Adaptive Randomization of Veliparib-Carboplatin Treatment in Breast Cancer

Exploration of therapeutic applicability and different signaling mechanism of various phytopharmacological agents for treatment of breast cancer

BACKGROUND

Cancer is one of the most dreaded diseases characterized by uncontrolled proliferation of abnormal cells that occurs due to impairment of cell division and apoptosis process. Cancer is categorized into several types on the basis of affected organs and breast cancer (BC) is the most predominant cause of mortality among women. Although, several synthetic and semi-synthetic therapies have been developed for the treatment of BC but they exhibit numerous serious adverse effects therefore; pharmacological agents with fewer/no side effects need to be explored. Plants and phytoconstituents perhaps fulfill the aforementioned requirement and could serve as a potential and alternative therapy for BC treatment. The ongoing biomedical research, clinical trials and number of patents granted have further boosted the acceptance of the plants and plant-derived constituents in the effective treatment of BC.

PURPOSE OF STUDY

Various treatment strategies such as checkpoint inhibitors, targeting micro RNA, apoptotic pathway, BRCA-1 gene, P53 protein, P13K/Akt/mTOR pathway, notch signaling pathway, hedgehog/gli-1 signaling pathway, poly-ADP ribose polymerase inhibitors, mitogen-activated protein kinase inhibitors etc. are available for BC. In addition to these synthetic and semi-synthetic drug therapies, several natural constituents such as alkaloids, sesquiterpenes, polyphenols, flavonoids and diterpenoids from medicinal plants, vegetables and fruits are reported to possess promising anti-cancer activity. The purpose of the present review is to highlight the various signaling pathways through which plants/herbs show the anti-cancer potential especially against the BC.

STUDY DESIGN

The literature for the present study was collected from various databases such as Pubmed, Scopus, Chemical Abstracts, Medicinal and aromatic plant abstracts, Web of Science etc. The different patent databases were also reviewed for the anti-cancer (BC) potential of the particular herbs/plants and their formulations.

RESULT AND CONCLUSION

In this review, we have discussed the number of plants along with their patents of different herbal formulations which are being used for the treatment of BC and other types of cancers. We have also delineated the different signaling mechanisms through which they inhibit the growth of BC cells. In nutshell, we can conclude that large numbers of herbs or their extracts are reported for the treatment of BC. But still, there is further need for research in-depth to translate the use of natural products clinically BC treatment.

Comparison of Segmentation Methods in Assessing Background Parenchymal Enhancement as a Biomarker for Response to Neoadjuvant Therapy

Breast parenchymal enhancement (BPE) has shown association with breast cancer risk and response to neoadjuvant treatment. However, BPE quantification is challenging, and there is no standardized segmentation method for measurement. We investigated the use of a fully automated breast fibroglandular tissue segmentation method to calculate BPE from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for use as a predictor of pathologic complete response (pCR) following neoadjuvant treatment in the I-SPY 2 TRIAL. In this trial, patients had DCE-MRI at baseline (T0), after 3 weeks of treatment (T1), after 12 weeks of treatment and between drug regimens (T2), and after completion of treatment (T3). A retrospective analysis of 2 cohorts was performed: one with 735 patients and another with a final cohort of 340 patients, meeting a high-quality benchmark for segmentation. We evaluated 3 subvolumes of interest segmented from bilateral T1-weighted axial breast DCE-MRI: full stack (all axial slices), half stack (center 50% of slices), and center 5 slices. The differences between methods were assessed, and a univariate logistic regression model was implemented to determine the predictive performance of each segmentation method. The results showed that the half stack method provided the best compromise between sampling error from too little tissue and inclusion of incorrectly segmented tissues from extreme superior and inferior regions. Our results indicate that BPE calculated using the half stack segmentation approach has potential as an early biomarker for response to treatment in the hormone receptor–negative and human epidermal growth factor receptor 2–positive subtype.

Tumor Sphericity Predicts Response in Neoadjuvant Chemotherapy for Invasive Breast Cancer

This retrospective study examined magnetic resonance imaging (MRI)–derived tumor sphericity (SPH) as a quantitative measure of breast tumor morphology, and investigated the association between SPH and reader-assessed morphological pattern (MP). In addition, association of SPH with pathologic complete response was evaluated in patients enrolled in an adaptively randomized clinical trial designed to rapidly identify new agents for breast cancer. All patients underwent MRI examinations at multiple time points during the treatment. SPH values from pretreatment (T0) and early-treatment (T1) were investigated in this study. MP on T0 dynamic contrast-enhanced MRI was ranked from 1 to 5 in 220 patients. Mean SPH values decreased with the increased order of MP. SPH was higher in patients with pathologic complete response than in patients without (difference at T0: 0.04, 95% confidence interval [CI]: 0.02–0.05, P < .001; difference at T1: 0.03, 95% CI: 0.02–0.04, P < .001). The area under the receiver operating characteristic curve was estimated as 0.61 (95% CI, 0.57–0.65) at T0 and 0.58 (95% CI, 0.55–0.62) at T1. When the analysis was performed by cancer subtype defined by hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status, highest area under the receiver operating characteristic curve were observed in HR−/HER2+: 0.67 (95% CI, 0.54–0.80) at T0, and 0.63 (95% CI, 0.51–0.76) at T1. Tumor SPH showed promise to quantify MRI MPs and as a biomarker for predicting treatment outcome at pre- or early-treatment time points.

A Neoadjuvant Chemotherapy Trial for Early Breast Cancer is Impacted by COVID-19: Addressing Vaccination and Cancer Trials Through Education, Equity, and Outcomes

While COVID-19 vaccine distribution has addressed vulnerabilities related to age and comorbidities, there is a need to ensure vaccination of patients with cancer receiving experimental and routine treatment, where interruption of treatment by infection is likely to result in inferior outcomes. Among patients with cancer, those undergoing neoadjuvant chemotherapy (NAC) or adjuvant chemotherapy (Adj chemo) for early breast cancer (EBC) are at particularly high risk for inferior outcomes, in part, because optimal timing of chemotherapy is essential for promoting distant disease-free survival. COVID-19 data from the ongoing multicenter I-SPY 2 trial of NAC for EBC provides a window into the magnitude of the problem of treatment interruption, not only for the trial itself but also for routine Adj chemo. In the I-SPY 2 trial, 4.5% of patients had disruption of therapy by COVID-19, prior to wide vaccine availability, suggesting that nationally up to 5,700 patients with EBC were at risk for adverse outcomes from COVID-19 infection in 2020. To address this problem, vaccine education and public engagement are essential to overcome hesitancy, while equity of distribution is needed to address access. To accomplish these goals, healthcare organizations (HCO) need to not only call out disinformation but also engage the public with vaccine education and find common ground for vaccine acceptance, while partnering with state/local governments to improve efficiency of vaccine distribution. These approaches are important to improve trial access and to reduce susceptibility to COVID-19, as the pandemic could continue to impact access to clinical trials and routine cancer treatment.

Perspectives on PARP inhibitors as pharmacotherapeutic strategies for breast cancer

Introduction Approximately 10% of all breast cancer cases occur in individuals who have germline pathogenic variants of the BRCA 1, BRCA 2, and other genes associated with impaired DNA damage repair that is associated with an increased risk of breast, ovarian, and other cancers. Inhibitors of poly-ADP ribose polymerase (PARP) induce synthetic lethality in cancer cells harboring such pathogenic variants.Area covered In this review, the authors review the mechanisms of action, antitumor activity, and adverse events associated with PARP inhibitors for the treatment of advanced breast cancer. The authors then summarize the area and provide their expert perspectives on the area.Expert opinion Two PARP inhibitors are approved in metastatic breast cancer, including olaparib and talozaparib. Both agents were approved based on phase III trials demonstrating that they were associated with improved progression-free survival compared with treatment of physician's choice in patients receiving second-third line therapy for locally advanced, inoperable, or metastatic breast cancer in patients with germline pathogenic BRCA 1 or BRCA2 variants.

Breaking the therapeutic ceiling in drug development in ulcerative colitis

Increased knowledge of the intricate pathogenesis of ulcerative colitis has triggered an advance in drug development during the past two decades, resulting in the advent of several biological agents and small-molecule therapies. Although the increase in therapeutic options is positive, remission rates of patients with ulcerative colitis given new therapeutic agents in induction trials remain at a modest 20-30%, seemingly facing a so-called therapeutic ceiling. This therapeutic ceiling requires a critical appraisal and highlights the need for alternative strategies for drug development. In this Review, we objectively itemise the boundaries of therapeutic efficacy in ulcerative colitis, provide possible explanations for the shortcomings of current strategies, and propose solutions to achieve better therapeutic outcomes in ulcerative colitis.

