Gemcitabine as adjuvant chemotherapy in patients with high-risk early breast cancer-results from the randomized phase III SUCCESS-A trial

Background

When chemotherapy is indicated in patients with early breast cancer, regimens that contain anthracyclines and taxanes are established standard treatments. Gemcitabine has shown promising effects on the response and prognosis in patients with metastatic breast cancer. The SUCCESS-A trial (NCT02181101) examined the addition of gemcitabine to a standard chemotherapy regimen in high-risk early breast cancer patients.

Methods

A total of 3754 patients with at least one of the following characteristics were randomly assigned to one of the two treatment arms: nodal positivity, tumor grade 3, age ≤ 35 years, tumor larger than 2 cm, or negative hormone receptor status. The treatment arms received either three cycles of 5-fluorouracil, epirubicin, and cyclophosphamide, followed by three cycles of docetaxel (FEC → Doc); or three cycles of FEC followed by three cycles of docetaxel and gemcitabine (FEC → Doc/Gem). The primary study aim was disease-free survival (DFS), and the main secondary objectives were overall survival (OS) and safety.

Results

No differences were observed in the 5-year DFS or OS between FEC → Doc and FEC → Doc/Gem. The hazard ratio was 0.93 (95% CI, 0.78 to 1.12; P = 0.47) for DFS and 0.94 (95% CI, 0.74 to 1.19; P = 0.60) for OS. For patients treated with FEC → Doc and FEC → Doc/Gem, the 5-year probabilities of DFS were 86.6% and 87.2%, and the 5-year probabilities of OS were 92.8% and 92.5%, respectively.

Conclusion

Adding gemcitabine to a standard chemotherapy does not improve the outcomes in patients with high-risk early breast cancer and should therefore not be included in the adjuvant treatment setting.

Trial registration

Clinicaltrials.gov NCT02181101 and EU Clinical Trials Register EudraCT 2005-000490-21. Registered September 2005.

Addition of gemcitabine to paclitaxel, epirubicin, and cyclophosphamide adjuvant chemotherapy for women with early-stage breast cancer (tAnGo): final 10-year follow-up of an open-label, randomised, phase 3 trial

BACKGROUND

The tAnGo trial was designed to investigate the potential role of gemcitabine when added to anthracycline and taxane-containing adjuvant chemotherapy for early breast cancer. When this study was developed, gemcitabine had shown significant activity in metastatic breast cancer, and there was evidence of a favourable interaction with paclitaxel.

METHODS

tAnGo was an international, open-label, randomised, phase 3 superiority trial that enrolled women aged 18 years or older with newly diagnosed, early-stage breast cancer who had a definite indication for chemotherapy, any nodal status, any hormone receptor status, Eastern Cooperative Oncology Group performance status of 0-1, and adequate bone marrow, hepatic, and renal function. Women were recruited from 127 clinical centres and hospitals in the UK and Ireland, and randomly assigned (1:1) to one of two treatment regimens: epirubicin, cyclophosphamide, and paclitaxel (four cycles of 90 mg/m2 intravenously administered epirubicin and 600 mg/m2 intravenously administered cyclophosphamide on day 1 every 3 weeks, followed by four cycles of 175 mg/m2 paclitaxel as a 3 h infusion on day 1 every 3 weeks) or epirubicin, cyclophosphamide, and paclitaxel plus gemcitabine (the same chemotherapy regimen as the other group, with the addition of 1250 mg/m2 gemcitabine to the paclitaxel cycles, administered intravenously as a 0·5 h infusion on days 1 and 8 every 3 weeks). Patients were randomly assigned by a central computerised deterministic minimisation procedure, with stratification by country, age, radiotherapy intent, nodal status, and oestrogen receptor and HER-2 status. The primary endpoint was disease-free survival and the trial aimed to detect 5% differences in 5-year disease-free survival between the treatment groups. Recruitment completed in 2004 and this is the final, intention-to-treat analysis. This trial is registered with EudraCT (2004-002927-41), ISRCTN (51146252), and ClinicalTrials.gov (NCT00039546).

