Trade-offs Between Efficacy and Cardiac Toxicity of Adjuvant Chemotherapy in Early-Stage Breast Cancer Patients: Do Competing Risks Matter?

Clinical results of fibroblast activation protein (FAP) specific PET for non-malignant indications: systematic review

PURPOSE

Small molecules targeting fibroblast activation protein (FAP) have emerged as a new group of tracers for positron emission tomography (PET) in 2018. While most of the existing literature has been focussed on the application of FAP-specific PET in various kinds of cancers, some researchers have, both intentionally or unintentionally, used FAP-specific PET in patients with non-cancerous diseases. The purpose of this systematic review is therefore to summarize the available evidence of FAP-specific PET for non-malignant indications.

METHODS

The MEDLINE database was searched for studies presenting the clinical use of FAP-specific PET, the records were screened according to PRISMA guidelines and articles containing patients suffering from non-malignant diseases were included.

RESULTS

Sixteen studies with 303 patients were included. FAP-specific PET has been used in cardiac imaging, IgG₄-related disease, benign tumors as well as various kinds of inflammation. Two prospective studies on FAP-specific PET for IgG₄-related disease show its potential to differentiate inflammatory from fibrotic lesions, which could be used to determine the management of these patients.

CONCLUSION

While publications on FAP-specific PET for non-malignant indications are mostly limited to case reports and incidental findings, the first retrospective and prospective studies present promising results for IgG₄-related as well as cardiovascular disease that warrant further research. Several currently recruiting trials will add to the body evidence in the next few years.

A Value of Information Analysis of Research on the 21-Gene Assay for Breast Cancer Management

OBJECTIVES

The 21-gene assay Oncotype DX (21-GA) shows promise as a guide in deciding when to initiate adjuvant chemotherapy in women with hormone receptor-positive early-stage breast cancer. Nevertheless, its routine use remains controversial, owing to insufficient evidence of its clinical utility and cost-effectiveness. Accordingly, we aim to quantify the value of conducting further research to reduce decision uncertainty in the use of the 21-GA.

METHODS

Using value of information methods, we first generated probability distributions of survival and costs for decision making with and without the 21-GA alongside traditional risk prediction. These served as the input to a comparison of 3 alternative study designs: a retrospective observational study to update risk classification from the 21-GA, a prospective observational study to estimate prevalence of chemotherapy use, and a randomized controlled trial (RCT) of the 21-GA predictive value.

RESULTS

We found that current evidence strongly supports the use of the 21-GA in intermediate- and high-risk women. Further research should focus on low-risk women, among whom the cost-effectiveness findings remained equivocal. For this population, we identified a high value of reducing uncertainty in the 21-GA use for all proposed research studies. The RCT had the greatest potential to efficiently reduce the likelihood of choosing a suboptimal strategy, providing a value between $162 million and $1.1 billion at willingness-to-pay thresholds of $150 000 to $200 000/quality-adjusted life years.

CONCLUSION

Future research to inform 21-GA decision making is of high value. The RCT of the 21-GA predictive value has the greatest potential to efficiently reduce decision uncertainty around 21-GA use in women with low-risk early-stage breast cancer.

21-Gene recurrence score influences the chemotherapy decision for patients with breast cancer of different luminal subtypes