Polyphenolic-Rich Compounds From Dillenia pentagyna (Roxb.) Attenuates the Doxorubicin-Induced Cardiotoxicity: A High-Frequency Ultrasonography Assisted Approach

Cardiovascular complications are the foremost concern in patients undergoing anticancer therapy. There is an unmet need to address the problems arising from the drug-induced toxicity for the long-term benefit of the patients undergoing chemotherapy. Alternative medicines are gaining their prosperity in addressing the various drug-induced organ toxicity. Dillenia pentagyna Roxb (DP) is an ethnomedicinal plant rich in flavonoids and phenolic contents. In India & Nepal, DP is a common ingredient of traditional medicines used to treat multiple ailments like inflammation, cancer, and diabetes. However, its protective role against doxorubicin (Dox) induced cardiotoxicity remains unexplored. Herein, we investigated the potential effects of various extracts/fractions obtained from the DP's bark against Dox-induced cardiotoxicity, both in-vitro and in-vivo. The anti-oxidant content of the extracts/fractions was evaluated by using DPPH, ABTS and FRAP chemical assays. The results indicated that the hydroalcoholic (HA) extract of DP has intense anti-oxidant potential. Further fractionation of DP revealed that the phenolic-rich fraction (F1) has a high anti-oxidant potential. The protective effect of extract/fraction was also investigated in the H9c2 cell line following the Dox-induced cardiotoxicity model. We observed that the pre-treatment of extract/fraction in cardiomyocytes had exhibited increased cell viability. Fluorescence-based chemical assays indicated a decreased ROS levels in the treated groups in comparison to the Dox control group. The effect of DP was evaluated further in balb/c mice by the Dox-induced cardiotoxicity model. Non-invasive techniques like high-frequency ultrasonography and electrocardiogram revealed that the mice pre-treated with DP had improved cardiac functionality (left ventricular ejection fraction and stroke volume) and normalized the electrocardiograms compared to the Dox control group. Further, biochemical analysis with the cardiac tissues revealed that the cytoprotective proteins like HO-1, SOD-2, and Nrf-2 were elevated in the DP treated groups compared to the Dox control group. Overall, our results suggested that the bioactive extract/fractions of DP helped alleviate the Dox-induced cardiotoxicity. LC-QTOF-ESI-MS analysis of DP and F1 indicated that polyphenolic anti-oxidant compounds like gallic acid, syringic acid, and sinapic acid could be responsible for the potent -cardioprotective effect. Future understanding of the pharmacokinetics and pharmacodynamic parameters can help translate from the bench to the bedside.

Neoadjuvant approach as a platform for treatment personalization: focus on HER2-positive and triple-negative breast cancer

The neoadjuvant setting provides unquestionable clinical benefits for high-risk breast cancer (BC) patients, mainly in terms of expansion of locoregional treatment options and prognostic stratification. Additionally, it is also emerging as a strategical tool in the research field. In the present review, by focusing on HER2-positive and triple-negative subtypes, we examined the role of the neoadjuvant setting as a research platform to facilitate and rationalize the placement of escalation strategies, promote the adoption of biomarker-driven approaches for the investigation of de-escalated treatments, and foster the conduction of comprehensive translational analyses, thus ultimately aiming at pursuing treatment personalization. The solid prognostic role of pathologic complete response after neoadjuvant therapy, and its use as a surrogate endpoint to accelerate the drug approval process were discussed. In this context, available data on escalated treatment strategies capable of enhancing pathologic complete response (pCR) rate or improving prognosis of patients with residual disease (RD) after neoadjuvant treatment, were comprehensively reviewed. We also summarized evidence regarding the possibility of obtaining pCR with de-escalated strategies, with particular emphasis on the role of biomarker-driven approaches for patient selection. Pitfalls of the dichotomy of pCR/RD were also deepened, and data on alternative/complementary biomarkers with a possible clinical relevance in this regard were reviewed.

Neoadjuvant Chemotherapy, Endocrine Therapy, and Targeted Therapy for Breast Cancer: ASCO Guideline

PURPOSE

To develop guideline recommendations concerning optimal neoadjuvant therapy for breast cancer.

METHODS

ASCO convened an Expert Panel to conduct a systematic review of the literature on neoadjuvant therapy for breast cancer and provide recommended care options.

RESULTS

A total of 41 articles met eligibility criteria and form the evidentiary basis for the guideline recommendations.

RECOMMENDATIONS

Patients undergoing neoadjuvant therapy should be managed by a multidisciplinary care team. Appropriate candidates for neoadjuvant therapy include patients with inflammatory breast cancer and those in whom residual disease may prompt a change in therapy. Neoadjuvant therapy can also be used to reduce the extent of local therapy or reduce delays in initiating therapy. Although tumor histology, grade, stage, and estrogen, progesterone, and human epidermal growth factor receptor 2 (HER2) expression should routinely be used to guide clinical decisions, there is insufficient evidence to support the use of other markers or genomic profiles. Patients with triple-negative breast cancer (TNBC) who have clinically node-positive and/or at least T1c disease should be offered an anthracycline- and taxane-containing regimen; those with cT1a or cT1bN0 TNBC should not routinely be offered neoadjuvant therapy. Carboplatin may be offered to patients with TNBC to increase pathologic complete response. There is currently insufficient evidence to support adding immune checkpoint inhibitors to standard chemotherapy. In patients with hormone receptor (HR)-positive (HR-positive), HER2-negative tumors, neoadjuvant chemotherapy can be used when a treatment decision can be made without surgical information. Among postmenopausal patients with HR-positive, HER2-negative disease, hormone therapy can be used to downstage disease. Patients with node-positive or high-risk node-negative, HER2-positive disease should be offered neoadjuvant therapy in combination with anti-HER2-positive therapy. Patients with T1aN0 and T1bN0, HER2-positive disease should not be routinely offered neoadjuvant therapy.Additional information is available at www.asco.org/breast-cancer-guidelines.

PrecISE: Precision Medicine in Severe Asthma: An adaptive platform trial with biomarker ascertainment

Severe asthma accounts for almost half the cost associated with asthma. Severe asthma is driven by heterogeneous molecular mechanisms. Conventional clinical trial design often lacks the power and efficiency to target subgroups with specific pathobiological mechanisms. Furthermore, the validation and approval of new asthma therapies is a lengthy process. A large proportion of that time is taken by clinical trials to validate asthma interventions. The National Institutes of Health Precision Medicine in Severe and/or Exacerbation Prone Asthma (PrecISE) program was established with the goal of designing and executing a trial that uses adaptive design techniques to rapidly evaluate novel interventions in biomarker-defined subgroups of severe asthma, while seeking to refine these biomarker subgroups, and to identify early markers of response to therapy. The novel trial design is an adaptive platform trial conducted under a single master protocol that incorporates precision medicine components. Furthermore, it includes innovative applications of futility analysis, cross-over design with use of shared placebo groups, and early futility analysis to permit more rapid identification of effective interventions. The development and rationale behind the study design are described. The interventions chosen for the initial investigation and the criteria used to identify these interventions are enumerated. The biomarker-based adaptive design and analytic scheme are detailed as well as special considerations involved in the final trial design.

Evaluating Bayesian adaptive randomization procedures with adaptive clip methods for multi-arm trials

Bayesian adaptive randomization is a heuristic approach that aims to randomize more patients to the putatively superior arms based on the trend of the accrued data in a trial. Many statistical aspects of this approach have been explored and compared with other approaches; yet only a limited number of works has focused on improving its performance and providing guidance on its application to real trials. An undesirable property of this approach is that the procedure would randomize patients to an inferior arm in some circumstances, which has raised concerns in its application. Here, we propose an adaptive clip method to rectify the problem by incorporating a data-driven function to be used in conjunction with Bayesian adaptive randomization procedure. This function aims to minimize the chance of assigning patients to inferior arms during the early time of the trial. Moreover, we propose a utility approach to facilitate the selection of a randomization procedure. A cost that reflects the penalty of assigning patients to the inferior arm(s) in the trial is incorporated into our utility function along with all patients benefited from the trial, both within and beyond the trial. We illustrate the selection strategy for a wide range of scenarios.

PARP (Poly ADP-Ribose Polymerase) inhibitors for locally advanced or metastatic breast cancer

BACKGROUND

Locally advanced and metastatic breast cancer remains a challenge to treat. With emerging study results, it is important to interpret the available clinical data and apply the evidence offering the most effective treatment to the right patient. Poly(ADP Ribose) Polymerase (PARP) inhibitors are a new class of drug and their role in the treatment of locally advanced and metastatic breast cancer is being established.

OBJECTIVES

To determine the efficacy, safety profile, and potential harms of Poly(ADP-Ribose) Polymerase (PARP) inhibitors in the treatment of patients with locally advanced or metastatic breast cancer. The primary outcome of interest was overall survival; secondary outcomes included progression-free survival, tumour response rate, quality of life, and adverse events.

SEARCH METHODS

On 8 June 2020, we searched the Cochrane Breast Cancer Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via OvidSP, Embase via OvidSP, World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) search portal and ClinicalTrials.gov. We also searched proceedings from the major oncology conferences as well as scanned reference lists from eligible publications and contacted corresponding authors of trials for further information, where needed.

SELECTION CRITERIA

We included randomised controlled trials on participants with locally advanced or metastatic breast cancer comparing 1) chemotherapy in combination with PARP inhibitors, compared to the same chemotherapy without PARP inhibitors or 2) treatment with PARP inhibitors, compared to treatment with other chemotherapy. We included studies that reported on our primary outcome of overall survival and secondary outcomes including progression-free survival, tumour response rate, quality of life, and adverse events.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures defined by Cochrane. Summary statistics for the endpoints used hazard ratios (HR) with 95% confidence intervals (CI) for overall survival and progression-free survival, and odds ratios (OR) for response rate (RR) and toxicity.

