Multimodality imaging of indolent B cell lymphoma from diagnosis to transformation: what every radiologist should know

Indolent B cell lymphomas are a group of lymphoid malignancies characterized by their potential to undergo histologic transformation to aggressive lymphomas. While different subtypes of indolent B cell lymphomas demonstrate specific clinical and imaging features, histologic transformation can be suspected on cross-sectional imaging when disproportionate lymph node enlargement or new focal lesions in extranodal organs are seen. On PET/CT, transformed indolent lymphoma may show new or increased nodal FDG avidity or new FDG-avid lesions in different organs. In this article, we will (1) review the imaging features of different subtypes of indolent B cell lymphomas, (2) discuss the imaging features of histologic transformation, and (3) propose a diagnostic algorithm for transformed indolent lymphoma. The purpose of this review is to familiarize radiologists with the spectrum of clinical and imaging features of indolent B cell lymphomas and to define the role of imaging in raising concern for transformation and in guiding biopsy for confirmation.

Lobular breast cancer: patterns of intraabdominal metastatic spread on imaging and prognostic significance

OBJECTIVE

To retrospectively review the frequency, patterns and intra-abdominal sites of metastatic invasive lobular breast cancer, and to correlate the findings with overall survival.

MATERIALS AND METHODS

From a pathology database search revealing 327 patients with metastatic lobular breast cancer at our institution from January 2004 through August 2014, imaging was available in 116 patients (age range, 31-87 years, mean age, 55). Simple descriptive statistics were performed to record and tabulate the abdominal metastatic spread. Prognostic significance of abdominal metastases and individual abdominal metastatic sites was studied using the Log-rank test and construction of Kaplan-Meier curves.

RESULTS

The most frequent sites of intra-abdominal metastatic invasive lobular breast cancer were peritoneum (55 patients, 47%), followed by liver (37 patients, 32%), bowel (34 patients, 29%), ovary (33 patients, 28%), retroperitoneum (16 patients, 14%), ureter (16 patients, 14%), and lymph nodes (15 patients, 13%). Bowel obstruction was noted in 15 patients (13%) and hydronephrosis in 25 patients (22%). The median abdominal metastasis-free survival was 76 months (interquartile range: 17-191). The overall survival (OS) was 86 months (interquartile range: 49-188). Patients with abdominal metastases had shorter OS. Patients with hepatic metastases had shorter overall survival than those patients without hepatic metastases (p = 0.02, Log-Rank test).

CONCLUSION

Invasive lobular breast cancer has a predilection for metastasizing to both typical (liver) and atypical intra-abdominal sites (peritoneum, GI tract, and adnexa). Presence of intra-abdominal disease and hepatic metastases in patients with ILC negatively affects overall survival.

Optimal Phase of Dynamic Computed Tomography for Reliable Size Measurement of Metastatic Neuroendocrine Tumors of the Liver: Comparison between Pre- and Post-Contrast Phases

Objective

The reliability of size measurements of liver metastases from neuroendocrine tumors (NETs) on contrast-enhanced computed tomography (CT) phases made by different readers may be hampered due to transient, variable rim enhancement in arterial phase (AP) or portal venous phase (PVP) images. We aimed to assess the reliability of tumor size measurements in pre- and post-contrast scans.

Materials and Methods

The study coordinator selected target lesions according to Response Evaluation Criteria in Solid Tumors 1.1 guidelines in 44 consecutive patients with pathologically confirmed NET liver metastases. Two blinded readers measured the longest diameters of target lesions on pre-contrast, AP, and PVP images twice with a 4-week interval. Inter- and intra-observer agreements were evaluated using Bland-Altman plots and 95% limit of agreement (LOA) calculations.

Results

Of the 79 target lesions (approximate mean size of 3 cm), 45 showed rim enhancement. Inter-observer agreement assessed based on LOA was highest in pre-contrast CT images (−6.1–5.7 mm), followed by PVP (−7.9–7.1 mm) and AP (−8.5–7.4 mm) images. Intra-observer agreement showed the same trend: −2.8–2.9 mm and −2.9–2.9 mm for readers 1 and 2, respectively, on pre-contrast CT, −2.8–2.9 mm and −3.0–3.2 mm, respectively, on PVP, and −3.2–4.2 mm and −3.4–3.2 mm, respectively, on AP images. Mean tumor diameters differed significantly among the phases in the following increasing order: pre-contrast CT, PVP, and AP images.

