Efficacy of neoadjuvant Cisplatin in triple-negative breast cancer

Targeting triple negative breast cancer: is p53 the answer?

Triple negative breast cancers, which are defined by lack of expression of estrogen, progesterone, or HER2 receptors, represent approximately 15% of all breast cancers, although they account for a much higher proportional of breast cancer mortality. This is due both to their innate aggressive biological characteristics, but also to lack of effective therapies. Conventional chemotherapy is currently the only treatment option, thus there is a critical need to find new and effective targeted therapies in this disease. While investigation of agents such as poly (ADP-ribose) polymerase (PARP) inhibitors and EGFR inhibitors continues, results from recent clinical trials indicate that these therapies are not as active in sporadic triple negative breast cancers as initially hoped. It is important therefore to consider other emerging therapeutic agents. Mutation in p53 is found in the vast majority of triple negative breast cancers, and as such is a target of particular interest. Within this review, several agents with potential activity against aberrant p53 signaling have been considered, as a novel approach to finding an effective targeted therapy for this aggressive breast cancer subtype.

Nonfamilial breast cancer subtypes

Over the last decade, our knowledge in somatic genetic events related to breast cancer has increased -enormously. Through usage of various genome-wide molecular approaches, it has become increasingly clear that breast cancer is a vastly heterogeneous disease. Microarray-based gene expression profiling has divided breast cancer into five distinct intrinsic subtypes termed basal-like, HER2-enriched, normal-like, luminal A, and luminal B. Importantly, these subtypes are closely correlated to clinical variables as well as different outcomes, with luminal A tumors as the good prognostic group. Initial studies using genome-wide DNA copy number data broadly partitioned breast cancers into three types, complex, amplifier, and simple, and moreover associated distinct copy number changes with the intrinsic subtypes defined by gene expression profiles. More recently, this genomic classification was refined into six genomic subtypes demonstrating strong resemblance to the intrinsic gene expression classification. Additionally, inherited BRCA1- and BRCA2-mutated tumors were significantly correlated to specific subtypes. In this chapter, we will review the current status regarding genomic subtypes of nonfamilial breast cancer.

Emerging therapies for triple-negative breast cancer

SUMMARY Triple-negative breast cancer (TNBC) lacks expression of the estrogen, progesterone and HER2 receptors and is a clinical problem representing 15–20% of diagnosed breast cancers. TNBC is over-represented among premenopausal, African–American women and among women with incurable disease. Tremendous efforts in the preclinical and clinical setting are dedicated to developing more effective, targeted agents to treat this aggressive disease. Promising therapies, including inhibitors of the EGF receptor, VEGF receptor and PARP, have not had the desired success, potentially due to heterogeneity within TNBC. Ongoing preclinical work is focused on inhibition of Chk1, HDAC and the PI3K and/or mTOR pathways.

Platinum-based chemotherapy in triple-negative breast cancer: A meta-analysis

Triple-negative breast cancer (TNBC) tumors do not express estrogen, progesterone or HER2/neu-receptors. There are no specific treatment guidelines for TNBC patients, however, it has been postulated that their phenotypic and molecular similarity to BRCA1-associated cancers would confer sensitivity to certain cytotoxic agents, including platinum. The aim of this meta-analysis was to evaluate the clinical outcome of breast cancer patients treated with platinum-based chemotherapy who had TNBC compared with those with non-TNBC. Electronic (MEDLINE, EMBASE and Cochrane Library databases) and manual searches were conducted throughout December 2011 to identify trials evaluating the use of platinum-based chemotherapy for patients with breast cancer. The methodological quality was assessed in accordance with the QUOROM statement. Seven studies met the eligibility criteria, with a total of 717 patients. Of these patients, 225 were TNBC patients (31%), 492 were non-TNBC patients (69%), 275 received platinum-based neo-adjuvant chemotherapy and 442 had advanced/metastatic breast cancers. The results showed that during neo-adjuvant chemotherapy, the clinical complete response (cCR) rate and the pathological complete response (pCR) rates were significantly higher for the TNBC group compared with the non-TNBC group (OR, 2.68; 95% CI, 1.69–6.57; P=0.03 and OR, 2.89; 95% CI, 1.28, 6.53; P= 0.01, respectively). However, in advanced/metastatic breast cancers, the cCR, partial response (PR) and the disease control rates for the TNBC group were not significantly different compared with the non-TNBC group. The 6-month progression-free survival (PFS) rate for the TNBC group was higher than that of the non-TNBC group in all patients (OR, 1.81; 95% CI, 1.11–2.96; P= 0.02). However, the 1- and 2-year PFS rates were not significantly different (OR, 1.42; 95% CI, 0.69–2.92; P=0.35 and OR, 1.11; 95% CI, 0.35–3.52; P= 0.85, respectively). Furthermore, the PFS rates were not significantly different between the groups in patients with advanced/metastatic breast cancer. In conclusion, platinum-based chemotherapy in the breast cancer patients with TNBC showed an improved short-term efficacy compared with the non-TNBC group during neo-adjuvant chemotherapy, but has not yet been demonstrated to have an improved effect in advanced breast cancer.

New developments and future directions in systemic therapy

Adjuvant systemic therapies for breast cancer have led to a significant reduction in the risk of relapse and improvement in overall survival. However, a substantial proportion of breast cancer patients still ultimately experience relapse with metastatic disease. Here we review recent progress in trials of systemic therapies, including endocrine therapy, chemotherapy and targeted therapies for breast cancer. A current challenge for translational research is to identify drivers of resistance that may be amenable to therapy, as well as potential compensatory mechanisms that might limit the effectiveness of novel therapies. Unfortunately, not all targeted agents entering clinical trials will show sufficient efficacy to be approved for use. We highlight key findings from trials of novel agents, and the need for further research to identify biomarkers of response to systemic therapies in breast cancer.

Computation as the mechanistic bridge between precision medicine and systems therapeutics

Over the past 50 years, like molecular cell biology, medicine and pharmacology have been driven by a reductionist approach. The focus on individual genes and cellular components as disease loci and drug targets has been a necessary step in understanding the basic mechanisms underlying tissue/organ physiology and drug action. Recent progress in genomics and proteomics, as well as advances in other technologies that enable large-scale data gathering and computational approaches, is providing new knowledge of both normal and disease states. Systems-biology approaches enable integration of knowledge from different types of data for precision medicine and systems therapeutics. In this review, we describe recent studies that contribute to these emerging fields and discuss how together these fields can lead to a mechanism-based therapy for individual patients.

Docetaxel-cisplatin might be superior to docetaxel-capecitabine in the first-line treatment of metastatic triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) may be more sensitive to platinum. This study was to compare platinum-based regimen with nonplatinum regimen in the first-line treatment of advanced TNBC.

