Predictive relevance of HOXB13 protein expression for tamoxifen benefit in breast cancer

Prognostic and Predictive Significance of Stromal Tumor-Infiltrating Lymphocytes (sTILs) in ER-Positive/HER2-Negative Postmenopausal Breast Cancer Patients

The clinical impact of tumor-infiltrating lymphocytes (TILs) is less known for breast cancer patients with the estrogen receptor-positive (ER+)/human epidermal growth factor receptor-negative (HER−) subtype. Here, we explored the prognostic and predictive value of TILs regarding distant recurrence-free interval (DRFI) and breast cancer-specific survival (BCSS) in 763 postmenopausal patients randomized to receive tamoxifen vs. no systemic treatment. TILs were assessed in whole section tumor samples stained with H&E and divided into low (<10%), intermediate (10−39%), or high (≥40%). High TILs were associated with poor prognostic variables and good prognoses for all patients, but not within the ER+/HER2− group. Within the ER+/HER2− group, high gene expression of CD19 and PD-L1 and high IMMUNE1 score indicated good prognosis in multivariable analysis while high CD8 and CD19 gene expression and high IMMUNE1 score were associated with less tamoxifen benefit. These results indicate that within the ER+/HER2− subtype there could be subsets of patients where expression of specific TIL markers might be used to reveal candidates for immune therapy interventions upon failure of the endocrine therapy.

Excessive activation of HOXB13/PIMREG axis promotes hepatocellular carcinoma progression and drug resistance

The transcription factor HOXB13 is bound up with the occurrence, progression and drug fast of many kinds of cancer. Nevertheless, the specific molecular mechanism of HOXB13 in hepatocellular carcinoma (HCC) is still unknown. This provides an obstacle to the exploration of HCC treatments targeting HOXB13. This study found that HOXB13 was up-regulated in HCC tissues. HOXB13 enhanced the multiplication and metastasis of HCC cells. It enhanced HCC cell drug and anoikis resistance. The analysis of HCC RNA seq data indicated that the expression of HOXB13 and PIMREG were positively correlated. Luciferase report assay showed that HOXB13 could activate PIMREG promoter transcription. The results of RT-qPCR and western blot showed that HOXB13 regulated the transcription of PIMREG. Western blot proved that high expression of PIMREG participated in DNA damage repair and cell cycle regulation by up-regulating RAD51, BRCA1, CDC25A, CDC25B and CDC25C and down-regulating HIPK2. This led to a significant increase in DNA repair capacity, accelerated cell cycle progression, and insensitive to DNA damage. Down-regulation of PIMREG in Hep3B cells overexpressing HOXB13 attenuated the phenotype induced by HOXB13. Therefore, HOXB13 functioned through PIMREG instead of directly regulating the transcription of RAD51, BRCA1, CDC25A, CDC25B and CDC25C. The same results were obtained in vivo. It was concluded that HOXB13 affected the expression of cell cycle and DNA repair related factors by up-regulating the transcription of PIMREG, thereby promoting the progression of HCC and enhancing the resistance of HCC to chemotherapeutics.

Germline HOXB13 mutation p.G84E do not confer an increased bladder or kidney cancer risk in polish population

Introduction

The role of HOXB13 in bladder and renal tumorigenesis is unclear. Our goal was to determine the prevalence of HOXB13 p.G84E mutation in bladder and kidney cancer patients from Poland.

Materials and methods

1418 patients with bladder cancer and 813 cases with kidney cancer and 4497 controls were genotyped for HOXB13 p.G84E.

Results

p.G84E mutation of HOXB13 gene was detected in three of 1418 (0.2%) bladder cancer cases and in six of 4497 controls (odds ratio [OR], 1.6; 95% CI 0.39–6.36; p = 0.8). Among 813 kidney cancer cases HOXB13 mutations was reported in three patients (0,4%) (odds ratio [OR], (OR = 2,8; 95% CI 0.69–11.11; p = 0.3). In cases with mutations in the HOXB13 gene, the family history of cancer was negative.