Conclusion

There was better inter- and intra-observer agreement in size measurements of NET liver metastases on precontrast scans than on AP and PVP scans. Pre-contrast CT may be the optimal for measuring NET liver metastases if its accuracy is proven.

Value of hepatocellular phase imaging after intravenous gadoxetate disodium for assessing hepatic metastases from gastroenteropancreatic neuroendocrine tumors: comparison with other MRI pulse sequences and with extracellular agent

OBJECTIVE

To compare hepatocellular phase imaging after intravenous gadoxetate disodium with other MRI pulse sequences and with extracellular agent for assessing hepatic metastases from gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN).

MATERIALS AND METHODS

In this IRB-approved, HIPAA-compliant retrospective study, we included 30 patients (15 women, mean age: 58 years, range 44-77 years) with GEP-NEN metastatic to the liver, who underwent MRI with gadoxetate disodium. Six MRI sequences were reviewed by two radiologists to score tumor-liver interface (TLI) on a 5-point scale, to assess lesion detectability in different liver segments (divided into 3 zones/patient), and to measure lesion size. Contrast-to-noise ratio (CNR) was calculated on each sequence. In 19 patients, lesion size and CNR on dynamic imaging with gadopentetate dimeglumine was compared with hepatocellular phase. Wilcoxon signed-rank test was used to compare TLI scores, lesion size, and median CNR, using Bonferroni correction for multiple testing. Interobserver agreement for TLI was analyzed using Krippendorff's alpha, and for lesion size using concordance correlation coefficient (CCC) and mean relative difference.

RESULTS

Hepatocellular phase had the best TLI (mean TLI for reader 1 = 1.2, reader 2 = 1.3) compared to all other sequences (p < 0.0001) with excellent interobserver agreement (Krippendorff's alpha = 1.0), maximum lesion detectability (61/90 zones), highest interobserver agreement for lesion measurement (CCC 0.9875 and smallest mean relative difference - 1.567%), and highest median CNR (31.2, p < 0.008). Hepatocellular phase also had the highest CNR when compared with gadopentetate imaging.

CONCLUSION

Hepatocellular phase imaging offers significant advantages for assessment of hepatic metastasis in GEP-NEN, and should be routinely considered for follow-up of these patients.

Perception of Breast Oncologists and Physician Extenders on Imaging Consultation Service at a Tertiary Cancer Institute

OBJECTIVE

To evaluate the perception and ease of utilization of the imaging consultation service by different types of referring clinicians and physician extenders within the breast oncology disease center at our tertiary cancer institute using a survey-based questionnaire.

METHODS

An institutional review board-exempted survey was created using a freely available online survey software and questionnaire tool. The survey was sent to 83 clinicians associated with the breast oncology disease center at our tertiary cancer center through an institutional e-mail list. The survey included 2 questions about demographics and 8 statements regarding various aspects of the consultation service scored on a 5-point Likert-type scale. "1'' being "agree completely," "3" being "neutral/neither agree nor disagree," and "5" being "disagree completely." The survey was sent online and was answered anonymously. Responses were tallied and analyzed.

RESULTS

A total of 56 responses (67%) were received. The weighted average of each Likert item ranged from 1.07 to 1.58. Highest positive concordance (95%) pertained to the access to the consult radiologist having a positive impact on patient care. The least concordant statement (78%), though still strong (with weighted average of 1.58% and 78% of respondents agreeing or agreeing completely) pertained to the role of direct consultation with radiologist in clinical management. Although there was variability of agreement to all statements (including responders feeling neutral), there was no one that disagreed with any of the Likert items. The mean Likert score for all the statements together was 1.23 (range: 1.07-1.58).

CONCLUSION

Presence of dedicated oncologic imaging consultation service is perceived positively by the breast oncology team at our tertiary cancer center.

Imaging in Soft Tissue Sarcomas: Current Updates

Soft tissue sarcomas (STS) are heterogeneous malignant tumors that have nonspecific imaging features. A combination of clinical, demographic, and imaging characteristics can aid in the diagnosis. Imaging provides important information regarding the tumor extent, pretreatment planning, and surveillance of patients with STS. In this article, we illustrate the pertinent imaging characteristics of the commonly occurring STS and some uncommon sarcomas with unique imaging characteristics.