PATIENTS AND METHODS

Eligible metastatic TNBC (mTNBC) women without prior treatment for advanced disease were randomized (1 : 1) to receive either docetaxel-cisplatin (TP) or docetaxel -capecitabine (TX) q3w for up to 6 cycles, until disease progression or unacceptable toxicity. The primary end point was objective response rate (ORR) and the secondary end points included progression-free survival (PFS) and overall survival (OS). In total 53 patients were enrolled.

RESULTS

The median follow-up was 24 months. ORR was higher in the TP group than in the TX group (63.0% versus 15.4%, P = 0.001). PFS was more than doubled (10.9 months versus 4.8 months, P < 0.001) and median OS was also greatly improved (32.8 months versus 21.5 months, P = 0.027). Toxic effects were not different except G3/4 vomiting and G2/3 hand-foot syndrome.

CONCLUSIONS

This study suggested that cisplatin-based chemotherapy was superior to capecitabine-based regimen in the first-line treatment of mTNBC, as measured by ORR, PFS and OS. Further large-scale study should be warranted. These results are not sufficient to change clinical practice.

Gene signatures in breast cancer: current and future uses

Gene signatures have been developed for estrogen receptor-positive breast cancer to complement pathological factors in providing prognostic information. The 70-gene and the 21-gene signatures identify patients who may not require adjuvant chemotherapy. Gene signatures in triple-negative disease and HER2-positive disease have not been fully developed yet, although studies demonstrate heterogeneity within these subgroups. Further research is needed before genotyping will help in making clinical decisions in triple-negative and HER2-positive disease. Molecular subtyping of breast cancer led to define luminal, basal, and HER2-enriched subtypes, which have specific clinical behavior. This approach may lead to identify new subgroups requiring specific therapies. Standardization of techniques will be required to translate investigations to the clinic.

The risk of primary and contralateral breast cancer after ovarian cancer in BRCA1/BRCA2 mutation carriers: Implications for counseling

BACKGROUND

The objective of this study was to assess the incidence of primary breast cancer (PBC) and contralateral breast cancer (CBC) in patients who had BRCA1/BRCA2-associated epithelial ovarian cancer (OC).

METHODS

From the database of the Rotterdam Family Cancer Clinic, patients who had BRCA-associated OC without a history of unilateral breast cancer (BC) (at risk of PBC; n = 79) or with a history of unilateral BC (at risk of CBC; n = 37) were selected. The control groups consisted of unaffected BRCA mutation carriers (n = 351) or mutation carriers who had a previous unilateral BC (n = 294), respectively. The risks of PBC and CBC were calculated using the Kaplan-Meier survival method with death considered as a competing risk event.

RESULTS

Women with BRCA-associated OC had lower 2-year, 5-year, and 10-year risks of PBC (3%, 6%, and 11%, respectively) compared with unaffected mutation carriers (6%, 16%, and 28%, respectively; P = .03), although they had a considerably higher mortality rate at similar time points (13%, 33%, and 61%, respectively, vs 1%, 2%, and 2%, respectively; P < .001). In BRCA mutation carriers with a previous unilateral BC, the 2-year, 5-year, and 10-year risks of CBC were nonsignificantly lower in patients with OC than in those without OC (0%, 7%, and 7%, respectively, vs 6%, 16%, and 34%, respectively; P = .06), whereas the mortality rate was higher in patients with OC (19%, 34%, and 55%, respectively, vs 4%, 11%, and 21%, respectively; P < .001).

CONCLUSIONS

Patients with BRCA-associated OC had a lower risk of developing a subsequent PBC or CBC than mutation carriers without OC, whereas the risk of dying from OC was greater than the risk of developing BC. These data may facilitate more tailored counseling for this patient subgroup, although confirmative studies are warranted.

A DNA repair BRCA1 estrogen receptor and targeted therapy in breast cancer

BRCA1 is a key mediator of DNA repair pathways and participates in the maintenance of the genomic integrity of cells. The control of DNA damage repair mechanisms by BRCA1 is of great interest since molecular defects in this pathway may reflect a predictive value in terms of a cell’s sensitivity to DNA damaging agents or anticancer drugs. BRCA1 has been found to exhibit a hormone-dependent pattern of expression in breast cells. Wild-type BRCA1 is required for the inhibition of the growth of breast tumor cells in response to the pure steroidal ERα antagonist fulvestrant. Also a loss of BRCA1-mediated transcriptional activation of ERα expression results in increased resistance to ERα antagonists. Platinum-based drugs, poly(ADP-ribose) polymerase (PARP) inhibitors, and their combination are currently included in chemotherapy regimens for breast cancer. Preclinical and clinical studies in a BRCA1-defective setting have recently indicated a rationale for the use of these compounds against hereditary breast cancers. Initial findings indicate that neoadjuvant use of cisplatin results in high rates of complete pathological response in patients with breast cancer who have BRCA1 mutations. Cisplatin produces a better response in triple-negative breast cancer (TNBC) than in non-TNBC diseases in both the neoadjuvant and adjuvant settings. This implies that TNBC cells may harbor a dysfunctional BRCA1 repair pathway.

Platinum chemotherapy for BRCA1-related breast cancer: do we need more evidence?

A recent prospective clinical trial provides further evidence that breast cancers arising in germline BRCA1 mutation carriers are highly sensitive to cisplatin chemotherapy. The potential significance of these data for the management of patients with BRCA1-related and BRCA2-related breast cancer is discussed.

Mutation analysis of BRCA1, BRCA2, PALB2 and BRD7 in a hospital-based series of German patients with triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive form of breast carcinoma with a poor prognosis. Recent evidence suggests that some patients with TNBC harbour germ-line mutations in DNA repair genes which may render their tumours susceptible to novel therapies such as treatment with PARP inhibitors. In the present study, we have investigated a hospital-based series of 40 German patients with TNBC for the presence of germ-line mutations in BRCA1, BRCA2, PALB2, and BRD7 genes. Microfluidic array PCR and next-generation sequencing was used for BRCA1 and BRCA2 analysis while conventional high-resolution melting and Sanger sequencing was applied to study the coding regions of PALB2 and BRD7, respectively. Truncating mutations in BRCA1 were found in six patients, and truncating mutations in BRCA2 and PALB2 were detected in one patient each, whereas no truncating mutation was identified in BRD7. One patient was a double heterozygote for the PALB2 mutation, c.758insT, and a BRCA1 mutation, c.927delA. Our results confirm in a hospital-based setting that a substantial proportion of German TNBC patients (17.5%) harbour germ-line mutations in genes involved in homology-directed DNA repair, with a preponderance of BRCA1 mutations. Triple-negative breast cancer should be considered as an additional criterion for future genetic counselling and diagnostic sequencing.

