Liver metastases resection for gastric and esophageal tumors: is there enough evidence to go down this path?

Introduction: Surgical resection of liver metastases from colorectal and neuroendocrine tumours has become a standard of care for resectable patients with isolated hepatic disease and good performance status, leading to extended survival in a carefully selected subgroup of these patients. However, the role of hepatic surgery in gastric and oesophageal liver metastases is controversial and not clearly defined.

Areas covered:a systematic electronic literature search was performed to select the most representative evidence regarding hepatectomies in liver metastases from these two tumours. PubMed, Medline, Embase Ovid and Google Scholar databases were scanned for articles written in English and published in peer-reviewed journals between 1994 and May 2016.

Expert commentary: Given the shortage of randomised studies and the limited number of patients in many of the studies discussed here, the evidence base for the use of hepatectomies in these settings is not strong. Thus, while the data for resections of gastric liver metastases may in particular seem encouraging, the results should be interpreted with caution.     

Cabozantinib for the treatment of kidney cancer

Introduction: Cabozantinib is a small molecule tyrosine kinase inhibitor that initially showed activity in medullary thyroid cancer and was recently approved by the Food and Drug Administration for the treatment of metastatic renal cell carcinoma after progression on first line therapy.

Areas covered: In the METEOR trial, cabozantinib demonstrated significantly improved efficacy in all three endpoints; response rates, progression free survival and overall survival in a randomized trial with everolimus as an active comparator. Cabozantinib also showed activity in the front line setting in RCC within the CABOSUN trial. The study randomized untreated metastatic RCC patients to either cabozantinib or sunitinib and the former showed improved progression free survival which was the primary endpoint. The future holds promise for indications in other malignancies, given the preliminary efficacy and unique mechanism of action of cabozantinib.

In this review we address the mechanism of action, pharmacodynamics and pharmacokinetics of cabozantinib, and also review the development pathway of this agent in the treatment of advanced renal cell carcinoma. The potential benefit in specific patient populations, such as poor risk patients and bone metastases subgroups is also discussed.

Expert commentary: The clinical applications of cabozantinib will be addressed within the context of the current competitive therapeutic landscape of RCC.     

The safety and efficacy of bevacizumab in the treatment of patients with recurrent or metastatic cervical cancer

Introduction: Bevacizumab is a recombinant humanized monoclonal antibody against vascular endothelial growth factor (VEGF). (Avastin; Genetech, Inc, San Francisco, CA) Angiogenesis is blocked by the binding of bevacizumab to VEGF, inhibiting the binding of this ligand to the VEGF receptor. On 14 August 2014 the Food and Drug Administration (FDA) approved use of bevacizumab in persistent, recurrent, or metastatic cervical cancer.

Areas covered: Herein we review pharmacodynamics and kinetics, clinical data and treatment-related toxicities of bevacizumab in the treatment of metastatic, recurrent or persistent cervical cancer. Additionally, future areas of development are reviewed.

Expert commentary: Anti-angiogenesis therapy with bevacizumab is central to metastatic, persistent, and recurrent cervical cancer treatment. Additional anti-angiogenesis drugs are in development. Future studies will need to establish if the addition of multiple anti-angiogenesis agents or anti-angiogenesis in combination with immunotherapy is more effective than bevacizumab with chemotherapy.     

Adjuvant therapy for advanced renal cell carcinoma

Introduction: Locally advanced, non-metastatic renal cell carcinoma (RCC) is conventionally managed with surgery. However, patients are at a high risk of RCC recurrence and have poor survival outcomes. An effective adjuvant systemic treatment is needed to improve on these outcomes. Targeted molecular and immune-based therapies have been investigated, or are under investigation, but their role in this setting remains unclear.

Areas covered: A comprehensive search of PubMed and ClinicalTrials.gov was performed for relevant literature. The following topics pertinent to adjuvant therapy in RCC were evaluated: strategies for patient selection, cytokine-based immunotherapy, vaccine therapy, VEGF and non-VEGF targeted molecular agents, and immune checkpoint inhibitors.

Expert commentary: Strong evidence for the incorporation of adjuvant therapy in high-risk RCC is lacking. Multiple targeted molecular therapies have been examined with only one approved for use. Genetic and molecular-based prognostic models are needed to determine who may benefit from adjuvant therapy. Developing adjuvant therapy strategies in the future depends on the results of important ongoing trials with immunotherapy and targeted agents.     

Targeted therapy for metastatic colorectal cancer

Introduction: Outcomes in metastatic colorectal cancer are improving, with better understanding and use of targeted therapies.