A cost-effectiveness analysis of the diagnostic strategies for differentiating focal nodular hyperplasia from hepatocellular adenoma

OBJECTIVES

We evaluated the cost-effectiveness of a gadoxetic acid-enhanced MRI (EOB-MRI) strategy compared with conventional MRI strategy and biopsy to differentiate focal nodular hyperplasia (FNH) from hepatocellular adenoma (HCA).

METHODS

A decision tree model was constructed to compare the cost-effectiveness of EOB-MRI, conventional MRI with extracellular contrast agents, and biopsy as the initial diagnostic modality in patients with incidentally detected focal liver lesions suspected of being FNH or HCA. We analysed the cost and effectiveness, i.e. probability of successful diagnosis of each strategy. Costs were based on utilisation rates and Medicare reimbursements in the USA and South Korea.

RESULTS

In the base case analysis of our decision tree model, the effectiveness of the three strategies was similar. The cost of the EOB-MRI strategy ($1283 in USA, $813 in South Korea) was lowest compared with the biopsy strategy ($1725 in USA, $847 in South Korea) and the conventional MRI strategy ($1750 in USA, $962 in South Korea). One-way, two-way and probabilistic sensitivity analysis showed unchanged results over an acceptable range.

CONCLUSIONS

EOB-MRI strategy is the most cost-effective strategy for differentiating FNH from HCA in patients with incidentally detected focal liver lesions in a non-cirrhotic liver.

KEY POINTS

• The effectiveness of the three strategies was similar. • The cost of the EOB-MRI strategy was lowest. • EOB-MRI strategy is the most cost-effective for differentiating FNH from HCA.

Thoracic Complications of Precision Cancer Therapies: A Practical Guide for Radiologists in the New Era of Cancer Care

Recent advances in understanding the molecular mechanisms of cancer have opened a new era of precision medicine for cancer treatment. Precision cancer therapies target specific molecules that are responsible for cancer development and progression, and they achieve marked treatment benefits in specific cohorts of patients. However, these therapies are also associated with a variety of complications that are often unique to specific groups of anticancer agents. The rapidly increasing use of immune checkpoint inhibitors in the treatment of various advanced malignancies has brought new challenges in diagnosing and monitoring a unique set of toxic effects termed immune-related adverse events. Familiarity with cutting-edge cancer treatment approaches and awareness of the emerging complications from novel therapies are essential for radiologists, who play a key role in the care of patients with cancer. This article provides a comprehensive review of the thoracic complications of precision cancer therapies, describes their imaging features and clinical characteristics, and discusses the role of radiologists in the diagnosis and monitoring of these entities. The authors also address the molecular mechanisms of anticancer agents that relate to thoracic complications and emphasize emerging challenges in novel cancer therapies. This article is designed to serve as a practical reference guide for day-to-day practice for radiologists in the era of precision cancer medicine. ^©RSNA, 2017.

Updates for the radiologist in non-muscle-invasive, muscle-invasive, and metastatic bladder cancer

Urothelial bladder cancer is a common malignancy requiring a multidisciplinary approach to treatment. Significant recent advances have been made in terms of the genetic and molecular characterization of bladder cancer subtypes, and novel treatment approaches are being investigated and approved. Given the important role of imaging in the diagnosis, staging, and follow-up of this disease, it is necessary for radiologists to remain up-to-date in terms of nomenclature and standards of care. In this review, recent developments in bladder cancer characterization and treatment will be discussed, with reference to the contributions of imaging in non-muscle-invasive, muscle-invasive, and metastatic settings.

Immune-Related Tumor Response Dynamics in Melanoma Patients Treated with Pembrolizumab: Identifying Markers for Clinical Outcome and Treatment Decisions

