Design, synthesis and development of novel indolocarbazole derivatives as potential anti-cancer agents

This thesis describes work carried out on the design of new routes to a range of bisindolylmaleimide and indolo[2,3-a]carbazole analogs, and investigation of their potential as successful anti-cancer agents. Following initial investigation of classical routes to indolo[2,3-a]pyrrolo[3,4-c]carbazole aglycons, a new strategy employing base-mediated condensation of thiourea and guanidine with a bisindolyl β-ketoester intermediate afforded novel 5,6-bisindolylpyrimidin-4(3H)-ones in moderate yields. Chemical diversity within this H-bonding scaffold was then studied by substitution with a panel of biologically relevant electrophiles, and by reductive desulfurisation. Optimisation of difficult heterogeneous literature conditions for oxidative desulfurisation of thiouracils was also accomplished, enabling a mild route to a novel 5,6-bisindolyluracil pharmacophore to be developed within this work. The oxidative cyclisation of selected acyclic bisindolyl systems to form a new planar class of indolo[2,3-a]pyrimido[5,4-c]carbazoles was also investigated. Successful conditions for this transformation, as well as the limitations currently prevailing for this approach are discussed. Synthesis of 3,4-bisindolyl-5-aminopyrazole as a potential isostere of bisindolylmaleimide agents was encountered, along with a comprehensive derivatisation study, in order to probe the chemical space for potential protein backbone H-bonding interactions. Synthesis of a related 3,4-arylindolyl-5-aminopyrazole series was also undertaken, based on identification of potent kinase inhibition within a closely related heterocyclic template. Following synthesis of approximately 50 novel compounds with a diversity of H-bonding enzyme-interacting potential within these classes, biological studies confirmed that significant topo II inhibition was present for 9 lead compounds, in previously unseen pyrazolo[1,5-a]pyrimidine, indolo[2,3-c]carbazole and branched S,N-disubstituted thiouracil derivative series. NCI-60 cancer cell line growth inhibition data for 6 representative compounds also revealed interesting selectivity differences between each compound class, while a new pyrimido[5,4-c]carbazole agent strongly inhibited cancer cell division at 10 µM, with appreciable cytotoxic activity observed across several tumour types.

Design, synthesis and evaluation of novel ellipticine derivatives and analogues as anti-cancer agents

This thesis describes work carried out on the synthesis of novel 5- and 11-substituted ellipticines and derivatives of the ellipticine analogues, isoellipticine and deazaellipticine, followed by investigation of their potential as anti-cancer agents. Preparation of the key 5- and 11-substituted ellipticine targets involved the development of regiospecific, sequential alkylation reactions with alkenyllithium and Grignard reagents. Investigation of these novel reactions resulted in a new route towards 5-substituted ellipticines via Grignard reaction with vinylmagnesium bromide. These novel 5-vinylellipticine derivatives were further functionalised in an ozonolysis reaction, followed by oxidation to give a range of novel 5-substituted ellipticines. Less success was encountered in the 11-substituted ellipticine series, however preparation of these derivatives using a previously published route was accomplished, and the resulting 11-formylellipticine was further derivatised to give a panel of novel 9- and 11-substituted ellipticines, incorporating amide, carboxylate, imine and amine functionality. The successful route towards 5-substituted ellipticines was applied to the preparation of a range of novel 11-substituted isoellipticines and 6-substituted deazaellipticines, the first time substantial synthesis has been undertaken with these analogues. In addition to this, the first preparation of isoellipticinium salts is described, and a panel of novel isoellipticinium, 7 formylisoellipticinium and 7-hydroxyisoellipticinium salts were synthesised in good yields. Biological evaluation of a panel of 43 novel ellipticine, isoellipticine and deazaellipticine derivatives was accomplished with a topoisomerase II decatenation assay and submission to the NCI 60-cell line screen. Four novel isoellipticine topoisomerase II inhibitors were identified from the decatenation assay, with strong activity at 10 μM. In addition to this, NCI screening identified five highly cytotoxic ellipticine and isoellipticine compounds with remarkable selectivity profiles for different cancer types. These novel lead compounds represent new templates for further research and synthesis.

