Pembrolizumab plus chemotherapy as neoadjuvant treatment of high-risk, early-stage triple-negative breast cancer: results from the phase 1b open-label, multicohort KEYNOTE-173 study.

BACKGROUND: The phase Ib KEYNOTE-173 study was conducted to assess the safety and preliminary antitumor activity of neoadjuvant chemotherapy plus pembrolizumab in high-risk, early-stage, non-metastatic triple-negative breast cancer (TNBC). PATIENTS AND METHODS: Six pembrolizumab plus chemotherapy regimens were evaluated (cohorts A-F). All cohorts received a pembrolizumab 200-mg run-in dose (cycle 1), then eight cycles of pembrolizumab in combination with a taxane with or without carboplatin for 12 weeks, and then doxorubicin and cyclophosphamide for an additional 12 weeks before surgery. Primary end points were safety and recommended phase II dose (RP2D); secondary end points were pathological complete response (pCR) rate, objective response rate, and event-free and overall survival. Exploratory end points were the relationship between outcome and potential biomarkers, such as tumor programmed death ligand 1 (PD-L1) expression (combined positive score) and stromal tumor-infiltrating lymphocyte levels (sTILs). RESULTS: Sixty patients were enrolled between 18 February 2016, and 28 February 2017. Dose-limiting toxicities occurred in 22 patients, most commonly febrile neutropenia (n = 10 across cohorts). Four cohorts (B, C, D, F) did not meet the RP2D threshold; two cohorts did (A, E). The most common grade ≥3 treatment-related adverse event was neutropenia (73%). Immune-mediated adverse events and infusion reactions occurred in 18 patients (30%) and were grade ≥3 in six patients (10%). The pCR rate (ypT0/Tis ypN0) across all cohorts was 60% (range 49%-71%). Twelve-month event-free and overall survival rates ranged from 80% to 100% across cohorts (100% for four cohorts). Higher pre-treatment PD-L1 combined positive score, and pre- and on-treatment sTILs were significantly associated with higher pCR rates (P = 0.0127, 0.0059, and 0.0085, respectively). CONCLUSION: Combination neoadjuvant chemotherapy and pembrolizumab for high-risk, early-stage TNBC showed manageable toxicity and promising antitumor activity. In an exploratory analysis, the pCR rate showed a positive correlation with tumor PD-L1 expression and sTIL levels. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02622074.

Avoiding over- and undertreatment in patients with resected node-positive breast cancer with the use of gene expression signatures: are we there yet?

Prediction of benefit from adjuvant chemotherapy following resection of early breast cancer and, as a result, proper selection of candidates remains an elusive goal since the relative magnitude of benefit is the same regardless of the presence of clinicopathologic factors. Multiple studies, including randomized trials, establish the role of certain gene expression signatures in node-negative disease since they predict the risk of breast cancer relapse being so low that adjuvant chemotherapy can be omitted. In contrast, more limited data are available in higher risk, node-positive breast cancer patients, making the exclusion of adjuvant chemotherapy potentially hazardous. 'Prospective-retrospective' studies and limited prospective data show that several signatures, namely Oncotype Dx, MammaPrint, Prosigna, EndoPredict and Breast Cancer Index, select with different levels of success node-positive patients at very low risk for distant recurrence despite not receiving chemotherapy, although the long-term follow-up is still awaited. Pending, however the publication of the results from ongoing randomized studies which enroll patients with node-positive disease, major caution is warranted. Improper use and misinterpretation of these transcriptomic profiles can lead to undertreatment and exposure of patients to unnecessary risks resulting in increased breast cancer mortality for patients with axillary node-positive disease. With this review we critically discuss the available data on gene expression signatures that are used in clinical practice and offer practical recommendations regarding the management of patients with ER-positive, human epidermal growth factor receptor 2 (HER2)-negative, node-positive breast cancer.

Dose tailoring of adjuvant chemotherapy for breast cancer based on hematologic toxicities: further results from the prospective PANTHER study with focus on obese patients.