Conclusion

HOXB13 mutation was not associated with bladder or kidney cancer. Mutation p.G84E in HOXB13 seem not to play a role in bladder and kidney cancer development in Polish patients.

Homeobox Genes in Cancers: From Carcinogenesis to Recent Therapeutic Intervention

The homeobox (HOX) genes encoding an evolutionarily highly conserved family of homeodomain-containing transcriptional factors are essential for embryogenesis and tumorigenesis. HOX genes are involved in cell identity determination during early embryonic development and postnatal processes. The deregulation of HOX genes is closely associated with numerous human malignancies, highlighting the indispensable involvement in mortal cancer development. Since most HOX genes behave as oncogenes or tumor suppressors in human cancer, a better comprehension of their upstream regulators and downstream targets contributes to elucidating the function of HOX genes in cancer development. In addition, targeting HOX genes may imply therapeutic potential. Recently, novel therapies such as monoclonal antibodies targeting tyrosine receptor kinases, small molecular chemical inhibitors, and small interfering RNA strategies, are difficult to implement for targeting transcriptional factors on account of the dual function and pleiotropic nature of HOX genes-related molecular networks. This paper summarizes the current state of knowledge on the roles of HOX genes in human cancer and emphasizes the emerging importance of HOX genes as potential therapeutic targets to overcome the limitations of present cancer therapy.

IP6K2 predicts favorable clinical outcome of primary breast cancer

The inositol hexakisphosphate kinase (IP6K) 1 and 2 genes are localized at 3p21.31, a highly altered gene-dense chromosomal region in cancer. The IP6Ks convert IP6 to IP7, which inhibits activation of the tumor-promoting PI3K/Akt/mTOR signaling pathway. IP6K2 has been suggested to be involved in p53-induced apoptosis, while IP6K1 may stimulate tumor growth and migration. The present study aimed to elucidate the role of the two IP6Ks in predicting outcome in patients with breast cancer. To the best of our knowledge, the role of IP6K was analyzed for the first time in tumors from three cohorts of patients with breast cancer; one Swedish low-risk cohort, one Dutch cohort and the TCGA dataset. Analyses of gene -and protein expression and subcellular localization were included. IP6K2 gene expression was associated with ER positivity and nuclear p-Akt. Improved prognosis was detected with high IP6K2 gene expression compared with low IP6K2 gene expression in systemically untreated patients in the Swedish low-risk and Dutch cohorts. In the TCGA dataset, IP6K2 prognostic value was significant when selecting for tumors with wild-type TP53. A multivariable analysis testing IP6K2 against other cancer-related genes at 3p.21.31, including IP6K1 and clinical biomarkers, revealed that IP6K2 was associated with decreased risk of distant recurrence. IP6K1 was associated with increased risk of distant recurrence in the multivariable test and protein analysis revealed trends of worse prognosis with high IP6K1 in the cytoplasm. The expression levels of IP6K1 and IP6K2 were associated to a high extent; however, a diverging prognostic value of the two genes was observed in breast cancer. The present data suggest that IP6K2 can be a favorable prognostic factor, while IP6K1 may not be.

Gene Expression Assay in the Management of Early Breast Cancer

The addition of adjuvant chemotherapy to hormonal therapy is often considered questionable in patients with estrogen receptor-positive early breast cancer. Low risk of disease relapse after endocrine treatment alone and/or a low sensitivity to chemotherapy are reasons behind not all patients benefit from chemotherapy. Most of the patients could be exposed to unnecessary treatment- related adverse events and health care costs when treatment decision-making is based only on classical clinical histological features. Gene expression profile has been developed to refine physician's decision-making process and to tailor personalized treatment to patients. In particular, these tests are designed to spare patients the side effects of unnecessary treatment, and ensure that adjuvant chemotherapy is correctly recommended to patients with early breast cancer. In this review, we will discuss the main diagnostic tests and their potential clinical applications (Oncotype DX, MammaPrint, PAM50/Prosigna, EndoPredict, MapQuant Dx, IHC4, and Theros-Breast Cancer Gene Expression Ratio Assay).