FINDINGS

Between Aug 22, 2001, and Nov 26, 2004, 3152 patients were enrolled and randomly assigned to epirubicin, cyclophosphamide, paclitaxel, and gemcitabine (gemcitabine group; n=1576) or to epirubicin, cyclophosphamide, and paclitaxel (control group; n=1576). 11 patients (six in the gemcitabine group and five in the control group) were ineligible because of pre-existing metastases and were therefore excluded from the analysis. At this protocol-specified final analysis (median follow-up 10 years [IQR 10-10]), 1087 disease-free survival events and 914 deaths had occurred. Disease-free survival did not differ significantly between the treatment groups at 10 years (65% [63-68] in the gemcitabine group vs 65% [62-67] in the control group), and median disease-free survival was not reached (adjusted hazard ratio 0·97 [95% CI 0·86-1·10], p=0·64). Toxicity, dose intensity, and a detailed safety substudy showed both regimens to be safe, deliverable, and tolerable. Grade 3 and 4 toxicities were reported at expected levels in both groups. The most common were neutropenia (527 [34%] of 1565 patients in the gemcitabine group vs 412 [26%] of 1567 in the control group), myalgia and arthralgia (207 [13%] vs 186 [12%]), fatigue (207 [13%] vs 152 [10%]), infection (202 [13%] vs 141 [9%]), vomiting (143 [9%] vs 108 [7%]), and nausea (132 [8%] vs 102 [7%]).

INTERPRETATION

The addition of gemcitabine to anthracycline and taxane-based adjuvant chemotherapy at this dose and schedule confers no therapeutic advantage in terms of disease-free survival in early breast cancer, although it can cause increased toxicity. Therefore, gemcitabine has not been added to standard adjuvant chemotherapy in breast cancer for any subgroup.

FUNDING

Cancer Research UK core funding for Clinical Trials Unit at the University of Birmingham, Eli Lilly, Bristol-Myers Squibb, and Pfizer.

The Relationship between Common Genetic Markers of Breast Cancer Risk and Chemotherapy-Induced Toxicity: A Case-Control Study

Ninety-four common genetic variants are confirmed to be associated with breast cancer. This study tested the hypothesis that breast cancer susceptibility variants may also be associated with chemotherapy-induced toxicity through shared mechanistic pathways such as DNA damage response, an association that, to our knowledge, has not been previously investigated. The study included breast cancer patients who received neoadjuvant/adjuvant chemotherapy from the Pharmacogenetic SNPs (PGSNPS) study. For each patient, a breast cancer polygenic risk score was created from the 94 breast cancer risk variants, all of which were genotyped or successfully imputed in PGSNPS. Logistic regression was performed to test the association with two clinically important toxicities: taxane- related neuropathy (n = 1279) and chemotherapy-induced neutropenia (n = 1676). This study was well powered (≥96%) to detect associations between polygenic risk score and chemotherapy toxicity. Patients with high breast cancer risk scores experienced less neutropenia compared to those with low risk scores (adjusted p-value = 0.06). Exploratory functional pathway analysis was performed and no functional pathways driving this trend were identified. Polygenic risk was not associated with taxane neuropathy (adjusted p-value = 0.48). These results suggest that breast cancer patients with high genetic risk of breast cancer, conferred by common variants, can safely receive standard chemotherapy without increased risk of taxane-related sensory neuropathy or chemotherapy-induced neutropenia and may experience less neutropenia. As neutropenia has previously been associated with improved survival and may reflect drug efficacy, these patients may be less likely to benefit from standard chemotherapy treatment.

A nested cohort study of 6,248 early breast cancer patients treated in neoadjuvant and adjuvant chemotherapy trials investigating the prognostic value of chemotherapy-related toxicities

BACKGROUND

The relationship between chemotherapy-related toxicities and prognosis is unclear. Previous studies have examined the association of myelosuppression parameters or neuropathy with survival and reported conflicting results. This study aims to investigate 13 common chemotherapy toxicities and their association with relapse-free survival and breast cancer-specific survival.

METHODS

Chemotherapy-related toxicities were collected prospectively for 6,248 women with early-stage breast cancer from four randomised controlled trials (NEAT; BR9601; tAnGo; Neo-tAnGo). Cox proportional-hazards modelling was used to analyse the association between chemotherapy-related toxicities and both breast cancer-specific survival and relapse-free survival. Models included important prognostic factors and stratified by variables violating the proportional hazards assumption.