Luminal subtypes and the 21-gene recurrence score (RS) are important factors in the decision-making process for adjuvant chemotherapy in patients with hormonal receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer. However, their effect on adjuvant chemotherapy decisions in the real world has not been thoroughly investigated, particularly for patients of the luminal A-like subtype with a high RS or the luminal B-like subtype with a low RS. The present study, a total of 772 HR⁺/HER2^- patients who underwent 21-gene testing, were included in a retrospective analysis. The impact of clinicopathological factors and the 21-gene RS on chemotherapy recommendation was analyzed in the whole population and for patients of different luminal subgroups. The results revealed that chemotherapy was highly recommended for patients of younger age, with larger tumor size, node involvement, higher grade, luminal B-like subtype and higher RS. A high RS was identified to be the most important impact factor for chemotherapy recommendation among all patients [odds ratio (OR), 62.54; 95% CI, 25.58-152.92], the luminal A-like group (OR, 435.05; 95% CI, 29.90-6331.06) and the luminal B-like group (OR, 57.20; 95% CI, 22.42-145.96). For patients of the luminal A-like subtype with a high RS or patients of the luminal B-like subtype with low RS, the 21-gene RS was demonstrated to be the most important independent factor for chemotherapy recommendation, with an adjusted OR of 134.52 (95% CI, 10.39-1741.89). In conclusion, luminal subtypes and the 21-gene RS were found to be associated with chemotherapy recommendation for HR⁺/HER2^- patients. For patients with a discordant luminal subtype and 21-gene RS risk, the 21-gene RS score was found to be the most important factor that influences chemotherapy decision, which warrants further clinical evaluation.

Chemical exchange saturation transfer MRI to assess cell death in breast cancer xenografts at 7T

Purpose

Detecting cell death and predicting tumor response early in a course of chemotherapy could help optimize treatment regimens and improve clinical outcomes. Chemical exchange saturation transfer (CEST) MRI was investigated in vivo to study properties that may be able to detect cancer death.

Results

Using a magnetization transfer ratio (MTR) cutoff of 0.12 at 1.8 ppm was able to differentiate between viable tumor and cell death regions. Comparison of MTR values at this frequency showed significant differences (p < 0.0001) between viable tumor and cell death regions, matching patterns seen on histology. Using this cutoff, the mean increase in cell death index (± standard error of the mean) after chemotherapy was 4 ± 4%, 10% ± 7%, 10 ± 8%, and 4 ± 9% at 4, 8, 12, and 24 h, respectively.

Conclusions

CEST MRI can detect cell death in MDA-231 xenografts but further work is needed to characterize the clinical applications of this finding. Maximum response to chemotherapy occurred at 8-12 h after chemotherapy injection in this in vivo tumor model.

Materials and Methods

Breast cancer xenografts (MDA-MB-231) were scanned using 7 T MRI before and after chemotherapy. As a measure of CEST effect at 0.5 µT saturation amplitude, MTR values at frequency offsets of 1.8 and -3.3 ppm were evaluated. CEST signals after chemotherapy treatment were compared to cell-death histopathology of tumors.

Patterns of on-treatment cardiac adverse events within three clinical trials of adjuvant anthracycline-based chemotherapy

BACKGROUND

This study aims to assess the patterns of development of on-treatment cardiac side effects among patients with early breast cancer receiving anthracycline-based chemotherapy.

METHODS

This is a pooled analysis of patient-level data of patients with early-stage breast cancer who were recruited into three clinical trials to receive different adjuvant chemotherapy regimens. Univariable and multivariable analyses of factors predicting the development of on-treatment cardiac adverse events were conducted through logistic regression analysis. The following factors were evaluated in the univariable analysis: age, menopausal status, body mass index, T stage, and type of chemotherapy protocol.

RESULTS

Among the studied patients, 226 patients (6.7%) experienced 230 incidents of on-treatment cardiac toxicities. Cardiac ischemia was reported among 8 patients, cardiac dysfunction was reported among 19 patients, arrhythmias were reported in 161 patients and other non-specified forms of cardiac adverse events were reported in 42 patients. In univariable logistic regression, the following parameters were predictive of a higher probability of on-treatment cardiac adverse events (P < 0.05): higher age, higher body mass index and FAC chemotherapy protocol. When these factors were included in the multivariable logistic regression analysis, the following factors were predictive of a higher probability of cardiac adverse events: higher body mass index (P = 0.050) and FAC chemotherapy protocol (P = 0.001).

CONCLUSION

On-treatment cardiac events are not uncommon during adjuvant chemotherapy for early breast cancer. Higher dose of anthracyclines and higher body mass index are associated with a higher risk of on-treatment cardiac events.