Can genetic testing guide treatment in breast cancer?

Adjuvant Olaparib for Patients with BRCA1- or BRCA2-Mutated Breast Cancer

BACKGROUND

Poly(adenosine diphosphate-ribose) polymerase inhibitors target cancers with defects in homologous recombination repair by synthetic lethality. New therapies are needed to reduce recurrence in patients with BRCA1 or BRCA2 germline mutation-associated early breast cancer.

METHODS

We conducted a phase 3, double-blind, randomized trial involving patients with human epidermal growth factor receptor 2 (HER2)-negative early breast cancer with BRCA1 or BRCA2 germline pathogenic or likely pathogenic variants and high-risk clinicopathological factors who had received local treatment and neoadjuvant or adjuvant chemotherapy. Patients were randomly assigned (in a 1:1 ratio) to 1 year of oral olaparib or placebo. The primary end point was invasive disease-free survival.

RESULTS

A total of 1836 patients underwent randomization. At a prespecified event-driven interim analysis with a median follow-up of 2.5 years, the 3-year invasive disease-free survival was 85.9% in the olaparib group and 77.1% in the placebo group (difference, 8.8 percentage points; 95% confidence interval [CI], 4.5 to 13.0; hazard ratio for invasive disease or death, 0.58; 99.5% CI, 0.41 to 0.82; P<0.001). The 3-year distant disease-free survival was 87.5% in the olaparib group and 80.4% in the placebo group (difference, 7.1 percentage points; 95% CI, 3.0 to 11.1; hazard ratio for distant disease or death, 0.57; 99.5% CI, 0.39 to 0.83; P<0.001). Olaparib was associated with fewer deaths than placebo (59 and 86, respectively) (hazard ratio, 0.68; 99% CI, 0.44 to 1.05; P = 0.02); however, the between-group difference was not significant at an interim-analysis boundary of a P value of less than 0.01. Safety data were consistent with known side effects of olaparib, with no excess serious adverse events or adverse events of special interest.

CONCLUSIONS

Among patients with high-risk, HER2-negative early breast cancer and germline BRCA1 or BRCA2 pathogenic or likely pathogenic variants, adjuvant olaparib after completion of local treatment and neoadjuvant or adjuvant chemotherapy was associated with significantly longer survival free of invasive or distant disease than was placebo. Olaparib had limited effects on global patient-reported quality of life. (Funded by the National Cancer Institute and AstraZeneca; OlympiA ClinicalTrials.gov number, NCT02032823.).

Screening High-Risk Women Veterans for Breast Cancer

BACKGROUND

Within the US Department of Veterans Affairs (VA), breast cancer prevalence has more than tripled from 1995 to 2012. Women veterans may be at an increased breast cancer risk based on service-related exposures and posttraumatic stress disorder (PTSD).

METHODS

Women veterans aged ≥ 35 years with no personal history of breast cancer were enrolled at 2 urban VA medical centers. We surveyed women veterans for 5-year and lifetime risks of invasive breast cancer using the Gail Breast Cancer Risk Assessment Tool (BCRAT). Data regarding demographics, PTSD status, eligibility for chemoprevention, and genetic counseling were also collected. Descriptive statistics were used to determine results.

RESULTS

A total of 99 women veterans participated, of which 60% were Black. In total, 35% were high risk with a 5-year BCRAT > 1.66%. Breast biopsies had been performed in 22% of our entire population; 57% had a family history positive for breast cancer. Comparatively, in our high-risk Black population, 33% had breast biopsies and 94% had a family history. High-risk patients were referred for chemoprevention; 5 accepted and 13 were referred for genetic counseling. PTSD was present in 31% of the high-risk subgroup.

CONCLUSIONS

A high percentage of Black patients participated in this pilot study, which also showed an above average rate of PTSD among women veterans who are at high risk for developing breast cancer. Historically, breast cancer rates among Black women are lower than those found in the general population. High participation among Black women veterans in this pilot study uncovered the potential for further study of this population, which is otherwise underrepresented in research. Limitations included a small sample size, exclusively urban population, and self-selection for screening. Future directions include the evaluation of genetic and molecular mutations in high risk Black women veterans, possibly even a role for PTSD epigenetic changes.

