p-53 gene mutations as a predictive marker in a population of advanced breast cancer patients randomly treated with doxorubicin or docetaxel in the context of a phase III clinical trial

Regulation of P53 signaling in breast cancer by the E3 ubiquitin ligase RNF187

The tumor suppressor P53 plays critical role in preventing cancer. P53 is rarely mutated and remains functional in luminal-type breast cancer(1). According to current knowledge, wild-type P53 function is tightly controlled by posttranslational modifications, such as ubiquitination. Several ubiquitin ligases have been shown to regulate P53 ubiquitination and protein stability. Here, we report that RNF187, a RING family ubiquitin ligase, facilitates breast cancer growth and inhibits apoptosis by modulating P53 signaling. RNF187 expression was elevated in breast cancer and correlated with breast cancer survival only in the P53 wild-type groups. Bioinformatic analysis showed that the expression of RNF187 was negatively correlated with the expression of P53 target genes, such as IGFBP3 and FAS, in breast cancer. RNF187 depletion inhibited breast cancer growth and facilitated cell death. RNA sequencing analysis indicated that RNF187 could be an important modulator of P53 signaling. Further experiments showed that RNF187 interacts with P53 and promotes its degradation by facilitating its polyubiquitination in breast cancer cells. Interestingly, the in vitro ubiquitin assay showed that RNF187 can directly ubiquitinate P53 in a manner independent of MDM2. These findings reveal a novel direct P53 regulator and a potential therapeutic target for breast cancer.

Platinum-based systematic therapy in triple-negative breast cancer

Due to the lack of definitive hormone receptors, triple negative breast cancer (TNBC) patients receive little clinical benefit from endocrine or molecular targeted therapies, leading to a highly aggressive disease with a high recurrence rate and poor prognosis. In the past decades, chemotherapy has been the mainstay of treatment for TNBC, with taxane/anthracyclines as the representative regimen. However, increasing irreversible cardiotoxicity of anthracyclines and drug-resistance had to be noticed. Gradually, platinum-based chemotherapy has become a topic of interest for researchers. Based on the accumulating studies on platinum-containing regimens for TNBC patients, we will summarize the progress of relevant clinical trials focusing on platinum monotherapy (e.g., cisplatin, carboplatin and oxaliplatin) or in combination with other therapeutic modalities (e.g., other chemotherapeutic agents, molecular targeted therapies and immunotherapy). To further evaluate patient response to platinum and screen for the optimal population to benefit from platinum, we will also analyze current potential biomarkers, such as breast cancer susceptibility genes (BRCA1/2), homologous recombination repair deficiency (HRD), tumor infiltrating lymphocytes (TILs), TP53 family and other emerging indicators (e.g., intrinsic subtype, cyclin-dependent kinase 2 (CDK2) expression, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9)).

A careful reassessment of anthracycline use in curable breast cancer

It has been over three decades since anthracyclines took their place as the standard chemotherapy backbone for breast cancer in the curative setting. Though the efficacy of anthracycline chemotherapy is not debatable, potentially life-threatening and long-term risks accompany this class of agents, leading some to question their widespread use, especially when newer agents with improved therapeutic indices have become available. Critically assessing when to incorporate an anthracycline is made more relevant in an era where molecular classification is enabling not only the development of biologically targeted therapeutics but also is improving the ability to better select those who would benefit from cytotoxic agents. This comprehensive analysis will present the problem of overtreatment in early-stage breast cancer, review evidence supporting the use of anthracyclines in the pre-taxane era, analyze comparative trials evaluating taxanes with or without anthracyclines in biologically unselected and selected patient populations, and explore published work aimed at defining anthracycline-sensitive tumor types.

Clinical spectrum and prognostic value of TP53 mutations in circulating tumor DNA from breast cancer patients in China

Background

TP53 mutations are common in breast cancer. There is currently no large‐scale cohort study to investigate the TP53 landscape in breast cancer patients from China. The predictive value of TP53 mutations for the efficacy of human epidermal growth factor receptor 2 (HER2)‐targeted therapy in breast cancer remains controversial. In the present study, we aimed to analyze the clinical spectrum and prognostic value of TP53 mutations in circulating tumor DNA (ctDNA) from breast cancer patients in China.

Methods

We retrospectively analyzed the clinical data and TP53 mutation features in ctDNA samples from 804 patients with metastatic breast cancer. TP53 mutations were detected by target region capture‐based next‐generation sequencing. The relationship between TP53 mutation status and disease‐free survival (DFS) was analyzed in 444 patients with metastatic breast cancer. Moreover, the relationship between TP53 mutation status and progression‐free survival (PFS) was analyzed in 55 HER2‐positive patients treated with first‐line trastuzumab‐based therapy. Kaplan‐Meier analysis was performed to estimate the survival curves of the different subgroups, and the log‐rank test was used to compare the curves. A Cox regression model was used to estimate multivariable‐adjusted hazard ratios and their 95% confidence intervals (CIs) associated with the DFS and PFS.

Results

Among the 804 investigated patients, 431 (53.6%) patients harbored TP53 mutations. TP53 mutations were differentially distributed among different molecular subtypes of breast cancer (P < 0.05). Patients with TP53 mutations had a shorter DFS than those with wild‐type TP53 (hazard ratio = 1.32, 95% CI = 1.09‐1.61, P = 0.005). TP53 mutations in exons 5‐8 were associated with worse outcome (hazard ratio = 1.50, 95% CI = 1.11‐2.03, P = 0.009). However, TP53 mutation status was not significantly associated with PFS in HER2‐positive patients who received first‐line trastuzumab‐based therapy (P = 0.966). Interestingly, in the taxane combination group, patients with TP53 mutations exhibited longer PFS than those without TP53 mutations (hazard ratio = 0.08, 95% CI = 0.02‐0.30, P < 0.001). However, in the non‐taxane combination group, patients with TP53 mutations displayed shorter PFS than those with wild‐type TP53 (hazard ratio = 4.84, 95% CI = 1.60‐14.66, P = 0.005).