Purpose: Characterize tumor burden dynamics during PD-1 inhibitor therapy and investigate the association with overall survival (OS) in advanced melanoma.Experimental Design: The study included 107 advanced melanoma patients treated with pembrolizumab. Tumor burden dynamics were assessed on serial CT scans using irRECIST and were studied for the association with OS.Results: Among 107 patients, 96 patients had measurable tumor burden and 11 had nontarget lesions alone at baseline. In the 96 patients, maximal tumor shrinkage ranged from -100% to 567% (median, -18.5%). Overall response rate was 44% (42/96; 5 immune-related complete responses, 37 immune-related partial responses). Tumor burden remained <20% increase from baseline throughout therapy in 57 patients (55%). Using a 3-month landmark analysis, patients with <20% tumor burden increase from baseline had longer OS than patients with ≥20% increase (12-month OS rate: 82% vs. 53%). In extended Cox models, patients with <20% tumor burden increase during therapy had significantly reduced hazards of death [HR = 0.19; 95% confidence interval (CI), 0.08-0.43; P < 0.0001 univariate; HR = 0.18; 95% CI, 0.08-0.41; P < 0.0001, multivariable]. Four patients (4%) experienced pseudoprogression; 3 patients had target lesion increase with subsequent response, which was noted after confirmed immune-related progressive disease (irPD). One patient without measurable disease progressed with new lesion that subsequently regressed.Conclusions: Tumor burden increase of <20% from the baseline during pembrolizumab therapy was associated with longer OS, proposing a practical marker for treatment decision guides that needs to be prospectively validated. Pseudoprogressors may experience response after confirmed irPD, indicating a limitation of the current strategy for immune-related response evaluations. Evaluations of patients without measurable disease may require further attention. Clin Cancer Res; 23(16); 4671-9. ©2017 AACR.

Drug-Related Pneumonitis in the Era of Precision Cancer Therapy

Drug-related pneumonitis as a result of novel cancer therapy provides new challenges for providers of cancer care in the era of precision medicine. Awareness of this emerging entity and knowledge of its manifestations and management guidelines are essential for state-of-the-art practice of clinical oncology. Here, we provide a detailed review of drug-related pneumonitis that develops during precision cancer therapies using immune-checkpoint inhibitors and molecular targeting agents, and we summarize the emerging data that have been obtained by recent investigations to provide a state-of-the-art overview for clinicians involved in cancer care. We focus on immune-checkpoint inhibitor-related pneumonitis, which is an immune-related adverse event of growing interest and increasing clinical significance in current oncology practice that has rapidly expanding access to these agents. Clinical characteristics, radiographic spectrum, and risk factors and outcome of pneumonitis are described for each class of agents, and current treatment guidelines and monitoring recommendations are discussed. This review also indicates the area of unmet clinical need and provides direction for future investigations, as well as emphasizing the importance of a multidisciplinary approach to further understand the mechanisms, develop methods for accurate diagnosis, and optimize management guidelines of drug-related pneumonitis in the era of precision oncology.

Immune-related tumor response dynamics in melanoma patients (pts) treated with pembrolizumab: Identifying markers for clinical outcome and treatment decisions

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Background: PD-1 inhibitors have shown marked efficacy in advanced melanoma and are associated with unique response patterns. We aimed to characterize the tumor burden dynamics and identify quantitative imaging markers for overall survival (OS) in melanoma pts treated with pembrolizumab. Methods: The study included 107 advanced melanoma pts (63 males; median age: 63) treated with pembrolizumab monotherapy at DFCI. Tumor burden dynamics were assessed on serial CT scans during therapy by irRECIST, which uses unidimensional measurements and includes new lesions in tumor burden [Clin Cancer Res. 2013;19:3936-43]. The relationships between tumor burden dynamics and OS were studied. Results: Among 107 pts, 96 pts had measurable tumor burden at baseline and 11 had non-target lesions alone at baseline. Among the 96 pts, maximal tumor shrinkage ranged from -100% to 567% (median:-18.5%). Overall response rate was 44% (42/96; irCR in 5, irPR in 37). Tumor burden remained < 20% increase from baseline throughout therapy in 57 pts (55%). Using a 3-month landmark analysis, pts with < 20% tumor burden increase from baseline at 3 months had longer OS than pts with ≥ 20% increase (12-month OS rate: 82 vs. 53%). In extended Cox models, pts with < 20% tumor burden increase during therapy had significantly reduced hazards of death (HR = 0.19, 95%CI: 0.08–0.43, p < 0.0001 univariate; HR = 0.18, 95%CI: 0.08-0.41, p < 0.0001, multivariable). Five pts (5%) experienced pseudoprogression; 3 pts had increase of target lesions with subsequent response, which was noted after confirmed irPD on consecutive scans. Two pts with no measurable tumor burden progressed with new/non-target lesions that subsequently regressed. Conclusions: Tumor burden increase of < 20% from the baseline during pembrolizumab therapy was associated with longer OS, proposing a practical prognostic marker to guide treatment decisions. Pseudoprogressors may experience response after confirmed irPD, indicating a limitation of the current strategy for immune-related response assessment. Evaluations of non-measurable tumor burden may require further attention in the clinical setting of immuno-oncology.