Background: Adjuvant chemotherapy (ACT) for breast cancer improves relapse-free survival (BCRFS) and overall survival. Differences in terms of efficacy and toxicity could partly be explained by the significant interpatient variability in pharmacokinetics which cannot be captured by dosing according to body surface area. Consequently, tailored dosing was prospectively evaluated in the PANTHER trial. Patients and methods: PANTHER is a multicenter, open-label, randomized phase III trial which compared tailored, dose-dense (DD) epirubicin/cyclophosphamide (E/C) and tailored docetaxel (D) (tDD) with standard interval 5-fluorouracil/E/C and D. The primary end point was BCRFS and the primary efficacy analysis has been previously published. In this secondary analysis, we aimed to retrospectively explore the concept of dose tailoring. Our two hypotheses were that BCRFS would not vary depending on the cumulative administered epirubicin dose; and that dose tailoring would lead to appropriate dosing and improved outcomes for obese patients, who are known to have worse prognosis and increased toxicity after DD ACT. Results: Patients treated with tDD had similar BCRFS regardless of the cumulative epirubicin dose (P = 0.495), while obese patients in this group [body mass index (BMI) ≥30] had improved BCRFS compared with nonobese ones (BMI <30) [hazard ratio (HR) = 0.51, 95% confidence interval (CI) 0.30-0.89, P = 0.02]. Moreover, tDD was associated with improved BCRFS compared with standard treatment only in obese patients (HR = 0.49, 95% CI 0.26-0.90, P = 0.022) but not in nonobese ones (HR = 0.79, 95% CI 0.60-1.04, P = 0.089). The differences were not formally statistically significant (P for interaction 0.175). There were no differences in terms of toxicity across the epirubicin dose levels or the BMI groups. Conclusions: Dose tailoring is a feasible strategy that can potentially improve outcomes in obese patients without increasing toxicity and should be pursued in further clinical studies. ClinicalTrials.gov identifier: NCT00798070.

The importance of molecular markers for diagnosis and selection of targeted treatments in patients with cancer.

The past 30 years have seen the introduction of a number of cancer therapies with the aim of restricting the growth and spread of primary and metastatic tumours. A shared commonality among these therapies is their targeting of various aspects of the cancer hallmarks, that is traits that are essential to successful tumour propagation and dissemination. The evolution of molecular-scale technology has been central to the identification of new cancer targets, and it is not a coincidence that improved therapies have emerged at the same time as gene expression arrays and DNA sequencing have enhanced our understanding of cancer genetics. Modern tumour pathology is now viewed at the molecular level ranging from IHC biomarkers, to gene signature classifiers and gene mutations, all of which provide crucial information about which patients will respond to targeted therapy regimens. In this review, we briefly discuss the general types of targeted therapies used in a clinical setting and provide a short background on immunohistochemical, gene expression and DNA sequencing technologies, before focusing on three tumour types: breast, lung and colorectal cancers. For each of these cancer types, we provide a background to the disease along with an overview of the current standard therapies and then focus on the relevant targeted therapies and the pathways they inhibit. Finally, we highlight several strategies that are pivotal to the successful development of targeted anti-cancer drugs.

Time-dependent risk of developing distant metastasis in breast cancer patients according to treatment, age and tumour characteristics.

BACKGROUND: Metastatic breast cancer is a severe condition without curative treatment. How relative and absolute risk of distant metastasis varies over time since diagnosis, as a function of treatment, age and tumour characteristics, has not been studied in detail. METHODS: A total of 9514 women under the age of 75 when diagnosed with breast cancer in Stockholm and Gotland regions during 1990-2006 were followed up for metastasis (mean follow-up=5.7 years). Time-dependent development of distant metastasis was analysed using flexible parametric survival models and presented as hazard ratio (HR) and cumulative risk. RESULTS: A total of 995 (10.4%) patients developed distant metastasis; the most common sites were skeleton (32.5%) and multiple sites (28.3%). Women younger than 50 years at diagnosis, with lymph node-positive, oestrogen receptor (ER)-negative, >20 mm tumours and treated only locally, had the highest risk of distant metastasis (0-5 years' cumulative risk =0.55; 95% confidence interval (CI): 0.47-0.64). Women older than 50 years at diagnosis, with ER-positive, lymph node-negative and ≤20-mm tumours, had the same and lowest cumulative risk of developing metastasis 0-5 and 5-10 years (cumulative risk=0.03; 95% CI: 0.02-0.04). In the period of 5-10 years after diagnosis, women with ER-positive, lymph node-positive and >20-mm tumours were at highest risk of distant recurrence. Women with ER-negative tumours showed a decline in risk during this period. CONCLUSION: Our data show no support for discontinuation at 5 years of clinical follow-up in breast cancer patients and suggest further investigation on differential clinical follow-up for different subgroups of patients.

When to order a biopsy to characterise a metastatic relapse in breast cancer.

Today, the diagnosis of metastatic breast cancer is usually based on radiological findings, and therapeutic decisions are made by considering the pathological characteristics and predictive markers of the primary tumour. Accumulating evidence suggests that tumour characteristics, including estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2), are unstable through tumour progression. Several retrospective studies and, recently, two prospective studies have investigated the discrepancies in receptor status between primary tumours and the corresponding metastases in a total of 1773 patients (for ER) and 2845 patients (for HER2). Changes in ER and HER2 status in these studies range from 14.5% to 40% and from 0% to 37.5%, respectively. In the two prospective studies, a different diagnosis, usually non-malignant, was obtained in 3% and 9% of the cases, and the biopsy led to a treatment modification in about one out of seven patients. Here, we review and discuss the currently available data and provide our recommendations on when a metastatic biopsy should be obtained.