Targeting aberrant kinase activity in myeloid leukaemias

Acute myeloid leukaemia (AML) is the most common form of acute leukaemia in adults. Its treatment has remained largely unchanged for the past 30 years. Chronic myeloid leukaemia (CML) represents a tremendous success story in the era of targeted therapy but significant challenges remain including the development of drug resistance and disease persistence due to presence of CML stem cells. The Aurora family of kinases is essential for cell cycle regulation and their aberrant expression in cancer prompted the development of small molecules that selectively inhibit their activity. Chapter 2 of this thesis outlines the efficacy and mechanism of action of alisertib, a novel inhibitor of Aurora A kinase, in preclinical models of CML. Alisertib possessed equipotent activity against CML cells expressing unmutated and mutated forms of BCR-ABL. Notably, this agent retained high activity against the T315I and E255K BCR-ABL mutations, which confer the greatest degree of resistance to standard CML therapy. Chapter 3 explores the activity of alisertib in preclinical models of AML. Alisertib disrupted cell viability, diminished clonogenic survival, induced expression of the forkhead box O3 (FOXO3a) targets p27 and BCL-2 interacting mediator (BIM), and triggered apoptosis. A link between Aurora A expression and sensitivity to ara-C was established. Chapter 4 outlines the role of the proto-oncogene serine/threonine-protein (PIM) kinases in resistance to ara-C in AML. We report that the novel small molecule PIM kinase inhibitor SGI-1776 disrupted cell viability and induced apoptosis in AML. We establish a link between ara-C resistance and PIM over-expression. Finally, chapter 5 explores how the preclinical work outlined in this thesis may be translated into clinical studies that may lead to novel therapeutic approaches for patients with refractory myeloid leukaemia.

An evaluation of reovirus as an effective therapeutic for cancer

Cancer is a global problem. Despite the significant advances made in recent years, a definitively effective therapeutic has yet to be developed. Oncolytic virology has fallen back into favour for the treatment of cancer with several viruses and viral vectors currently under investigation including vesicular stomatitis virus (VSV), adenovirus vectors and herpes simplex virus (HSV) vectors. Reovirus has an advantage over many viral vectors in that its wild-type form is non-pathogenic and will selectively infect transformed cells, particularly those mutated in the Ras pathway. These advantages make Reovirus an ideal candidate as a safe and non-toxic therapeutic. The aim of the first part of this study was to determine the effect, if any, of Reovirus on cell lines derived from cancers of the gastrointestinal tract. These cancers, particularly those of the oesophagus and stomach, have extremely poor prognoses and little improvement has been seen in survival of these patients in recent years. Reovirus as a single therapy showed promising results in cell lines of oesophageal, gastric and colorectal origin. Further study of partially resistant cell lines using a combination of Reovirus and conventional therapies, either chemotherapy or radiation, showed that a multi-modal approach to therapy is possible with Reovirus and no antagonism between Reovirus and other treatments was observed. The second part of this study focused on investigating a novel use of Reovirus in an in vivo setting. Cancer vaccination or the use of vaccines in cancer therapy is gaining momentum and success has been seen both in a prophylactic approach and a therapeutic approach. A cell-based Reovirus vaccine was used in both these approaches with encouraging success. When used as a prophylactic vaccine tumour development was subsequently inhibited even upon exposure to a tumorigenic dose of cells. The use of the cell-based Reovirus vaccine as a therapeutic for established tumours showed significant delay in tumour growth and a prolongation of survival in all models. This study has proven that Reovirus is an effective therapeutic in a range of cancers and the successful use of a cell-based Reovirus vaccine leads the way for new advancements in cancer immunotherapy.