Germline HOXB13 mutations p.G84E and p.R217C do not confer an increased breast cancer risk

In breast cancer, high levels of homeobox protein Hox-B13 (HOXB13) have been associated with disease progression of ER-positive breast cancer patients and resistance to tamoxifen treatment. Since HOXB13 p.G84E is a prostate cancer risk allele, we evaluated the association between HOXB13 germline mutations and breast cancer risk in a previous study consisting of 3,270 familial non-BRCA1/2 breast cancer cases and 2,327 controls from the Netherlands. Although both recurrent HOXB13 mutations p.G84E and p.R217C were not associated with breast cancer risk, the risk estimation for p.R217C was not very precise. To provide more conclusive evidence regarding the role of HOXB13 in breast cancer susceptibility, we here evaluated the association between HOXB13 mutations and increased breast cancer risk within 81 studies of the international Breast Cancer Association Consortium containing 68,521 invasive breast cancer patients and 54,865 controls. Both HOXB13 p.G84E and p.R217C did not associate with the development of breast cancer in European women, neither in the overall analysis (OR = 1.035, 95% CI = 0.859-1.246, P = 0.718 and OR = 0.798, 95% CI = 0.482-1.322, P = 0.381 respectively), nor in specific high-risk subgroups or breast cancer subtypes. Thus, although involved in breast cancer progression, HOXB13 is not a material breast cancer susceptibility gene.

Low RAB6C expression is a predictor of tamoxifen benefit in estrogen receptor-positive/progesterone receptor-negative breast cancer

Over the last few decades, improved and more individualized treatment has contributed to the increased survival rate of patients with breast cancer. However, certain patients may receive excessive treatment resulting in undesired side effects. In a previous study, it was demonstrated that systemically untreated patients with estrogen receptor (ER)-positive/progesterone receptor (PR)-negative tumors with high Ras-related protein Rab-6C (RAB6C) expression levels (RAB6C⁺) had prolonged distant recurrence-free survival compared with that of patients exhibiting low RAB6C (RAB6C^-)-expressing tumors. The aim of the present study was to investigate whether RAB6C predicts the effectiveness of tamoxifen treatment. The present study used a dataset comprising 486 female patients with ER⁺ tumors from a randomized study conducted by the Stockholm Breast Cancer Study Group between November 1976 and August 1990. The patients were considered as low-risk if their tumor size was ≤30 mm and their lymph node status was negative. Patients were followed up until distant recurrence, mortality or when 25 years after randomization was achieved, whichever occurred first. For patients with ER⁺/PR^-/RAB6C⁺ tumors, prolonged distant recurrence-free survival could not be observed if the patients were treated with tamoxifen [hazard ratio (HR), 1.82; 95% confidence interval (CI), 0.69-4.79; P=0.23], whereas patients with ER⁺/PR^-/RAB6C^- tumors had 75% reduced distant recurrence risk (HR, 0.25; 95% CI, 0.09-0.70; P=0.008). In the ER⁺/PR⁺ subgroup, patients with RAB6C^- and RAB6C⁺ tumors benefited from tamoxifen treatment, though it was most evident in the RAB6C⁺ group (HR, 0.27; 95% CI, 0.13-0.58; P=0.001). The results of the present study indicated that, for patients with ER⁺/PR^- tumors, those with low RAB6C expression benefited from tamoxifen treatment, whereas no benefit was observed in patients with high RAB6C levels.