MAIN RESULTS

We identified 49 articles for qualitative synthesis, describing five randomised controlled trials that were included in the quantitative synthesis (meta-analysis). A sixth trial was assessed as eligible but had ended prematurely and no data were available for inclusion in our meta-analysis. Risk of bias was predominately low to unclear across all studies except in regards to performance bias (3/5 high risk) and detection bias for the outcomes of quality of life (2/2 high risk) and reporting of adverse events (3/5 high risk). High-certainty evidence shows there may be a small advantage in overall survival (HR 0.87, 95% CI 0.76 to 1.00; 4 studies; 1435 patients). High-certainty evidence shows that PARP inhibitors offer an improvement in PFS in locally advanced/metastatic HER2-negative, BRCA germline mutated breast cancer patients (HR 0.63, 95% CI 0.56 to 0.71; 5 studies; 1474 patients). There was no statistical heterogeneity for these outcomes. Subgroup analyses for PFS outcomes based on trial level data were performed for triple-negative breast cancer, hormone-positive and/or HER2-positive breast cancer, BRCA1 and BRCA2 germline mutations, and patients who had received prior chemotherapy for advanced breast cancer or not. The subgroup analyses showed a persistent PFS benefit regardless of the subgroup chosen. Pooled analysis shows PARP inhibitors likely result in a moderate improvement in tumour response rate compared to other treatment arms (66.9% vs 48.9%; RR 1.39, 95% CI 1.24 to 1.54; 5 studies; 1185 participants; moderate-certainty evidence). The most common adverse events reported across all five studies included neutropenia, anaemia and fatigue. Grade 3 or higher adverse events probably occur no less frequently in patients receiving PARP inhibitors (59.4% for PARP arm versus 64.5% for non-PARP arm, RR 0.98, 95% CI 0.91 to 1.04; 5 studies; 1443 participants; moderate-certainty evidence). Only two studies reported quality of life outcomes so this was not amenable to meta-analysis. However, both studies that did assess quality of life showed PARP inhibitors were superior compared to physician's choice of chemotherapy in terms of participant-reported outcomes.

AUTHORS' CONCLUSIONS

In people with locally advanced or metastatic HER2-negative, BRCA germline mutated breast cancer, PARP inhibitors offer an improvement in progression-free survival, and likely improve overall survival and tumour response rates. This systematic review provides evidence supporting the use of PARP inhibitors as part of the therapeutic strategy for breast cancer patients in this subgroup. The toxicity profile for PARP inhibitors is probably no worse than chemotherapy but more information is required regarding quality of life outcomes, highlighting the importance of collecting such data in future studies. Future studies should also be powered to detect clinically important differences in overall survival and could focus on the role of PARP inhibitors in other relevant breast cancer populations, including HER2-positive, BRCA-negative/homologous recombination repair-deficient and Programmed Death-Ligand 1 (PDL1) positive.

In vivo visualization of PARP inhibitor pharmacodynamics

BACKGROUND

[¹⁸F]FluorThanatrace ([¹⁸F]FTT) is a radiolabeled poly (adenosine diphosphate-ribose) polymerase inhibitor (PARPi) that enables noninvasive quantification of PARP with potential to serve as a biomarker for patient selection for PARPi therapy. Here we report for the first time to our knowledge noninvasive in vivo visualization of drug-target engagement during PARPi treatment.

METHODS

Two single-arm, prospective, nonrandomized clinical trials were conducted at the University of Pennsylvania from May 2017 to March 2020. PARP expression in breast cancer was assessed in vivo via [¹⁸F]FTT PET before and after initiation of PARPi treatment and in vitro via [¹²⁵I]KX1 (an analog of [¹⁸F]FTT) binding to surgically removed breast cancer.

RESULTS

Thirteen patients had baseline [¹⁸F]FTT PET. Nine of these then had resection and in vitro evaluation of [¹⁸F]FTT uptake with an analog and uptake was blocked with PARPi. Of the other 4 patients, 3 had [¹⁸F]FTT PET uptake, and all had uptake blocked with treatment with a therapeutic PARPi. Initial in vivo [¹⁸F]FTT tumor uptake ranged from undetectable to robust. Following initiation of PARPi therapy, [¹⁸F]FTT uptake was not detectable above background in all cases. In vitro tumor treatment with a PARPi resulted in 82% reduction in [¹²⁵I]KX1 binding.

CONCLUSION

[¹⁸F]FTT noninvasively quantifies PARP-1 expression. Early results indicate ability to visualize PARPi drug-target engagement in vivo and suggest the utility of further study to test [¹⁸F]FTT PET as a predictive and pharmacodynamic biomarker.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers NCT03083288 and NCT03846167.

FUNDING

Metavivor Translational Research Award, Susan G. Komen for the Cure (CCR 16376362), Department of Defense BC190315, and Abramson Cancer Center Breakthrough Bike Challenge.

Human PARP inhibitor drug-target engagement can be visualized, with future possibilities including a precision diagnostic and drug discovery tool.

ARID2 deficiency promotes tumor progression and is associated with higher sensitivity to chemotherapy in lung cancer

The survival rate in lung cancer remains stubbornly low and there is an urgent need for the identification of new therapeutic targets. In the last decade, several members of the SWI/SNF chromatin remodeling complexes have been described altered in different tumor types. Nevertheless, the precise mechanisms of their impact on cancer progression, as well as the application of this knowledge to cancer patient management are largely unknown. In this study, we performed targeted sequencing of a cohort of lung cancer patients on genes involved in chromatin structure. In addition, we studied at the protein level the expression of these genes in cancer samples and performed functional experiments to identify the molecular mechanisms linking alterations of chromatin remodeling genes and tumor development. Remarkably, we found that 20% of lung cancer patients show ARID2 protein loss, partially explained by the presence of ARID2 mutations. In addition, we showed that ARID2 deficiency provokes profound chromatin structural changes altering cell transcriptional programs, which bolsters the proliferative and metastatic potential of the cells both in vitro and in vivo. Moreover, we demonstrated that ARID2 deficiency impairs DNA repair, enhancing the sensitivity of the cells to DNA-damaging agents. Our findings support that ARID2 is a bona fide tumor suppressor gene in lung cancer that may be exploited therapeutically.

Association of Immunophenotype With Pathologic Complete Response to Neoadjuvant Chemotherapy for Triple-Negative Breast Cancer: A Secondary Analysis of the BrighTNess Phase 3 Randomized Clinical Trial

IMPORTANCE

Adding carboplatin to standard neoadjuvant chemotherapy (NAC) in triple-negative breast cancer (TNBC) likely benefits a subset of patients; however, determinants of benefit are poorly understood.

OBJECTIVE

To define the association of molecular subtype, tumor proliferation, and immunophenotype with benefit of carboplatin added to NAC for patients with stages II to III TNBC.

DESIGN, SETTING, AND PARTICIPANTS

This was a prespecified secondary analysis of a phase 3, double-blind, randomized clinical trial (BrighTNess) that enrolled 634 women across 145 centers in 15 countries. Women with clinical stages II to III TNBC who had undergone pretreatment biopsy were eligible to participate. Whole transcriptome RNA sequencing was performed on the biopsy specimens. The prespecified end point was association of pathologic complete response (pCR) with gene expression-based molecular subtype, with secondary end points investigating established signatures (proliferation, immune) and exploratory analyses of immunophenotype. Data were collected from April 2014 to March 2016. The study analyses were performed from January 2018 to March 2019.

INTERVENTIONS

Neoadjuvant chemotherapy with paclitaxel followed by doxorubicin and cyclophosphamide, or this same regimen with carboplatin or carboplatin plus veliparib.

MAIN OUTCOMES AND MEASURES

Association of gene expression-based molecular subtype (PAM50 and TNBC subtypes) with pCR.

RESULTS

Of the 634 women (median age, 51 [range, 22-78] years) enrolled in BrighTNess, 482 (76%) patients had evaluable RNA sequencing data, with similar baseline characteristics relative to the overall intention-to-treat population. Pathologic complete response was significantly more frequent in PAM50 basal-like vs nonbasal-like cancers overall (202 of 386 [52.3%] vs 34 of 96 [35.4%]; P = .003). Carboplatin benefit was not significantly different in basal-like vs nonbasal-like subgroups (P = .80 for interaction). In multivariable analysis, proliferation (hazard ratio, 0.36; 95% CI, 0.21-0.61; P < .001) and immune (hazard ratio, 0.62; 95% CI, 0.49-0.79; P < .001) signatures were independently associated with pCR. Tumors above the median for proliferation and immune signatures had the highest pCR rate (84 of 125; 67%), while those below the median for both signatures had the lowest pCR rate (42 of 125; 34%). Exploratory gene expression immune analyses suggested that tumors with higher inferred CD8+ T-cell infiltration may receive greater benefit with addition of carboplatin.

CONCLUSIONS AND RELEVANCE

In this secondary analysis of a randomized clinical trial, triple-negative breast cancer subtyping revealed high pCR rates in basal-like and immunomodulatory subsets. Analysis of biological processes related to basal-like and immunomodulatory phenotypes identified tumor cell proliferation and immune scores as independent factors associated with achieving pCR; the benefit of carboplatin on pCR was seen across all molecular subtypes. Further validation of immunophenotype with existing biomarkers may help to escalate or de-escalate therapy for patients with TNBC.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02032277.

The Affinity of Carboplatin to B-Vitamins and Nucleobases

Platinum compounds have found wide application in the treatment of various types of cancer and carboplatin is one of the main platinum-based drugs used as antitumor agents. The anticancer activity of carboplatin arises from interacting with DNA and inducing programmed cell death. However, such interactions may occur with other chemical compounds, such as vitamins containing aromatic rings with lone-pair orbitals, which reduces the anti-cancer effect of carboplatin. The most important aspect of the conducted research was related to the evaluation of carboplatin affinity to vitamins from the B group and the potential impact of such interactions on the reduction of therapeutic capabilities of carboplatin in anticancer therapy. Realized computations, including estimation of Gibbs Free Energies, allowed for the identification of the most reactive molecule, namely vitamin B6 (pyridoxal phosphate). In this case, the computational estimations indicating carboplatin reactivity were confirmed by spectrophotometric measurements.