Synthesis and evaluation of novel azaindolocarbazole derivatives as cancer chemotherapeutics

This thesis details the design and implementation of novel chemical routes towards a series of highly propitious 7-azaindolyl derivatives of the indolocarbazole (ICZ) and bisindolylmaleimide (BIM) families, with subsequent evaluation for use as cancer chemotherapeutic agents. A robust synthetic strategy was devised to allow the introduction of a 7-azaindolyl moiety into our molecular template. This approach allowed access to a wide range of β-keto ester and β-keto nitrile intermediates. Critical analysis identified F-ring modulation as a major theme towards the advancement of ICZ and BIM derivatives in drug therapy. Thus, the employment of cyclocondensation methodology furnished a number of novel aminopyrazole, isoxazolone, pyrazolone and pyrimidinone analogues, considerably widening the scope of the prevalent maleimide functionality. Photochemical cyclisation provided for the first reported aza ICZ containing a six-membered F-ring. Another method towards achieving the aza ICZ core involved use of a Perkin-type condensation approach, with chemical elaboration of the headgroup instigated post-aromatisation. Subsequent use of a modified Lossen rearrangement allowed access to further analogues containing a six-membered F-ring. Extensive screening of the novel aza ICZ and BIM derivatives was carried out against the NCI-60 cancer cell array, with nine prospective candidates selected for continued biological evaluation. From these assays, a number of compounds were shown to inhibit cancer cell growth at concentrations of below 10 nM. Indeed, the most active aza ICZ tested is currently under assessment by the Biological Evaluation Committee of the NCI due to excellent antiproliferative activity demonstrated across the panel of cell lines, with a mean GI50 of 34 nM, a mean total growth inhibition (TGI) of 4.6 μM and a mean cytotoxicity (LC50) of 63.1 μM. Correlation to known topoisomerase I (topo I) inhibitors was revealed by COMPARE analysis, and subsequent topo I-mediated DNA cleavage assays showed inhibitory activity below 1 μM for several derivatives.

The gut microbiota as a contributing factor to antipsychotic-induced weight gain and metabolic dysfunction

Schizophrenia represents one of the world’s most devastating illnesses due to its often lifelong course and debilitating nature. The treatment of schizophrenia has vastly improved over recent decades with the discovery of several antipsychotic compounds; however these drugs are not without adverse effects that must be addressed to maximize their therapeutic value. Newer, atypical, antipsychotics are associated with a compilation of serious metabolic side effects including weight gain, insulin resistance, fat deposition, glucose dysregulation and ensuing co-morbidities such as type II diabetes mellitus. The mechanisms underlying these side effects remain to be fully elucidated and adequate interventions are lacking. Further understanding of the factors that contribute these side effects is therefore required in order to develop effective adjunctive therapies and to potentially design antipsychotic drugs in the future with reduced impact on the metabolic health of patients. We investigated if the gut microbiota represented a novel mechanism contributing to the metabolic dysfunction associated with atypical antipsychotics. The gut microbiota comprises the bacteria that exist symbiotically within the gastrointestinal tract, and has been shown in recent years to be involved in several aspects of energy balance and metabolism. We have demonstrated that administration of certain antipsychotics in the rat results in an altered microbiota profile and, moreover, that the microbiota is required for the full scale of metabolic dysfunction to occur. We have further shown that specific antibiotics can attenuate certain aspects of olanzapine and risperidone–induced metabolic dysfunction, in particular fat deposition and adipose tissue inflammation. Mechanisms underlying this novel link appear to involve energy utilization via expression of lipogenic genes as well as reduced inflammatory tone. Taken together, these data indicate that the gut microbiota is an important factor involved in the myriad of metabolic complications associated with antipsychotic therapy. Furthermore, these data support the future investigation of microbial-based therapeutics for not only antipsychotic-induced weight gain but also for tackling the global obesity epidemic.