RAB6C is an independent prognostic factor of estrogen receptor-positive/progesterone receptor-negative breast cancer

The majority of breast cancer tumors are estrogen receptor-positive (ER⁺) and can be treated with endocrine therapy. However, certain patients may exhibit a good prognosis without systemic treatment. The aim of the present study was to identify novel prognostic factors for patients with ER⁺ breast cancer tumors using gene copy data, and to investigate if these factors have prognostic value in subgroups categorized by progesterone receptor status (PR). Public data, including the whole genome gene copy data of 199 systemically untreated patients with ER⁺ tumors, were utilized in the present study. To assess prognostic value, patients were divided into two groups using the median gene copy number as a cut-off for the SNPs that were the most variable. One SNP was identified, which indicated that the Ras-related protein Rab-6C (RAB6C) gene may exhibit prognostic significance. Therefore, RAB6C protein expression was subsequently investigated in a second independent cohort, consisting of 469 systematically untreated patients (of which 310 were ER⁺) who received long term follow-up. In the public data set, a distant recurrence risk reduction of 55% was determined for copy numbers above the median value of RAB6C compared with numbers below [multivariable adjusted hazard ratio (HR), 0.45; 95% CI 0.28–0.72; P=0.001)]. It was also more pronounced in the ER⁺/PR⁻ subgroup (HR, 0.15; 95% CI, 0.05–0.46; P=0.001). In the second cohort, patients of the ER⁺/PR⁻ subgroup who exhibited high RAB6C expression had a reduced distant recurrence risk (HR, 0.17; 95% CI, 0.05–0.60; P=0.006). However, this was not identified among ER⁺/PR⁺ tumors (HR, 1.31; 95% CI, 0.69–2.48; P=0.41). The results of the present study indicated that RAB6C serves as an independent prognostic factor of distant recurrence risk in systemically untreated patients with an ER⁺/PR⁻ tumor.

Paralogous HOX13 Genes in Human Cancers

Hox genes (HOX in humans), an evolutionary preserved gene family, are key determinants of embryonic development and cell memory gene program. Hox genes are organized in four clusters on four chromosomal loci aligned in 13 paralogous groups based on sequence homology (Hox gene network). During development Hox genes are transcribed, according to the rule of “spatio-temporal collinearity”, with early regulators of anterior body regions located at the 3’ end of each Hox cluster and the later regulators of posterior body regions placed at the distal 5’ end. The onset of 3’ Hox gene activation is determined by Wingless-type MMTV integration site family (Wnt) signaling, whereas 5’ Hox activation is due to paralogous group 13 genes, which act as posterior-inhibitors of more anterior Hox proteins (posterior prevalence). Deregulation of HOX genes is associated with developmental abnormalities and different human diseases. Paralogous HOX13 genes (HOX A13, HOX B13, HOX C13 and HOX D13) also play a relevant role in tumor development and progression. In this review, we will discuss the role of paralogous HOX13 genes regarding their regulatory mechanisms during carcinogenesis and tumor progression and their use as biomarkers for cancer diagnosis and treatment.

Oncoprotein HBXIP enhances HOXB13 acetylation and co-activates HOXB13 to confer tamoxifen resistance in breast cancer

Background

Resistance to tamoxifen (TAM) frequently occurs in the treatment of estrogen receptor positive (ER+) breast cancer. Accumulating evidences indicate that transcription factor HOXB13 is of great significance in TAM resistance. However, the regulation of HOXB13 in TAM-resistant breast cancer remains largely unexplored. Here, we were interested in the potential effect of HBXIP, an oncoprotein involved in the acceleration of cancer progression, on the modulation of HOXB13 in TAM resistance of breast cancer.

Methods

The Kaplan-Meier plotter cancer database and GEO dataset were used to analyze the association between HBXIP expression and relapse-free survival. The correlation of HBXIP and HOXB13 in ER+ breast cancer was assessed by human tissue microarray. Immunoblotting analysis, qRT-PCR assay, immunofluorescence staining, Co-IP assay, ChIP assay, luciferase reporter gene assay, cell viability assay, and colony formation assay were performed to explore the possible molecular mechanism by which HBXIP modulates HOXB13. Cell viability assay, xenograft assay, and immunohistochemistry staining analysis were utilized to evaluate the effect of the HBXIP/HOXB13 axis on the facilitation of TAM resistance in vitro and in vivo.