Conclusions

TP53 mutations in exons 5‐8 may be an independent prognostic marker for short DFS in patients with metastatic breast cancer. TP53 mutations had opposite effects on trastuzumab‐treated patients treated with and without taxanes.

Combination treatment with auranofin and nutlin-3a induces synergistic cytotoxicity in breast cancer cells

Auranofin is a gold complex categorized as an anti-rheumatic agent. Recently, several investigators suggested that auranofin may act as a potent anti-cancer drug for breast tumors. Nutlin-3a is a cis-imidazoline analog which prevents interaction between mouse double minute 2 homolog (MDM2) and the tumor suppressor p53. The aim of this study was to examine cell growth inhibition mediated by auranofin or nutlin-3a individually as well as in combination with MCF-7 and MDA-MB-231 cells. To assess any potential synergistic effects between auranofin and nutlin-3a, low concentrations of auranofin and nutlin-3a were simultaneously incubated with MCF-7 and MDA-MB-231 cells. Cell viability assay, caspase-3/7 assay, and poly (ADP-ribose) polymerase cleavage revealed that auranofin and nutlin-3a exerted a synergistic effect on cancer cell apoptosis. Isobologram analysis of MCF-7 and MDA-MB-231 cells noted evident synergism between auranofin and nutlin-3a. The combined treatment increased the expression of mitochondrial pro-apoptotic factors such as Bcl-2 associated X protein and Bcl-2 homologous antagonist/killer. Further, combination treatment significantly enhanced reactive oxygen species (ROS) generation in MCF-7 and MDA-MB-231 cells. In conclusion, data demonstrated that combined treatment with auranofin and nutlin-3a exhibited a synergistic action on breast cancer cells and this combination may be considered for use as a novel therapeutic strategy for breast cancer.

The Presence of Serum p53 Antibody Predicts the Pathological Tumor Response to Neoadjuvant Chemotherapy with Docetaxel, Cisplatin and Fluorouracil (DCF) in Esophageal Squamous Cell Carcinoma

BACKGROUND

Docetaxel, cisplatin and fluorouracil (DCF) is a candidate neoadjuvant chemotherapy (NAC) regimen for esophageal squamous cell carcinoma (ESCC). Although the efficacy and safety of DCF have been reported, the markers that predict the patient's response are still unknown. The aim of this study was to identify the predictive markers for a response to NAC with DCF in patients with ESCC.

METHODS

A total of 79 patients who received preoperative DCF followed by esophagectomy between August 2008 and December 2014 were enrolled in this study. All of the patients completed 2 preoperative courses of DCF. The clinical and pathological responses to DCF were investigated, and the associations between the pathological response, the clinicopathological factors and the prognosis were retrospectively analyzed.

RESULTS

Among the 79 patients, the pathological response to DCF (evaluated according to the Japanese Classification of Esophageal Cancer) was grade 3 (complete pathological response) in 7 patients (8.9 %), grade 2 in 13 patients (16.5 %), grade 1b in 8 patients (10.1 %) and grade 1a in 51 patients (64.6 %). A good pathological response (grade 2-3) was significantly associated with both favorable disease-free survival (P = 0.0051) and favorable cancer-specific survival (P = 0.0366). A multivariate analysis revealed that a good clinical response (HR 13.743, 95 % CI 2.455-76.917) and the presence of serum p53 antibody before treatment (HR 3.987, 95 % CI 1.103-14.416) were independent predictors of good pathological response.

CONCLUSIONS

The presence of serum p53 antibody can be used as a novel, noninvasive predictor of the pathological tumor response to NAC with DCF in ESCC patients.

Antioxidant and Antiproliferative Activities of an Ethylacetate Fraction of Picria Fel-Terrae Lour. Herbs

Background: Excessive production of oxygen free radicals and imbalance in the mechanisms responsible for antioxidant protection may result in the onset of many diseases including breast cancer. Objective: To evaluate antiproliferative and antioxidant activity of an ethylacetate fraction (EAF) of Picria fel-terrae Lour. Herbs in the T47D cell line. Methods: Phenolic and total flavonoid contents in EAF were determined. EAF was tested for cytotoxicity and effects on the cell cycle and apoptosis, as well as antioxidant activity. Results: EAF was found to contain high levels of phenolic agents (92.88 ± 0.50 mg GAE/g), total flavonoid (84.39 ± 0.07 mg QE/g). The EAF of Picria fel-terrae Lour. herbs was found to have an IC50 of 62.98μg/mL, caused accumulation in G0-G1 and S phase and increased early and late apoptosis. Antioxidant activity in DPPH assays gave an IC50 of 166.90 ± 0.10 μg/mL. Conclusions: The results reveal that EAF of Picria fel-terrae Lour. herbs has antiproliferative activity and strong antioxidant potential. Further studies are now needed to isolate the responsible antiproliferative and antioxidant components.