Treatment allocation strategies for umbrella trials in the presence of multiple biomarkers: A comparison of methods

Umbrella trials are an innovative trial design where different treatments are matched with subtypes of a disease, with the matching typically based on a set of biomarkers. Consequently, when patients can be positive for more than one biomarker, they may be eligible for multiple treatment arms. In practice, different approaches could be applied to allocate patients who are positive for multiple biomarkers to treatments. However, to date there has been little exploration of how these approaches compare statistically. We conduct a simulation study to compare five approaches to handling treatment allocation in the presence of multiple biomarkers – equal randomisation; randomisation with fixed probability of allocation to control; Bayesian adaptive randomisation (BAR); constrained randomisation; and hierarchy of biomarkers. We evaluate these approaches under different scenarios in the context of a hypothetical phase II biomarker-guided umbrella trial. We define the pairings representing the pre-trial expectations on efficacy as linked pairs, and the other biomarker-treatment pairings as unlinked. The hierarchy and BAR approaches have the highest power to detect a treatment-biomarker linked interaction. However, the hierarchy procedure performs poorly if the pre-specified treatment-biomarker pairings are incorrect. The BAR method allocates a higher proportion of patients who are positive for multiple biomarkers to promising treatments when an unlinked interaction is present. In most scenarios, the constrained randomisation approach best balances allocation to all treatment arms. Pre-specification of an approach to deal with treatment allocation in the presence of multiple biomarkers is important, especially when overlapping subgroups are likely.

Role of Platinums in Triple-Negative Breast Cancer

PURPOSE OF REVIEW

Platinum compounds are used in the treatment of various types of cancer. Here, we review the current role of cisplatin and carboplatin in the treatment of early stage and advanced triple-negative breast cancer (TNBC), and the use of biomarkers in predicting response to platinum therapy.

RECENT FINDINGS

Addition of carboplatin to a neoadjuvant chemotherapy regimen can result in improvement in the pathological complete response rates. The long-term benefit of the addition of carboplatin to standard chemotherapy regimens remains unproven. Single-agent platinum is an option in the treatment of advanced breast cancer. BRCA1/2 mutations predicted benefit from platinums in advanced, but not early stage breast cancer. There are yet no biomarkers to predict response to platinum in sporadic TNBC. Platinum compounds are an option in the treatment of TNBC. Identification of biomarkers to select tumors most likely to derive benefit from these agents is still needed. Ongoing trials are exploring the role of platinum in the adjuvant setting and in combination with other agents, including immune checkpoint inhibitors.

Incidence of myelodysplastic syndrome and acute myeloid leukemia in patients receiving poly-ADP ribose polymerase inhibitors for the treatment of solid tumors: A meta-analysis of randomized trials

BACKGROUND

Clinical trials demonstrated that PARPi (poly [adenosine diphosphate-ribose]-ADP polymerase inhibitor) therapy is effective in solid tumors. However, long term effects such as therapy-related myelodysplastic syndrome or acute myeloid leukemia (MDS/AML) are poorly described. We sought to quantify whether PARPi therapy is associated with the development of MDS/AML.

METHODS

Medline, Embase, and Cochrane databases were searched (inception to January 6, 2020) and phase 2 and 3 clinical trials that randomized patients with solid tumors to a PARPi or control therapy were included. The PRISMA guidelines were used to extract data independently by multiple authors. We extracted person-time and number of cases of MDS/AML in the PARPi and control arms of each study and pooled results with a random-effects Poisson regression model. The pooled incidence rate ratio (IRR) for MDS/AML among patients randomized to PARPi therapy was compared to those randomized to a control.

RESULTS

We identified 14 studies that included 5739 patients. Accounting for intra-study clustering, the risk of MDS/AML was similar in patients who were randomly assigned to receive PARPi compared to controls (IRR 1.32, 95% confidence interval [CI] 0.78-2.26). In the front-line setting, PARPi therapy was associated with developing MDS/AML (IRR 5.43, 95% CI 1.51-19.60). Among patients treated for recurrence, however, the risk of MDS/AML appeared to be similar among patients randomized to PARPi or control treatment. Among studies that included only patients with a BRCA mutation, the risk of MDS/AML was similar in both treatment groups (IRR 0.83, 95% CI 0.45-1.53), but PARPi therapy was associated with MDS/AML in studies with an unrestricted population (IRR 2.43, 95% CI 1.17-5.06).

CONCLUSION

The pooled overall effect was not statistically significant. However, treatment with PARPi was associated with a statistically significant increase in the incidence of MDS/AML among patients receiving front-line cancer therapy and those with limited prior exposure to chemotherapy.

Combining poly(ADP-ribose) polymerase inhibitors and immune checkpoint inhibitors in breast cancer: rationale and preliminary clinical results

PURPOSE OF REVIEW

Recently, both immune checkpoint inhibitors and poly(ADP-ribose) polymerase inhibitors have demonstrated clinical benefit in some subsets of HER2-negative breast cancer patients. A biological rationale exists supporting a potential synergism between these compounds, which may further increase their antitumor activity in the clinic.

RECENT FINDINGS

PARP inhibitors were shown to activate type I interferon pathway, thus eliciting local and general immune response, while inducing programmed cell death-ligand 1 (PD-L1) up-regulation. In addition, the DNA damages created by PARP inhibition may increase tumor mutational burden and neo-antigens, thereby favoring efficacy of immune checkpoint inhibitors. Accordingly, clinical trials combining PARP inhibitors and agents targeting the PD-1/PD-L1 axis have been initiated in breast cancer in both advanced and early stages, enrolling patients with germline BRCA1/2 mutation, homologous recombination deficiency and/or with triple negative phenotype. Preliminary safety and efficacy results are encouraging, but it is still unclear whether the combination adds benefit compared with each therapeutic administered as single agent.

SUMMARY

Although a strong rationale exists to support the combination of PARP inhibitors with immune checkpoint inhibitors, future clinical trials will have to demonstrate whether it improves outcome and to identify which patients are the most likely to benefit from.

Identification of a novel RNA aptamer that selectively targets breast cancer exosomes

Breast cancer is a leading cause of cancer mortality in women. Despite advances in its management, the identification of new options for early-stage diagnosis and therapy of this tumor still represents a crucial challenge. Increasing evidence indicates that extracellular vesicles called exosomes may have great potential as early diagnostic biomarkers and regulators of many cancers, including breast cancer. Therefore, exploiting molecules able to selectively recognize them is of great interest. Here, we developed a novel differential SELEX strategy, called Exo-SELEX, to isolate nucleic acid aptamers against intact exosomes derived from primary breast cancer cells. Among the obtained sequences, we optimized a high-affinity aptamer (ex-50.T) able to specifically recognize exosomes from breast cancer cells or patient serum samples. Furthermore, we demonstrated that the ex.50.T is a functional inhibitor of exosome cellular uptake and antagonizes cancer exosome-induced cell migration in vitro. This molecule provides an innovative tool for the specific exosome detection and the development of new therapeutic approaches for breast cancer.

When the World Throws You a Curve Ball: Lessons Learned in Breast Cancer Management

In the care of patients with operable breast cancer, there has been a shift toward increasing use of neoadjuvant therapy. There are benefits to neoadjuvant therapy, such as monitoring for response, as well as an increased rate of breast conservation and reduction of potential morbidity associated with breast surgery, including axillary management. Among patients with highly proliferative tumors, such as HER2-positive or triple-negative breast cancer, those with residual disease are at higher risk of recurrence, which informs the recommended systemic therapy in the adjuvant setting. For instance, in patients with residual disease after neoadjuvant chemotherapy and HER2-targeted therapy, there is a role for adjuvant trastuzumab emtansine for those with residual disease at the time of surgery. The same holds true regarding the role of adjuvant capecitabine in patients with residual disease after neoadjuvant chemotherapy. With the added complexities of treating patients in the era of the COVID-19 outbreak, additional considerations are critical, including initiation of surgery within an appropriate time from completion of neoadjuvant therapy. National consensus guidelines on time to surgery must be developed to improve measurement and comparison across systems. In addition, there is emerging radiation treatment management research addressing a number of factors, including hypofractionation, role of proton beam therapy, safe omission of radiotherapy, and preoperative radiotherapy with or without drug combination. In this article, the multidisciplinary approach of treating patients with operable breast cancer is highlighted, with updates and future considerations described.

Predicted sensitivity to endocrine therapy for stage II-III hormone receptor-positive and HER2-negative (HR+/HER2-) breast cancer before chemo-endocrine therapy

BACKGROUND

We proposed that a test for sensitivity to the adjuvant endocrine therapy component of treatment for patients with stage II-III breast cancer (SET2,3) should measure transcription related to estrogen and progesterone receptors (SET_ER/PR index) adjusted for a baseline prognostic index (BPI) combining clinical tumor and nodal stage with molecular subtype by RNA4 (ESR1, PGR, ERBB2, and AURKA).

PATIENTS AND METHODS

Patients with clinically high-risk, hormone receptor-positive (HR+), human epidermal growth factor receptor 2 (HER2)-negative (HR+/HER2-) breast cancer received neoadjuvant taxane-anthracycline chemotherapy, surgery with measurement of residual cancer burden (RCB), and then adjuvant endocrine therapy. SET2,3 was measured from pre-treatment tumor biopsies, evaluated first in an MD Anderson Cancer Center (MDACC) cohort (n = 307, 11 years' follow-up, U133A microarrays), cut point was determined, and then independent, blinded evaluation was carried out in the I-SPY2 trial (n = 268, high-risk MammaPrint result, 3.8 years' follow-up, Agilent-44K microarrays, NCI Clinical Trials ID: NCT01042379). Primary outcome measure was distant relapse-free survival. Multivariate Cox regression models tested prognostic independence of SET2,3 relative to RCB and other molecular prognostic signatures, and whether other prognostic signatures could substitute for SET_ER/PR or RNA4 components of SET2,3.