Subtyping of triple-negative breast cancer: implications for therapy

Triple-negative breast cancer (TNBC) is a heterogeneous disease; gene expression analyses recently identified 6 distinct TNBC subtypes, each of which displays a unique biology. Exploring novel approaches for the treatment of these subtypes is critical, especially because the median survival for women with metastatic TNBC is less than 12 months, and virtually all women with metastatic TNBC ultimately will die of their disease despite systemic therapy. To date, not a single targeted therapy has been approved for the treatment of TNBC, and cytotoxic chemotherapy remains the standard treatment. In this review, the authors discuss recent developments in subtyping TNBC and the current and upcoming therapeutic strategies being explored in an attempt to target TNBC.

Testing for the recurrent HOXB13 G84E germline mutation in men with clinical indications for prostate biopsy

PURPOSE

The G84E variant of HOXB13 was recently found to be associated with a significantly increased risk of prostate cancer in a case control study. We estimated the prevalence of this mutation in a clinical population of men at risk for prostate cancer who were scheduled to undergo prostate biopsy.

MATERIALS AND METHODS

We prospectively collected clinical information and DNA samples from men who underwent diagnostic prostate biopsy between June 2005 and October 2011. We genotyped samples for HOXB13 G84E using the MassARRAY® system. We determined the prevalence of the G84E variant in the overall cohort, among patients with a positive family history and among men age 55 years or younger.

RESULTS

A total of 1,175 subjects underwent biopsy, of whom 948 had a DNA sample for analysis. The G84E variant was detected in 4 patients (prevalence 0.42%, 95% CI 0.12-1.08), of whom 3 had prostate cancer on biopsy. None of 301 patients with a positive family history (prevalence 0.00%, 95% CI 0.00-1.22) and 1 of 226 patients age 55 years or younger tested positive (prevalence 0.44%, 95% CI 0.01-2.44).

CONCLUSIONS

The HOXB13 G84E variant is rare in this cohort, even among those with a positive family history. Our findings question the utility of testing for this variant among unselected men presenting for a diagnostic prostate biopsy.

Cancer treatment according to BRCA1 and BRCA2 mutations

Identification of germline mutations associated with significant cancer susceptibility has the potential to change all aspects of an individual's care, from screening to cancer treatment. For example, women with germline mutations in BRCA1 and BRCA2 have markedly elevated risks of breast and ovarian cancer and the identification of these germline mutations has led to specific screening and prevention strategies. More recently, advances in the understanding of the biological function of BRCA1 and BRCA2 have led to clinical trials testing targeted therapies in this population, particularly poly(ADP-ribose) polymerase (PARP) inhibitors. Unfortunately, the development of PARP inhibitors has not been as rapid as anticipated and has been more challenging than expected. Somatic mutations identified in many cancer types have allowed the development of therapeutics that target these mutated genes, and many of these agents obtained rapid regulatory approval and are currently in widespread clinical practice. Diagnostic testing has a central role in targeted cancer therapeutics for both somatic and germline mutations. Although the era of molecular medicine and targeted therapies has led to significant changes in the practice of oncology, new challenges continue to arise.

Getting to the point: what women newly diagnosed with breast cancer want to know about treatment-focused genetic testing

PURPOSE/OBJECTIVES

To identify young women's information preferences regarding treatment-focused genetic testing (TFGT) and to develop and evaluate a novel educational resource.

RESEARCH APPROACH

Qualitative interview study and pilot testing of a novel resource.

SETTING

Two familial cancer services and one outpatient oncology clinic in Sydney and Melbourne, Australia.

PARTICIPANTS

26 women with breast cancer aged 50 years and younger who either previously had TFGT (n = 14) or had a diagnosis of breast cancer within the previous 6-12 months.

METHODOLOGIC APPROACH

Participants were asked about their views of TFGT in semistructured interviews. A brief pamphlet on TFGT then was developed and pilot tested with 17 of the 26 women.