Profiles of genomic instability in high-grade serous ovarian cancer predict treatment outcome

PURPOSE

High-grade serous cancer (HGSC) is the most common cancer of the ovary and is characterized by chromosomal instability. Defects in homologous recombination repair (HRR) are associated with genomic instability in HGSC, and are exploited by therapy targeting DNA repair. Defective HRR causes uniparental deletions and loss of heterozygosity (LOH). Our purpose is to profile LOH in HGSC and correlate our findings to clinical outcome, and compare HGSC and high-grade breast cancers.

EXPERIMENTAL DESIGN

We examined LOH and copy number changes using single nucleotide polymorphism array data from three HGSC cohorts and compared results to a cohort of high-grade breast cancers. The LOH profiles in HGSC were matched to chemotherapy resistance and progression-free survival (PFS).

RESULTS

LOH-based clustering divided HGSC into two clusters. The major group displayed extensive LOH and was further divided into two subgroups. The second group contained remarkably less LOH. BRCA1 promoter methylation was associated with the major group. LOH clusters were reproducible when validated in two independent HGSC datasets. LOH burden in the major cluster of HGSC was similar to triple-negative, and distinct from other high-grade breast cancers. Our analysis revealed an LOH cluster with lower treatment resistance and a significant correlation between LOH burden and PFS.

CONCLUSIONS

Separating HGSC by LOH-based clustering produces remarkably stable subgroups in three different cohorts. Patients in the various LOH clusters differed with respect to chemotherapy resistance, and the extent of LOH correlated with PFS. LOH burden may indicate vulnerability to treatment targeting DNA repair, such as PARP1 inhibitors.

BRCA1 epigenetic inactivation predicts sensitivity to platinum-based chemotherapy in breast and ovarian cancer

Germline mutations in the BRCA1 or BRCA2 genes are associated with an increased risk of breast and ovarian cancer development. Both genes are involved in DNA repair, and tumors harboring genetic defects in them are thought to be more sensitive to DNA-damaging agents used in chemotherapy. However, as only a minority of breast and ovarian cancer patients carry BRCA1 or BRCA2 mutations, few patients are likely to benefit from these pharmacogenetic biomarkers. Herein, we show that, in cancer cell lines and xenografted tumors, BRCA1 CpG island promoter hypermethylation-associated silencing also predicts enhanced sensitivity to platinum-derived drugs to the same extent as BRCA1 mutations. Most importantly, BRCA1 hypermethylation proves to be a predictor of longer time to relapse and improved overall survival in ovarian cancer patients undergoing chemotherapy with cisplatin.

DNA methylation profiling in breast cancer discordant identical twins identifies DOK7 as novel epigenetic biomarker

Using whole blood from 15 twin pairs discordant for breast cancer and high-resolution (450K) DNA methylation analysis, we identified 403 differentially methylated CpG sites including known and novel potential breast cancer genes. Confirming the results in an independent validation cohort of 21 twin pairs determined the docking protein DOK7 as a candidate for blood-based cancer diagnosis. DNA hypermethylation of the promoter region was also seen in primary breast cancer tissues and cancer cell lines. Hypermethylation of DOK7 occurs years before tumor diagnosis, suggesting a role as a powerful epigenetic blood-based biomarker as well as providing insights into breast cancer pathogenesis.

Triple-negative breast cancer is associated with EGFR, CK5/6 and c-KIT expression in Malaysian women

BACKGROUND

Triple-negative breast cancer (TNBC) is a heterogeneous subgroup of breast cancer characterized by the lack of estrogen receptor (ER), progesterone receptor (PR) and the human epidermal growth factor receptor 2 (HER2) expressions. This subgroup of refractory disease tends to have aggressive clinical behavior, high frequency of metastasis and lack of response to current hormonal or targeted therapies. Despite numerous studies reporting the clinicopathological features of TNBC and its association with the basal-like phenotype in the Western population, only limited data are available in the Asian population. Therefore, the aim of this study was to investigate the clinicopathological characteristics of TNBC and its association with epidermal growth factor receptor (EGFR), cytokeratin 5/6 (CK5/6) and mast/stem cell growth factor receptor (c-KIT or CD117) expression in Malaysian women.

METHODS

A total of 340 patients diagnosed with primary breast cancer between 2002 and 2006 in Malaysia were reviewed and analyzed.

RESULTS

The incidence of TNBC was 12.4% (42/340). Bivariate analysis revealed that TNBC was strongly associated with a younger age, higher grade tumor and p53 expression. Further immunohistochemical analysis suggested that TNBC in Malaysian women was strongly associated with EGFR, CK5/6 and c-KIT expression with high a Ki-67 proliferation index.

CONCLUSION

In conclusion, our study confirms the association of TNBC with basal-like marker expression (EGFR, CK5/6 and c-KIT) in Malaysian women, consistent with studies in other populations.

Overexpression of epithelial growth factor receptor (EGFR) predicts better response to neo-adjuvant chemotherapy in patients with triple-negative breast cancer

Background

Triple negative breast cancer (TNBC) occurs in approximately 10% to 25% of all patients with breast cancer and is associated with poor prognosis. Neo-adjuvant chemotherapy has been reported to produce a higher pathologic complete response (pCR) rate in TNBC. If pCR is achieved, patients with TNBC had a similar survival with non-TNBC patients. The aim of our study was to investigate the protein expression of epithelial growth factor receptor (EGFR) and response to neo-adjuvant chemotherapy and clinical outcome in patients with TNBC compared with non-TNBC.

Methods

A total of 198 locally advanced breast cancer patients who received neo-adjuvant chemotherapy were studied. Immunohistochemistry (IHC) was carried out to detect the protein expression of EGFR in tumor samples. Clinical and pathological parameters, pCR rate and survival data were compared between 40 TNBCs and 158 non-TNBCs.

Results

In 198 cases who received neo-adjuvant chemotherapy, significant differences exist in surgical therapy (P=0.005) and pCR rate (P=0.012) between patients with TNBCs and non-TNBCs. Overexpression of EGFR was significantly associated with pCR rate in patients with TNBCs (P < 0.001). Survival analysis revealed that patients with TNBCs had worse DFS and OS than those with non-TNBCs (P = 0.001, P < 0.001 respectively). Furthermore, for patients with non-TNBCs, those who acheived pCR had better DFS and OS than those who acheived RD (both P < 0.001).

Conclusions

Our results suggested that patients with TNBCs had increased pCR rates compared with non-TNBC. Overexpression of EGFR predicted better response to neo-adjuvant chemotherapy in patients with TNBCs.

