All subjects had excellent visual acuity and healthy eyes, based on conventional photographic assessment.

Results

The cup volumes of the tamoxifen users were shown to be significantly smaller than the cup volumes of the anastrozole users, which were indistinguishable from normal. Because the cup volumes of the tamoxifen users decreased markedly with age at about 50 years and because anastrozole is indicated only for post-menopausal women, comparisons were reassessed for subjects older than 50 years. For these subjects, the cup volumes of the tamoxifen users averaged less than half of the volumes for each of the other two subject groups, and significant between-group differences existed in both the lateral (cup area) and axial (cup depth) directions. In contrast, any between-group differences at the ONH margin were small and not significant.

Conclusions

The results of this study suggest that the ONH be assessed biomorphometrically for tamoxifen users reporting visual change that cannot be attributed to non-tamoxifen causes. The ability of modern intraocular imaging techniques to reveal anatomic change on the order of tens of microns may be useful for assessing tamoxifen-induced effects occurring simultaneously elsewhere in the brain, particularly since the presence of small cups is consistent with the possibility of tamoxifen-induced astrocytic swelling.

Estrogen receptor α/β isoforms, but not βcx, modulate unique patterns of gene expression and cell proliferation in Hs578T cells

The actions of 17beta-estradiol (E2) and selective estrogen receptor modulators (SERMs) have been extensively investigated regarding their ability to act through estrogen receptor-alpha (ERalpha) to perturb estrogen receptor positive (ER+) breast cancer (BC) growth. However, many BCs also express ERbeta, along with multiple estrogen receptor (ER) splice variants such as ERbetacx, an ERbeta splice variant incapable of binding ligand. To gain a more comprehensive understanding of ER action in BC cells, we stably expressed ERalpha, ERbeta, or ERbetacx under doxycycline (Dox) control in Hs578T cells. Microarrays performed on E2 or 4OH-tamoxifen (4HT) treated Hs578T ERalpha and ERbeta cells revealed distinct ligand and receptor-dependent patterns of gene regulation, while the induction of ERbetacx did not alter gene expression patterns. E2 stimulation of Hs578T ERbeta cells resulted in a 27% decrease in cellular proliferation, however, no significant change in proliferation was observed following the exposure of Hs578T ERalpha or ERbeta cells to 4HT. Expression of ERbetacx in Hs578T cells did not effect cellular proliferation. Flow cytometry assays revealed a 50% decrease in E2-stimulated Hs578T ERbeta cells entering S-phase, along with a 17% increase in G0/G1 cell-cycle arrest. We demonstrate here that ERalpha and ERbeta regulate unique gene expression patterns in Hs578T cells, and such regulation likely is responsible for the observed isoform-specific changes in cell proliferation. Hs578T ER expressing cell-lines provide a unique BC model system, permitting the comparison of ERalpha, ERbeta, and ERbetacx actions in the same cell-line.

Epigenetic reprogramming of liver cells in tamoxifen-induced rat hepatocarcinogenesis

Tamoxifen, a nonsteroidal anti-estrogen, is a potent genotoxic hepatocarcinogen in rats, with both tumor initiating and promoting properties. Recently it has been demonstrated that genotoxic carcinogens, in addition to exerting genotoxic effects, often cause epigenetic alterations and these induced epigenetic changes may play important mechanistic role in carcinogenesis. In the present study, we investigated the role of tamoxifen-induced epigenetic changes in hepatocarcinogenic process. The results of the study showed that exposure of female F344 rats to tamoxifen resulted in progressive loss of CpG methylation in regulatory sequences of long interspersed nucleotide elements (LINE-1) and prominent increase in expression of LINE-1 elements and c-myc proto-oncogene. The accumulation of tamoxifen-induced DNA lesions was accompanied by the decreased level of Rad51, Ku70, and DNA polymerase beta (Polbeta) proteins that play a crucial role in maintenance of genomic stability. Furthermore, feeding rats with tamoxifen-containing diet led to increased regenerative cell proliferation, as indicated by the increased level of Ki-67 and proliferating cell nuclear antigen (PCNA) proteins. These data indicate that exposure of animals to genotoxic hepatocarcinogen tamoxifen led to early phenotypical alterations in livers characterized by emergence of epigenetically reprogrammed cells with a specific cancer-related epigenetic phenotype prior to tumor formation.