Areas covered: A review of the literature and recent conference presentations was undertaken on the topic of systemic treatment of metastatic colorectal cancer. This article reviews the current evidence for targeted therapies in advanced colorectal cancer, including up-to-date data regarding anti-epidermal growth factor receptor (EGFR) and anti-vascular endothelial growth factor (VEGF) agents, the relevance of primary tumor location and novel subgroups such as BRAF mutated, HER2 amplified, and mismatch-repair-deficient cancers.

Expert commentary: EGFR-targeted and VEGF-targeted antibodies are now routinely incorporated into treatment strategies for metastatic colorectal cancer (mCRC). The use of EGFR-targeted antibodies should be restricted to patients with extended RAS wild-type profiles, and there is evidence that they should be further restricted to patients with left-sided tumors. Clinically, mCRC can be divided into subgroups based on RAS, BRAF, HER2, and MMR status, each of which have distinct treatment pathways.     

Recent advances in intensity modulated radiotherapy and proton therapy for esophageal cancer

Introduction: Radiotherapy is an important component of the standard of care for esophageal cancer. In the past decades, significant improvements in the planning and delivery of radiation techniques have led to better dose conformity to the target volume and improved normal tissue sparing.

Areas covered: This review focuses on the advances in radiotherapy techniques and summarizes the availably dosimetric and clinical outcomes of intensity-modulated radiation therapy (IMRT), volumetric modulated arc therapy, proton therapy, and four-dimensional radiotherapy for esophageal cancer, and discusses the challenges and future development of proton therapy.

Expert commentary: Although three-dimensional conformal radiotherapy is the standard radiotherapy technique in esophageal cancer, the retrospectively comparative studies strongly suggest that the dosimetric advantage of IMRT over three-dimensional conformal radiotherapy can translate into improved clinical outcomes, despite the lack of prospective randomized evidence. As a novel form of conventional IMRT technique, volumetric modulated arc therapy can produce equivalent or superior dosimetric quality with significantly higher treatment efficiency in esophageal cancer. Compared with photon therapy, proton therapy has the potential to achieve further clinical improvement due to their physical properties; however, prospective clinical data, long-term results, and cost-effectiveness are needed.     

Difference between right-sided and left-sided colorectal cancers: from embryology to molecular subtype

Introduction: Colorectal cancer is one of the most common malignancies in the world, and it exhibits differences in incidence, pathogenesis, molecular pathways, and outcome depending on the location of the tumor. Differences in the microbiome, clinical characteristics, and chromosomal and molecular characteristics have been reported between the right and left side of the colon.

Areas covered: This review focuses on the latest developments in epidemiological and chromosomal and molecular studies, which have enhanced our understanding on the underlying genetic and immunological differences between the right-sided colon and the left-sided colorectum in metastatic colorectal cancer.

Expert commentary: The numerous findings regarding differences between right- and left-sided colon cancers should have an impact on colorectal cancer screening and therapy. The location of the colorectal cancer should be considered before group stratification into genetic, clinical, and especially chemotherapy trials. A more tailored approach to colon cancer treatment would be highly desirable if future trials further support the hypothesis of two distinct tumor entities.     

How to use neoadjuvant medical treatment to maximize surgery in melanoma

Introduction: The aim of this work is to discuss the role of neoadjuvant therapy in melanoma patients, namely the potential to improve control and surgical resectability of locoregional disease. Moreover, potential survival benefits for high-risk stage III and IV melanoma patients will be addressed.

Areas covered: In this review, the different available neoadjuvant treatments including chemotherapy, bio-chemotherapy, targeted therapy, immunotherapy and local therapy will be presented and discussed. The PubMed published articles were identified and searched using the following terms located in the publication title: neoadjuvant therapy and melanoma. Studies investigating targeted therapy, immunotherapy and local melanoma treatments were included. Clinicaltrial.gov was also used as a source for recruiting or ongoing but not recruiting neoadjuvant clinical trials, for which no published results are available.

Expert commentary: Targeted therapy and immunotherapy in a neoadjuvant setting are still under investigation and not yet approved, however several neoadjuvant trials are ongoing. Shortly, results from these trials will answer the question whether neoadjuvant treatment translates into survival benefit and improves local disease control in stage III and IV melanoma patients. Immunotherapy and targeted therapy will play as relevant a role as in the metastatic setting, whereas chemotherapy will be used seldom.     

Nivolumab for the treatment of colorectal cancer

Introduction: Despite a variety of therapies for advanced metastatic colorectal cancer being available, the outcomes in this malignancy remain suboptimal. Immunotherapy has been slow to impact the management of this patient group. Checkpoint inhibitors, such as nivolumab, have had disappointing results when used broadly. However, for the subset of patients with microsatellite unstable colorectal cancer, the use of checkpoint inhibitors such as nivolumab appears to be transformative, and will provide a new therapeutic option for patient with advanced disease.