Hypoxia-induced protein CAIX is associated with somatic loss of BRCA1 protein and pathway activity in triple negative breast cancer

The purpose of this study is to explore the relationship between tumor hypoxia assessed by CA IX protein expression and loss of BRCA1 function in triple negative breast cancer (TNBC). Protein expression of CA IX and BRCA1 was evaluated by AQUA™ technology on two breast cancer cohorts: an unselected cohort of 637 breast cancer patients and a TNBC cohort of 120 patients. Transcriptional profiling was performed on FFPE samples from the TNBC cohort to evaluate a gene expression signature associated with BRCA1 mutation (van't Veer et al., Nature 415(6871):530-536, 2002). CA IX is expressed in 7 % of the unselected breast cancer cohort and in 25 % of the TNBCs and is significantly associated with the triple negative phenotype. CA IX protein expression and BRCA1 protein expression are inversely correlated in both cohorts. Patients expressing high levels of CA IX show significantly worse overall survival (p = 0.02). Importantly, high CA IX protein expression occurs in patients who show the BRCA1 mutant signature and low levels of BRCA1 protein. These data suggest that elevated CA IX protein in TNBC is associated with a BRCA1 mutant signature and loss of BRCA1 function. CA IX may be a useful biomarker to identify triple negative patients with defective homologous recombination, who might benefit from PARP inhibitor therapy.

DNA methylation profiling in the clinic: applications and challenges

Knowledge of epigenetic alterations in disease is rapidly increasing owing to the development of genome-wide techniques for their identification. The ever-growing number of genes that show epigenetic alterations in disease emphasizes the crucial role of these epigenetic alterations - particularly DNA methylation - for future diagnosis, prognosis and prediction of response to therapies. This Review focuses on epigenetic profiling, which has started to be of clinical value in cancer and may in the future be extended to other diseases, such as neurological and autoimmune disorders.

Targeting triple-negative breast cancer: optimising therapeutic outcomes

BACKGROUND

Triple-negative breast cancer (TNBC) is a distinct subset of breast cancer (BC) defined by the lack of immunohistochemical expression of the estrogen and progesterone receptors and human epidermal growth factor receptor 2. It is highly heterogeneous and displays overlapping characteristics with both basal-like and BC susceptibility gene 1 and 2 mutant BCs. This review evaluates the activity of emerging targeted agents in TNBC.

DESIGN

A systematic review of PubMed and conference databases was carried out to identify randomised clinical trials reporting outcomes in women with TNBC treated with targeted and platinum-based therapies.

RESULTS AND DISCUSSION

Our review identified TNBC studies of agents with different mechanisms of action, including induction of synthetic lethality and inhibition of angiogenesis, growth, and survival pathways. Combining targeted agents with chemotherapy in TNBC produced only modest gains in progression-free survival, and had little impact on survival. Six TNBC subgroups have been identified and found to differentially respond to specific targeted agents. The use of biological preselection to guide therapy will improve therapeutic indices in target-bearing populations.

CONCLUSION

Ongoing clinical trials of targeted agents in unselected TNBC populations have yet to produce substantial improvements in outcomes, and advancements will depend on their development in target-selected populations.

Clinical correlates of 'BRCAness' in triple-negative breast cancer of patients receiving adjuvant chemotherapy

BACKGROUND

We have previously reported an array comparative genomic hybridization profile that identifies triple-negative breast cancers (TNBC), with BRCA1 dysfunction and a high sensitivity to intensified dose bifunctional alkylating agents. To determine the effect of conventional-dose chemotherapy in patients with this so-called BRCA1-like profile, clinical characteristics and survival were studied in a large group of TNBC patients.

PATIENTS AND METHODS

DNA was isolated and BRCA1-like status was assessed in 101 patients with early-stage TNBC receiving adjuvant cyclophosphamide-based chemotherapy. Clinical characteristics and survival were compared between BRCA1-like and non-BRCA1-like groups. Results Sixty-six tumors (65%) had a BRCA1-like profile. Patients with BRCA1-like tumors tended to be younger and had more often node-negative disease (P = 0.06 and P = 0.03, respectively). Five-year recurrence-free survival was 80% for the BRCA1-like group and 75% for the non-BRCA1-like group (P = 0.35). T stage was the only variable significantly associated with survival.

CONCLUSIONS

BRCA1-like tumors share clinical features, like young age at diagnosis and similar nodal status, with breast cancers in BRCA1 mutation carriers. Their prognosis is similar to that of non-BRCA1-like tumors when conventional-dose chemotherapy is administered. TNBCs that are classified as BRCA1-like may contain a defect in homologous recombination and could, in theory, benefit from the addition of poly ADP ribose polymerase inhibitors.

Ploidy and large-scale genomic instability consistently identify basal-like breast carcinomas with BRCA1/2 inactivation

BRCA1 inactivation is a frequent event in basal-like breast carcinomas (BLC). However, BRCA1 can be inactivated by multiple mechanisms and determining its status is not a trivial issue. As an alternate approach, we profiled 65 BLC cases using single-nucleotide polymorphism arrays to define a signature of BRCA1-associated genomic instability. Large-scale state transitions (LST), defined as chromosomal break between adjacent regions of at least 10 Mb, were found to be a robust indicator of BRCA1 status in this setting. Two major ploidy-specific cutoffs in LST distributions were sufficient to distinguish highly rearranged BLCs with 85% of proven BRCA1-inactivated cases from less rearranged BLCs devoid of proven BRCA1-inactivated cases. The genomic signature we defined was validated in a second independent series of 55 primary BLC cases and 17 BLC-derived tumor cell lines. High numbers of LSTs resembling BRCA1-inactivated BLC were observed in 4 primary BLC cases and 2 BLC cell lines that harbored BRCA2 mutations. Overall, the genomic signature we defined predicted BRCA1/2 inactivation in BLCs with 100% sensitivity and 90% specificity (97% accuracy). This assay may ease the challenge of selecting patients for genetic testing or recruitment to clinical trials of novel emerging therapies that target DNA repair deficiencies in cancer.

BRCA1 and HSP90 cooperate in homologous and non-homologous DNA double-strand-break repair and G2/M checkpoint activation

Expression of functional breast cancer susceptibility gene 1 (BRCA1) in human breast and ovarian cancers is associated with resistance to platinum-based chemotherapeutics and poly(ADP ribose) polymerase (PARP) inhibitors. BRCA1 is a nuclear tumor suppressor that is critical for resolving double-strand DNA breaks (DSBs) and interstrand crosslinks (ICLs) by homologous recombination (HR). In vitro, animal and human clinical data have demonstrated that BRCA1-deficient cancers are highly sensitive to ICL-inducing chemotherapeutic agents, are amenable to synthetic lethal approaches that exploit defects in DSB/ICL repair, and may be associated with improved survival. Conversely, high or restored expression of BRCA1 in breast and ovarian cancer is associated with therapeutic resistance and poor prognosis. There has been much interest in identifying agents that interfere with BRCA1-dependent DSB/ICL repair to restore or enhance sensitivity to cancer therapeutics. We demonstrate that the heat-shock protein 90 (HSP90) inhibitor 17-allylamino-17-demethoxygeldanamycin [17-AAG (Tanespimycin)], currently in Phase II/III clinical evaluation for several cancers, induces BRCA1 ubiquitination and proteasomal degradation, resulting in compromised repair of ionizing radiation- and platinum-induced DNA damage. We show that loss of HSP90 function abolishes BRCA1-dependent DSB repair and that BRCA1-deficient cells are hypersensitive to 17-AAG due to impaired Gap 2/Mitosis (G2/M) checkpoint activation and resultant mitotic catastrophe. In summary, we document an upstream HSP90-dependent regulatory point in the Fanconi anemia/BRCA DSB/ICL repair pathway, illuminate the role of BRCA1 in regulating damage-associated checkpoint and repair responses to HSP90 inhibitors, and identify BRCA1 as a clinically relevant target for enhancing sensitivity in refractory and/or resistant malignancies.