RESULTS

Multivariable analysis identified severe neutropenia (grades ≥3) as an independent predictor of relapse-free survival (hazard ratio (HR) = 0.86; 95% confidence interval (CI), 0.76-0.97; P = 0.02). A similar trend was seen for breast cancer-specific survival (HR = 0.87; 95% CI, 0.75-1.01; P = 0.06). Normal/low BMI patients experienced more severe neutropenia (P = 0.008) than patients with higher BMI. Patients with fatigue (grades ≥3) showed a trend towards reduced survival (breast cancer-specific survival: HR = 1.17; 95% CI, 0.99-1.37; P = 0.06). In the NEAT/BR9601 sub-group analysis by treatment component, this effect was statistically significant (HR = 1.61; 95% CI, 1.13-2.30; P = 0.009).

CONCLUSIONS

This large study shows a significant association between chemotherapy-induced neutropenia and increased survival. It also identifies a strong relationship between low/normal BMI and increased incidence of severe neutropenia. It provides evidence to support the development of neutropenia-adapted clinical trials to investigate optimal dose calculation and its impact on clinical outcome. This is important in populations where obesity may lead to sub-optimal chemotherapy doses.

Identification of novel genetic markers of breast cancer survival

BACKGROUND

Survival after a diagnosis of breast cancer varies considerably between patients, and some of this variation may be because of germline genetic variation. We aimed to identify genetic markers associated with breast cancer-specific survival.

METHODS

We conducted a large meta-analysis of studies in populations of European ancestry, including 37954 patients with 2900 deaths from breast cancer. Each study had been genotyped for between 200000 and 900000 single nucleotide polymorphisms (SNPs) across the genome; genotypes for nine million common variants were imputed using a common reference panel from the 1000 Genomes Project. We also carried out subtype-specific analyses based on 6881 estrogen receptor (ER)-negative patients (920 events) and 23059 ER-positive patients (1333 events). All statistical tests were two-sided.

RESULTS

We identified one new locus (rs2059614 at 11q24.2) associated with survival in ER-negative breast cancer cases (hazard ratio [HR] = 1.95, 95% confidence interval [CI] = 1.55 to 2.47, P = 1.91 x 10(-8)). Genotyping a subset of 2113 case patients, of which 300 were ER negative, provided supporting evidence for the quality of the imputation. The association in this set of case patients was stronger for the observed genotypes than for the imputed genotypes. A second locus (rs148760487 at 2q24.2) was associated at genome-wide statistical significance in initial analyses; the association was similar in ER-positive and ER-negative case patients. Here the results of genotyping suggested that the finding was less robust.

CONCLUSIONS

This is currently the largest study investigating genetic variation associated with breast cancer survival. Our results have potential clinical implications, as they confirm that germline genotype can provide prognostic information in addition to standard tumor prognostic factors.

The development of dose-dense adjuvant chemotherapy

Dose-dense chemotherapy has made a significant contribution to the adjuvant treatment of breast cancer. One way of achieving dose-density is through the use of sequential therapy with noncross resistant therapies to cause cell kill in tumors composed of heterogeneous cells. Another way to achieve this is to shorten the inter-treatment interval to minimize the re-growth of tumor cells, thus allowing for more effective cell killing. Several trials have tested this concept with the majority demonstrating improved efficacy with a dose-density when compared with the traditional schedule. One such notable trial was CALGB 9741 that showed that when dose size and cycle numbers were kept constant, shortening the interval between each chemotherapy dose, with granulocyte-colony stimulating factor support, significantly improved disease-free and overall survival. This important and practice-changing trial led to the wide adoption of dose-dense chemotherapy and formed the basis of many subsequent studies, including allowing for the addition of biologic and targeted agents with excellent safety profile.

Replication of genetic polymorphisms reported to be associated with taxane-related sensory neuropathy in patients with early breast cancer treated with Paclitaxel

PURPOSE

Associations between taxane-related sensory neuropathy (TRSN) and single-nucleotide polymorphisms (SNP) have previously been reported, but few have been replicated in large, independent validation studies. This study evaluates the association between previously investigated SNPs and TRSN, using genotype data from a study of chemotherapy-related toxicity in patients with breast cancer.