Areas covered: Nivolumab gained regulatory approval for the treatment of dMMR/MSI-H metastatic colorectal cancer in mid 2017. The current review will summarize the clinical evidence of checkpoint inhibitors in metastatic colorectal cancer, with a focus on nivolumab.

Expert commentary: For patients with dMMR/MSI-H mCRC, the use of nivolumab has now been shown to have objective and sustained clinical responses in a pivotal phase II trial. While additional data are limited, the therapeutic role for augmenting an immune response in metastatic colorectal cancer is likely to continue to expand. Further combination trials of nivolumab with immunologic and non-immunologic agents are ongoing.     

Therapeutic approaches for refractory germ cell cancer

Introduction: Most germ cell cancer patients with metastatic disease are cured by cisplatin-based combination chemotherapy. 30% of metastatic patients will develop relapse or progress despite adequate first-line treatment and will require salvage therapy, with about 10% of metastasized patients ultimately developing platinum-resistant and fatal disease.

Areas covered: Based on a comprehensive literature search of MEDLINE, EMBASE and conference proceedings of ESMO, ASCO and EAU meetings, this review provides an overview on current and potential future treatment options for platinum-refractory germ cell cancer patients including cytostatics and molecularly targeted therapies.

Expert commentary: Treatment of platinum-refractory disease remains challenging and long-term survival is rarely achieved despite multimodal treatment approaches. Targeted treatment approaches do not yet play a role in the treatment of platinum-refractory disease due to lacking efficacy in small, unselected clinical trials. Inclusion of patients into clinical trials is strongly recommended.     

Advances in the use of surgery and multimodality treatment for N2 non-small cell lung cancer

Introduction: Stage IIIA-N2 non-small cell lung cancer (NSCLC) represents a heterogeneous group of bronchogenic carcinomas with locoregional involvement. Different categories of N2 disease exist, ranging from unexpectedly encountered N2 involvement after detailed preoperative staging or ‘surprise’ N2, to potentially resectable disease treated within a combined modality setting, and finally, bulky N2 involvement treated by chemoradiation.

Areas covered: Large randomised controlled trials and meta-analyses on stage IIIA-N2 NSCLC have been published but their implications for treatment remain a matter of debate. No definite recommendations can be provided as diagnostic and therapeutic algorithms vary according to local, national or international guidelines.

Expert commentary: From the literature, it is clear that patients with stage IIIA-N2 NSCLC should be treated by combined modality therapy including chemotherapy, radiotherapy and surgery. The relative contribution of each modality has not been firmly established. For patients undergoing induction therapy, adequate restaging is important as only down-staged patients will clearly benefit from surgical resection. Each patient should be discussed within a multidisciplinary team to determine the best diagnostic and therapeutic approach according to the specific local expertise. In the near future, it might be expected that targeted therapies and immunotherapy will be incorporated as possible therapeutic options.     

Combination targeted therapy of VEGFR inhibitor,sorafenib, with an mTOR inhibitor,sirolimus induced a remakable response of rapid progressive Uterine PEComa

Perivascular epithelioid cell tumor is a rare tumor. To date, there is no consensus of therapy to be recommended for unresectable disease. For a low incidence and a rarely curable disease, the finding of new therapy is essential.

Here we report the first case of a patient with perivascular epithelioid cell tumor whose disease had a rapid progression after surgery and had a rapid remarkable response of combination therapy of a VEGFR inhibitor, sorafenib, with an mTOR inhibitor, sirolimus.

This result may have potential to deliver a new treatment option and inhibiting the mTOR pathway combined with inhibiting the VEGF pathways may be a useful strategy for malignant PEComas.     

Intra-arterial therapies for liver cancer: assessing tumor response

Introduction: Intra-arterial therapies (IATs) play an integral role in the management of unresectable hepatocellular carcinoma and liver metastases. The ability to accurately assess tumor response to intra-arterial therapies is crucial for clinical management. Several one- and two-dimensional manual imaging-based response assessment techniques, based both on tumor size or enhancement, have shown to be highly subjective and merely surrogate for the actual tumor as a whole.

Areas covered: Given the currently existing literature, we will discuss all available tumor assessment techniques and criteria for liver cancer with a strong emphasis on 3D quantitative imaging biomarkers of tumor response in this review.