Over-using chemotherapy in the adjuvant setting

Avoidance of unnecessary or ineffective treatment should be one of the main goals in adjuvant breast oncology today. Unfortunately, both patients and doctors hunt for tiny statistical differences in survival curves. This search could not only lead to an oncological approach of unlimited addition that we will not be able to afford, but would also end inevitably in indeterminate overtreatment with substantial risks of unexpected toxic effects eating away whatever progress we might make. "Do not harm" remains the main principle in medicine. To be able to follow this rule, we need to better understand the biology of breast cancer. The mistake of "one treatment fits all" can only be changed when we critically review trial designs of adjuvant breast oncology. The risk of overtreatment is there and selection of precisely defined cohorts for phase 3 trials is necessary, despite pressure of scientific ambition, pragmatism, and demands of industry. The "add on" clinical trial design model accepts the inability to confirm that standard therapy is still necessary if a positive result from the addition of the new therapy is obtained. The same model can be applied to "extended" adjuvant treatments in breast cancer subtypes. Addition of "miraculin" to the standard of care should generate a new standard. Such trials that show a modest benefit on average at a population level take us a step away from refining care for the individual, and might support the use of multiple and costly interventions with potential short and long term side effects. It is essential to escalate treatment when necessary and to de-escalate when un-necessary.

Molecular characterization of apocrine salivary duct carcinoma

Contemporary classification and treatment of salivary duct carcinoma (SDC) require its thorough molecular characterization. Thirty apocrine SDCs were analyzed by the Ion Ampliseq Cancer HotSpot panel v2 for mutations in 50 cancer-related genes. Mutational findings were corroborated by immunohistochemistry (eg, TP53, BRAF, β-catenin, estrogen, and androgen receptors) or Sanger sequencing/SNaPshot polymerase chain reaction. ERBB2 (HER2), PTEN, FGFR1, CDKN2A/P16, CMET, EGFR, MDM2, and PIK3CA copy number changes were studied by fluorescence in situ hybridization. TP53 mutations (15/27, 56%), PTEN loss (11/29, 38%, including 2 cases with PTEN mutation), PIK3CA hotspot mutations (10/30, 33%), HRAS hotspot mutations (10/29; 34%), and ERBB2 amplification (9/29, 31%, including 1 case with mutation) represented the 5 most common abnormalities. There was no correlation between genetic changes and clinicopathologic parameters. There was substantial overlap between genetic changes: 8 of 9 cases with ERBB2 amplification also harbored a PIK3CA, HRAS, and TP53 mutation and/or PTEN loss. Six of 10 cases with PIK3CA mutation also had an HRAS mutation. These findings provide a molecular rationale for dual targeting of mitogen-activated protein kinase and phosphoinositide 3-kinase pathways in SDC. FGFR1 amplification (3/29, 10%) represents a new potential target. On the basis of studies of breast carcinomas, the efficacy of anti-ERBB2 therapy will likely be decreased in SDC with ERBB2 amplification co-occurring with PIK3CA mutation or PTEN loss. Therefore, isolated ERBB2 testing is insufficient for theranostic stratification of apocrine SDC. On the basis of the prevalence and type of genetic changes, apocrine SDC appears to resemble one subtype of breast carcinoma-"luminal androgen receptor positive/molecular apocrine."

Genotype and Haplotype Analyses of TP53 Gene in Breast Cancer Patients: Association with Risk and Clinical Outcomes

Variations in the TP53 gene have been suggested to play a role in many cancers, including breast. We previously observed an association between TP53 haplotypes based on four polymorphisms (rs17878362, rs1042522, rs12947788, and rs17884306) and the risk of colorectal and pancreatic cancer. Based on these results, in the present study, we have investigated the same polymorphisms and their haplotypes in 705 breast cancer cases and 611 healthy controls in relation to the disease risk, histopathological features of the tumor and clinical outcomes. In comparison to the most common haplotype A₁-G-C-G, all the other identified haplotypes were globally associated with a significantly decreased breast cancer risk (P = 0.006). In particular, the A₂-G-C-G haplotype was associated with a marked decreased risk of breast cancer when compared with the common haplotype (P = 0.0001). Moreover, rs1042522 in patients carrying the GC genotype and receiving only the anthracycline-based chemotherapy was associated with both overall and disease-free survival (recessive model for overall survival HR = 0.30 95% CI 0.11–0.80, P = 0.02 and for disease-free survival HR = 0.42 95% CI 0.21–0.84, P = 0.01). Present results suggest common genetic features in the susceptibility to breast and gastrointestinal cancers in respect to TP53 variations. In fact, similar haplotype distributions were observed for breast, colorectal, and pancreatic patients in associations with cancer risk. Rs1042522 polymorphism (even after applying the Dunn-Bonferroni correction for multiple testing) appears to be an independent prognostic marker in breast cancer patients.

Use of Biomarkers to Guide Decisions on Systemic Therapy for Women With Metastatic Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline

PURPOSE

To provide recommendations on the appropriate use of breast tumor biomarker assay results to guide decisions on systemic therapy for metastatic breast cancer.

METHODS

A literature search and prospectively defined study selection identified systematic reviews, meta-analyses, randomized controlled trials (RCTs), prospective-retrospective studies, and prospective comparative observational studies published from 2006 through September 2014.

RESULTS

The literature search revealed 17 articles that met criteria for further review: 11 studies reporting discordances between primary tumors and metastases in expression of hormone receptors or human epidermal growth factor receptor 2 (HER2), one RCT that addressed the use of a biomarker to decide whether to change or continue a treatment regimen, and five prospective-retrospective studies that evaluated the clinical utility of biomarkers.