EXPERIMENTAL DESIGN

We investigated 73 SNPs in 50 genes for their contribution to TRSN risk, using genotype data from 1,303 European patients. TRSN was assessed using National Cancer Institute common toxicity criteria for adverse events classification. Unconditional logistic regression evaluated the association between each SNP and TRSN risk (primary analysis). Cox regression analysis assessed the association between each SNP and cumulative taxane dose causing the first reported moderate/severe TRSN (secondary analysis). The admixture likelihood (AML) test, which considers all SNPs with a prior probability of association with TRSN together, tested the hypothesis that certain SNPs are truly associated.

RESULTS

The AML test provided strong evidence for the association of some SNPs with TRSN (P = 0.023). The two most significantly associated SNPs were rs3213619(ABCB1) [OR = 0.47; 95% confidence interval (CI), 0.28-0.79; P = 0.004] and rs9501929(TUBB2A) (OR = 1.80; 95% CI, 1.20-2.72; P = 0.005). A further 9 SNPs were significant at P-value ≤ 0.05.

CONCLUSION

This is currently the largest study investigating SNPs associated with TRSN. We found strong evidence that SNPs within genes in taxane pharmacokinetic and pharmacodynamic pathways contribute to TRSN risk. However, a large proportion of the inter-individual variability in TRSN remains unexplained. Further validated results from GWAS will help to identify new pathways, genes, and SNPs involved in TRSN susceptibility.

Effects of the addition of gemcitabine, and paclitaxel-first sequencing, in neoadjuvant sequential epirubicin, cyclophosphamide, and paclitaxel for women with high-risk early breast cancer (Neo-tAnGo): an open-label, 2×2 factorial randomised phase 3 trial

BACKGROUND

Anthracyclines and taxanes have been the standard neoadjuvant chemotherapies for breast cancer in the past decade. We aimed to assess safety and efficacy of the addition of gemcitabine to accelerated paclitaxel with epirubicin and cyclophosphamide, and also the effect of sequencing the blocks of epirubicin and cyclophosphamide and paclitaxel (with or without gemcitabine).

METHODS

In our randomised, open-label, 2×2 factorial phase 3 trial (Neo-tAnGo), we enrolled women (aged >18 years) with newly diagnosed breast cancer (tumour size >20 mm) at 57 centres in the UK. Patients were randomly assigned via a central randomisation procedure to epirubicin and cyclophosphamide then paclitaxel (with or without gemcitabine) or paclitaxel (with or without gemcitabine) then epirubicin and cyclophosphamide. Four cycles of each component were given. The primary endpoint was pathological complete response (pCR), defined as absence of invasive cancer in the breast and axillary lymph nodes. This study is registered with EudraCT (2004-002356-34), ISRCTN (78234870), and ClinicalTrials.gov (NCT00070278).

FINDINGS

Between Jan 18, 2005, and Sept 28, 2007, we randomly allocated 831 participants; 207 received epirubicin and cyclophosphamide then paclitaxel; 208 were given paclitaxel then epirubicin and cyclophosphamide; 208 had epirubicin and cyclophosphamide followed by paclitaxel and gemcitabine; and 208 received paclitaxel and gemcitabine then epirubicin and cyclophosphamide. 828 patients were eligible for analysis. Median follow-up was 47 months (IQR 37-51). 207 (25%) patients had inflammatory or locally advanced disease, 169 (20%) patients had tumours larger than 50 mm, 413 (50%) patients had clinical involvement of axillary nodes, 276 (33%) patients had oestrogen receptor (ER)-negative disease, and 191 (27%) patients had HER2-positive disease. Addition of gemcitabine did not increase pCR: 70 (17%, 95% CI 14-21) of 404 patients in the epirubicin and cyclophosphamide then paclitaxel group achieved pCR compared with 71 (17%, 14-21) of 408 patients who received additional gemcitabine (p=0·98). Receipt of a taxane before anthracycline was associated with improved pCR: 82 (20%, 95% CI 16-24) of 406 patients who received paclitaxel with or without gemcitabine followed by epirubicin and cyclophosphamide achieved pCR compared with 59 (15%, 11-18) of 406 patients who received epirubicin and cyclophosphamide first (p=0·03). Grade 3 toxicities were reported at expected levels: 173 (21%) of 812 patients who received treatment and had full treatment details had grade 3 neutropenia, 66 (8%) had infection, 41 (5%) had fatigue, 41 (5%) had muscle and joint pains, 37 (5%) had nausea, 36 (4%) had vomiting, 34 (4%) had neuropathy, 23 (3%) had transaminitis, 16 (2%) had acute hypersensitivity, and 20 (2%) had a rash. 86 (11%) patients had grade 4 neutropenia and 3 (<1%) had grade 4 infection.