RESULTS

SET2,3 added independent prognostic information to RCB in the MDACC cohort: SET2,3 [hazard ratio (HR) 0.23, P = 0.004] and RCB (HR 1.77, P < 0.001); and the I-SPY2 trial: SET2,3 (HR 0.27, P = 0.031) and RCB (HR 1.68, P = 0.008). SET2,3 provided similar prognostic information irrespective of whether RCB-II or RCB-III after chemotherapy, and in both luminal subtypes. Conversely, RCB was most strongly prognostic in cancers with low SET2,3 status (MDACC P < 0.001, I-SPY2 P < 0.001). Other molecular signatures were not independently prognostic; they could effectively substitute for RNA4 subtype within the BPI component of SET2,3, but they could not effectively substitute for SET_ER/PR index.

CONCLUSIONS

SET2,3 added independent prognostic information to chemotherapy response (RCB) and baseline prognostic score or subtype. Approximately 40% of patients with clinically high-risk HR+/HER2- disease had high SET2,3 and could be considered for clinical trials of neoadjuvant endocrine-based treatment.

In vitro to Clinical Translation of Combinatorial Effects of Doxorubicin and Abemaciclib in Rb-Positive Triple Negative Breast Cancer: A Systems-Based Pharmacokinetic/Pharmacodynamic Modeling Approach

Background

Doxorubicin (DOX) and its pegylated liposomal formulation (L_DOX) are the standard of care for triple-negative breast cancer (TNBC). However, resistance to DOX often occurs, motivating the search for alternative treatment approaches. The retinoblastoma protein (Rb) is a potential pharmacological target for TNBC treatment since its expression has been associated with resistance to DOX-based therapy.

Methods

DOX (0.01–20 μM) combination with abemaciclib (ABE, 1–6 μM) was evaluated over 72 hours on Rb-positive (MDA-MB-231) and Rb-negative (MDA-MB-468) TNBC cells. Combination indices (CI) for DOX+ABE were calculated using Compusyn software. The TNBC cell viability time-course and fold-change from the control of phosphorylated-Rb (pRb) protein expression were measured with CCK8-kit and enzyme-linked immunosorbent assay. A cell-based pharmacodynamic (PD) model was developed, where pRb protein dynamics drove cell viability response. Clinical pharmacokinetic (PK) models for DOX, L_DOX, and ABE were developed using data extracted from the literature. After scaling cancer cell growth to clinical TNBC tumor growth, the time-to-tumor progression (TTP) was predicted for human dosing regimens of DOX, ABE, and DOX+ABE.

Results

DOX and ABE combinations were synergistic (CI<1) in MDA-MB-231 and antagonistic (CI>1) in MDA-MB-468. The maximum inhibitory effects (Imax) for both drugs were set to one. The drug concentrations producing 50% of Imax for DOX and ABE were 0.565 and 2.31 μM (MDA-MB-231) and 0.121 and 1.61 μM (MDA-MB-468). The first-orders rate constants of abemaciclib absorption (k_a) and doxorubicin release from L_DOX (k_Rel) were estimated at 0.31 and 0.013 h⁻¹. Their linear clearances were 21.7 (ABE) and 32.1 L/h (DOX). The estimated TTP for intravenous DOX (75 mg/m2 every 21 days), intravenous L_DOX (50 mg/m² every 28 days), and oral ABE (200 mg twice a day) were 125, 31.2, and 8.6 days shorter than drug-free control. The TTP for DOX+ABE and L_DOX+ABE were 312 days and 47.5 days shorter than control, both larger than single-agent DOX, suggesting improved activity with the DOX+ABE combination.

Conclusion

The developed translational systems-based PK/PD model provides an in vitro-to-clinic modeling platform for DOX+ABE in TNBC. Although model-based simulations suggest improved outcomes with combination over monotherapy, tumor relapse was not prevented with the combination. Hence, DOX+ABE may not be an effective treatment combination for TNBC.

DNA damage response inhibitors: An avenue for TNBC treatment

The DNA damage response (DDR) is critical for the maintenance of genomic stability by sensing DNA damage, regulating cell cycle and initiating DNA repair. Drugs targeting DDR pathways have been increasingly exploited in treating various tumors. Triple negative breast cancer (TNBC) is a highly heterogeneous and aggressive tumor with constitutive activation of oncogenes, inducing replication stress and DNA damage, which require the DDR for survival. In addition, emerging studies have demonstrated that TNBC harbors aberrant genetic alterations in DDR pathways, such as a high frequency of p53 dysfunction and BRCA1/2 mutations. DDR alterations force TNBC to rely on the existing DDR pathways for survival, and make TNBC particularly sensitive to specific DDR inhibitors, such as high sensitivity of TNBC with BRCA1/2 mutations to PARP inhibitors. This review first and comprehensively covers the current status of the development of DDR inhibitors and discusses the mechanism of targeting the DDR in TNBC. Preclinical and clinical studies on inhibitors of the ATR-CHK1-WEE1 pathway and PARP inhibitors, the most studied inhibitors, and some other DDR inhibitors as monotherapy or combination therapy in TNBC are summarized. We also highlight the possible predictive biomarkers for these DDR inhibitors and their potential combination strategies with chemotherapy, radiotherapy or other targeted agents to optimize the efficacy of DDR inhibitors in TNBC treatment. In conclusion, this review discussed the recent considerations related to the use of DDR inhibitors for TNBC and provides a perspective to address future directions and potential therapeutic strategies for patients with TNBC.

Innovations in targeted therapies for triple negative breast cancer

PURPOSE OF REVIEW

Triple negative breast cancer (TNBC) is defined by a lack of targets, namely hormone receptor (HR) expression and human epidermal growth factor receptor 2 amplification. Cytotoxic chemotherapy remains the mainstay of treatment. Though TNBC constitutes approximately 10-15% of breast cancer, it is disproportionally lethal, but it is hoped that outcomes will improve as targetable oncogenic drivers are identified.

RECENT FINDINGS

Translational work in TNBC has focused on subsets defined by defects in homologous recombination repair, immune cell infiltration, or programmed death ligand receptor 1 expression, an over-active phosphoinositide-3 kinase pathway, or expression of androgen receptors. Though not specific to TNBC, the novel cell surface antigen trophoblast antigen 2 has also been identified and successfully targeted. This work has led to Food and Drug Administration approvals for small molecule poly-ADP-ribosyl polymerase inhibitors in patients with deleterious germline mutations in BRCA1 or BRCA2, the combination of nab-paclitaxel with immune checkpoint inhibitor antibodies in the first-line metastatic setting for programmed death ligand receptor 1+ TNBC, and use of the antibody-drug conjugate sacituzumab govitecan in the later-line metastatic setting.

SUMMARY

Identification of targetable oncogenic drivers in TNBC is an area of intense cancer biology research, hopefully translating to new therapies and improved outcomes.

PARP Inhibitors in Triple-Negative Breast Cancer Including Those With BRCA Mutations

ABSTRACT

Poly(ADP-ribose) polymerase (PARP) is involved in single-strand DNA break base excision repair. PARP inhibition causes synthetic lethality in breast cancers associated with germline BRCA1 and BRCA2 mutations and is routinely used in clinical practice for metastatic breast cancer. Breast cancers with homologous recombination deficiency or BRCAness, most commonly triple-negative breast cancers, may also benefit. Currently, PARP inhibitor use for triple-negative breast cancer with wild-type BRCA does not have definitive efficacy; however, this is an area of active research. Further clinical and translational data may identify additional patient populations that will benefit from PARP inhibitor therapy.

Immunotherapy in Triple-Negative Breast Cancer

ABSTRACT

Triple-negative breast cancer (TNBC) is an aggressive subtype of mammary carcinoma. A subset of TNBC is immune activated, suggesting that immunotherapy may be a viable treatment strategy. Phase III clinical trials have shown that atezolizumab or pembrolizumab is well-tolerated in combination with chemotherapy, with progression-free survival benefit in metastatic programmed death ligand-1 (PD-L1)-positive TNBC patients treated first line. Based on IMpassion130, the combination of atezolizumab and nab-paclitaxel is now considered a standard of care for the treatment of PD-L1-positive advanced TNBC. In early TNBC, pembrolizumab and atezolizumab have been tested in combination with standard neoadjuvant chemotherapy, resulting in a higher complete pathologic response rate than standard neoadjuvant chemotherapy alone, regardless of disease PD-L1 status. These findings establish proof of principle for immunotherapy in both early and advanced TNBC. High priorities for the field include developing more active immunotherapy combination regimens and more refined biomarkers that optimally identify patients most likely to benefit from immunotherapy.