RECOMMENDATIONS

In patients with accessible metastases, biopsy for confirmation of disease process and retesting of estrogen receptor, progesterone receptor, and HER2 status should be offered, but evidence is lacking to determine whether changing anticancer treatment on the basis of change in receptor status affects clinical outcomes. With discordance of results between primary and metastatic tissues, the Panel consensus is to use preferentially the estrogen receptor, progesterone receptor, and HER2 status of the metastasis to direct therapy if supported by the clinical scenario and patient's goals for care. Carcinoembryonic antigen, cancer antigen 15-3, and cancer antigen 27-29 may be used as adjunctive assessments, but not alone, to contribute to decisions regarding therapy. Recommendations for tumor rebiopsy and use of circulating tumor markers are based on clinical experience and Panel informal consensus in the absence of studies designed to evaluate the clinical utility of the markers. As such, it is also reasonable for clinicians to not use these markers as adjunctive assessments.

RING finger protein 31 promotes p53 degradation in breast cancer cells

The atypical E3 ubiquitin ligase RNF31 is highly expressed in human breast cancer, the most frequent neoplastic lethality among women. Here, RNF31 depletion in breast cancer cells in combination with global gene expression profiling revealed p53 (TP53) signaling as a potential RNF31 target. Interestingly, RNF31 decreased p53 stability, whereas depletion of RNF31 in breast cancer cells caused cell cycle arrest and cisplatin-induced apoptosis in a p53-dependent manner. Furthermore, RNF31 associated with the p53/MDM2 complex and facilitated p53 polyubiquitination and degradation by stabilizing MDM2, suggesting a molecular mechanism by which RNF31 regulates cell death. Analysis of publically available clinical data sets displayed a negative correlation between RNF31 and p53 target genes, including IGFBP3 and BTG1, consistent with RNF31 regulating p53 function in vivo as well. Together, our findings suggest RNF31 as a potential therapeutic target to restore p53 function in breast cancer.

Combinational effects of hexane insoluble fraction of Ficus septica Burm. F. and doxorubicin chemotherapy on T47D breast cancer cells

OBJECTIVE

To evaluate the effects of n-hexane insoluble fraction (HIF) of Ficus septica leaves in combination with doxorubicin on cytotoxicity, cell cycle and apoptosis induction of breast cancer T47D cell lines.

METHODS

The in vitro drugs-stimulated cytotoxic effects were determined using MTT assay. Analysis of cell cycle distribution was performed using flowcytometer and the data was analyzed using ModFit LT 3.0 program. Apoptosis assay was carried out by double staining method using ethydium bromide-acridin orange. The expression of cleaved-poly (ADP-ribose) polymerase (PARP) on T47D cell lines was identified using immunocytochemistry.

RESULTS

The combination exhibited higher inhibitory effect on cell growth than the single treatment of doxorubicin in T47D cells. In addition, combination of doxorubicin and HIF increased the incidence of cells undergoing apoptosis. HIF could improve doxorubicin cytotoxic effect by changing the accumulation of cell cycle phase from G2/M to G1 phase. The combination also exhibited upregulation of cleaved-PARP in T47D cells.

CONCLUSIONS

Based on this results, HIF is potential to be developed as co-chemotherapeutic agent for breast cancer by inducing apoptosis and cell cycle arrest. However, the molecular mechanism need to be explored further.

Optimal adjuvant chemotherapy in breast cancer: selection of agents

Historically, the selection of the most effective adjuvant regimen for breast cancer patients was based on tumor size and nodal status but this approach took into account the stage only, without considering that the biology of the tumor matters as well, as breast cancer is a heterogeneous disease at the molecular level. In the present manuscript we will attempt to address the issue of selecting the most appropriate cytotoxic agents for adjuvant programs in the clinically and biologically distinct subgroups of endocrine responsive (luminal A and luminal B), HER2 positive and triple negative breast cancer patients.

The biomarker TP53 divides patients with neoadjuvantly treated esophageal cancer into 2 subgroups with markedly different outcomes. A p53 Research Group study

BACKGROUND

Fluorouracil and cisplatin have been used most frequently as neoadjuvant therapy for esophageal cancer. Both drugs are believed to act via a p53-dependent apoptosis pathway. The TP53 gene is frequently mutated in esophageal cancer.

OBJECTIVE

To test the value of TP53 as a biomarker prognosing outcome in patients with neoadjuvantly treated esophageal cancer.

PATIENTS AND METHODS

The investigation included 36 patients with primary operable esophageal cancer who were treated neoadjuvantly with cisplatin and fluorouracil. The TP53 genotype was assessed from paraffin-embedded diagnostic tumor biopsies using a standardized gene-specific TP53 sequencing protocol (mark53 kit; mark53 Ltd, Vienna, Austria).

RESULTS

Mutations in the TP53 gene were present in 50% of tumors. Two-year overall survival rates were 55.6% in patients with a normal TP53 marker status, compared with 16.7% in those with a mutant TP53 gene. In patients with normal TP53, neoadjuvant treatment resulted in significant advantages in terms of tumor-associated survival (P=.0049) and overall survival (P=.0304) compared with those with mutant TP53. The median tumor-associated survival was 34.2 months for patients with normal TP53, compared with 8.9 months for those with mutant TP53. The latter had a 3-fold higher risk of dying (hazard ratio, 3.01; 95% confidence interval, 1.359-6.86).

CONCLUSIONS

The biomarker TP53 divides esophageal cancer patients into 2 categories with markedly different outcomes: patients with a normal TP53 marker status may experience notable benefits from neoadjuvant chemotherapy with cisplatin/fluorouracil, whereas those with a mutant TP53 marker status appear to be at risk for lack of response.