Treating metastatic breast cancer with systemic chemotherapies: current trends and future perspectives

Treatment selection for metastatic breast cancer (MBC) is guided by multiple factors, most importantly hormone receptor (HR) or HER2 expression, treatment history, and prognostic factors such as short disease-free interval, presence of visceral metastases, performance status, and degree of symptoms. Chemotherapy is indicated as initial therapy for patients with HR-negative disease and following failure of hormonal therapies in HR-positive disease. Patients treated with an anthracycline or a taxane in early-stage settings may no longer be candidates for those drugs in MBC, thus underscoring the need for alternative options. Sequential single-agent therapy or combination therapy are viable strategies. Trials have shown that ixabepilone plus capecitabine significantly improves progression-free survival compared with capecitabine alone in anthracycline- or taxane-pretreated or -resistant patients, and single-agent eribulin improves survival compared with the physician's choice of treatment in patients treated previously with at least two regimens for MBC. Regardless of the regimen, proactive management to detect treatment-related adverse events in a timely manner remains important for ensuring effective delivery of treatment. Many promising investigational agents are in development, including T-DM1 (trastuzumab emtansine) and pertuzumab for HER2-positive disease, as well as PARP-1 (poly[adenosine diphosphate ribose] polymerase-1) inhibitors and cetuximab for triple-negative disease. In addition, new options for the treatment of MBC following failure of an anthracycline and a taxane promise to improve patient outcomes. Nurses should remain vigilant for adverse events and remember that the goal of treatment remains control of the disease and palliation.

Feature extraction via composite scoring and voting in breast cancer

Identification and characterization of tumor subtypes using gene expression profiles of triple negative breast cancer patients. Microarray data of four breast cancer studies were pooled and evaluated. Molecular subtype classification was performed using random forest and a novel algorithm for feature extraction via composite scoring and voting. Biological and clinical properties were evaluated via GSEA, functional annotation clustering and clinical endpoint analysis. The subtype signatures are highly predictive for distant metastasis free survival of tamoxifen-treated patients. Consensus clustering and the novel algorithm proposed three triple negative subtypes. One subtype shows low E2F4 gene expression and is predictive for survival of ER negative breast cancer patients. The other two subtypes share commonalities with luminal B tumors. Classification of breast cancer expression profiles may reveal novel tumor subtypes, possessing clinical impact. Furthermore, subtype characterizing gene signatures might hold potential for novel strategies in cancer therapy.

Systemic therapy options in BRCA mutation-associated breast cancer

BRCA mutation-associated breast cancers are characterized by deficient homologous recombination of DNA, and 80 % of BRCA1-associated breast cancers display the basal-like molecular subtype. Traditionally, BRCA carriers have received conventional systemic chemotherapy based on their baseline tumor characteristics, and it is generally accepted that after the appropriate treatment the prognosis of a mutation carrier is equivalent to that of a patient with sporadic breast cancer. However, with the growing understanding of the functions of BRCA1/2 proteins in homologous DNA repair, it is recognized that BRCA-associated breast cancer tumors may have distinct biochemical characteristics and thus require tailored treatment strategies. Tumors arising in patients with BRCA mutations were shown to be particularly sensitive to platinum compounds or inhibitors of poly(ADP-ribose) polymerase. In addition, BRCA1-mutation carriers seem to benefit from anthracycline-taxane-containing regimens as much as sporadic triple-negative breast cancers do. In this article, we review the functions of the BRCA1 and BRCA2 genes, and their differential chemosensitivity in both the preclinical and clinical settings. The optimal chemotherapy regimen for this subset of patients still remains to be determined.

Enhancement of synthetic lethality via combinations of ABT-888, a PARP inhibitor, and carboplatin in vitro and in vivo using BRCA1 and BRCA2 isogenic models

Individuals with an inherited BRCA1 or BRCA2 mutation have an elevated risk of developing breast cancer. The resulting tumors typically lack homologous recombination repair as do a subset of sporadic tumors with acquired BRCA deficiency. Clinical responses to monotherapy with platinum drugs or poly PARP inhibitors (PARPi) have been shown for BRCA-associated cancers. However, there are limited data on combination therapy with PARPi and platinum drugs, the mechanism of action of this combination, and the role of BRCA1 or BRCA2 in chemosensitivity. We compared the efficacy of ABT-888 (a PARPi) with that of cisplatin or carboplatin (platinum drugs) alone or in combinations by examining the survival of treated Brca-proficient and -deficient mouse embryonic stem cells. In addition, drug-induced growth inhibition of a BRCA1 and a BRCA2 null cell line were compared with their isogenic BRCA-complemented lines. Although each monotherapy killed or inhibited proliferation of Brca/BRCA-deficient cells, an enhanced effect was observed after treatment with ABT-888 in combination with carboplatin. Moreover, the ABT-888/carboplatin combination delayed tumor growth in Brca2 xenografts. The drugs caused DNA damage and apoptosis. Along with greater PARP activity in Brca/BRCA-deficient cells, these effects correlated with increased chemosensitivity. Our data suggest that ABT-888 and carboplatin combination treatment will be more successful than monotherapy in addressing many BRCA-associated cancers. A randomized phase II trial has recently been initiated to test this hypothesis to assist in the discovery of more effective therapies for patients with BRCA.

Estrogen receptor status confers a distinct pattern of response to neoadjuvant chemotherapy: implications for optimal durations of therapy: distinct patterns of response according to ER expression

Estrogen receptor (ER) expression status is an independent factor predicting response to neoadjuvant systemic treatment (NST). In the current study, we aimed to investigate the characteristics of NST response and benefits of extended NST cycles according to ER expression status. We investigated the outcomes of different durations of anthracycline-taxane-based NST in 377 operable breast cancer patients treated between Aug 2008 and June 2011. In 89 patients, the serial radiologic tumor response was assessed with either ultrasonography or computed tomography. Ninety-six patients (25.5 %) received extended cycles of anthracycline-taxane-based NST (6-8 cycles) and 281 patients (74.5 %) received 3-4 cycles of NST. Treatment with extended cycles of NST led to a significant increase in the pCR rate in ER-positive tumors only (2.1-11.7 %, p = 0.008 for ER-positive tumors and 20.0-19.4 %, p = 0.941 for ER-negative tumors). Serial assessment of radiologic tumor size during extended NST therapy revealed continuous shrinkage of ER-positive tumors during the chemotherapy cycles, while ER-negative tumors mainly achieved size reduction during the first 3-4 cycles with no significant additional tumor shrinkage during the extended cycles of NST. In this study, we report a distinct pattern of response to NST according to ER expression status in breast cancer. Our observation generates the hypothesis that the optimal duration of NST can be tailored to the molecular phenotypes of tumors.