Results

The analysis of the Kaplan-Meier plotter and the GEO dataset showed that mono-TAM-treated breast cancer patients with higher HBXIP expression levels had shorter relapse-free survivals than patients with lower HBXIP expression levels. Overexpression of HBXIP induced TAM resistance in ER+ breast cancer cells. The tissue microarray analysis revealed a positive association between the expression levels of HBXIP and HOXB13 in ER+ breast cancer patients. HBXIP elevated HOXB13 protein level in breast cancer cells. Mechanistically, HBXIP prevented chaperone-mediated autophagy (CMA)-dependent degradation of HOXB13 via enhancement of HOXB13 acetylation at the lysine 277 residue, causing the accumulation of HOXB13. Moreover, HBXIP was able to act as a co-activator of HOXB13 to stimulate interleukin (IL)-6 transcription in the promotion of TAM resistance. Interestingly, aspirin (ASA) suppressed the HBXIP/HOXB13 axis by decreasing HBXIP expression, overcoming TAM resistance in vitro and in vivo.

Conclusions

Our study highlights that HBXIP enhances HOXB13 acetylation to prevent HOXB13 degradation and co-activates HOXB13 in the promotion of TAM resistance of breast cancer. Therapeutically, ASA can serve as a potential candidate for reversing TAM resistance by inhibiting HBXIP expression.

Electronic supplementary material

The online version of this article (10.1186/s13045-018-0577-5) contains supplementary material, which is available to authorized users.

Predicting and Overcoming Chemotherapeutic Resistance in Breast Cancer

Our understanding of breast cancer and its therapeutic approach has improved greatly due to the advancement of molecular biology in recent years. Clinically, breast cancers are characterized into three basic types based on their immunohistochemical properties. They are triple-negative breast cancer, estrogen receptor (ER) and progesterone receptor (PR)-positive-HR positive breast cancer, and human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Even though these subtypes have been characterized, assessment of a breast cancer's receptor status is still widely used to determine whether or not a targeted therapy could be applied. Moreover, drug resistance is common in all breast cancer types despite the different treatment modalities applied. The development of resistance to different therapeutics is not mutually exclusive. It seems that tumor could be resistant to multiple treatment strategies, such as being both chemoresistant and monoclonal antibody resistant. However, the underlying mechanisms are complicated and need further investigation. In this chapter, we aim to provide a brief review of the different types of breast cancer and their respective treatment strategies. We also review the possible mechanisms of potential drug resistance associated with each treatment type. We believe that a better understanding of the drug resistance mechanisms can lead to a more effective and efficient therapeutic success.

High expression of stromal PDGFRβ is associated with reduced benefit of tamoxifen in breast cancer

Cancer‐associated fibroblasts (CAFs) regulate tumour growth, metastasis and response to treatment. Recent studies indicate the existence of functionally distinct CAF subsets. Suggested mechanisms whereby CAFs can impact on treatment response include paracrine signalling affecting cancer cell drug sensitivity and effects on tumour drug uptake. PDGFRβ is an important regulator of fibroblasts. Experimental studies have linked PDGFRβ‐positive fibroblasts to metastasis and also to reduced tumour drug uptake. This study has investigated the potential role of PDGFRβ‐positive fibroblasts in response to adjuvant tamoxifen treatment of breast cancer. Analyses of two breast cancer collections from randomised studies analysing adjuvant tamoxifen treatment in early breast cancer demonstrated significant benefit of tamoxifen in the group with low stromal PDGFRβ, which was not observed in the group with high stromal PDGFRβ. In general terms these findings provide novel evidence, derived from analyses of randomised clinical studies, of response‐predictive capacity of a marker‐defined subset of CAFs and, more specifically, identify stromal PDGFRβ as a marker related to tamoxifen benefit in early breast cancer.