TP53 mutation, epithelial-mesenchymal transition, and stemlike features in breast cancer subtypes

Altered p53 protein is prevalently associated with the pathologic class of triple-negative breast cancers and loss of p53 function has recently been linked to the induction of an epithelial-mesenchymal transition (EMT) and acquisition of stemness properties. We explored the association between TP53 mutational status and expression of some genes involved in the canonical TGF-β signaling pathway (the most potent EMT inducer) and in two early EMT associated events: loss of cell polarity and acquisition of stemness-associated features. We used a publicly accessible microarray dataset consisting of 251 p53-sequenced primary breast cancers. Statistical analysis indicated that mutant p53 tumors (especially those harboring a severe mutation) were consistent with the aggressive class of triple-negative cancers and that, differently from cell cultures, surgical tumors underexpressed some TGF-β related transcription factors known as involved in EMT (ID1, ID4, SMAD3, SMAD4, SMAD5, ZEB1). These unexpected findings suggest an interesting relationship between p53 mutation, mammary cell dedifferentiation, and the concomitant acquisition of stemlike properties (as indicated by the overexpression of PROM1 and NOTCH1 genes), which improve tumor cells aggressiveness as indicated by the overexpression of genes associated with cell proliferation (CDK4, CDK6, MKI67) and migration (CXCR4, MMP1).

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.

Somatic mutations in cancer prognosis and prediction: lessons from TP53 and EGFR genes

PURPOSE OF REVIEW

We used two examples of genes, TP53 and EGFR, which are somatically altered by intragenic mutations in common cancer types to illustrate how somatic mutations have followed very different routes to clinical applications.

RECENT FINDINGS

TP53 somatic mutations are frequent in many cancers. Their prognostic and predictive values are currently assessed in several clinical trials and TP53 gene therapy is in use in China. Mutations in EGFR have been proved to be predictive of response to tyrosine kinase inhibitors, allowing for the licensing of gefitinib in lung adenocarcinomas carrying a mutated EGFR gene.

SUMMARY

With the accumulation of knowledge on the predictive and prognostic value of somatic mutations, and with recent advances in large-scale sequencing techniques and reduction in cost of sequencing, sequencing several genes in human tumors is on the verge of becoming routine clinical practice.

TP53 genomics predict higher clinical and pathologic tumor response in operable early-stage breast cancer treated with docetaxel-capecitabine ± trastuzumab

To determine rates of pathologic complete response (pCR) and near-complete response (npCR) in operable early-stage breast cancer using neoadjuvant capecitabine plus docetaxel, with or without trastuzumab, and investigate biomarkers of pathologic response. Women with operable early-stage breast cancer were enrolled in a multicenter study of neoadjuvant therapy for four 21-day cycles with capecitabine 825 mg/m(2) plus docetaxel 75 mg/m(2) if human epidermal growth factor receptor 2 (HER2)-negative, and additionally, a standard trastuzumab dose if HER2-positive. Primary endpoint was rate of pCR and npCR. Secondary endpoints were potential associations between response and TP53 mutational analysis using the AmpliChip TP53 assay or immunohistochemical (IHC) staining, and genomic subtyping using the PAM50 assay. In patients who completed treatment and surgery, pCR and npCR rates were 15.8% in patients with HER2-negative and 50% in patients with HER2-positive tumors. Stratified by genomic subtype, patients of HER2-enriched subtype had the best response (72.2%), and luminal A (9.1%) and B (4.8%) subtypes, the poorest. Of 147 patients tested for TP53 mutations using the AmpliChip assay, 78 variants were detected; 55 were missense. Response rate among TP53-mutated patients was 30%, significantly higher than TP53 wild-type patients (10%; P = 0.0032). Concordance between AmpliChip mutation status versus TP53 IHC staining was 65%, with AmpliChip status predictive of response and IHC status not predictive. Capecitabine plus docetaxel in HER2-negative, and with trastuzumab in HER2-positive patients, provided a good response rate with four cycles of non-anthracycline-containing therapy. TP53 mutational analysis and genomic subtyping were predictive.

Clinical significance of Ki-67 in neoadjuvant chemotherapy for primary breast cancer as a predictor for chemosensitivity and for prognosis

BACKGROUND

Neoadjuvant chemotherapy (NAC) is one of the main strategies for patients with locally advanced breast cancer. In recent years several biological markers such as estrogen receptor (ER), progesterone receptor (PgR), and HER2 were discovered to be predictive factors for the effectiveness of NAC to help individualize treatment. In this retrospective study, we focused on Ki-67 as a biological marker and examined the correlation between Ki-67 and chemosensitivity, and the prognosis after the start of treatment.

PATIENTS AND METHODS

Between July 1996 and March 2008, 148 patients with tumors ≥ 3 cm in diameter or lymph node metastases received NAC and surgery. The items investigated were ER/PgR and Ki-67 from core needle biopsy. The treatment regimens were EC in 36 cases, ET in 51 cases, and FEC-DOC in 61 cases. The patients with FEC-DOC regimen had smaller tumors and higher Ki-67 values than the others.

RESULTS

Clinical response (cCR + cPR) was 79.7%, and the pathological complete response (pCR) was 14.2%. Multivariate analysis revealed that Ki-67 was significantly related to pCR. Moreover, there was no pathological responder in cases with Ki-67 < 25%. The Ki-67 values significantly decreased after NAC (median from 45.0 to 17.5%). Patients with cCR had significantly lower Ki-67 values after NAC than those with cPR, cSD, and cPD. There was a significant difference in the Ki-67 value in terms of the presence and the absence of recurrence (median 26.0% with recurrence vs. 12% without recurrence). The disease-free survival (DFS) rate after the start of treatment was significantly higher in the patients with Ki-67 < 12% after NAC than those with Ki-67 ≥ 12%.