Triple-negative breast cancer: are we making headway at least?

The so-called triple-negative breast cancer, as defined by tumors that lack estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 (HER2) overexpression, has generated growing interest in recent years despite representing less than 20% of all breast cancers. These tumors constitute an important clinical challenge, as they do not respond to endocrine treatment and other targeted therapies. As a group they harbor an aggressive clinical phenotype with early development of visceral metastases and a poor long-term prognosis. While chemotherapy remains effective in triple-negative disease, research continues to further identify potential new targets based on phenotypical and molecular characteristics of these tumors. In this respect, the presence of a higher expression of different biomarkers including epidermal growth factor receptor, vascular endothelial growth factor receptor, fibroblast growth factor receptor and Akt activation has led to a proliferation of clinical trials assessing the role of inhibitors to these pathways in triple-negative tumors. Moreover, the described overlap between triple-negative and basal-like tumors, and the similarities with tumors arising in the BRCA1 mutation carriers has offered potential therapeutic avenues for patients with these cancers including poly (ADP-ribose) polymerase inhibitors and a focus on a higher sensitivity to alkylating chemotherapy agents. Results from these trials have shown some benefit in small subgroups of patients, even in single-agent therapy, which reflects the heterogeneity of triple-negative breast cancer and highlights the need for a further subclassification of these types of tumors for better prognosis identification and treatment individualization.

Management of women with BRCA1/2 mutation-associated breast cancer

SUMMARY BRCA mutation-associated breast cancer differs from sporadic breast cancer as studies show that mutation carriers have a higher risk of breast and ovarian cancer, and also have differential sensitivity to chemotherapeutic agents. With the more readily available BRCA genetic testing, BRCA mutation status should be considered in high-risk women, including women who are diagnosed with breast cancer at an early age, have a strong family history or have tumors with triple-negative status. This article reviews the risk-reducing surgeries, including the prophylactic contralateral mastectomy and bilateral salpingo-oophorectomy, in women diagnosed with BRCA-associated breast cancer. Additionally, the sensitivity of BRCA-defective breast cancer cell lines to platinum cytotoxic compounds, PARP and endocrine therapy is reviewed.

Value of TP53 status for predicting response to neoadjuvant chemotherapy in breast cancer: a meta-analysis

Background

Numerous studies have yielded inconclusive results regarding the relationship between tumor suppressor protein TP53 overexpression and/or TP53 gene mutations and the response to neoadjuvant chemotherapy in patients with breast cancer. The purpose of the current study was therefore to evaluate the relationship between TP53 status and response to chemotherapy in breast cancer.

Methods and Findings

A total of 26 previously published eligible studies including 3,476 cases were identified and included in this meta-analysis. TP53 status (over expression of TP53 protein and/or TP53 gene mutations) was associated with good response in breast cancer patients who received neoadjuvant chemotherapy (total objective response: risk ratio [RR]  = 1.20, 95% confidence interval [CI]  = 1.09–1.33, p<0.001; pathological objective response: RR = 1.37, 95% CI = 1.20–1.57, p<0.01; total complete response: RR = 1.33, 95% CI = 1.15–1.53, p<0.001; pathological complete response: RR = 1.45, 95% CI = 1.25–1.68, p<0.001). In further stratified analyses, this association also existed among the studies using anthracycline-based neoadjuvant chemotherapy, and the association between response and the presence of gene alterations was stronger than that between response and immunohistochemistry positivity.

Conclusion

The results of the present meta-analysis suggest that TP53 status is a predictive factor for response in breast cancer patients undergoing neoadjuvant chemotherapy. Further larger and well-designed prospective studies are required to evaluate the predictive role of TP53 status in clinical practice.

Impact of triple-negative breast cancer phenotype on prognosis in patients with stage I breast cancer

PURPOSE

Although most patients with stage I breast cancer have a good prognosis, their clinical outcomes may vary significantly. We assessed clinical outcomes and prognostic factors in stage I breast cancer patients with and without triple-negative breast cancer (TNBC) phenotype.

METHODS

Of 2,489 patients undergoing breast cancer surgery between January 1998 and December 2002, 554 (22.3%) had stage I breast cancer (tumor size ≤2 cm, and lymph node-negative). TNBC was defined as a primary tumor negative for estrogen and progesterone receptors (Allred scores <3/8) and for HER2/neu (0-1+ by immunohistochemistry).

RESULTS

Of the 554 patients with stage I breast cancer, 78 (14.1%) had TNBC. A significant proportion of TNBC patients had histologic grade 3 tumors (47.4% vs. 34.5%, p=0.031) and tumors >1 cm (87.2% vs. 75.8%, p=0.028) and received adjuvant chemotherapy (79.5% vs. 44.7%, p<0.001). During a median follow-up time of 8.7 years, 72 patients experienced tumor recurrences; 18 (23.1%) in the TNBC group and 54 (11.3%) in the non-TNBC group (p=0.010), with cumulative 3-year rate of recurrence of 12.8% and 5.3%, respectively (p=0.010). Ten-year relapse-free survival (RFS; 75.6% vs. 87.5%, p=0.004) and overall survival (OS; 83.0% vs. 91.4%, p=0.002) rates were significantly lower in the TNBC group. Multivariate analysis showed that triple negativity and histologic grade were independent predictors of shorter RFS and OS.

CONCLUSION

TNBC had more aggressive clinicopathologic characteristics and was associated with poorer survival in patients with stage I breast cancer. More intensive adjuvant chemotherapy or a different therapeutic strategy targeting this population is warranted.

The role of targeted therapy and biomarkers in breast cancer treatment

Breast cancer is the most prevalent life-threatening cancer in women and the second leading cause of cancer associated deaths. Consequently, optimizing breast cancer therapy to increase cure rates in early stage disease and improve life expectancy and palliation for patients with metastasis is a critical need and major area of research in medical oncology. This article focuses on the development of personalized therapy in breast cancer though the use of targeted therapies and their associated biomarkers. Topics reviewed include the historic advances in targeting the HER2 receptor and the current avenues being studied to circumvent resistance; new developments in the management of triple negative and metastatic breast cancer; and the challenges and pitfalls associated with targeting angiogenesis. Using these as examples, many of the innovations and challenges in the treatment of women with breast cancer are explored.