ERRα Is a Marker of Tamoxifen Response and Survival in Triple-Negative Breast Cancer

PURPOSE

Estrogen-related receptor alpha (ERRα) signaling has recently been implicated in breast cancer. We investigated the clinical value of ERRα in randomized cohorts of tamoxifen-treated and adjuvant-untreated patients.

EXPERIMENTAL DESIGN

Cox proportional hazards regression was used to evaluate the significance of associations between ERRα gene expression levels and patient DMFS in a previously published microarray dataset representing 2,000 breast tumor cases derived from multiple medical centers worldwide. The 912 tumors used for immunostaining were from a tamoxifen-randomized primary breast cancer trial conducted in Stockholm, Sweden, during 1976-1990. Mouse model was used to study the effect of tamoxifen treatment on lung colonization of MDA-MB-231 control cells and MDA-MB-231 cells with stable knockdown of ERRα. The phenotypic effects associated with ERRα modulation were studied using immunoblotting analyses and wound-healing assay.

RESULTS

We found that in ER-negative and triple-negative breast cancer (TNBC) adjuvant-untreated patients, ERRα expression indicated worse prognosis and correlated with poor outcome predictors. However, in tamoxifen-treated patients, an improved outcome was observed with high ERRα gene and protein expression. Reduced ERRα expression was oncogenic in the presence of tamoxifen, measured by in vitro proliferation and migration assays and in vivo metastasis studies.

CONCLUSIONS

Taken together, these data show that ERRα expression predicts response to tamoxifen treatment, and ERRα could be a biomarker of tamoxifen sensitivity and a prognostic factor in TNBC.

Imputation of the rare HOXB13 G84E mutation and cancer risk in a large population-based cohort

An efficient approach to characterizing the disease burden of rare genetic variants is to impute them into large well-phenotyped cohorts with existing genome-wide genotype data using large sequenced referenced panels. The success of this approach hinges on the accuracy of rare variant imputation, which remains controversial. For example, a recent study suggested that one cannot adequately impute the HOXB13 G84E mutation associated with prostate cancer risk (carrier frequency of 0.0034 in European ancestry participants in the 1000 Genomes Project). We show that by utilizing the 1000 Genomes Project data plus an enriched reference panel of mutation carriers we were able to accurately impute the G84E mutation into a large cohort of 83,285 non-Hispanic White participants from the Kaiser Permanente Research Program on Genes, Environment and Health Genetic Epidemiology Research on Adult Health and Aging cohort. Imputation authenticity was confirmed via a novel classification and regression tree method, and then empirically validated analyzing a subset of these subjects plus an additional 1,789 men from Kaiser specifically genotyped for the G84E mutation (r² = 0.57, 95% CI = 0.37−0.77). We then show the value of this approach by using the imputed data to investigate the impact of the G84E mutation on age-specific prostate cancer risk and on risk of fourteen other cancers in the cohort. The age-specific risk of prostate cancer among G84E mutation carriers was higher than among non-carriers. Risk estimates from Kaplan-Meier curves were 36.7% versus 13.6% by age 72, and 64.2% versus 24.2% by age 80, for G84E mutation carriers and non-carriers, respectively (p = 3.4×10⁻¹²). The G84E mutation was also associated with an increase in risk for the fourteen other most common cancers considered collectively (p = 5.8×10⁻⁴) and more so in cases diagnosed with multiple cancer types, both those including and not including prostate cancer, strongly suggesting pleiotropic effects.

An efficient approach to characterizing the disease burden of rare genetic variants is to impute them into existing well-phenotyped cohorts with genome-wide data by using large sequenced reference panels; however, the efficacy of this approach remains controversial. A recent study suggested that it is not possible to impute the rare HOXB13 G84E variant using neighboring SNP markers. We show that by using an enriched reference sequenced sample of 22 mutation carriers, we were able to impute this mutation into a large cohort of 83,285 non-Hispanic White individuals from the Kaiser Permanente Research Program on Genes, Environment, and Health Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort. The imputation was confirmed via a novel classification and regression tree method, and then empirically validated by direct mutation genotyping of a subset of 1,673 of these individuals in addition to 1,789 other men from Kaiser. Using the same GERA cohort, we then confirmed that the G84E mutation is associated with increased risk of prostate cancer, and estimated the age-specific risk for carriers of the mutation. Finally, we obtained evidence that the mutation is associated with additional types of cancer in the GERA cohort.