Frequency and Outcomes of New Suspicious Lesions on Breast MRI in the Setting of Neoadjuvant Therapy

OBJECTIVE. The purpose of this article was to determine the frequency and outcomes of new suspicious findings on breast MRI after initiation of neoadjuvant therapy. MATERIALS AND METHODS. A retrospective database review identified all breast MRI examinations performed to assess response to neoadjuvant therapy between 2010 and 2018. Cases with new suspicious lesions assessed as BI-RADS 4 or 5 and found after the initiation of neoadjuvant treatment were included. Cases with no pretreatment MRI, cases in which the suspicious lesion was present on the baseline MRI but remained suspicious, and cases with insufficient follow-up were excluded. Radiologic, pathologic, and surgical reports were reviewed. Malignant outcomes were determined by pathologic examination. Benignity was established by pathologic examination, follow-up imaging, or both. A total of 419 breast MRI examinations in 297 women were performed to assess response to neoadjuvant therapy. After exclusions, 23 MRI examinations (5.5%) with new suspicious findings, all assessed as BI-RADS 4, comprised the final cohort. RESULTS. Of the 23 lesions, 13 new suspicious findings (56.5%) were contralateral to the known malignancy, nine (39.1%) were ipsilateral, and one (4.3%) involved the bilateral breasts. Lesion types included mass (16, 69.6%), nonmass enhancement (5, 21.7%) and focus (2, 8.7%). None of the new suspicious findings were malignant. CONCLUSION. New suspicious findings occurred in 5.5% of breast MRI examinations performed to monitor response to neoadjuvant therapy, and none of these new lesions were malignant. Our findings suggest that new lesions that arise in the setting of neoadjuvant therapy are highly unlikely to represent a new site of malignancy, particularly if the index malignancy shows treatment response. Larger studies are needed to confirm whether biopsy may be safely averted in this scenario.

Molecular Profiling-Based Assignment of Cancer Therapy (NCI-MPACT): A Randomized Multicenter Phase II Trial

This trial assessed the utility of applying tumor DNA sequencing to treatment selection for patients with advanced, refractory cancer and somatic mutations in one of four signaling pathways by comparing the efficacy of four study regimens that were either matched to the patient's aberrant pathway (experimental arm) or not matched to that pathway (control arm).

MATERIALS AND METHODS

Adult patients with an actionable mutation of interest were randomly assigned 2:1 to receive either (1) a study regimen identified to target the aberrant pathway found in their tumor (veliparib with temozolomide or adavosertib with carboplatin [DNA repair pathway], everolimus [PI3K pathway], or trametinib [RAS/RAF/MEK pathway]), or (2) one of the same four regimens, but chosen from among those not targeting that pathway.

RESULTS

Among 49 patients treated in the experimental arm, the objective response rate was 2% (95% CI, 0% to 10.9%). One of 20 patients (5%) in the experimental trametinib cohort had a partial response. There were no responses in the other cohorts. Although patients and physicians were blinded to the sequencing and random assignment results, a higher pretreatment dropout rate was observed in the control arm (22%) compared with the experimental arm (6%; P = .038), suggesting that some patients may have had prior tumor mutation profiling performed that led to a lack of participation in the control arm.

CONCLUSION

Further investigation, better annotation of predictive biomarkers, and the development of more effective agents are necessary to inform treatment decisions in an era of precision cancer medicine. Increasing prevalence of tumor mutation profiling and preference for targeted therapy make it difficult to use a randomized phase II design to evaluate targeted therapy efficacy in an advanced disease setting.

Recent Discoveries of Macromolecule- and Cell-Based Biomarkers and Therapeutic Implications in Breast Cancer

Breast cancer is the most commonly diagnosed cancer type and the leading cause of cancer-related mortality in women worldwide. Breast cancer is fairly heterogeneous and reveals six molecular subtypes: luminal A, luminal B, HER2+, basal-like subtype (ER−, PR−, and HER2−), normal breast-like, and claudin-low. Breast cancer screening and early diagnosis play critical roles in improving therapeutic outcomes and prognosis. Mammography is currently the main commercially available detection method for breast cancer; however, it has numerous limitations. Therefore, reliable noninvasive diagnostic and prognostic biomarkers are required. Biomarkers used in cancer range from macromolecules, such as DNA, RNA, and proteins, to whole cells. Biomarkers for cancer risk, diagnosis, proliferation, metastasis, drug resistance, and prognosis have been identified in breast cancer. In addition, there is currently a greater demand for personalized or precise treatments; moreover, the identification of novel biomarkers to further the development of new drugs is urgently needed. In this review, we summarize and focus on the recent discoveries of promising macromolecules and cell-based biomarkers for the diagnosis and prognosis of breast cancer and provide implications for therapeutic strategies.

The Bayesian Design of Adaptive Clinical Trials

This paper presents a brief overview of the recent literature on adaptive design of clinical trials from a Bayesian perspective for statistically not so sophisticated readers. Adaptive designs are attracting a keen interest in several disciplines, from a theoretical viewpoint and also—potentially—from a practical one, and Bayesian adaptive designs, in particular, have raised high expectations in clinical trials. The main conceptual tools are highlighted here, with a mention of several trial designs proposed in the literature that use these methods, including some of the registered Bayesian adaptive trials to this date. This review aims at complementing the existing ones on this topic, pointing at further interesting reading material.

Haematologic toxicities with PARP inhibitors in cancer patients: an up-to-date meta-analysis of 29 randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

Poly ADP-ribose polymerase (PARP) inhibitors have emerged as one of the most exciting new treatments for patients with certain types of cancer. Haematologic toxicities are common adverse events (AEs) for all PARP inhibitors. We conducted a meta-analysis to fully investigate the haematologic toxicities of PARP inhibitors in cancer patients.

STUDY DESIGN

PubMed/Medline and Embase were searched for articles published till September 2020. The relevant randomized controlled trials (RCTs) in cancer patients treated with PARP inhibitors were retrieved, and the systematic evaluation was performed.

RESULTS

Twenty-nine RCTs and 9247 patients were included. The current meta-analysis suggests that the use of PARP inhibitors significantly increases the risk of all-grade anaemia (RR, 2.32; 95% CI, 1.78-3.01; p < 0.00001), neutropenia (RR, 1.69; 95% CI, 1.38-2.07; p < 0.00001) and thrombocytopenia (RR, 2.54; 95% CI, 1.87-3.45; p < 0.00001). The use of these agents also significantly increased the risk of high-grade anaemia (RR, 3.06; 95% CI, 2.11-4.43; p < 0.00001), neutropenia (RR, 1.66; 95% CI, 1.33-2.07; p < 0.00001) and thrombocytopenia (RR, 2.76; 95% CI, 1.83-4.16; p < 0.00001). Anaemia was the most common haematologic toxicity, and all the five included PARP inhibitors were associated with a significant increased risk of anaemia. Combination treatment may reduce the risk of anaemia and thrombocytopenia compared to those receiving PARP inhibitor monotherapy.

WHAT IS NEW AND CONCLUSION

The available data suggested that the use of PARP inhibitors was associated with a significantly increased risk of haematologic toxicities.

Molecular Subtyping and Precision Medicine for Pancreatic Cancer

Substantial progress in recent years has dramatically increased our knowledge of the molecular basis of cancer, revealing new potential therapeutic targets and paving the way for effective personalised medicine for the treatment of many tumour types. However, pancreatic cancer has been lagging behind in this success and continues to be one of the most lethal solid malignancies. Its molecular heterogeneity and the unselected design of the majority of clinical trials to date can in part explain the reason for our failure to make a significant change in the survival outcomes for patients with pancreatic cancer. A changing paradigm in drug development is required to validate the new molecular taxonomy and to rapidly translate preclinical discovery into clinical trials. Here, we review the molecular subtyping of pancreatic cancer, the challenges in identifying effective treatment regimens according to defined low-prevalence molecular subgroups and we illustrate a new model of translational therapeutic development that was established in the U.K. (Precision-Panc) as a potentially effective solution to improve outcomes for patients with pancreatic cancer.

Recent advances in neoadjuvant therapy for breast cancer

Neoadjuvant trials for early breast cancer have accelerated the identification of novel active agents, enabling streamlined conduct of registration trials with fewer subjects. Measurement of neoadjuvant drug effects has also enabled the identification of patients with high risk of distant recurrence and has justified development of additional adjuvant approaches to improve outcomes. Neoadjuvant evaluation of new drugs was significantly improved by the introduction of pathologic complete response (pCR) rate as a quantitative surrogate endpoint for distant disease-free survival (DDFS) and event free survival (EFS). The neoadjuvant phase 2 platform trial I-SPY 2 simultaneously tests multiple drugs across multiple breast cancer subtypes using Bayesian methods of adaptive randomization for assessment of drug efficacy. In addition to the pCR endpoint, the I-SPY 2 trial has demonstrated that the residual cancer burden (RCB) score measures gradations of tumor response that correlate with DDFS and EFS across treatments and subtypes. For HER2-positive and triple-negative breast cancers that have failed to attain pCR with neoadjuvant chemotherapy (NAC), effective modifications of adjuvant treatment have improved outcomes and changed the standard of care for these subtypes. Neoadjuvant therapy is therefore preferred for stage II and III, as well as some stage I, HER2-positive and triple-negative tumors. Neoadjuvant endocrine therapy (NET) strategies have also emerged from innovative trials for stage II and III estrogen receptor (ER)-positive/HER2-negative tumors, as in the ALTERNATE trial. From neoadjuvant trials, opportunities have emerged to de-escalate therapy on the basis of metrics of response to chemotherapy or hormonal therapy. Neoadjuvant therapy for early breast cancer is therefore emerging as a promising approach to accelerate new drug development, optimize treatment strategies, and (where appropriate) de-escalate neoadjuvant therapy.