TBCRC 001: randomized phase II study of cetuximab in combination with carboplatin in stage IV triple-negative breast cancer

PURPOSE

Epidermal growth factor receptor (EGFR) is a targetable receptor frequently overexpressed in basal-like breast cancer, which comprises most triple-negative breast cancers (TNBCs), the only subtype without established targeted therapy.

PATIENTS AND METHODS

In this randomized phase II trial, patients with metastatic TNBC received anti-EGFR antibody cetuximab (400 mg/m(2) load then 250 mg/m(2) per week intravenously [IV]) alone, with carboplatin (area under the curve of 2, once per week IV) added after progression or as concomitant therapy from the beginning. Response rate (RR) was the primary end point; others included time to progression (TTP), overall survival (OS), and toxicity. Embedded correlative studies included molecular subtyping on archival tissue. Fresh tumor tissue before and after 7 to 14 days of therapy was used for microarray analyses exploring EGFR pathway activity and inhibition.

RESULTS

In 102 patients with TNBC, RRs were 6% (two of 31) to cetuximab and 16% (four of 25) to cetuximab plus carboplatin after progression. RR to those treated from the beginning with cetuximab plus carboplatin was 17% (12 of 71); 31% of patients responded or had prolonged disease stabilization. The cetuximab plus carboplatin regimen was well tolerated, but both TTP and OS were short at 2.1 months (95% CI, 1.8 to 5.5 months) and 10.4 months (95% CI, 7.7 to 13.1 months), respectively. Of 73 patients with archival tissue for analysis, 74% had basal-like molecular subtype. Sixteen patients had tumor biopsies before and 1 week after therapy; genomic patterns of the EGFR pathway showed activation in 13 and inhibition by therapy in five.

CONCLUSION

Despite strong preclinical data, combination cetuximab plus carboplatin in metastatic TNBC produced responses in fewer than 20% of patients. EGFR pathway analysis showed that most TNBCs involved activation. However, cetuximab blocked expression of the EGFR pathway in only a minority, suggesting that most had alternate mechanisms for pathway activation.

Basal-like Breast cancer DNA copy number losses identify genes involved in genomic instability, response to therapy, and patient survival

Breast cancer is a heterogeneous disease with known expression-defined tumor subtypes. DNA copy number studies have suggested that tumors within gene expression subtypes share similar DNA Copy number aberrations (CNA) and that CNA can be used to further sub-divide expression classes. To gain further insights into the etiologies of the intrinsic subtypes, we classified tumors according to gene expression subtype and next identified subtype-associated CNA using a novel method called SWITCHdna, using a training set of 180 tumors and a validation set of 359 tumors. Fisher's exact tests, Chi-square approximations, and Wilcoxon rank-sum tests were performed to evaluate differences in CNA by subtype. To assess the functional significance of loss of a specific chromosomal region, individual genes were knocked down by shRNA and drug sensitivity, and DNA repair foci assays performed. Most tumor subtypes exhibited specific CNA. The Basal-like subtype was the most distinct with common losses of the regions containing RB1, BRCA1, INPP4B, and the greatest overall genomic instability. One Basal-like subtype-associated CNA was loss of 5q11-35, which contains at least three genes important for BRCA1-dependent DNA repair (RAD17, RAD50, and RAP80); these genes were predominantly lost as a pair, or all three simultaneously. Loss of two or three of these genes was associated with significantly increased genomic instability and poor patient survival. RNAi knockdown of RAD17, or RAD17/RAD50, in immortalized human mammary epithelial cell lines caused increased sensitivity to a PARP inhibitor and carboplatin, and inhibited BRCA1 foci formation in response to DNA damage. These data suggest a possible genetic cause for genomic instability in Basal-like breast cancers and a biological rationale for the use of DNA repair inhibitor related therapeutics in this breast cancer subtype.

Association of HER-2 copy number and HER-2/CEP-17 ratio with neoadjuvant taxane-containing chemotherapy sensitivity in locally advanced breast cancer

PURPOSE

Aneusomy 17 causes inconsistency in fluorescence in situ hybridization (FISH)-based human epidermal growth factor receptor (HER)-2 status assessment using different algorithms (copy number or the HER-2/centromere enumerator probe 17 [CEP-17] ratio). We investigated the effects of FISH-based HER-2 status assessment and aneusomy 17 on responsiveness to neoadjuvant chemotherapy (NAC).

PATIENTS AND METHODS

This prospective study recruited 152 patients with locally advanced breast cancer who underwent four-cycle weekly paclitaxel plus carboplatin without trastuzumab.

RESULTS

The pathologic complete remission (pCR) rate in the breast and axilla was 24.3% (95% confidence interval [CI], 17.7%-32.0%). Although HER-2 status, assessed by either HER-2/CEP-17 ratio-based FISH or copy number-based FISH, was a predictor of NAC sensitivity, ratio-assessed HER-2 status had a poorer performance in determining patients' responsiveness to NAC (p = .029). Patients who were not HER-2 amplified when assessed using the HER-2/CEP-17 ratio but were HER-2 amplified when assessed using copy number (~5%) were eventually proven to be responsive to NAC, with a pCR rate of 57% (95% CI, 18.4%-90.1%). In contrast, patients who were HER-2 amplified when assessed by the ratio but not HER-2 amplified when assessed using copy number (~3%) were completely irresponsive. Higher HER-2 copy numbers represented increasing chances of a pCR (adjusted odds ratio, 3.09; 95% CI, 1.35-7.08), with an apparent gene-dose effect (p for trend < .001).

CONCLUSION

It is likely that HER-2 copy number but not the HER-2/CEP-17 ratio determines NAC sensitivity. Additional studies to validate our findings are warranted.

Prognostic and predictive value of TP53 mutations in node-positive breast cancer patients treated with anthracycline- or anthracycline/taxane-based adjuvant therapy: results from the BIG 02-98 phase III trial

INTRODUCTION

Pre-clinical data suggest p53-dependent anthracycline-induced apoptosis and p53-independent taxane activity. However, dedicated clinical research has not defined a predictive role for TP53 gene mutations. The aim of the current study was to retrospectively explore the prognosis and predictive values of TP53 somatic mutations in the BIG 02-98 randomized phase III trial in which women with node-positive breast cancer were treated with adjuvant doxorubicin-based chemotherapy with or without docetaxel.

METHODS

The prognostic and predictive values of TP53 were analyzed in tumor samples by gene sequencing within exons 5 to 8. Patients were classified according to p53 protein status predicted from TP53 gene sequence, as wild-type (no TP53 variation or TP53 variations which are predicted not to modify p53 protein sequence) or mutant (p53 nonsynonymous mutations). Mutations were subcategorized according to missense or truncating mutations. Survival analyses were performed using the Kaplan-Meier method and log-rank test. Cox-regression analysis was used to identify independent predictors of outcome.