The prognostic and predictive impact of low estrogen receptor expression in early breast cancer: a systematic review and meta-analysis.

INTRODUCTION: Traditionally, estrogen receptor (ER)-positive breast cancer has been defined as tumors with ≥1% positive for ER. The updated American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines recommend that tumors with ER expression of 1%-10% should be classified as ER-low-positive, recognizing the limited clinical evidence on the prognostic and predictive role of low ER expression. We aimed to investigate the predictive role of ER-low expression to neoadjuvant chemotherapy (NeoCT) and the prognostic significance of ER-low expressing breast tumors compared with ER-positive or ER-negative breast tumors. METHODS: A meta-analysis was conducted using the Meta-analyses Of Observational Studies in Epidemiology (MOOSE) guidelines and eligible articles were identified on PubMed and ISI Web of Science databases. The primary outcome was pathologic complete response and secondary outcomes were disease-free survival (DFS) and overall survival (OS). Twelve retrospective cohort studies were included in the meta-analysis. NeoCT resulted in higher pathologic complete response among patients with ER-low expression compared with ER-positive and comparable to ER-negative. Patients with ER-low breast cancer had a statistically significant worse DFS and OS compared with patients with ER-positive breast cancer, whereas no difference in DFS or OS was observed between ER-low and ER-negative subgroups. DISCUSSION: The current evidence suggests that ER-low breast cancer has a more similar outcome to ER-negative than to ER-positive breast cancer in terms of DFS and OS. ER-low expression seems also to have a predictive role regarding NeoCT. Considering the certainty of current evidence categorized as low to moderate, our results urge the need for well-designed prospective studies investigating the molecular background and the most appropriate treatment strategy for ER-low expressing breast cancer.

Benefit of pazopanib in advanced gastrointestinal stromal tumours: results from a phase II trial (SSG XXI, PAGIST).

BACKGROUND: Patients with advanced gastrointestinal stromal tumours (GISTs) resistant to the tyrosine kinase inhibitors imatinib and sunitinib may be treated with regorafenib, which resulted in a median progression-free survival (PFS) of 4.8 months in the GRID trial. Also, pazopanib, another tyrosine kinase inhibitor, has been studied in a randomized, placebo-controlled trial (PAZOGIST) in the third line, which showed a PFS of 45.2% 4 months after study entry, but patients intolerant to sunitinib were also included. We designed another trial evaluating pazopanib, enrolling only patients with progression on both imatinib and sunitinib. PATIENTS AND METHODS: Since all eligible patients had progressive disease, we preferred a non-randomized, phase II multicentre trial so that all patients could receive a potentially active drug. Patients had a progressive metastatic or locally advanced GIST and were ≥18 years of age, with a performance status of 0-2, and sufficient organ functions. The primary endpoint was disease control rate (defined as complete remission + partial remission + stable disease) at 12 weeks on pazopanib. A Simon's two-stage analysis was used with an interim analysis 12 weeks after enrollment of the first 22 patients, and if passed, there was a full enrolment of 72 patients. GIST mutational analysis was done, and most patients had pazopanib plasma concentration measured after 12 weeks. RESULTS: Seventy-two patients were enrolled. The disease control rate after 12 weeks was 44%, and the median PFS was 19.6 weeks (95% confidence interval 12.6-23.4 weeks). Pazopanib-related toxicity was moderate and manageable. No statistically significant differences were found related to mutations. Plasma concentrations of pazopanib had a formal but weak correlation with outcome. CONCLUSION: Pazopanib given in the third line to patients with GIST progressing on both imatinib and sunitinib was beneficial for about half of the patients. The PAGIST trial confirms the results from the PAZOGIST trial, and the median PFS achieved seems comparable to the PFS achieved with regorafenib in the third-line setting.

Prognostic role of serum thymidine kinase 1 kinetics during neoadjuvant chemotherapy for early breast cancer.