Response in breast vs axilla after neoadjuvant treatment and implications for nonoperative management of invasive breast cancer

Improved imaging and neoadjuvant chemotherapy (NAT) have led to higher pathologic complete response rates (pCR) in patients with invasive breast cancer. This has questioned the necessity of surgery and axillary lymph node (ALN) dissection in these patients. Prospective clinical trials are implementing extensive core biopsies of the tumor bed of patients with clinical complete response as a means to identify and spare them breast surgery. In addition, it is anticipated that patients with pCR are most likely going to have no or minimal disease in ALN as well. To verify the feasibility of these trials, we performed a pathologic analysis of all our patients who have undergone NAT from 2009 to present. Using pathology data base, we identified 362 patients treated with neoadjuvant chemotherapy followed by surgery. Clinical and pathologic information including gross and microscopic descriptions as well as biomarker status was collected. pCR was 50% for patients with negative ALN pretreatment but only 28% for patients with positive ALN at diagnosis. Despite achieving pCR in the breast, up to 10% of patients with positive ALN and 1% with negative ALN had persistent disease. Eight percent of patients that were presumed to have no ALN disease either clinically and or by imaging were found to have metastatic carcinoma in ALN. The metastases were predominantly (80%) <5 mm, and not palpable on physical examination and or due to biopsy sampling error. pCR in breast and ALN directly correlated with tumor size, ALN disease, and Her2 positive and triple negative receptor phenotype. In breast cancer patients who are node positive at time of diagnosis with pCR in the breast after neoadjuvant chemotherapy, residual lymph node disease was very uncommon. Further study is warranted to select patients who may avoid breast and axillary surgery post neoadjuvant chemotherapy.

Adjuvant and Neoadjuvant Treatment of Triple-Negative Breast Cancer With Chemotherapy

ABSTRACT

Triple-negative breast cancer (TNBC) accounts for 15% to 20% of all invasive breast carcinomas and is defined by the lack of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. Although TNBC is characterized by high rates of disease recurrence and worse survival, it is significantly more sensitive to chemotherapy as compared with other breast cancer subtypes. Accordingly, despite great efforts in the genomic characterization of TNBC, chemotherapy still represents the cornerstone of treatment. For the majority of patients with early-stage TNBC, sequential anthracycline- and taxane-based neoadjuvant chemotherapy (NACT) represents the standard therapeutic approach, with pathological complete response that strongly correlates with long-term survival outcomes. However, some issues about the optimal neoadjuvant regimen, as well as the effective role of chemotherapy in patients with residual disease after NACT, are still debated. Herein, we will review the current evidences that guide the use of (neo)adjuvant chemotherapy in patients with early-stage TNBC. Furthermore, we will discuss current controversies, including the incorporation of platinum compounds to the neoadjuvant backbone and the optimal treatment for patients with residual disease after NACT. Lastly, we will outline potential future directions that can guide treatment escalation and de-escalation, as well as the development of new therapies. In our view, the application of multi-omics technologies, liquid biopsy assays, and machine learning algorithms are strongly warranted to pave the way toward personalized anticancer treatment for early-stage TNBC.

Neoadjuvant Chemotherapy in Early Triple-Negative Breast Cancer: A Pairwise and Network Meta-Analysis of Pathological Complete Response

We performed a pairwise and network meta-analysis to compare pathological complete response (pCR) among neoadjuvant chemotherapy in patients with triple-negative breast cancer. We searched PubMed for randomized clinical trials between January 1, 2000 and December 1, 2020. Abstracts from meetings were also searched. A frequentist random-effect model was applied to compare pCR and toxicities. The P-score was used to rank treatment effects. Nineteen trials with 16 treatments and 7794 patients were included. On the basis of SoC, the addition of carboplatin (OR = 1.82, 95% CI, 1.24 to 2.68, P < .01) and the addition of checkpoint inhibitors (OR = 1.69, 95% CI, 1.23 to 2.32, P < .01) increased pCR in pairwise meta-analysis; compared with paclitaxel, nab-paclitaxel did not improve pCR rates (OR = 1.81, 95% CI, .80 to 4.12, P = .16). The anthracycline-sparing regimen led to similar pCR compared with the anthracycline-containing regimen (OR = 1.50, 95% CI, .82 to 2.76, P = .19). In network meta-analysis, the addition of carboplatin plus a PD-1 inhibitor (pembrolizumab), carboplatin plus bevacizumab, and carboplatin plus veliparib ranked as the top three treatments for achieving pCR, with corresponding P-scores of .91, .84, and .72, respectively. Among patients with homologous recombination deficiency, the addition of carboplatin (OR = 1.31, 95% CI, .69 to 2.50, P = .41) or carboplatin plus PARP inhibitors (OR = 1.19, 95% CI, .58 to 2.47, P = .63) did not increase pCR. For triple-negative breast cancer, combining carboplatin with taxane-anthracycline-containing neoadjuvant chemotherapy could be the standard of care, and the combination containing checkpoint inhibitor is promising. However, their role in long-term oncologic outcome remains to be determined.

Neoadjuvant Chemotherapy for Breast Cancer: Past, Present, and Future

Neoadjuvant chemotherapy (NAC) had been developed as a systematic approach before definitive surgery for the treatment of locally advanced or inoperable breast cancer such as inflammatory breast cancer in the past. In addition to its impact on surgery, the neoadjuvant setting has a benefit of providing the opportunity to monitor the individual drug response. Currently, the subject of NAC has expanded to include patients with early-stage, operable breast cancer because it is revealed that the achievement of a pathologic complete response (pCR) is associated with excellent long-term outcomes, especially in patients with aggressive phenotype breast cancer. In addition, this approach provides the unique opportunity to escalate adjuvant therapy in those with residual disease after NAC. Neoadjuvant chemotherapy in breast cancer is a rapidly evolving topic with tremendous interest in ongoing clinical trials. Here, we review the improvements and further challenges in the NAC setting in translational breast cancer research.

Molecular Features and Clinical Management of Hereditary Gynecological Cancers

Hereditary gynecological cancers are caused by several inherited genes. Tumors that arise in the female reproductive system, such as ovaries and the uterus, overlap with hereditary cancers. Several hereditary cancer-related genes are important because they might lead to therapeutic targets. Treatment of hereditary cancers should be updated in line with the advent of various new methods of evaluation. Next-generation sequencing has led to rapid, economical genetic analyses that have prompted a concomitant and significant paradigm shift with respect to hereditary cancers. Molecular tumor profiling is an epochal method for determining therapeutic targets. Clinical treatment strategies are now being designed based on biomarkers based on tumor profiling. Furthermore, the National Comprehensive Cancer Network (NCCN) guidelines significantly changed the genetic testing process in 2020 to initially consider multi-gene panel (MGP) evaluation. Here, we reviewed the molecular features and clinical management of hereditary gynecological malignancies, such as hereditary breast and ovarian cancer (HBOC), and Lynch, Li–Fraumeni, Cowden, and Peutz–Jeghers syndromes. We also reviewed cancer-susceptible genes revealed by MGP tests.

Predicting breast cancer response to neoadjuvant treatment using multi-feature MRI: results from the I-SPY 2 TRIAL

Dynamic contrast-enhanced (DCE) MRI provides both morphological and functional information regarding breast tumor response to neoadjuvant chemotherapy (NAC). The purpose of this retrospective study is to test if prediction models combining multiple MRI features outperform models with single features. Four features were quantitatively calculated in each MRI exam: functional tumor volume, longest diameter, sphericity, and contralateral background parenchymal enhancement. Logistic regression analysis was used to study the relationship between MRI variables and pathologic complete response (pCR). Predictive performance was estimated using the area under the receiver operating characteristic curve (AUC). The full cohort was stratified by hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status (positive or negative). A total of 384 patients (median age: 49 y/o) were included. Results showed analysis with combined features achieved higher AUCs than analysis with any feature alone. AUCs estimated for the combined versus highest AUCs among single features were 0.81 (95% confidence interval [CI]: 0.76, 0.86) versus 0.79 (95% CI: 0.73, 0.85) in the full cohort, 0.83 (95% CI: 0.77, 0.92) versus 0.73 (95% CI: 0.61, 0.84) in HR-positive/HER2-negative, 0.88 (95% CI: 0.79, 0.97) versus 0.78 (95% CI: 0.63, 0.89) in HR-positive/HER2-positive, 0.83 (95% CI not available) versus 0.75 (95% CI: 0.46, 0.81) in HR-negative/HER2-positive, and 0.82 (95% CI: 0.74, 0.91) versus 0.75 (95% CI: 0.64, 0.83) in triple negatives. Multi-feature MRI analysis improved pCR prediction over analysis of any individual feature that we examined. Additionally, the improvements in prediction were more notable when analysis was conducted according to cancer subtype.

Olaparib monotherapy as primary treatment in unselected triple negative breast cancer

BACKGROUND

The antitumor efficacy of PARP inhibitors (PARPi) for breast cancer patients harboring germline BRCA1/2 (gBRCA1/2) mutations is well established. While PARPi monotherapy was ineffective in patients with metastatic triple negative breast cancer (TNBC) wild type for BRCA1/2, we hypothesized that PARPi may be effective in primary TNBCs without previous chemotherapy exposure.

PATIENTS AND METHODS

In the phase II PETREMAC trial, patients with primary TNBC >2 cm received olaparib for up to 10 weeks before chemotherapy. Tumor biopsies collected before and after olaparib underwent targeted DNA sequencing (360 genes) and BRCA1 methylation analyses. In addition, BRCAness (multiplex ligation-dependent probe amplification), PAM50 gene expression, RAD51 foci, tumor-infiltrating lymphocytes (TILs) and PD-L1 analyses were performed on pretreatment samples.