MAIN RESEARCH VARIABLES

Women's attitudes and preferences with regard to timing, mode of delivery, and amount and format of information regarding TFGT were explored.

FINDINGS

Most women wanted to be informed about TFGT at or around the time of their cancer diagnosis via a face-to-face consultation. No clear preference existed for which type of healthcare professional should provide information on TFGT. Brief written information about TFGT was viewed as important supporting material. The educational resource developed was well received.

CONCLUSIONS

The potential for more widespread TFGT in the future indicates a need for patient educational materials that enable women to make informed choices about TFGT. This pilot study has provided timely initial evidence on the efficacy of a brief written resource in preparing women for decision making about TFGT.

INTERPRETATION

The resource developed in this study will assist oncology nurses to make important genetic risk information available to women newly diagnosed with breast cancer at a stressful time.

Drug therapy for hereditary cancers

Tumors arising in patients with hereditary cancer syndromes may have distinct drug sensitivity as compared to their sporadic counterparts. Breast and ovarian neoplasms from BRCA1 or BRCA2 mutation carriers are characterized by deficient homologous recombination (HR) of DNA, that makes them particularly sensitive to platinum compounds or inhibitors of poly (ADP-ribose) polymerase (PARP). Outstandingly durable complete responses to high dose chemotherapy have been observed in several cases of BRCA-related metastatic breast cancer (BC). Multiple lines of evidence indicate that women with BRCA1-related BC may derive less benefit from taxane-based treatment than other categories of BC patients. There is virtually no reports directly assessing drug response in hereditary colorectal cancer (CRC) patients; studies involving non-selected (i.e., both sporadic and hereditary) CRC with high-level microsatellite instability (MSI-H) suggest therapeutic advantage of irinotecan. Celecoxib has been approved for the treatment of familial adenomatous polyposis (FAP). Hereditary medullary thyroid cancers (MTC) have been shown to be highly responsive to a multitargeted tyrosine kinase inhibitor vandetanib, which exerts specific activity towards mutated RET receptor. Given the rapidly improving accessibility of DNA analysis, it is foreseen that the potential predictive value of cancer-associated germ-line mutations will be increasingly considered in the future studies.

Breast cancer predisposition syndromes

A small, but important, percentage of breast cancer cases is caused by the inheritance of a single copy of a mutated gene. BRCA1 and BRCA2 are the genes most commonly associated with inherited breast cancer; however, mutations in TP53 and PTEN cause Li-Fraumeni syndrome and Cowden syndrome, respectively, both of which are associated with high lifetime risks of breast cancer. Advances in the field of breast cancer genetics have led to an improved understanding of detection and prevention strategies. More recently, strategies to target the underlying genetic defects in BRCA1- and BRCA2-associated breast and ovarian cancers are emerging and may have implications for certain types of sporadic breast cancer.

The use of referenced-EEG (rEEG) in assisting medication selection for the treatment of depression

OBJECTIVE

To evaluate the efficacy of rEEG(®)-guided pharmacotherapy for the treatment of depression in those circumstances where rEEG and STAR*D provided different recommendations.

MATERIALS AND METHODS

This was a randomized, single-blind, parallel group, 12 center, US study of rEEG-guided pharmacotherapy vs. the most effective treatment regimens reported in the NIH sponsored STAR*D study. Relatively treatment-resistant subjects ≥18 years who failed one or more antidepressants were required to have a QIDS-16-SR score ≥13 and a MADRS score ≥26 at baseline. All subjects underwent a washout of all current medications (with some protocol-specified exceptions) for at least five half-lives before receiving a QEEG and rEEG report. Subjects randomized to rEEG were assigned a regimen based on the rEEG report. Control subjects who had failed only SSRI's in their current episode were randomized to receive venlafaxine XR. Control subjects who had failed antidepressants from ≥2 classes of antidepressants were randomized to receive a regimen from Steps 2-4 of the STAR*D study. Treatment lasted 12 weeks. The primary outcome measures were change from baseline for self-rated QIDS-SR16 and Q-LES-Q-SF.