INTERPRETATION

Although addition of gemcitabine to paclitaxel and epirubicin and cyclophosphamide chemotherapy does not improve pCR, sequencing chemotherapy so that taxanes are received before anthracyclines could improve pCR in standard neoadjuvant chemotherapy for breast cancer.

FUNDING

Cancer Research UK, Eli Lilly, Bristol-Myers Squibb.

Neoadjuvant chemotherapy with sequential anthracycline-docetaxel with gemcitabine for large operable or locally advanced breast cancer: ANZ 0502 (NeoGem)

BACKGROUND

Neoadjuvant chemotherapy has a sound rationale for use in women with large operable breast cancer, and achievement of pathological complete response (pCR) is prognostic. Epirubicin and cyclophosphamide followed by docetaxel is a standard chemotherapy regimen for early breast cancer. In metastatic breast cancer the combination of gemcitabine and a taxane has shown promising results. This phase II study investigated the efficacy and safety of incorporating gemcitabine into neoadjuvant therapy.

METHODS

Female patients with operable breast cancer that was clinically T2 (≥3 cm) or T3-4, N0-1, M0 were enrolled to receive 24 weeks of neoadjuvant chemotherapy using epirubicin and cyclophosphamide followed by docetaxel and gemcitabine, plus trastuzumab if HER2-positive. The primary endpoint was the pathological complete response (pCR) rate in the breast in separate HER2-negative and HER2-positive cohorts. Secondary endpoints included pCR in both the breast and axillary lymph nodes, clinical and radiological response rates, disease free survival and safety.

RESULTS

81 patients were enrolled: 63 HER2-negative and 18 HER2-positive. 67 (84%) completed all cycles of chemotherapy, and 78 (96%) proceeded to surgery. pCR was achieved by 12 (20%) patients with HER2-negative, and 9 (53%) with HER2-positive disease. At the first interim analysis, addition of prophylactic G-CSF was recommended due to excess neutropenia. The HER2-negative cohort was closed to accrual because it did not meet the pre-specified target for pCR, and the HER2-positive cohort was closed due to slow accrual. At a median follow-up of 24 months, 12 of 81 (15%) patients had experienced a relapse of their breast cancer.

CONCLUSION

Neoadjuvant gemcitabine, when added to docetaxel, after epirubicin and cyclophosphamide, did not reach the pre-specified expectations for pCR rate in HER2-negative tumours. Excess neutropenia was observed, requiring growth factor support. Addition of gemcitabine to docetaxel in this schedule cannot be recommended. Australia and New Zealand Clinical Trials Registry (www.anzctr.org.au) registration number ACTRN12606000191594.

Definitive results of a phase III adjuvant trial comparing three chemotherapy regimens in women with operable, node-positive breast cancer: the NSABP B-38 trial

PURPOSE

Anthracycline- and taxane-based three-drug chemotherapy regimens have proven benefit as adjuvant therapy for early-stage breast cancer. This trial (NSABP B-38; Combination Chemotherapy in Treating Women Who Have Undergone Surgery for Node-Positive Breast Cancer) asked whether the incorporation of a fourth drug could improve outcomes relative to two standard regimens and provided a direct comparison of those two regimens.

PATIENTS AND METHODS

We randomly assigned 4,894 women with node-positive early-stage breast cancer to six cycles of docetaxel, doxorubicin, and cyclophosphamide (TAC), four cycles of dose-dense (DD) doxorubicin and cyclophosphamide followed by four cycles of DD paclitaxel (P; DD AC→P), or DD AC→P with four cycles of gemcitabine (G) added to the DD paclitaxel (DD AC→PG). Primary granulocyte colony-stimulating factor support was required; erythropoiesis-stimulating agents (ESAs) were used at the investigator's discretion.