Imaging of hepatic toxicity of systemic therapy in a tertiary cancer centre: chemotherapy, haematopoietic stem cell transplantation, molecular targeted therapies, and immune checkpoint inhibitors

The purpose of this review is to familiarise radiologists with the spectrum of hepatic toxicity seen in the oncology setting, in view of the different systemic therapies used in cancer patients. Drug-induced liver injury can manifest in various forms, and anti-neoplastic agents are associated with different types of hepatotoxicity. Although chemotherapy-induced liver injury can present as hepatitis, steatosis, sinusoidal obstruction syndrome, and chronic parenchymal damages, molecular targeted therapy-associated liver toxicity ranges from mild liver function test elevation to fulminant life-threatening acute liver failure. The recent arrival of immune checkpoint inhibitors in oncology has introduced a new range of immune-related adverse events, with differing mechanisms of liver toxicity and varied imaging presentation of liver injury. High-dose chemotherapy regimens for haematopoietic stem cell transplantation are associated with sinusoidal obstruction syndrome. Management of hepatic toxicity depends on the clinical scenario, the drug in use, and the severity of the findings. In this article, we will (1) present the most common types of oncological drugs associated with hepatic toxicity and associated liver injuries; (2) illustrate imaging findings of hepatic toxicities and the possible differential diagnosis; and (3) provide a guide for management of these conditions.

Incidence of Programmed Cell Death 1 Inhibitor-Related Pneumonitis in Patients With Advanced Cancer: A Systematic Review and Meta-analysis

Importance

Programmed cell death 1 (PD-1) inhibitor-related pneumonitis is a rare but clinically serious and potentially life-threatening adverse event. Little is known about its incidence across different tumor types and treatment regimens.

Objective

To compare the incidence of PD-1 inhibitor-related pneumonitis among different tumor types and therapeutic regimens.

Data Sources

A PubMed search through November 10, 2015, and a review of references from relevant articles. For the PubMed search, the following keywords or corresponding Medical Subject Heading terms were used: nivolumab, pembrolizumab, and PD-1 inhibitor.

Study Selection

Twenty-six original articles of PD-1 inhibitor trial results were identified. Among them, 20 studies of melanoma, non-small cell lung cancer (NSCLC), or renal cell carcinoma (RCC) were eligible for a meta-analysis.

Data Extraction and Synthesis

The data were extracted by 1 primary reviewer and then independently reviewed by 2 secondary reviewers following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Comparisons of the incidence were based on marginal, exact generalized linear models with generalized estimating equations.

Main Outcomes and Measures

Incidence of all-grade and grade 3 or higher pneumonitis and pneumonitis-related deaths.

Results

Twenty studies of single-tumor-type trials of PD-1 inhibitor (12 melanoma studies, 5 NSCLC studies, and 3 RCC studies) (a total of 4496 unique patients) were included in the meta-analysis. The overall incidence of pneumonitis during PD-1 inhibitor monotherapy was 2.7% (95% CI, 1.9%-3.6%) for all-grade and 0.8% (95% CI, 0.4%-1.2%) for grade 3 or higher pneumonitis. The incidence was higher in NSCLC for all-grade (4.1% vs 1.6%; P = .002) and grade 3 or higher pneumonitis (1.8% vs 0.2%; P < .001) compared with melanoma. The incidence in RCC was higher than in melanoma for all-grade pneumonitis (4.1% vs 1.6%; P < .001) but not for grade 3 or higher pneumonitis. Four pneumonitis-related deaths were observed in patients with NSCLC in the monotherapy group. Pneumonitis was more frequent during combination therapy than monotherapy for all-grade (6.6% vs 1.6%; P < .001) and grade 3 or higher pneumonitis (1.5% vs 0.2%; P = .001) in melanoma, with 1 pneumonitis-related death during combination therapy. Multivariable analyses demonstrated higher odds of pneumonitis in NSCLC for all-grade (odds ratio [OR], 1.43; 95% CI, 1.08-1.89; P = .005) and grade 3 or higher pneumonitis (OR, 2.85; 95% CI, 1.60-5.08; P < .001) and in RCC for all-grade pneumonitis (OR, 1.59; 95% CI, 1.32-1.92; P < .001) compared with melanoma. The combination therapy had significantly higher odds than monotherapy for all-grade (OR, 2.04; 95% CI, 1.69-2.50; P < .001) and grade 3 or higher pneumonitis (OR, 2.86; 95% CI, 1.79- 4.35; P < .001).