Expert commentary: The growing role of information technology in medicine has brought about the advent of software-assisted, segmentation-based assessment techniques that address the outstanding issues of a subjective reader and provide for more accurate assessment techniques for the locally treated lesions. Three-dimensional quantitative tumor assessment techniques are superior to one- and two-dimensional measurements. This allows for treatment alterations and more precise targeting, potentially resulting in improved patient outcome.     

Radiofrequency ablation combined with percutaneous ethanol injection for hepatocellular carcinoma: a systematic review and meta-analysis

Background: Radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) are important treatments for patients with hepatocellular carcinoma (HCC) who are not eligible for resection and liver transplantation. Therefore, it is important to establish comparisons between RFA, PEI and the two therapies in combination.

Aims: To evaluate the clinical efficacy and safety of combined RFA-PEI versus monotherapy with either RFA or PEI for HCC to provide references for clinical practice and further research.

Methods: We searched all eligible studies published before September 2015 in the Cochrane Library, PubMed, Embase, Web of Science and Chinese databases, such as CBM, CNKI, VIP and WanFang and also retrieved papers from other sources. All relevant controlled trials were collected. Meta-analyses were performed using RevMan version 5.3 software (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark).

Results: Thirteen trials with 1621 patients were identified. Compared with PEI, RFA was associated with significant improvement in overall survival (OS) rate at 1, 2, 3 and 4 years, cancer-free survival (CFS) rate at 1, 2 and 3 years and complete tumour necrosis. RFA was associated with a significant reduction in the local recurrence rate at 1, 2 and 3 years. However, RFA was also associated with a higher total risk of complications. Compared with RFA alone, combined RFA-PEI was associated with a significant improvement in the OS rate at 1.5, 2 and 3 years and a significant reduction in the local recurrence rate. However, combined RFA-PEI was also associated with a higher risk of fever.

Conclusion: The combination of RFA and PEI appears to be the optimal treatment strategy when considering combined RFA-PEI or either RFA or PEI alone. Combined RFA-PEI significantly improves OS and reduces the risk of local recurrence without increasing major complications. Further large-scale studies are needed to assess economic outcomes and quality of life.     

Opportunities and challenges of long term anti-estrogenic adjuvant therapy: treatment forever or intermittently?

Introduction: Extended adjuvant (5–10 years) therapy targeted to the estrogen receptor (ER) has

significantly decreased mortality from breast cancer (BC).

Areas covered: Translational research advanced clinical testing of extended adjuvant therapy with tamoxifen or aromatase inhibitors (AIs). Short term therapy or non-compliance increase

recurrence, but surprisingly recurrence and death does not increase dramatically after 5 years of adjuvant therapy stops.

Expert commentary: Compliance ensures optimal benefit from extended antihormone adjuvant therapy.Retarding acquired resistance using CDK4/6 or mTOR inhibitors is discussed. Preventing acquired resistance from mutations of ER could be achieved with Selective ER Downregulators (SERDs), eg fulvestrant. Fulvestrant is a depot injectable so oral SERDs are sought for extended use. In reality, a ‘super SERD’ which destroys ER but improves women’s health like a Selective ER Modulator (SERM), would aid compliance to prevent recurrence and death. Estrogen-induced apoptosis occurs in 30% of BC with antihormone resistance. The ‘one in three’ rule that dictates that one in three unselected patients respond to either hormonal or antihormonal therapy in BC occurs with estrogen or antiestrogen therapy and must be improved. The goal is to maintain patients for their natural lives by blocking cancer cell survival through precision medicine using short cycles of estrogen apoptotic salvage therapy, and further extended antihormone maintenance.     

Myoglobin does not predict local toxicity in isolated limb perfusion

Introduction: Isolated limb perfusion (ILP) is a treatment option for patients with in-transit metastases of malignant melanoma in the extremities, as well as locally advanced sarcoma. ILP allows for a delivery of high-dose chemotherapy to an isolated extremity with minimal systemic toxicity. However, local toxicity like oedema, blistering, nerve damage and compartment syndrome can occur. Myoglobin measurements have been used as a screening method to predict the most severe cases of local toxicity. The aim was to investigate if myoglobin is a predictive factor for local toxicity after ILP in patients with melanoma in-transit metastases.

Methods: One hundred and ninety-three patients were treated for the first time with ILP for in-transit metastases between 2001 and 2015. Myoglobin was measured once the first hours after the perfusion (POD0), and for the first five post-operative days (POD1-5). Local toxicity was graded according to Wieberdink, and grouped in mild (I and II), moderate (III), and severe (IV and V). Wieberdink-groups were compared with myoglobin measurements, and myoglobin measurements were compared between gender, perfusion time, perfusion temperature and cannulated vessels.