BACKGROUND: Emerging data support the use of thymidine kinase 1 (TK1) activity as a prognostic marker and for monitoring of response in breast cancer (BC). The long-term prognostic value of TK1 kinetics during neoadjuvant chemotherapy is unclear, which this study aimed to elucidate. METHODS: Material from patients enrolled to the single-arm prospective PROMIX trial of neoadjuvant epirubicin, docetaxel and bevacizumab for early BC was used. Ki67 in baseline biopsies was assessed both centrally and by automated digital imaging analysis. TK1 activity was measured from blood samples obtained at baseline and following two cycles of chemotherapy. The associations of TK1 and its kinetics as well as Ki67 with event-free survival and overall survival (OS) were evaluated using multivariable Cox regression models. RESULTS: Central Ki67 counting had excellent correlation with the results of digital image analysis (r = 0.814), but not with the diagnostic samples (r = 0.234), while it was independently prognostic for worse OS [adjusted hazard ratio (HRadj) = 2.72, 95% confidence interval (CI) 1.19-6.21, P = 0.02]. Greater increase in TK1 activity after two cycles of chemotherapy resulted in improved event-free survival (HRadj = 0.50, 95% CI 0.26-0.97, P = 0.04) and OS (HRadj = 0.46, 95% CI 0.95, P = 0.04). There was significant interaction between the prognostic value of TK1 kinetics and Ki67 (pinteraction 0.04). CONCLUSION: Serial measurement of serum TK1 activity during neoadjuvant chemotherapy provides long-term prognostic information in BC patients. The ease of obtaining serial samples for TK1 assessment motivates further evaluation in larger studies.

Treatment response assessment with (R)-[11CPAQ PET in the MMTV-PyMT mouse model of breast cancer.

BACKGROUND: The goal of the study was to assess the potential of the vascular endothelial growth factor receptor (VEGFR)-2-targeting carbon-11 labeled (R)-N-(4-bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3-piperidinyl)methoxy)-4-quinazolineamine ((R)-[11C]PAQ) as a positron emission tomography (PET) imaging biomarker for evaluation of the efficacy of anticancer drugs in preclinical models. METHODS: MMTV-PyMT mice were treated with vehicle alone (VEH), murine anti-VEGFA antibody (B20-4.1.1), and paclitaxel (PTX) in combination or as single agents. The treatment response was measured with (R)-[11C]PAQ PET as standardized uptake value (SUV)mean, SUVmax relative changes at the baseline (day 0) and follow-up (day 4) time points, and magnetic resonance imaging (MRI)-derived PyMT mammary tumor volume (TV) changes. Expression of Ki67, VEGFR-2, and CD31 in tumor tissue was determined by immunohistochemistry (IHC). Non-parametric statistical tests were used to evaluate the relation between (R)-[11C]PAQ radiotracer uptake and therapy response biomarkers. RESULTS: The (R)-[11C]PAQ SUVmax in tumors was significantly reduced after 4 days in the B20-4.1.1/PTX combinational and B20-4.1.1 monotherapy groups (p < 0.0005 and p < 0.003, respectively). No significant change was observed in the PTX monotherapy group. There was a significant difference in the SUVmax change between the VEH group and B20-4.1.1/PTX combinational group, as well as between the VEH group and the B20-4.1.1 monotherapy group (p < 0.05). MRI revealed significant decreases in TV in the B20-4.1.1/PTX treatment group (p < 0.005) but not the other therapy groups. A positive trend was observed between the (R)-[11C]PAQ SUVmax change and TV reduction in the B20-4.1.1/PTX group. Statistical testing showed a significant difference in the blood vessel density between the B20-4.1.1/PTX combinational group and the VEH group (p < 0.05) but no significant difference in the Ki67 positive signal between treatment groups. CONCLUSIONS: The results of this study are promising. However, additional studies are necessary before (R)-[11C]PAQ can be approved as a predictive radiotracer for cancer therapy response.

Frizzled-1 is down-regulated in follicular thyroid tumours and modulates growth and invasiveness.

The mechanisms of follicular thyroid carcinoma (FTC) transformation and progression are not well understood. Previously, we detected LOH at 7q21 in all FTCs examined, indicating that loss of genetic material in that region is a common trait in these lesions. To analyse the effects of LOH on gene expression, we performed an analysis of the mRNA expression levels of six different genes, located at 7q21.1-7q21.3. A total of 23 lesions, including eight follicular hyperplasias (FHs), eight follicular adenomas (FAs), two FTCs and five papillary thyroid carcinomas (PTCs) were analysed. The Frizzled-1 (FZD-1) gene, located at 7q21.13, showed the lowest levels of mRNA expression. Down-regulation of FZD-1 expression was also confirmed in an independent series of 69 follicular neoplastic lesions compared to 25 PTCs, analysed by quantitative RT-PCR. In vitro studies showed that FZD-1 expression was also markedly reduced at both protein and mRNA levels in three FTC-derived cell lines (FRO, WRO and FTC-133), while it was normal in the three PTC-derived cell lines (Ca300, Ca301 and K1) examined. We demonstrated that over-expression of FZD-1 in 3 FTC-derived cells decreased invasiveness and proliferation rate, indicating a possible pathogenetic role. In addition, FZD-1 RNA interference in the PTC-derived cell line K1 increased invasiveness. Our data indicated that FZD-1 is involved in growth of follicular tumours and may be considered as a novel marker of this type of tumour.