Conclusions and Relevance

The incidence of PD-1 inhibitor-related pneumonitis was higher in NSCLC and RCC and during combination therapy. These findings contribute to enhance awareness among clinicians and support further investigations to meet the clinical needs.

Radiation Therapy for Soft-Tissue Sarcomas: A Primer for Radiologists

Radiation therapy (RT) plays an important role in multimodality therapy for soft-tissue sarcomas (STS). RT treatment paradigms have evolved significantly in recent years, and many different complex RT modalities are commonly used in STS. These include external-beam RT, intensity-modulated RT, stereotactic body RT, and brachytherapy. Imaging is essential throughout the treatment process. Plain radiographs, computed tomography (CT), magnetic resonance imaging, ultrasonography, and positron emission tomography/CT all play potential roles in the management of STS. Before RT, high-quality imaging is needed to direct management decisions, both by global tumor staging and detailed assessment of the extent of local disease. At the time of RT, precise planning imaging is required to delineate tumor volumes, including gross tumor volume, clinical target volume, and planning target volume, which are used to direct therapy. In addition, imaging at the time of RT must outline the location of adjacent vital organs, to optimize treatment efficacy and minimize toxicity. After RT, imaging is needed to assess the patient for tumor response to therapy. In addition, imaging at regular intervals is often required to monitor for recurrence of disease and potential complications of therapy. The purpose of this review is to familiarize radiologists with the indications for RT in STS, common therapeutic modalities used, roles of imaging throughout the treatment process, and complications of therapy.

Solitary Fibrous Tumors: 2016 Imaging Update

Optimal management of solitary fibrous tumor requires a multidisciplinary approach with proper histopathological mapping and use of various imaging modalities for exact delineation of primary tumor and metastatic disease if present. In this article, the authors present a comprehensive review of the spectrum of imaging findings of solitary fibrous tumors involving various organ systems and discuss the role of molecular targeted therapies in the management of metastatic disease.

Radiology Consultation in the Era of Precision Oncology: A Review of Consultation Models and Services in the Tertiary Setting

The purpose of the article is to describe the various radiology consultation models in the Era of Precision Medicine. Since the inception of our specialty, radiologists have served as consultants to physicians of various disciplines. A variety of radiology consultation services have been described in the literature, including clinical decision support, patient-centric, subspecialty interpretation, and/or some combination of these. In oncology care in particular, case complexity often merits open dialogue with clinical providers. To explore the utility and impact of radiology consultation services in the academic setting, this article will further describe existing consultation models and the circumstances that precipitated their development. The hybrid model successful at our tertiary cancer center is discussed. In addition, the contributions of a consultant radiologist in breast cancer care are reviewed as the archetype of radiology consultation services provided to oncology practitioners.

Evolving Cancer Classification in the Era of Personalized Medicine: A Primer for Radiologists

Traditionally tumors were classified based on anatomic location but now specific genetic mutations in cancers are leading to treatment of tumors with molecular targeted therapies. This has led to a paradigm shift in the classification and treatment of cancer. Tumors treated with molecular targeted therapies often show morphological changes rather than change in size and are associated with class specific and drug specific toxicities, different from those encountered with conventional chemotherapeutic agents. It is important for the radiologists to be familiar with the new cancer classification and the various treatment strategies employed, in order to effectively communicate and participate in the multi-disciplinary care. In this paper we will focus on lung cancer as a prototype of the new molecular classification.