RESULTS

There were no significant differences in 5-year disease-free survival (DFS) between DD AC→PG and DD AC→P (80.6% v 82.2%; HR, 1.07; P = .41), between DD AC→PG and TAC (80.6% v 80.1%; HR, 0.93; P = .39), in 5-year overall survival (OS) between DD AC→PG and DD AC→P (90.8% v 89.1%; HR, 0.85; P = .13), between DD AC→PG and TAC (90.8% v 89.6%; HR, 0.86; P = .17), or between DD AC→P versus TAC for DFS (HR, 0.87; P = .07) and OS (HR, 1.01; P = .96). Grade 3 to 4 toxicities for TAC, DD AC→P, and DD AC→PG, respectively, were febrile neutropenia (9%, 3%, 3%; P < .001), sensory neuropathy (< 1%, 7%, 6%; P < .001), and diarrhea (7%, 2%, 2%; P < .001). Exploratory analyses for ESAs showed no association with DFS events (HR, 1.02; P = .95).

CONCLUSION

Adding G to DD AC→P did not improve outcomes. No significant differences in efficacy were identified between DD AC→P and TAC, although toxicity profiles differed.

Neoadjuvant treatment of breast cancer

Neoadjuvant treatment of breast cancer has become established as the safe and often effective therapeutic approach of choice for larger primary and for locally advanced breast cancer. The neoadjuvant approach offers the advantages of downstaging the disease, potentially reducing the extent of surgery and in an era of individualization of therapy, testing the efficacy of therapy administered to patients. The preoperative setting is also an effective way to study the activity of novel agents or therapeutic combinations in vivo against human breast cancer. For new therapies, preoperative trials avoid the issue of adaptive resistance and pretreatments that can be problematic in the advanced disease setting. For evidence of a drug targeting the cancer in vivo, comparisons of endocrine therapy, chemotherapy agents and/or targeted agents can provide data on activity and efficacy with a much shorter time frame and many fewer patients than for adjuvant trials; effects seen in neoadjuvant trials may even reflect what is found in the adjuvant setting. Patient benefits from the neoadjuvant approach may be greatest for those who experience complete pathologically documented response (and the consequent survival benefits) and women for whom breast conservation, rather than mastectomy, becomes possible.

Efficacy of taxanes as adjuvant treatment of breast cancer: a review and meta-analysis of randomised clinical trials

OBJECTIVES

To evaluate the magnitude of benefit obtained by taxanes as adjuvant treatment of breast cancer and to assess the best method for their administration.

MATERIAL AND METHODS

We performed a systematic search of phase III randomised clinical trials that included patients with non-metastatic breast cancer in whom comparisons were chemotherapy (CT) containing a taxane (docetaxel or paclitaxel) vs. CT without taxanes (first-generation trials), or CT with taxane in both treatment arms (second-generation trials), administered after surgery. The parameters of efficacy evaluated were disease-free survival (DFS) and overall survival (OS). The data obtained in the first-generation trials (number of relapses and deaths) were submitted to a meta-analysis. The odds ratio (OR) combined with DerSimonian and Laird (OR DL) and 95% confidence interval (95% CI) were calculated. Further, an analysis was performed of those trials that included only patients with nodal involvement (N+). In both cases, the results were also analysed as a function of the taxane used, and with indirect comparisons between the two. The second-generation trials were analysed to assess the optimum method of administration.

RESULTS

A total of 17 trials were selected for the meta-analysis (30,672 patients). The OR DL was 0.82 (95%CI: 0.76-0.88) for DFS and 0.83 (95% CI: 0.75-0.91) for OS. In N+ patients the results were 0.80 (95% CI: 0.74-0.86) and 0.79 (95% CI: 0.69-0.89), respectively. Docetaxel and paclitaxel significantly increased the DFS and OS. In our indirect comparison, the benefit of docetaxel on OS was significantly superior to that obtained with paclitaxel in N+ patients (OR: 0.79; 95% CI: 0.63-0.98).

CONCLUSIONS

The administration of adjuvant CT-based taxanes reduces the risk of relapse and death. This reduction is superior in clinical trials that included only N+ patients. With the available evidence, it would appear that the best method of administering paclitaxel is weekly and for docetaxel tri-weekly.