Optimisation of immune effector function within the tumour microenvironment

Cancer represents a leading of cause of death in the developed world, inflicting tremendous suffering and plundering billions from health budgets. The traditional treatment approaches of surgery, radiotherapy and chemotherapy have achieved little in terms of cure for this deadly disease. Instead, life is prolonged for many, with dubious quality of life, only for disease to reappear with the inevitable fatal outcome. “Blue sky” thinking is required to tackle this disease and improve outcomes. The realisation and acceptance of the intrinsic role of the immune system in cancer pathogenesis, pathophysiology and treatment represented such a “blue sky” thought. Moreover, the embracement of immunotherapy, the concept of targeting immune cells rather than the tumour cells themselves, represents a paradigm shift in the approach to cancer therapy. The harnessing of immunotherapy demands radical and innovative therapeutic endeavours – endeavours such as gene and cell therapies and RNA interference, which two decades ago existed as mere concepts. This thesis straddles the frontiers of fundamental tumour immunobiology and novel therapeutic discovery, design and delivery. The work undertaken focused on two distinct immune cell populations known to undermine the immune response to cancer – suppressive T cells and macrophages. Novel RNAi mediators were designed, validated and incorporated into clinically relevant gene therapy vectors – involving a traditional lentiviral vector approach, and a novel bacterial vector strategy. Chapter 2 deals with the design of novel RNAi mediators against FOXP3 – a crucial regulator of the immunosuppressive regulatory T cell population. Two mediators were tested and validated. The superior mediator was taken forward as part of work in chapter 3. Chapter 3 deals with transposing the RNA sequence from chapter 2 into a DNA-based construct and subsequent incorporation into a lentiviral-based vector system. The lentiviral vector was shown to mediate gene delivery in vitro and functional RNAi was achieved against FOXP3. Proof of gene delivery was further confirmed in vivo in tumour-bearing animals. Chapter 4 focuses on a different immune cell population – tumour-associated macrophages. Non-invasive bacteria were explored as a specific means of delivering gene therapy to this phagocytic cell type. Proof of delivery was shown in vitro and in vivo. Moreover, in vivo delivery of a gene by this method achieved the desired immune response in terms of cytokine profile. Overall, the data presented here advance exploration within the field of cancer immunotherapy, introduce novel delivery and therapeutic strategies, and demonstrate pre-clinically the potential for such novel anti-cancer therapies.

An exploration through interview and drawings of the experiences of patients diagnosed with oral cancer across their cancer trajectory

Background: The treatment of oral cancer is complex and lengthy. Curative treatment implies a combination of surgery, radiotherapy and chemotherapy. The main goal of treatment is to guarantee long-term tumour free survival with as little functional and cosmetic damage. Despite progress in developing these strategies, cancers of the oral cavity continue to have high mortality rates that have not improved dramatically over the past ten years. Aim: The aim of this study was to uniquely explore the dynamic changes in the physical, psychological, social and existential experiences of newly diagnosed patients with oral cancer at two points across their cancer illness trajectory i.e. at the time of diagnosis and at the end of treatment. Methodology: A qualitative prospective longitudinal design was employed. Non-probability purposive sampling allowed the recruitment of 10 participants. The principal data collection method used was a digital audio taped semi-structured interview along with drawings produced by the participants. Analysis: Data was analysed using latent content analyses. Summary: Three ‘dynamic’ themes, physical, psychosocial and existential experiences were revealed that interact and influence each other in a complex and compound whole. These experiences are present at different degrees and throughout the entire trajectory of care. Patients have a number of specific concerns and challenges that cannot be compartmentalised into unitary or discrete aspects of their daily lives. Conclusion & Implications: An understanding of the patient’s experience of their illness at all stages of the disease trajectory, is essential to inform service providers’ decision making if the delivery of care is to be client centred. Dynamic and fluctuating changes in the patient’s personal experience of the cancer journey require dynamic, energetic and timely input from health care professionals.

Synthesis and evaluation of novel quinolines and quinazolinediones as potential anti-cancer agents