CONCLUSION

The Ki-67 value before NAC was a significant predictive factor for the effectiveness of NAC. The Ki-67 values after NAC significantly decreased and correlated with clinical response and DFS. Therefore, higher Ki-67 values (≥ 25%) before NAC as well as lower values (<12%) after NAC might be clinically significant for treating patients.

p53 status identifies two subgroups of triple-negative breast cancers with distinct biological features

OBJECTIVE

Despite the clinical similarities triple-negative and basal-like breast cancer are not synonymous. Indeed, not all basal-like cancers are negative for estrogen receptor, progesterone receptor and HER2 expression while triple-negative also encompasses other cancer types. P53 protein appears heterogeneously expressed in triple-negative breast cancers, suggesting that it may be associated with specific biological subgroups with a different outcome.

METHODS

We comparatively analyzed p53 expression in triple-negative tumors from two independent breast cancer case series (633 cases from the University of Ferrara and 1076 cases from the University of Nottingham).

RESULTS

In both case series, p53 protein expression was able to subdivide the triple-negative cases into two distinct subsets consistent with a different outcome. In fact, triple-negative patients with a p53 expressing tumor showed worse overall and event-free survival.

CONCLUSIONS

The immunohistochemical evaluation of p53 expression may help in taming the currently stormy relationship between pathological (triple-negative tumors) and biological (basal breast cancers) classifications and in selecting patient subgroups with different biological features providing a potentially powerful prognostic contribution in triple-negative breast cancers.

Targeting anthracyclines in early breast cancer: new candidate predictive biomarkers emerge

The search for a predictive marker of sensitivity to anthracycline-based chemotherapy has proven challenging. Despite human epidermal growth factor receptor 2 (HER2) being a strong prognostic marker in breast cancer, the only therapies with which there is a recognized functional link to the HER2 oncogene are those directly targeting the molecule itself. Despite this, HER2 has been extensively assessed as a predictive marker in a variety of chemotherapy regimens including anthracyclines. Analysis of anthracycline response in patients with HER2 amplification has given conflicting results. This led to the suggestion that HER2 amplification was acting as a surrogate for the gene encoding topoisomerase IIα (TOP2A), a direct cellular target of anthracyclines. Despite an attractive functional link between TOP2A and anthracyclines, published studies have failed to show strong evidence of an interaction between TOP2A genetic aberrations and anthracycline response. A number of other biomarkers have also been assessed for their role in predicting anthracycline response, including TP53 (tumour protein 53) and BRCA1 (breast cancer 1, early onset), together with an increasing emergence of gene expression profiling to produce predictive signatures of response. Moreover, recent evidence has emerged from presentations suggesting new candidate markers of response that warrant further investigation: Chr17CEP duplication and tissue inhibitor of metalloproteases 1. This review will discuss research into HER2 and TOP2A as predictive markers of anthracycline response and will focus on current research into other possible candidate predictive markers.

Reinventing diagnostics for personalized therapy in oncology

Human cancers are still diagnosed and classified using the light microscope. The criteria are based upon morphologic observations by pathologists and tend to be subject to interobserver variation. In preoperative biopsies of non-small cell lung cancers, the diagnostic concordance, even amongst experienced pulmonary pathologists, is no better than a coin-toss. Only 25% of cancer patients, on average, benefit from therapy as most therapies do not account for individual factors that influence response or outcome. Unsuccessful first line therapy costs Canada CAN$1.2 billion for the top 14 cancer types, and this extrapolates to $90 billion globally. The availability of accurate drug selection for personalized therapy could better allocate these precious resources to the right therapies. This wasteful situation is beginning to change with the completion of the human genome sequencing project and with the increasing availability of targeted therapies. Both factors are giving rise to attempts to correlate tumor characteristics and response to specific adjuvant and neoadjuvant therapies. Static cancer classification and grading systems need to be replaced by functional classification systems that not only account for intra- and inter- tumor heterogeneity, but which also allow for the selection of the correct chemotherapeutic compounds for the individual patient. In this review, the examples of lung and breast cancer are used to illustrate the issues to be addressed in the coming years, as well as the emerging technologies that have great promise in enabling personalized therapy.

Altered-function p53 missense mutations identified in breast cancers can have subtle effects on transactivation

Mutations of the sequence-specific master regulator p53 that alter transactivation function from promoter response elements (RE) could result in changes in the strength of gene activation or spectra of genes regulated. Such mutations in this tumor suppressor might lead to dramatic phenotypic changes and diversification of cell responses to stress. We have determined "functional fingerprints" of sporadic breast cancer-related p53 mutants, many of which are also associated with familial cancer proneness such as the Li-Fraumeni syndrome and germline BRCA1/2 mutant-associated cancers. The ability of p53, wild-type and mutants, to transactivate from 11 human target REs has been assessed at variable expression levels using a cellular, isogenomic yeast model system that allows for the rapid analysis of p53 function using a qualitative and a quantitative reporter. Among 50 missense mutants, 29 were classified as loss of function. The remaining 21 retained transactivation toward at least one RE. At high levels of galactose-induced p53 expression, 12 of 21 mutants that retain transactivation seemed similar to wild-type. When the level of galactose was reduced, transactivation defects could be revealed, suggesting that some breast cancer-related mutants can have subtle changes in transcription. These findings have been compared with clinical data from an ongoing neoadjuvant chemotherapy treatment trial for locally advanced breast tumors. The functional and nonfunctional missense mutations may distinguish tumors in terms of demographics, appearance, and relapse, implying that heterogeneity in the functionality of specific p53 mutations could affect clinical behavior and outcome.