Characterization of HOX gene expression in canine mammary tumour cell lines from spontaneous tumours

Spatial/temporal controls of development are regulated by the homeotic (HOX) gene complex and require integration with oncogenes and tumour suppressors regulating cell cycle exit. Spontaneously derived neoplastic canine mammary carcinoma cell models were investigated to determine if HOX expression profiles were associated with neoplasia as HOX genes promote neoplastic potential in human cancers. Comparative assessment of human and canine breast cancer expression profiles revealed remarkable similarity for all four paralogous HOX gene clusters and several unlinked HOX genes. Five canine HOX genes were overexpressed with expression profiles consistent with oncogene-like character (HOXA1, HOXA13, HOXD4, HOXD9 and SIX1) and three HOX genes with underexpressed profiles (HOXA11, HOXC8 and HOXC9) were also identified as was an apparent nonsense mutation in HOXC6. This data, as well as a comparative analysis of similar data from human breast cancers suggested expression of selected HOX genes in canine mammary carcinoma could be contributing to the neoplastic phenotype.

HOXB13 G84E mutation in Finland: population-based analysis of prostate, breast, and colorectal cancer risk

BACKGROUND

A recently identified germline mutation G84E in HOXB13 was shown to increase the risk of prostate cancer. In a family-based analysis by The International Consortium for Prostate Cancer Genetics (ICPCG), the G84E mutation was most prevalent in families from the Nordic countries of Finland (22.4%) and Sweden (8.2%).

METHODS

To further investigate the importance of G84E in the Finns, we determined its frequency in more than 4,000 prostate cancer cases and 5,000 controls. In addition, 986 breast cancer and 442 colorectal cancer (CRC) cases were studied. Genotyping was conducted using TaqMan, MassARRAY iPLEX, and sequencing. Statistical analyses were conducted using Fisher exact test, and overall survival was analyzed using Cox modeling.

RESULTS

The frequency of the G84E mutation was significantly higher among patients with prostate cancer and highest among patients with a family history of the disease, hereditary prostate cancer [8.4% vs. 1.0% in controls; OR 8.8; 95% confidence interval (CI), 4.9-15.7]. The mutation contributed significantly to younger age (≤55 years) at onset and high prostate-specific antigen (PSA; ≥20 ng/mL) at diagnosis. An association with increased prostate cancer risk in patients with prior benign prostate hyperplasia (BPH) diagnosis was also revealed. No statistically significant evidence for a contribution in CRC risk was detected, but a suggestive role for the mutation was observed in familial BRCA1/2-negative breast cancer.

CONCLUSIONS

These findings confirm an increased cancer risk associated with the G84E mutation in the Finnish population, particularly for early-onset prostate cancer and cases with substantially elevated PSA.

IMPACT

This study confirms the overall importance of the HOXB13 G84E mutation in prostate cancer susceptibility.

Can predictive biomarkers in breast cancer guide adjuvant endocrine therapy?

Personalized medicine for oestrogen receptor-α (ERα)-positive breast cancer requires predictive biomarkers for broad endocrine resistance as well as biomarkers capable of predicting resistance to a specific agent. In addition, biomarkers could be used to select patients that might benefit from the addition of treatments that do not target ERα. However, biomarker identification studies seem to be far from consistent and identified biomarkers seldom face an introduction into clinical practice. Importantly, most of the studies that seek to identify biomarkers have been performed using material from consecutive series of patients treated with tamoxifen (the most commonly prescribed ERα antagonist). Consequently, the predictive value of any biomarker identified is confounded by its prognostic value. Another important issue is the lack of differentiation between premenopausal and postmenopausal patients with breast cancer. The hormonal environment of a tumour in patients who are premenopausal is intrinsically distinct from those arising in postmenopausal women. Biomarkers of different biological mechanisms might enable the prediction of either broad endocrine resistance or resistance to a specific agent in each of these patient subtypes. Ultimately, improvements to study design are needed to establish the clinical validity of the most promising biomarkers to predict benefit from endocrine therapy.