The cell cycle and cancer

Deregulation of the cell cycle underlies the aberrant cell proliferation that characterizes cancer and loss of cell cycle checkpoint control promotes genetic instability. During the past two decades, cancer genetics has shown that hyperactivating mutations in growth signalling networks, coupled to loss of function of tumour suppressor proteins, drives oncogenic proliferation. Gene expression profiling of these complex and redundant mitogenic pathways to identify prognostic and predictive signatures and their therapeutic targeting has, however, proved challenging. The cell cycle machinery, which acts as an integration point for information transduced through upstream signalling networks, represents an alternative target for diagnostic and therapeutic interventions. Analysis of the DNA replication initiation machinery and mitotic engine proteins in human tissues is now leading to the identification of novel biomarkers for cancer detection and prognostication, and is providing target validation for cell cycle-directed therapies.

Recent advances in systemic therapy: advances in adjuvant systemic chemotherapy of early breast cancer

Adjuvant treatment for early breast cancer is an evolving field. Since the advent of the initial cyclophosphamide, methotrexate and 5-fluorouracil (CMF) regimens, which reduced risk for recurrence and death, anthracyclines and subsequently taxanes were added to the cytotoxic armamentarium for use sequentially or in combination in the adjuvant setting. The efficacy and toxicity of each chemotherapy regimen must be viewed within the context of host co-morbidities and the specific biologic phenotype of the tumor. In the era of mammographic screening, small, node-negative breast cancer is the most frequent presentation of the disease. Patient selection for adjuvant chemotherapy has become a key issue. Traditional prognostic factors continue to be of value in determining the risk for relapse, but new and sophisticated genomic tools (such as Oncotype Dx^® and Mammaprint^®) are now available and may improve our ability to select patients. For those patients who do require adjuvant chemotherapy, the 'one size fits all' paradigm should never again feature in the treatment of early breast cancer, following the important insights yielded by biomarker research to identify those who will benefit the most from a particular drug. In this review we focus on some of the current controversies and potential future steps in adjuvant chemotherapy for treatment of early breast cancer.

Cell-cycle-phase progression analysis identifies unique phenotypes of major prognostic and predictive significance in breast cancer

Multiparameter analysis of core regulatory proteins involved in G1–S and G2–M cell-cycle transitions provides a powerful biomarker readout for assessment of the cell-cycle state. We have applied this algorithm to breast cancer to investigate how the cell cycle impacts on disease progression. Protein expression profiles of key constituents of the DNA replication licensing pathway (Mcm2, geminin) and mitotic machinery (Plk1, Aurora A and the Aurora substrate histone H3S10ph) were generated for a cohort of 182 patients and linked to clinicopathological parameters. Arrested differentiation and genomic instability were associated with an increased engagement of cells into the cell division cycle (P<0.0001). Three unique cell-cycle phenotypes were identified: (1) well-differentiated tumours composed predominantly of Mcm2-negative cells, indicative of an out-of-cycle state (18% of cases); (2) high Mcm2-expressing tumours but with low geminin, Aurora A, Plk1 and H3S10ph levels (S–G2–M progression markers), indicative of a G1-delayed/arrested state (24% cases); and (3) high Mcm2-expressing tumours and also expressing high levels of the S–G2–M progression markers, indicative of accelerated cell-cycle progression (58% of cases). The active cell-cycle progression phenotype had a higher risk of relapse when compared with out-of-cycle and G1-delayed/arrested phenotypes (HR=3.90 (1.81–8.40, P<0.001)), and was associated with Her-2 and triple negative subtypes (P<0.001). It is of note that high-grade tumours with the G1-delayed/arrested phenotype showed an identical low risk of relapse compared with well-differentiated out-of-cycle tumours (HR=1.00 (0.22–4.46), P=0.99). Our biomarker algorithm provides novel insights into the cell-cycle state of dynamic tumour cell populations in vivo. This information is of major prognostic significance and may impact on individualised therapeutic decisions. Patients with an accelerated phenotype are more likely to derive benefit from S- and M-phase-directed chemotherapeutic agents.

From the podium to the patient: bringing the 2008 ASCO meeting to the clinic

Around 4,800 abstracts on preclinical and clinical research in different oncology areas were presented and discussed by oncology clinicians and scientists at the 44th American Society of Clinical Oncology meeting, the largest international forum in the field. As expected, the meeting provided valuable insights into future developments as well as enlightening clinicians regarding current controversies. This manuscript is an opinion-based review of the studies presented at the meeting, focusing on findings from randomized phase III trials and translational researches that, in the authors' opinion, are most likely to modify clinical practice or help scientists in designing future translational and clinical studies.