Cyclophosphamide dose intensification may circumvent anthracycline resistance of p53 mutant breast cancers

The predictive value of p53 for the efficacy of front-line anthracycline-based chemotherapy regimens has been a matter of significant controversy. Anthracyclines are usually combined with widely different doses of alkylating agents, which may significantly modulate tumor response to these combinations. We analyzed three series of de novo stage II-III breast cancer patients treated front line with anthracycline-based regimens of various cyclophosphamide dose intensities: 65 patients with estrogen receptor (ER)(-) tumors treated with anthracyclines alone (Institut Jules Bordet, Brussels), 51 unselected breast cancer patients treated with intermediate doses of cyclophosphamide (MD Anderson Cancer Center, Houston, TX), and 128 others treated with a dose-dense anthracycline-cyclophosphamide combination (St. Louis, Paris). After chemotherapy and surgery, pathologic complete response (pCR) was evaluated. p53 status was determined by a yeast functional assay on the pretreatment tumor sample. In a multivariate analysis of the pooled results, a lack of ER expression and high-dose cyclophosphamide administration were associated with a higher likelihood of pCR. A sharp statistical interaction was detected between p53 status and cyclophosphamide dose intensity. Indeed, when restricting our analysis to patients with ER(-) tumors, we confirmed that a mutant p53 status was associated with anthracycline resistance, but found that p53 inactivation was required for response to the dose-intense alkylating regimen. The latter allowed very high levels of pCR in triple-negative tumors. Thus, our data strongly suggest that cyclophosphamide dose intensification in ER(-) p53-mutated breast cancer patients could significantly improve their response.

Efficacy of neoadjuvant Cisplatin in triple-negative breast cancer

PURPOSE Cisplatin is a chemotherapeutic agent not used routinely for breast cancer treatment. As a DNA cross-linking agent, cisplatin may be effective treatment for hereditary BRCA1-mutated breast cancers. Because sporadic triple-negative breast cancer (TNBC) and BRCA1-associated breast cancer share features suggesting common pathogenesis, we conducted a neoadjuvant trial of cisplatin in TNBC and explored specific biomarkers to identify predictors of response. PATIENTS AND METHODS Twenty-eight women with stage II or III breast cancers lacking estrogen and progesterone receptors and HER2/Neu (TNBC) were enrolled and treated with four cycles of cisplatin at 75 mg/m(2) every 21 days. After definitive surgery, patients received standard adjuvant chemotherapy and radiation therapy per their treating physicians. Clinical and pathologic treatment response were assessed, and pretreatment tumor samples were evaluated for selected biomarkers. Results Six (22%) of 28 patients achieved pathologic complete responses, including both patients with BRCA1 germline mutations;18 (64%) patients had a clinical complete or partial response. Fourteen (50%) patients showed good pathologic responses (Miller-Payne score of 3, 4, or 5), 10 had minor responses (Miller-Payne score of 1 or 2), and four (14%) progressed. All TNBCs clustered with reference basal-like tumors by hierarchical clustering. Factors associated with good cisplatin response include young age (P = .001), low BRCA1 mRNA expression (P = .03), BRCA1 promoter methylation (P = .04), p53 nonsense or frameshift mutations (P = .01), and a gene expression signature of E2F3 activation (P = .03). CONCLUSION Single-agent cisplatin induced response in a subset of patients with TNBC. Decreased BRCA1 expression may identify subsets of TNBCs that are cisplatin sensitive. Other biomarkers show promise in predicting cisplatin response.

The topoisomerase II alpha gene status in primary breast cancer is a predictive marker of the response to anthracycline-based neoadjuvant chemotherapy

This study aimed at evaluating the usefulness of topoisomerase II alpha (TOP2A) for predicting the effect of anthracycline-based neoadjuvant chemotherapy in breast cancer. The TOP2A status was examined using fluorescent in situ hybridization (FISH) in 14 pre-chemotherapeutic breast cancer tissues, and was also assessed by immunohistochemistry (IHC) in 14 pairs of pre- and post-chemotherapeutic breast cancer specimens. TOP2A gene aberration by IHC tended to show a correlation with pathological responses but this was not statistically significant (p=0.060). On the other hand, the low TOP2A/CEP17 ratio correlated with good pathological responses (p=0.012). TOP2A overexpression was not significantly associated with response (p=0.580). Our results thus suggest that the TOP2A/CEP17 ratio may be a useful predictor of the effects of anthracycline-based neoadjuvant chemotherapy in breast cancer.

Apocrine metaplasia of breast cancer: clinicopathological features and predicting response

BACKGROUND

Tailor-made therapies are currently gaining prominence, and the clarification of predictive markers for anticancer agents represents an important research issue. From our institutional neoadjuvant experience, apocrine carcinoma showed a high correlation with therapeutic effect against breast cancer. We thus considered that apocrine metaplasia (AM) might represent a predictive marker for breast cancer.

METHODS

A total of 210 primary invasive breast cancers from Japanese patients were scored according to the size of cytoplasmic granules and abundance of cytoplasm, then classified into three categories: non-AM, incomplete AM and complete AM. Clinicopathological features were evaluated based on these classifications.

RESULTS

Distribution according to the classification of AM was: non-AM, 61%; incomplete AM, 36%; and complete AM, 3%. No significant differences with regard to estrogen receptor, progesterone receptor, human epidermal growth factor receptor type 2, androgen receptor or bcl-2 were observed among the three groups. Gross cystic fluid protein-15 showed a high positive rate (83%) for complete AM. Cases of incomplete AM and complete AM were combined to form the AM group. Among lymph node-positive patients without chemotherapy, the 10-year recurrence-free survival (RFS) rate was 85% for non-AM and 44% for AM (p < 0.05). Conversely, among the lymph node-positive group with chemotherapy, the 10-year RFS rate was 45% for non-AM and 75% for AM (p < 0.05). Prognoses for non-AM and AM were turned around by chemotherapy. Lymph node metastasis was related to prognosis in multivariate analysis, although AM did not remain an independent prognosticator.