Clinical validity/utility, change in practice patterns, and economic implications of risk stratifiers to predict outcomes for early-stage breast cancer: a systematic review

BACKGROUND

At least 14 stratifiers exist to assess recurrence risk, chemotherapy response, and overall survival (OS) in women with early-stage breast cancer (ESBC). These stratifiers have not been compared using a recently developed rigorous framework. We performed a systematic review of the literature on clinical validity/utility, change in clinical practice, and economic implications of ESBC stratifiers.

METHODS

A systematic literature search was performed using PubMed, Cumulative Index to Nursing and Allied Health Literature, the Cochrane Database of Systematic Reviews, and bibliographies of relevant studies. Data were extracted by two investigators and graded using a previously published framework. The Level-of-Evidence determination for each study was summarized, and the studies that provide evidence on change in clinical practice and economic implications are reported.

RESULTS

Fifty-six articles published original evidence addressing the 21-gene recurrence score (n = 31), 70-gene signature (n = 14), Adjuvant! Online (n = 12), 5-antibody immunohistochemistry panel (n = 3), 5-gene expression index (n = 1), and 14-gene signature (n = 1). The 21-gene recurrence score satisfied Level I evidence (the highest level of evidence among five levels) for estimating distant recurrence risk (DRR), OS, and response to adjuvant chemotherapy, and Level II for estimating local recurrence risk. The 5-antibody immunohistochemistry panel and 70-gene signature satisfied Level II evidence for estimating DRR and OS. Adjuvant! Online satisfied Level II evidence for estimating DRR, OS, and chemotherapy response. The 5-gene expression index satisfied Level III evidence for predicting DRR. The 14-gene signature satisfied Level III evidence for predicting DRR and OS. Ten studies reported changes in clinical practice patterns; seven studies reported economic implications.

CONCLUSION

The available evidence on the ability of stratifiers to predict risks of recurrence and response to chemotherapy in ESBC is growing. Level-of-Evidence determinations using the newer framework provide a solid scientific foundation for clinical recommendations.

Prognostic utility of HOXB13:IL17BR and molecular grade index in early-stage breast cancer patients from the Stockholm trial

Background:

A dichotomous index combining two gene expression assays, HOXB13 : IL17BR (H : I) and molecular grade index (MGI), was developed to assess risk of recurrence in breast cancer patients. The study objective was to demonstrate the prognostic utility of the combined index in early-stage breast cancer.

Methods:

In a blinded retrospective analysis of 588 ER-positive tamoxifen-treated and untreated breast cancer patients from the randomised prospective Stockholm trial, H : I and MGI were measured using real-time RT–PCR. Association with patient outcome was evaluated by Kaplan–Meier analysis and Cox proportional hazard regression. A continuous risk index was developed using Cox modelling.

Results:

The dichotomous H : I+MGI was significantly associated with distant recurrence and breast cancer death. The >50% of tamoxifen-treated patients categorised as low-risk had <3% 10-year distant recurrence risk. A continuous risk model (Breast Cancer Index (BCI)) was developed with the tamoxifen-treated group and the prognostic performance tested in the untreated group was 53% of patients categorised as low risk with an 8.3% 10-year distant recurrence risk.

Conclusion:

Retrospective analysis of this randomised, prospective trial cohort validated the prognostic utility of H : I+MGI and was used to develop and test a continuous risk model that enables prediction of distant recurrence risk at the patient level.