This thesis outlines the design and effectuation of novel chemical routes towards a nascent class of functionalised quinoline-5,8-diones and the expansion of a series of contemporary quinazolinediones towards an innovative family of pyridinoquinazolinetetrone derivatives. This fragment based approach is envisaged to lead to advancements in the three scaffolds, expanding the SAR pool of both quinolines and quinazolinediones with subsequent evaluation of chemotherapeutic potential as well as furnishing a new class of tricycle for biological investigation. Development of novel quinoline-5,8-diones is provided for by expanding on existing methodology. Using a variety of nucleophiles on a critical intermediate, a broad range of novel compounds was afforded allowing chemotherapeutic potential to be assessed, while also serving as intermediates for accomplishing novel pyridinoquinazolinetetrone congeners. In order to incorporate functionality into our quinazolinedione template, an efficient synthetic strategy was constructed which provided a robust route to effectuate a highly derivatised pyrimidinedione ring. As derivatisation of this template is unreported our chief priority was to synthesise a range of diverse quinazolinediones. The application of annulation methodology using functionalised precursors provided a library of N-3 derivatised quinazolinedione analogues. These, along with their N-1 functionalised derivatives provide a wide scope from which to construct a series of pyridinoquinazolinetetrone derivatives while also serving as a unique class of molecules whose biological potential is uncharted. Although the actualisation of the pyridinoquinazolinetetrone was ultimately unsuccessful, our work has led to the development of novel quinoline-5,8-diones which were found to possess excellent anti-cancer activity when assessed by the NCI screen. Of the quinazolinediones synthesised eight compounds were accepted for screening by the NCI. Results from the single-dose tests however indicated that these compounds possessed little cytotoxic activity at 10 μM. The development of this novel template in conjunction with the highly active quinolinediones serves as an excellent rostrum for future synthetic endeavours.

Novel insights into the expression and function of p38δ MAPK in oesophageal squamous cell carcinoma

Oesophageal cancer is an aggressive malignancy which is resistant to conventional therapy and has a poor prognosis. A greater understanding of the underlying molecular biology of oesophageal cancer and the identification of novel targets is necessary for the future treatment of this disease. This thesis focuses specifically on the ill-defined and understudied p38δ mitogen-activated protein kinase (MAPK) and its function(s) in oesophageal squamous cell carcinoma (OESCC). In contrast to the three other p38 isoforms (p38α, -β and –γ which have to-date been relatively well-studied), p38δ MAPK signalling is poorly understood. Thus, this research elucidates some of the role(s) played by p38δ MAPK in cancer progression. This work outlines how loss of p38δ MAPK expression confers greater tumourigenicity in oesophageal cancer. Restoration of p38δ MAPK expression, however, has anti-proliferative and anti-migratory effects and decreases OESCC capacity for anchorageindependent growth. Using a novel application of an enzyme-substrate fusion approach, the effect of phosphorylated p38δ (p-p38δ) MAPK expression is also considered. The work goes onto describe the effect(s) of p38δ MAPK status on the chemosensitivity of OESCC to conventional cisplatin and 5-fluorouracil (CF) versus the effectiveness of doxorubicin, cisplatin and 5-fluorouracil (ACF). ACF treatment of p38δ MAPK-negative OESCC results in decreased proliferation, migration and recovery, and increased apoptosis when compared with CF treatment. This thesis examines the potential mechanisms by which p38δ MAPK expression is lost in OESCC and identifies epigenetic regulation as the probable cause of differential p38δ MAPK expression. Also analysed is the role p38δ MAPK and p-p38δ MAPK play in the cell cycle. In summary, this research identifies p38δ MAPK as a possible molecular target and a potential predictor of response to chemotherapy in OESCC patients.

Cancer associated malnutrition: prevalence of cachexia, sarcopenia and impact on treatment outcomes, survival and health related quality of life