CONCLUSIONS

Apocrine metaplasia appears to offer an effective predictive marker for anticancer therapy.

Recent advances in systemic therapy: new diagnostics and biological predictors of outcome in early breast cancer

The key to optimising our approach in early breast cancer is to individualise care. Each patient has a tumour with innate features that dictate their chance of relapse and their responsiveness to treatment. Often patients with similar clinical and pathological tumours will have markedly different outcomes and responses to adjuvant intervention. These differences are encoded in the tumour genetic profile. Effective biomarkers may replace or complement traditional clinical and histopathological markers in assessing tumour behaviour and risk. Development of high-throughput genomic technologies is enabling the study of gene expression profiles of tumours. Genomic fingerprints may refine prediction of the course of disease and response to adjuvant interventions. This review will focus on the role of multiparameter gene expression analyses in early breast cancer, with regards to prognosis and prediction. The prognostic role of genomic signatures, particularly the Mammaprint and Rotterdam signatures, is evolving. With regard to prediction of outcome, the Oncotype Dx multigene assay is in clinical use in tamoxifen treated patients. Extensive research continues on predictive gene identification for specific chemotherapeutic agents, particularly the anthracyclines, taxanes and alkylating agents.

TP53 Mutations in Breast Cancer: Association with Ductal Histology and Early Relapse of Disease

Purpose

This study aimed to investigate the incidence of core domain TP53 mutations in Serbian breast cancer patients in view of their possible correlation with prognostic parameters, tumor characteristics and clinical disease course.

Methods

145 breast cancer patients were included. Data on clinical disease course were available for 100 patients including 30 node-negative and 70 node-positive patients. After surgery, node-positive patients underwent adjuvant chemotherapy, mostly CMF. TP53 mutations were detected by PCR-SSCP.

Results

31 mutations were found in 27/145 patients including 4/59 node-negative patients and 23/83 node-positive patients (4 double mutations). 26/31 TP53 mutations were found in patients with invasive ductal carcinoma and only 2 in patients with invasive lobular carcinoma. The presence of TP53 mutations was correlated with clinical disease course in premenopausal node-positive patients (n=70). 11/20 patients with TP53 mutations relapsed. Within the first 24 months of follow-up, significantly shorter disease-free intervals were observed in TP5. 3-mutated patients.

Conclusions

TP53 mutations correlated only with nodal status and ductal histology. The significance of the predominant distribution of TP53 mutations in tumors with a ductal histology for the aggressive behavior of these tumors has yet to be proved, since the favorable biological features of tumors with a lobular histology do not result in a better prognosis. Early relapse in mutated- TP5. 3 carriers may support data on its predictive value with respect to adjuvant CMF.

Evaluation of biological pathways involved in chemotherapy response in breast cancer

Introduction

Our goal was to examine the association between biological pathways and response to chemotherapy in estrogen receptor-positive (ER⁺) and ER-negative (ER^-) breast tumors separately.

Methods

Gene set enrichment analysis including 852 predefined gene sets was applied to gene expression data from 51 ER^- and 82 ER⁺ breast tumors that were all treated with a preoperative paclitaxel, 5-fluoruracil, doxorubicin, and cyclophosphamide chemotherapy.

Results

Twenty-seven (53%) ER^- and 7 (9%) ER⁺ patients had pathologic complete response (pCR) to therapy. Among the ER^- tumors, a proliferation gene signature (false discovery rate [FDR] q = 0.1), the genomic grade index (FDR q = 0.044), and the E2F3 pathway signature (FDR q = 0.22, P = 0.07) were enriched in the pCR group. Among the ER⁺ tumors, the proliferation signature (FDR q = 0.001) and the genomic grade index (FDR q = 0.015) were also significantly enriched in cases with pCR. Ki67 expression, as single gene marker of proliferation, did not provide the same information as the entire proliferation signature. An ER-associated gene set (FDR q = 0.03) and a mutant p53 gene signature (FDR q = 0.0019) were enriched in ER⁺ tumors with residual cancer.

Conclusion

Proliferation- and genomic grade-related gene signatures are associated with chemotherapy sensitivity in both ER^- and ER⁺ breast tumors. Genes involved in the E2F3 pathway are associated with chemotherapy sensitivity among ER^- tumors. The mutant p53 signature and expression of ER-related genes were associated with lower sensitivity to chemotherapy in ER⁺ breast tumors only.

First-line chemotherapy for HER-2 negative metastatic breast cancer patients who received anthracyclines as adjuvant treatment

The treatment decision for patients with metastatic breast cancer who have received anthracyclines within the course of adjuvant chemotherapy is troublesome, particularly if trastuzumab and hormonal treatment are not indicated. In the first part of this review we discuss the value of retreatment with anthracyclines, a topic that has been indirectly evaluated by retrospective studies with conflicting results and within a small phase III trial with a negative outcome. Evidence on liposomal anthracyclines is also reviewed. In the second part of the review, alternative options of first-line chemotherapy are discussed. These include taxanes as single agents, taxanes in combination with other cytotoxic drugs, combinations without anthracyclines and taxanes, and innovative treatments including target-based agents. Both the amount and the quality of evidence on these treatments are poor. Few phase III studies are available and most of them have been performed with registrative aims sponsored by the companies who own the winning drug. Beyond indications derived from such studies, there is a great need for more clinical research in this setting.