RESULTS

TP53 gene status was determined for 18% (520 of 2887) of the women enrolled in BIG 02-98. TP53 gene variations were found in 17% (90 of 520). Nonsynonymous p53 mutations, found in 16.3% (85 of 520), were associated with older age, ductal morphology, higher grade and hormone-receptor negativity. Of the nonsynonymous mutations, 12.3% (64 of 520) were missense and 3.6% were truncating (19 of 520). Only truncating mutations showed significant independent prognostic value, with an increased recurrence risk compared to patients with non-modified p53 protein (hazard ratio = 3.21, 95% confidence interval = 1.740 to 5.935, P = 0.0002). p53 status had no significant predictive value for response to docetaxel.

CONCLUSIONS

p53 truncating mutations were uncommon but associated with poor prognosis. No significant predictive role for p53 status was detected.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00174655.

Triple negative breast cancer: a brief review of its characteristics and treatment options

Triple negative breast cancer (TNBC), an aggressive variant of breast cancer, is characterized by lack of expression of the estrogen (ER) and progesterone receptors (PRs) and the human epidermal growth factor receptor (HER-2) that are commonly observed in other breast cancer subtypes. The TNBC subtype primarily occurs in younger women of African American or Hispanic descent and tumors tend to be high grade and initially responsive to chemotherapy. However, TNBC is characteristically aggressive with high recurrence, metastatic, and mortality rates. Treatment options are limited since the hormonal receptor and HER-2 antagonists typically used for other breast cancers are ineffective. As such, the mainstay of treatment of TNBC is traditional systemic cytotoxic chemotherapy. Potential future therapies for TNBC include targeted molecular strategies including poly (adenosine diphosphate ribose) polymerase (PARP) and epidermal growth factor receptor (EGFR) inhibitors and antiangiogenic agents. Further research aimed at identifying unique genetic characteristics of TNBC may allow development of other targeted molecular chemotherapy treatment options.

Gene modules and response to neoadjuvant chemotherapy in breast cancer subtypes: a pooled analysis

PURPOSE

To investigate the association between chemotherapy response and gene expression modules describing important biologic processes and druggable oncogenic pathways in breast cancer (BC) subtypes.

PATIENTS AND METHODS

We searched for publicly available gene expression studies evaluating anthracycline with or without taxane-based neoadjuvant chemotherapy and identified eight studies with 996 patients. We computed 17 gene modules and calculated odds ratios (ORs) for pathologic complete response (pCR) for one-unit increases in scaled modules with and without adjustment for clinicopathologic characteristics. Added predictive accuracy was evaluated using the area under the receiver operating characteristic curve (AUC) and integrated discrimination index (IDI). We used the false discovery rate (FDR) to adjust for multiple testing.

RESULTS

High immune module scores were associated with increased pCR probability in all BC subtypes. High module scores of chromosomal instability, phosphatase and tensin homolog (PTEN) loss, and E2F3 transcription factor were associated with increased pCR probability in estrogen receptor (ER) -negative/human epidermal growth factor receptor 2 (HER2) -negative and ER-positive/HER2-negative but not in HER2-positive tumors (interactions between HER2 and each of these modules for their association with pCR: P < .05; FDR, 0.17; trend for interaction between HER2 and PTEN). High values of insulin-like growth factor 1 activation module were associated with increased pCR probability only in ER-positive/HER2-negative tumors (interaction between insulin-like growth factor 1 and ER: P = .002; FDR, 0.03). When adding the immune module to clinicopathologic characteristics, we observed substantial increases in predictive accuracy for pCR in the HER2-positive subtype (IDI, 0.093; P = .004; increase in AUC from 0.760 to 0.836).

CONCLUSION

Different processes and pathways are associated with pCR in different BC subtypes.

Low expression of stathmin in tumor predicts high response to neoadjuvant chemotherapy with docetaxel-containing regimens in locally advanced breast cancer

AIMS

We performed this retrospective study to evaluate the value of clinicopathological factors and a novel molecular marker stathmin in predicting treatment response to neoadjuvant chemotherapy (NCT) with docetaxel-containing regimens in patients with locally advanced breast cancer.

METHODS

Fifty-four consecutive locally advanced patients receiving docetaxel-containing NCT between January 2006 and July 2010 in Zhejiang Cancer Hospital were included. The expression levels of estrogen receptor (ER), progesterone receptor (PgR), epidermal growth factor receptor-2 (HER-2), and p53 were detected by immunohistochemistry, while expression of stathmin mRNA was measured by Quanti-Gene assay.

RESULTS

The overall clinical objective response (cOR) rate was 75.9% (41/54) in breast. A total of 34 patients (63.0%) experienced pathological OR (pOR), with pathological complete remission (pCR) rate of 20.4% (11/54) in breast and 16.7% (9/54) in both breast and axilla. In univariate analysis, there were associations of pOR in both breast and axilla with age (p=0.054), ER status (p=0.059), subtypes (p=0.062), p53 (p=0.030), and stathmin expression (three terciles) (p=0.039). Mean expression of stathmin in pOR group was 0.410, compared with that in no response group of 0.556 (p=0.051 by Student's t-test). Similarly, a lower expression of stathmin might represent a higher pCR rate (p=0.061). Moreover, the LOWESS smoothing plot showed the same trend, that is, that tumor with a lower level of stathmin expression had a higher probability of response to docetaxel-containing NCT. After multivariate adjustment, both ER and stathmin remained significant with hazard ratio of 4.58 (95% CI: 1.11-18.94, p=0.036) and 2.94 (95% CI: 1.26-6.86, p=0.012), respectively.

CONCLUSIONS

In conclusion, ER and stathmin were independent predictive factors for NCT with docetaxel-containing regimens.

Telomeric allelic imbalance indicates defective DNA repair and sensitivity to DNA-damaging agents

DNA repair competency is one determinant of sensitivity to certain chemotherapy drugs, such as cisplatin. Cancer cells with intact DNA repair can avoid the accumulation of genome damage during growth and also can repair platinum-induced DNA damage. We sought genomic signatures indicative of defective DNA repair in cell lines and tumors and correlated these signatures to platinum sensitivity. The number of subchromosomal regions with allelic imbalance extending to the telomere (N(tAI)) predicted cisplatin sensitivity in vitro and pathologic response to preoperative cisplatin treatment in patients with triple-negative breast cancer (TNBC). In serous ovarian cancer treated with platinum-based chemotherapy, higher levels of N(tAI) forecast a better initial response. We found an inverse relationship between BRCA1 expression and N(tAI) in sporadic TNBC and serous ovarian cancers without BRCA1 or BRCA2 mutation. Thus, accumulation of telomeric allelic imbalance is a marker of platinum sensitivity and suggests impaired DNA repair.

SIGNIFICANCE

Mutations in BRCA genes cause defects in DNA repair that predict sensitivity to DNA damaging agents, including platinum; however, some patients without BRCA mutations also benefit from these agents. NtAI, a genomic measure of unfaithfully repaired DNA, may identify cancer patients likely to benefit from treatments targeting defective DNA repair.