No abstract

Tumor immune evasion is one of the hallmarks of cancer, and expression of the B7 family of immune checkpoints (PD-L1, PD-L2, B7-H3, B7x and HHLA2) is one mechanism of immune evasion by tumors to suppress T-cell function. Antibodies blocking these interactions of B7-1/B7-2/CTLA-4 and PD-L1/PD-L2/ PD-1 have had remarkable clinical success in several cancers and are less toxic than traditional chemotherapy. Even though only a small proportion of patients respond to checkpoint blockade, the duration of such responders due to immunological memory is remarkable and is longer than would be expected with any other agent in refractory disease. In this article, we review the therapeutic trials of blocking these pathways in human lung cancer and hematological malignancies.

Under the broader category of extracellular vesicles (EVs), exosomes are now well recognized for their contribution and potential for biomedical research. During the last ten years, numerous technologies for purification and characterization of EVs have been developed. This enhanced knowledge has resulted in the development of novel applications of EVs. This review is an attempt to capture the exponential growth observed in EV science in the last decade and discuss the future potential to improve our understanding of EVs, develop technologies to overcome current limitations, and advance their utility for human benefit, especially in cancer medicine. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease

Background Pancreatic neuroendocrine tumors (panNETs) are a rare group of tumors that make up 2%–3% of pancreatic tumors. Recommended treatment for panNETs generally consists of resection for symptomatic or large asymptomatic tumors; however, optimal management for localized disease is still controversial, with conflicting recommendations in established guidelines. Our study aim is to compare surgical intervention versus active surveillance in nonmetastatic panNETs by size of primary tumor. Materials and Methods Using the National Cancer Database, we identified 2,004 patients diagnosed with localized well‐differentiated, nonfunctional panNETs (NF‐panNETs) between 2004 and 2015. Patients’ clinicopathologic characteristics, treatment modalities, and overall survival (OS) were analyzed using frequency statistics, chi‐square, and Kaplan‐Meier curves. The objective of the study is to assess the outcome of surgical resection versus nonoperative management in patients with panNETs with different tumor sizes. Results Tumor sizes were divided into three categories: <1 cm, 1–2 cm, and >2 cm. The number of patients with tumor size <1 cm, 1–2 cm, and >2 cm was 220 (11%), 794 (39.6%), and 990 (49.4%), respectively. Overall, 1,781 underwent surgical resection, whereas 223 patients did not. Median follow‐up was 25.9 months. After adjusting for covariates, surgical resection was associated with improved OS in patients with tumor size 1–2 cm (hazard ratio [HR] = 0.37) and >2c m (HR = 0.30) but not <1 cm (HR = 2.81). Independent prognostic factors were age at diagnosis, Charlson‐Deyo comorbidity score, stage, tumor location, and surgical resection. Higher tumor grade was not associated with worse OS. Conclusion Our findings suggest that active surveillance is potentially a safe approach for NF‐panNETs <1 cm. Larger tumors likely need active intervention. Intermediate‐grade tumors did not result in worse survival outcome compared with low‐grade tumors. Future studies might consider prospective randomized clinical trials to validate our findings. Implications for Practice The present study seeks to address the discrepancy in treatment recommendations in the management of nonfunctional pancreatic neuroendocrine tumors (NF‐panNETs) by evaluating whether surgical resection is associated with improved overall survival in different tumor size groups as well as elucidating independent prognostic factors in patients with NF‐panNETs. Data from the National Cancer Database were reviewed. This study's findings suggest that active surveillance is potentially a safe approach for NF‐panNETs <1 cm. Larger tumors likely need active intervention. Independent prognostic factors include age at diagnosis, Charlson‐Deyo comorbidity score, stage, tumor location, and surgical resection. These findings will help guide medical and surgical oncologists when formulating treatment plans for patients with small NF‐panNETs.