Characterizing the Tumor Immune Microenvironment with Tyramide-Based Multiplex Immunofluorescence.

Multiplex immunofluorescence (mIF) allows simultaneous antibody-based detection of multiple markers with a nuclear counterstain on a single tissue section. Recent studies have demonstrated that mIF is becoming an important tool for immune profiling the tumor microenvironment, further advancing our understanding of the interplay between cancer and the immune system, and identifying predictive biomarkers of response to immunotherapy. Expediting mIF discoveries is leading to improved diagnostic panels, whereas it is important that mIF protocols be standardized to facilitate their transition into clinical use. Manual processing of sections for mIF is time consuming and a potential source of variability across numerous samples. To increase reproducibility and throughput we demonstrate the use of an automated slide stainer for mIF incorporating tyramide signal amplification (TSA). We describe two panels aimed at characterizing the tumor immune microenvironment. Panel 1 included CD3, CD20, CD117, FOXP3, Ki67, pancytokeratins (CK), and DAPI, and Panel 2 included CD3, CD8, CD68, PD-1, PD-L1, CK, and DAPI. Primary antibodies were first tested by standard immunohistochemistry and single-plex IF, then multiplex panels were developed and images were obtained using a Vectra 3.0 multispectral imaging system. Various methods for image analysis (identifying cell types, determining cell densities, characterizing cell-cell associations) are outlined. These mIF protocols will be invaluable tools for immune profiling the tumor microenvironment.

Caveolin-1 and Sox-2 are predictive biomarkers of cetuximab response in head and neck cancer.

The epidermal growth factor receptor (EGFR) inhibitor cetuximab is the only FDA-approved oncogene-targeting therapy for head and neck squamous cell carcinoma (HNSCC). Despite variable treatment response, no biomarkers exist to stratify patients for cetuximab therapy in HNSCC. Here, we applied unbiased hierarchical clustering to reverse-phase protein array molecular profiles from patient-derived xenograft (PDX) tumors and revealed 2 PDX clusters defined by protein networks associated with EGFR inhibitor resistance. In vivo validation revealed unbiased clustering to classify PDX tumors according to cetuximab response with 88% accuracy. Next, a support vector machine classifier algorithm identified a minimalist biomarker signature consisting of 8 proteins - caveolin-1, Sox-2, AXL, STING, Brd4, claudin-7, connexin-43, and fibronectin - with expression that strongly predicted cetuximab response in PDXs using either protein or mRNA. A combination of caveolin-1 and Sox-2 protein levels was sufficient to maintain high predictive accuracy, which we validated in tumor samples from patients with HNSCC with known clinical response to cetuximab. These results support further investigation into the combined use of caveolin-1 and Sox-2 as predictive biomarkers for cetuximab response in the clinic.

Legal liability perspectives on abuse-deterrent opioids in the treatment of chronic pain.

Abuse-deterrent opioid analgesic formulations can help reduce the risk of opioid diversion and abuse. Not all opioid analgesics are available as both extended- and immediate-release dosage forms in abuse-deterrent formulations. Clinicians may have to balance the clinical benefit of a product that does not use abuse-deterrent technology versus the regulatory benefit of using a product with this technology. There is the possibility that a health care professional may be held legally liable when a product without abuse-deterrent qualities is used and a person suffers harm that would not have occurred had an abuse-deterrent formulation been provided. This article reviews legal precedents that inform an understanding of the need to reduce malpractice exposure by identifying patients who are at high risk of opioid diversion and/or abuse and considering the use of an abuse-deterrent formulation for these patients.

Taking back your turf: understanding the role of law in medical decision making in opioid management (Part II--putting legal/regulatory materials to work for you).

In Part I of this series, I discussed the basic role of the law in the decision-making process for opioid management. I set out three basic rules: 1) read and learn applicable federal and state legal/regulatory materials on using controlled substances to treat pain, 2) stay current on accepted clinical standards of care, and 3) use a compliance program to minimize the potential for abuse and diversion of controlled substances. Here in Part II, I focus on the third rule and offer a few suggestions on developing and maintaining a compliance program. I also discuss using language from legal/regulatory materials in your practice forms in a manner that, once again, allows you to "take back your turf" and prescribe opioids without fear of legal/regulatory sanction (see Disclaimer). Take a minute to review the self-audit questions that follow and see where you stand on your knowledge and use of legal/regulatory matters in your daily practice. More "yes" answers indicate better knowledge of key compliance and documentation issues. More "no" and "I don't know" answers indicate that more work should be done to minimize potential legal/regulatory compliance problems in your practice.