RESULTS

The median pretreatment tumor diameter was 60 mm (range 25-112 mm). Eighteen out of 32 patients obtained an objective response (OR) to olaparib (56.3%). Somatic or germline mutations affecting homologous recombination (HR) were observed in 10/18 responders [OR 55.6%, 95% confidence interval (CI) 33.7-75.4] contrasting 1/14 non-responders (OR 7.1%; CI 1.3-31.5, P = 0.008). Among tumors without HR mutations, 6/8 responders versus 3/13 non-responders revealed BRCA1 hypermethylation (P = 0.03). Thus, 16/18 responders (88.9%, CI 67.2-96.9), in contrast to 4/14 non-responders (28.6%, CI 11.7-54.7, P = 0.0008), carried HR mutations and/or BRCA1 methylation. Excluding one gPALB2 and four gBRCA1/2 mutation carriers, 12/14 responders (85.7%, CI 60.1-96.0) versus 3/13 non-responders (23.1%, CI 8.2-50.3, P = 0.002) carried somatic HR mutations and/or BRCA1 methylation. In contrast to BRCAness signature or basal-like subtype, low RAD51 scores, high TIL or high PD-L1 expression all correlated to olaparib response.

CONCLUSION

Olaparib yielded a high clinical response rate in treatment-naïve TNBCs revealing HR deficiency, beyond germline HR mutations.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02624973.

Circulating tumor DNA in neoadjuvant-treated breast cancer reflects response and survival

BACKGROUND

Pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) is strongly associated with favorable outcome. We examined the utility of serial circulating tumor DNA (ctDNA) testing for predicting pCR and risk of metastatic recurrence.

PATIENTS AND METHODS

Cell-free DNA (cfDNA) was isolated from 291 plasma samples of 84 high-risk early breast cancer patients treated in the neoadjuvant I-SPY 2 TRIAL with standard NAC alone or combined with MK-2206 (AKT inhibitor) treatment. Blood was collected at pretreatment (T0), 3 weeks after initiation of paclitaxel (T1), between paclitaxel and anthracycline regimens (T2), or prior to surgery (T3). A personalized ctDNA test was designed to detect up to 16 patient-specific mutations (from whole-exome sequencing of pretreatment tumor) in cfDNA by ultra-deep sequencing. The median follow-up time for survival analysis was 4.8 years.

RESULTS

At T0, 61 of 84 (73%) patients were ctDNA positive, which decreased over time (T1: 35%; T2: 14%; and T3: 9%). Patients who remained ctDNA positive at T1 were significantly more likely to have residual disease after NAC (83% non-pCR) compared with those who cleared ctDNA (52% non-pCR; odds ratio 4.33, P = 0.012). After NAC, all patients who achieved pCR were ctDNA negative (n = 17, 100%). For those who did not achieve pCR (n = 43), ctDNA-positive patients (14%) had a significantly increased risk of metastatic recurrence [hazard ratio (HR) 10.4; 95% confidence interval (CI) 2.3-46.6]; interestingly, patients who did not achieve pCR but were ctDNA negative (86%) had excellent outcome, similar to those who achieved pCR (HR 1.4; 95% CI 0.15-13.5).

CONCLUSIONS

Lack of ctDNA clearance was a significant predictor of poor response and metastatic recurrence, while clearance was associated with improved survival even in patients who did not achieve pCR. Personalized monitoring of ctDNA during NAC of high-risk early breast cancer may aid in real-time assessment of treatment response and help fine-tune pCR as a surrogate endpoint of survival.

Prior to Initiation of Chemotherapy, Can We Predict Breast Tumor Response? Deep Learning Convolutional Neural Networks Approach Using a Breast MRI Tumor Dataset

We hypothesize that convolutional neural networks (CNN) can be used to predict neoadjuvant chemotherapy (NAC) response using a breast MRI tumor dataset prior to initiation of chemotherapy. An institutional review board-approved retrospective review of our database from January 2009 to June 2016 identified 141 locally advanced breast cancer patients who (1) underwent breast MRI prior to the initiation of NAC, (2) successfully completed adriamycin/taxane-based NAC, and (3) underwent surgical resection with available final surgical pathology data. Patients were classified into three groups based on their NAC response confirmed on final surgical pathology: complete (group 1), partial (group 2), and no response/progression (group 3). A total of 3107 volumetric slices of 141 tumors were evaluated. Breast tumor was identified on first T1 postcontrast dynamic images and underwent 3D segmentation. CNN consisted of ten convolutional layers, four max-pooling layers, and dropout of 50% after a fully connected layer. Dropout, augmentation, and L2 regularization were implemented to prevent overfitting of data. Non-linear functions were modeled by a rectified linear unit (ReLU). Batch normalization was used between the convolutional and ReLU layers to limit drift of layer activations during training. A three-class neoadjuvant prediction model was evaluated (group 1, group 2, or group 3). The CNN achieved an overall accuracy of 88% in three-class prediction of neoadjuvant treatment response. Three-class prediction discriminating one group from the other two was analyzed. Group 1 had a specificity of 95.1% ± 3.1%, sensitivity of 73.9% ± 4.5%, and accuracy of 87.7% ± 0.6%. Group 2 (partial response) had a specificity of 91.6% ± 1.3%, sensitivity of 82.4% ± 2.7%, and accuracy of 87.7% ± 0.6%. Group 3 (no response/progression) had a specificity of 93.4% ± 2.9%, sensitivity of 76.8% ± 5.7%, and accuracy of 87.8% ± 0.6%. It is feasible for current deep CNN architectures to be trained to predict NAC treatment response using a breast MRI dataset obtained prior to initiation of chemotherapy. Larger dataset will likely improve our prediction model.

Gastrointestinal events with PARP inhibitors in cancer patients: A meta-analysis of phase II/III randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

PARP inhibitors are currently one of the most promising PARP targeted drugs for patients with certain types of cancer. Gastrointestinal (GI) events are common adverse events for all PARP inhibitors. We conducted this meta-analysis of randomized controlled trials (RCTs) to fully investigate the incidence and the relative risk of GI events in cancer patients receiving PARP inhibitors.

STUDY DESIGN

Randomized controlled trials in cancer patients treated with PARP inhibitors were retrieved, and the systematic evaluation was conducted. Embase and PubMed/Medline were searched for articles published till July 2020.

RESULTS

Twenty-nine RCTs and 9529 patients were included. The present meta-analysis suggests that the use of PARP inhibitors significantly increases the risk of developing all-grade nausea (RR, 1.46; 95% CI, 1.29-1.66; p < .00001), vomiting (RR, 1.39; 95% CI, 1.17-1.64; p = .0001), diarrhoea (RR, 1.14; 95% CI, 1.06-1.23; p = .0003) and decreased appetite (RR, 1.24; 95% CI, 1.14-1.36; p < .00001), but not for constipation. And the use of these agents significantly increased the risk of high-grade nausea (RR, 1.99; 95% CI, 1.44-2.74; p < .0001), vomiting (RR, 1.54; 95% CI, 1.11-2.14; p = .01) and decreased appetite (RR, 2.03; 95% CI, 1.22-3.40; p = .007), except for diarrhoea and constipation. Nausea was the most common GI event for these agents. Patients receiving veliparib were associated with a relatively lower risk of all-grade nausea and vomiting. Patients with ovarian cancer tend to have a higher risk of all-grade nausea and vomiting than those with non-ovarian cancer. The risk of all-grade nausea and vomiting tended to be higher when PARP inhibitors treatment was longer.

WHAT IS NEW AND CONCLUSION

PARP inhibitors were associated with a significant increased risk of GI events. Clinicians should be aware of these risks and perform regular monitoring.

Use of 18F-FDG PET/CT as an Initial Staging Procedure for Stage II-III Breast Cancer: A Multicenter Value Analysis

BACKGROUND

Metastatic staging imaging is not recommended for asymptomatic patients with stage I-II breast cancer. Greater distant metastatic disease risk may warrant baseline imaging in patients with stage II-III with high-risk biologic subtypes. NCCN Guidelines recommend considering CT of the chest, abdomen, and pelvis (CT CAP) and bone scan in appropriate patients. CT CAP and bone scan are considered standard of care (SoC), although PET/CT is a patient-centered alternative.

METHODS

Data were available for 799 high-risk patients with clinical stage II-III disease who initiated screening for the I-SPY2 trial at 4 institutions. A total of 564 complete records were reviewed to compare PET/CT versus SoC. Costs were determined from the payer perspective using the national 2018 Medicare Physician Fee Schedule and representative reimbursements to the University of California, San Francisco (UCSF). Incremental cost-effectiveness ratio (ICER) measured cost of using PET/CT per percent of patients who avoided a false-positive (FP).

RESULTS

The de novo metastatic disease rate was 4.6%. Imaging varied across the 4 institutions (P<.0001). The FP rate was higher using SoC versus PET/CT (22.1% vs 11.1%; P=.0009). Mean time between incidental finding on baseline imaging to FP determination was 10.8 days. Mean time from diagnosis to chemotherapy initiation was 44.3 days with SoC versus 37.5 days with PET/CT (P=.0001). Mean cost per patient was $1,132 (SoC) versus $1,477 (PET/CT) using the Medicare Physician Fee Schedule, with an ICER of $31. Using representative reimbursements to UCSF, mean cost per patient was $1,236 (SoC) versus $1,073 (PET/CT) for Medicare, and $3,083 (SoC) versus $1,656 (PET/CT) for a private payer, with ICERs of -$15 and -$130, respectively.

CONCLUSIONS

Considerable variation exists in metastatic staging practices. PET/CT reduced FP risk by half and decreased workup of incidental findings, allowing for earlier treatment start. PET/CT may be cost-effective, and at one institution was shown to be cost-saving. Better alignment is needed between hospital pricing strategies and payer coverage policies to deliver high-value care.