Malnutrition, sarcopenia and cancer cachexia (CC) are prevalent among cancer patients and can have detrimental effects on clinical outcomes such as quality of life (QoL) and overall survival. Cachexia is associated with lower tolerance for chemotherapy, which limits the total dose that can be delivered, the number of symptomatic responses and any survival advantage that might be accrued. Moreover, for the majority who do not respond, cachexia may be exacerbated by systemic chemotherapy, thus increasing the net symptom burden experienced by patients. The multitude of interactions between cancer location, treatments, nutritional status and QoL has never been thoroughly explored in an Irish cancer cohort. The objectives of this thesis were to further understand nutritional status, especially body composition in ambulatory cancer patients and determine the relationship between nutritional status using different assessment criteria and QoL, chemotherapy toxicity and survival among cancer patients undergoing chemotherapy. Results aimed to identify baseline factors that may be predictive of poor outcome, toxicities to chemotherapy and disease-free and overall survival. This thesis broadly divides into two sections. The first section (Chapters 3 & 4) focuses on improving our knowledge of the nutritional status of Irish cancer outpatients using a cross sectional study design. A study of 517 patients referred for chemotherapy was conducted using computed tomography (CT) imaging (body composition) and a survey that documented oncologic data, weight loss (WL) data and QoL data. We revealed that a significant proportion of Irish cancer patients undergoing chemotherapy experience unintentional WL over the previous 6 months (62%), sarcopenia (45%) and CC (43%), and the distribution of WL and nutritional risk were associated with site of primary tumour and treatment intent. Patients that had sarcopenia, nutritional risk, or CC had significantly reduced functional abilities, more symptoms and adverse global QoL. In the second section of this thesis (Chapters 5 & 6) the potential link between developing toxicity to antineoplastic regimens in patients with sarcopenia was conducted by way of retrospective studies. A retrospective serial CT analysis defined the prevalence of sarcopenia in patients with metastatic renal cell carcinoma (mRCC) and metastatic castrate resistant prostate cancer (mCRPC), which was then correlated with dose limiting toxicities of sunitinib and docetaxel respectively. Sarcopenia was prevalent in patients with mRCC and mCRPC, was an occult condition in patients with normal/high BMI, was associated with less treatment days, was a significant predictor of DLT in patients receiving sunitinib and a significant predictor of neutropenia and neurosensory toxicities in patients receiving docetaxel. This thesis attempted to address the underlying research deficiencies in Irish oncology nutritional data at national level. The findings from this thesis have implications for the planning of cancer care interventions and indicate that further research is required to improve nutritional screening, in particular for CC and sarcopenia, in the hope that timely intervention can improve both patient-centered and oncologic outcomes.

An EORTC-IDBBC phase I study of gemcitabine and continuous infusion 5-fluorouracil in patients with metastatic breast cancer resistant to anthracyclines or pre-treated with both anthracyclines and taxanes.

The aim of this study was to determine the maximum tolerated dose (MTD), dose-limiting toxicities (DLT), and potential activity of combined gemcitabine and continuous infusion 5-fluorouracil (5-FU) in metastatic breast cancer (MBC) patients that are resistant to anthracyclines or have been pretreated with both anthracyclines and taxanes. 15 patients with MBC were studied at three European Organization for Research and Treatment of Cancer centres. 13 patients had received both anthracylines and taxanes. Gemcitabine was given intravenously (i.v.) on days 1 and 8, and 5-FU as a continuous i.v. infusion on days 1 through to 14, both drugs given in a 21-day schedule at four different dose levels. Both were given at doses commonly used for the single agents for the last dose level (dose level 4). One of 6 patients at level 4 (gemcitabine 1200 mg/m2 and 5-FU 250 mg/m2/day) had a DLT, a grade 3 stomatitis and skin toxicity. One DLT, a grade 3 transaminase rise and thrombosis, occurred in a patient at level 2 (gemcitabine 1000 mg/m2 and 5-FU 200 mg/m2/day). Thus, the MTD was not reached. One partial response and four disease stabilisations were observed. Only 1 patient withdrew from the treatment due to toxicity. The MTD was not reached in the phase I study. The combination of gemcitabine and 5-FU is well tolerated at doses up to 1200 mg/m2 given on days 1 and 8 and 250 mg/m2/day given on days 1 through to 14, respectively, every 21 days. The clinical benefit rate (responses plus no change of at least 6 months) was 33% with one partial response, suggesting that MBC patients with prior anthracycline and taxane therapy may derive significant benefit from this combination with minimal toxicity.

A randomised phase II study of two different schedules of pegylated liposomal doxorubicin in metastatic breast cancer (EORTC-10993).