Results: There is no statistically significant difference in myoglobin serum levels during the first five days post perfusion between patients suffering from mild, moderate or severe local toxicity. There is no difference between toxicity groups when it comes to distribution of sex, tumour size, or tumour numbers.

Conclusion: Levels of myoglobin do not predict local toxicity for patients with melanoma in-transit metastases treated with ILP when measured during the first five post-operative days.     

The diagnosis and management of extramammary Paget’s disease

Introduction: Extramammary Paget’s disease (EMPD) is a rare neoplastic condition that commonly affects the anogenital area in the elderly. Owing to its low incidence, limited data regarding EMPD’s diagnosis and treatment have been available. This review article aims to explore the current knowledge of EMPD to improve the management of this disease.

Areas covered: This review outlines the diagnosis and management of EMPD. Articles on this issue that had been published in PubMed were identified and surveyed. We provide an overview of the reported studies, focusing on the recent advances in this field.

Expert commentary: A new TNM staging system specific for EMPD has been proposed in Japan; the T category was classified by tumor thickness and lymphovascular invasion, the N category by the number of metastatic lymph nodes, and the M category by systemic metastases. As new diagnostic tools for EMPD, dermoscopy and reflectance confocal microscopy have emerged. Recent reports about Mohs micrographic surgery, mapping biopsy, radiation therapy, photodynamic therapy, topical imiquimod, conventional chemotherapy, and targeted therapy are also discussed. Despite the increasing publications of EMPD, limited information on this condition is available and the accumulation of more data is required.     

Nivolumab in squamous cell carcinoma of the head and neck

Introduction: The prognosis of recurrent/metastatic (R/M) squamous cell carcinoma of the head and neck (HNSCC) after failure of first line chemotherapy is dismal. Until the publication of the results of CheckMate 141, not a single agent provided any survival benefit as a second line treatment for R/M HNSCC.

Areas covered: A comprehensive review of the literature was conducted on the role of nivolumab in HNSCC.

Expert commentary: Nivolumab is approved by the Food and Drug Administration for the treatment of patients based on the results of CheckMate 141 showing an overall survival benefit as compared to standard care (single agent docetaxel, methotrexate, or cetuximab). Of particular interest are immune-related adverse events which should be managed according to published guidelines.     

Dermatofibrosarcoma protuberans and gastrointestinal stromal tumor as models for targeted therapy in soft tissue sarcomas

Introduction: The development of novel targeted treatment in soft tissue sarcomas (STS) is important since many sarcoma subtypes are resistant to chemotherapy and effective therapeutic options are limited.

Areas covered: This review discusses the molecular background and treatment in two STS types which became a model for targeted therapy – gastrointestinal stromal tumor (GIST) and dermatofibrosarcoma protuberans (DFSP). DFSP is characterized, by chromosomal translocation which results in the formation of COL1A1-PDGFB fusion gene causing platelet-derived growth factor receptor beta(PDGFRB) signaling activation in tumor cells. The majority of GIST malignancies are associated with activating, constitutive, mutually exclusive mutations of two genes: KIT and PDGFRA (PDGF receptor-alpha). Molecular diagnostics are an essential part of GIST and DFSP management. The first effective systemic therapy in clinical practice in GIST and DFSP was imatinib – tyrosine kinase inhibitor acting on KIT and PDGFR alpha/beta. Use of the drug revolutionized treatment of inoperable and/or metastatic cases and demonstrated activity in locally advanced cases. This review summarizes the analogies of therapy and perspectives of GIST and DFSP management.

Expert commentary: The next generation of kinase inhibitors are approved for use after the progression of GIST during imatinib treatment. However, little is known about treatment beyond progression in DFSP.     

Pembrolizumab for the treatment of bladder cancer

Introduction: Until recently, patients with locally advanced or metastatic urothelial carcinoma after progression on cisplatin-containing chemotherapy had limited systemic treatment options with no significant survival benefit and poor tolerability. Advances in the field of immunotherapy with the introduction of checkpoint inhibitors have led to paradigm shifts in the treatment of various malignancies.

Areas covered: The current review will summarize the clinical evidence of checkpoint inhibitors in bladder cancer, with a focus on pembrolizumab.

Expert commentary: Category 1 evidence indicates that the checkpoint inhibitor pembrolizumab improves overall survival in patients with locally advanced or metastatic urothelial carcinoma who progressed after or during cisplatin-containing therapy as compared to current standard of care chemotherapy. Phase 1 and 2 evidence also indicates that checkpoint inhibitors are active in first line in patients who are ineligible for cisplatin-containing chemotherapy.