RESULTS

A total of 114 subjects were randomized and 89 subjects were evaluable. rEEG-guided pharmacotherapy exhibited significantly greater improvement for both primary endpoints, QIDS-SR16 (-6.8 vs. -4.5, p<0.0002) and Q-LES-Q-SF (18.0 vs. 8.9, p<0.0002) compared to control, respectively, as well as statistical superiority in 9 out of 12 secondary endpoints.

CONCLUSIONS

These results warrant additional studies to determine the role of rEEG-guided psychopharmacology in the treatment of depression. If these results were confirmed, rEEG-guided pharmacotherapy would represent an easy, relatively inexpensive, predictive, objective office procedure that builds upon clinical judgment to guide antidepressant medication choice.

Breast cancer in the personal genomics era

Breast cancer is a heterogeneous disease with a complex etiology that develops from different cellular lineages, progresses along multiple molecular pathways, and demonstrates wide variability in response to treatment. The "standard of care" approach to breast cancer treatment in which all patients receive similar interventions is rapidly being replaced by personalized medicine, based on molecular characteristics of individual patients. Both inherited and somatic genomic variation is providing useful information for customizing treatment regimens for breast cancer to maximize efficacy and minimize adverse side effects. In this article, we review (1) hereditary breast cancer and current use of inherited susceptibility genes in patient management; (2) the potential of newly-identified breast cancer-susceptibility variants for improving risk assessment; (3) advantages and disadvantages of direct-to-consumer testing; (4) molecular characterization of sporadic breast cancer through immunohistochemistry and gene expression profiling and opportunities for personalized prognostics; and (5) pharmacogenomic influences on the effectiveness of current breast cancer treatments. Molecular genomics has the potential to revolutionize clinical practice and improve the lives of women with breast cancer.

[Gene expression based multigene prognostic and predictive tests in breast cancer]

Patient tailored therapy will serve the fundamentals of future cancer treatment. For this it will be imperative to characterize the tumor and to acquire precise predictive and prognostic information. We can achieve this by using not only monogenic (like ER, PR, HER-2, Ki-67) but also multigene assays, which can provide answers to several diagnostic questions simultaneously. We present a summary of currently available RT-PCR and microarray based multigene tests including MammaPrint, Oncotype DX, BLN Assay, Theros Breast Cancer Index SM, MapQuant DX, ARUP Breast Bioclassifier, Celera Metastatic Score, eXagen BCtm, Invasive Gene Signature, Wound Response Indicator and Mammostrat. Two of these (Oncotype DX and MammaPrint) are already incorporated in several diagnostic protocols. However, multiple unsolved issues deteriorate the value of these tests: generally the validation is poor, the gene sets do not confirm each other, the associated costs are high and the necessary bioinformatics is highly complex.

Cumulative survival in early-onset unilateral and bilateral breast cancer: an analysis of 1907 Taiwanese women

As the epidemiological pattern of breast cancer in modernising Asian countries differs greatly from that in Western countries, it is worthwhile to investigate the long-term prognoses of unilateral and bilateral breast cancer in these nations. A retrospective cohort study composed of 1907 Taiwanese women was conducted to follow 1863 unilateral and 44 bilateral cases of breast cancer. Time-dependent Cox regression was used to assess the risk of breast cancer death by considering the time course of unilateral and bilateral tumour development. The 15-year survival rates were 68.37, 62.63, and 26.42% for unilateral, synchronous bilateral, and metachronous bilateral breast cancer, respectively. Differences among types were most apparent after 5 years of follow-up. After adjusting for significant prognostic factors, the risk of death for overall bilateral breast cancer was 2.50-fold greater (95% CI, 1.43-4.37) compared to unilateral breast cancer. The corresponding figures were 1.12-fold (95% CI, 0.42-3.02) and 6.11-fold (95% CI, 3.14-11.89) for synchronous and metachronous bilateral breast cancer, respectively. Taiwanese women, who are frequently diagnosed with breast cancer before 50 years of age, showed poorer survival for metachronous bilateral than for synchronous bilateral or unilateral breast cancer. Survival was markedly poorer compared to recent data from Sweden.