One hundred and sixteen women with measurable metastatic breast cancer participated in a randomised phase II study of single agent liposomal pegylated doxorubicin (Caelyx) given either as a 60 mg/m2 every 6 weeks (ARM A) or 50 mg/m2 every 4 weeks (ARM B) schedule. Patients were over 65 years of age or, if younger, had refused or been unsuitable for standard anthracyclines. The aims of the study were to evaluate toxicity and dose delivery with the two schedules and obtain further information on the response rate of liposomal pegylated doxorubicin as a single agent in anthracycline nai ve advanced breast cancer. Twenty-six patients had received prior adjuvant chemotherapy (including an anthracycline in 10). Sixteen had received non-anthracycline-based first-line chemotherapy for advanced disease. One hundred and eleven patients were evaluable for toxicity and 106 for response. The delivered dose intensity (DI) was 9.8 mg/m2 (95% CI, 7.2-10.4) with 37 (69%) achieving a DI of >90% on ARM A and 11.9 mg/m2 (95% CI, 7.5-12.8) with 37 (65%) achieving a DI of >90% on ARM B. The adverse event profiles of the two schedules were distinctly different. Mucositis was more common with the every 6 weeks regimen (35% CTC grade 3/4 in ARM A, 14% in ARM B) but palmar plantar erythrodysesthesia (PPE) was more frequent with the every 4 weeks regimen (2% CTC grade 3/4 in ARM A, 16% in ARM B). Confirmed objective partial responses by RECIST criteria were seen with both schedules; 15/51 (29%) on ARM A and 17/56 (31%) on ARM B. Liposomal pegylated doxorubicin showed significant activity in advanced breast cancer with a generally favourable side-effect profile. The high frequency of stomatitis seen with 6 weekly treatment makes this the less preferred of the two schedules tested.

Adjuvant therapy in elderly patients with breast cancer.

The elderly population has been neglected by the traditional approach to clinical breast cancer research. Elderly women have been underrepresented in breast cancer clinical trials, with the majority of studies being restricted to patients aged < 70 years. Elderly patients frequently have comorbidities and/or impaired organ function. These facts may often lead to death from causes other than cancer, thus nullifying any possible benefit of adjuvant treatment; furthermore, they render extrapolation of standard treatment recommendations to the elderly potentially hazardous, particularly with respect to chemotherapy. Therefore, specific clinical trials are needed to investigate adjuvant treatments tailored for the heterogeneous older population.

Clinical outcome of breast cancer patients with liver metastases alone in the anthracycline-taxane era: a retrospective analysis of two prospective, randomised metastatic breast cancer trials.

Liver metastases have long been known to indicate an unfavourable disease course in breast cancer (BC). However, a small subset of patients with liver metastases alone who were treated with pre-taxane chemotherapy regimens was reported to have longer survival compared with patients with liver and metastases at other sites. In the present study, we examined the clinical outcome of breast cancer patients with liver metastases alone in the context of two phase III European Organisation for Research and Treatment of Cancer (EORTC) trials which compared the efficacy of doxorubicin (A) versus paclitaxel (T) (trial 10923) and of AC (cyclophosphamide) versus AT (trial 10961), given as first-line chemotherapy in metastatic BC patients. The median follow-up for the patients with liver metastases was 90.5 months in trial 10923 and 56.6 months in trial 10961. Patients with liver metastases alone comprised 18% of all patients with liver metastases, in both the 10923 and 10961 trials. The median survival of patients with liver metastases alone and liver plus other sites of metastases were 22.7 and 14.2 months (log rank test, P=0.002) in trial 10923 and 27.1 and 16.8 months (log rank test, P=0.19) in trial 10961. The median TTP (time to progression) for patients with liver metastases alone was also longer compared with the liver plus other sites of metastases group in both trials: 10.2 versus 8.8 months (log rank test, P=0.02) in trial 10923 and 8.3 versus 6.7 months (log rank test, P=0.37) in trial 10961. Most patients with liver metastases alone have progression of their disease in their liver again (96 and 60% of patients in trials 10923 and 10961, respectively). Given the high prevalence of breast cancer, improved detection of liver metastases, encouraging survival achieved with currently available cytotoxic agents and the fact that a significant portion of patients with liver metastases alone have progression of their tumour in the liver again, a more aggressive multimodality treatment approach through prospective clinical trials seems worth exploring in this specific subset of women.