Phase II and Biomarker Study of Cabozantinib in Metastatic Triple-Negative Breast Cancer Patients

Currently, no targeted therapies are available for metastatic triplenegative breast cancer (mTNBC). We evaluated the safety, efficacy, and biomarkers of response to cabozantinib, a multikinase inhibitor, in patients with mTNBC. We conducted a single arm phase II and biomarker study that enrolled patients with measurable mTNBC. Patients received cabozantinib (60 mg daily) on a 3-week cycle and were restaged after 6 weeks and then every 9 weeks. The primary endpoint was objective response rate. Predefined secondary endpoints included progression-free survival (PFS), toxicity, and tissue and blood circulating cell and protein biomarkers. Of 35 patients who initiated protocol therapy, 3 (9% [95% confidence interval (CI): 2, 26]) achieved a partial response (PR). Nine patients achieved stable disease (SD) for at least 15 weeks, and thus the clinical benefit rate (PR+SD) was 34% [95% CI: 19, 52]. Median PFS was 2.0 months [95% CI: 1.3, 3.3]. The most common toxicities were fatigue, diarrhea, mucositis, and palmar-plantar erythrodysesthesia. There were no grade 4 toxicities, but 12 patients (34%) required dose reduction. Two patients had TNBCs with MET amplification. During cabozantinib therapy, there were significant and durable increases in plasma placental growth factor, vascular endothelial growth factor (VEGF), VEGF-D, stromal cell-derived factor 1a, and carbonic anhydrase IX, and circulating CD3 + cells and CD8 + T lymphocytes, and decreases in plasma soluble VEGF receptor 2 and CD14+ monocytes (all p < .05). Higher baseline concentrations of soluble MET (sMET) associated with longer PFS (p = .03). In conclusion, cabozantinib showed encouraging safety and efficacy signals but did not meet the primary endpoint in pretreated mTNBC. Exploratory analyses of circulating biomarkers showed that cabozantinib induces systemic changes consistent with activation of the immune system and antiangiogenic activity, and that sMET should be further evaluated a potential biomarker of response.

IMPLICATIONS FOR PRACTICE

Triple-negative breast cancer (TNBC)-a disease with a dearth of effective therapies-often overexpress MET, which is associated with poor clinical outcomes. However, clinical studies of agents targeting MET and VEGF pathways-alone or in combination-have shown disappointing results. This study of cabozantinib (a dual VEGFR2/MET) in metastatic TNBC, while not meeting its prespecified endpoint, showed that treatment is associated with circulating biomarker changes, and is active in a subset of patients. Furthermore, this study demonstrates that cabozantinib therapy induces a systemic increase in cytotoxic lymphocyte populations and a decrease in immunosuppressive myeloid populations. This supports the testing of combinations of cabozantinib with immunotherapy in future studies in breast cancer patients.

Immune-related response assessment during PD-1 inhibitor therapy in advanced non-small-cell lung cancer patients

Background

Tumor response characteristics using immune-related RECIST1.1 (irRECIST1.1) in advanced non-small-cell lung cancer (NSCLC) patients treated with nivolumab monotherapy in the clinical setting have not been previously described with a direct comparison with the assessments according to the conventional RECIST1.1.

Methods

Fifty-six advanced NSCLC patients treated with nivolumab monotherapy after its Food and Drug Administration (FDA) approval were retrospectively studied. Tumor burden was quantified on serial CT scans during therapy using irRECIST1.1, which uses unidimensional measurements and includes new lesion measurements in total tumor burden. Response assessments by irRECIST1.1 were compared with assessments by RECIST1.1. Responses of individual lesions in different organs were also compared.

Results

Tumor burden change at best overall response ranged from −66.8 to +278.1% (median: +3.9%). Response rate was 14% (8/56; 8 partial responses, 0 complete responses) by irRECIST1.1 and by RECIST1.1. Time-to-progression (TTP) by irRECIST1.1 was longer than TTP by RECIST1.1 (median TTP: not reached vs. 1.9 months, respectively). No patients experienced pseudoprogression during the study. Among 128 target lesions, the lesion-based size change at best response differed significantly across different organs, with adrenal lesions and lymph nodes having greater size decrease, followed by lung, while liver and other miscellaneous lesions had lesser degree of size decrease (p = 0.002).

Conclusions

Immune-related response evaluations using irRECIST1.1 in advanced NSCLC patients treated with nivolumab resulted in the identical response rate and longer TTP compared to RECIST1.1. No pseudoprogression cases were observed during the study. Adrenal lesions and lymph nodes were more responsive and liver lesions were less responsive to nivolumab.

Electronic supplementary material

The online version of this article (doi:10.1186/s40425-016-0193-2) contains supplementary material, which is available to authorized users.