Faculty Bibliography

IMPORTANCE/OBJECTIVE:Early-phase trials with monoclonal antibodies targeting PD-1 (programmed cell death protein 1) and PD-L1 (programmed cell death 1 ligand 1) have demonstrated durable clinical responses in patients with non-small-cell lung cancer (NSCLC). However, current assays for the prognostic and/or predictive role of tumor PD-L1 expression are not standardized with respect to either quantity or distribution of expression. OBJECTIVE:To demonstrate PD-L1 protein distribution in NSCLC tumors using both conventional immunohistochemistry (IHC) and quantitative immunofluorescence (QIF) and compare results obtained using 2 different PD-L1 antibodies. DESIGN, SETTING, AND PARTICIPANTS/METHODS:PD-L1 was measured using E1L3N and SP142, 2 rabbit monoclonal antibodies, in 49 NSCLC whole-tissue sections and a corresponding tissue microarray with the same 49 cases. Non-small-cell lung cancer biopsy specimens from 2011 to 2012 were collected retrospectively from the Yale Thoracic Oncology Program Tissue Bank. Human melanoma Mel 624 cells stably transfected with PD-L1 as well as Mel 624 parental cells, and human term placenta whole tissue sections were used as controls and for antibody validation. PD-L1 protein expression in tumor and stroma was assessed using chromogenic IHC and the AQUA (Automated Quantitative Analysis) method of QIF. Tumor-infiltrating lymphocytes (TILs) were scored in hematoxylin-eosin slides using current consensus guidelines. The association between PD-L1 protein expression, TILs, and clinicopathological features were determined. MAIN OUTCOMES AND MEASURES/METHODS:PD-L1 expression discordance or heterogeneity using the diaminobenzidine chromogen and QIF was the main outcome measure selected prior to performing the study. RESULTS:Using chromogenic IHC, both antibodies showed fair to poor concordance. The PD-L1 antibodies showed poor concordance (Cohen κ range, 0.124-0.340) using conventional chromogenic IHC and showed intra-assay heterogeneity (E1L3N coefficient of variation [CV], 6.75%-75.24%; SP142 CV, 12.17%-109.61%) and significant interassay discordance using QIF (26.6%). Quantitative immunofluorescence showed that PD-L1 expression using both PD-L1 antibodies was heterogeneous. Using QIF, the scores obtained with E1L3N and SP142 for each tumor were significantly different according to nonparametric paired test (P < .001). Assessment of 588 serial section fields of view from whole tissue showed discordant expression at a frequency of 25%. Expression of PD-L1 was correlated with high TILs using both E1L3N (P = .007) and SP142 (P = .02). CONCLUSIONS AND RELEVANCE/CONCLUSIONS:Objective determination of PD-L1 protein levels in NSCLC reveals heterogeneity within tumors and prominent interassay variability or discordance. This could be due to different antibody affinities, limited specificity, or distinct target epitopes. Efforts to determine the clinical value of these observations are under way.

PURPOSE/OBJECTIVE:Routine prophylactic pegylated granulocyte colony-stimulating factor (pGCSF) administration for patients receiving chemotherapy regimens associated with low risk (< 10%) for neutropenic fever (LRNF) is not recommended. Inappropriate use of pGCSF increases patient morbidity and health care costs. METHODS:A multidisciplinary team reviewed the charts of patients with non-small-cell lung cancer (NSCLC) at the Taussig Cancer Institute in whom a new chemotherapy regimen was initiated from April through November 2013. pGCSF use was identified and deemed appropriate if prescribed for chemotherapy associated with high risk of neutropenic fever (> 20%) or intermediate risk (10% to 20%) if other risk factors for neutropenic fever were present. Use with LRNF chemotherapy was recorded as inappropriate. RESULTS:One hundred eighty patients with NSCLC received a new chemotherapy regimen during the specified time period. Thirty-four of 119 patients (28%) treated with LRNF chemotherapy received pGCSF. Each patient received an average of 2.6 doses of pGCSF (total, 89 doses). We implemented three plan-do-study-act cycles: education of providers, development of Taussig Cancer Institute consensus guidelines for pGCSF in NSCLC, and removal of standing pGCSF orders from LRNF chemotherapy in the electronic medical record. Analysis during the change period revealed 4% of patients with NSCLC treated with LRNF chemotherapy received pGCSF. Cost analysis showed an 84% decrease in billed charges per month. No increase in neutropenic fever admissions was found. CONCLUSION/CONCLUSIONS:pGCSF was excessively prescribed for patients with NSCLC. Factors contributing to inappropriate use included provider lack of familiarity with guidelines and knowledge with regard to the risk of neutropenic fever for individual chemotherapy regimens, and electronic medical record chemotherapy templates that contain standing GCSF orders. Interventions to address these gaps quickly produced improved compliance with guidelines and led to significant cost savings.

BACKGROUND:Crizotinib has antitumor activity in ALK (anaplastic lymphoma receptor tyrosine kinase)-rearranged non-small cell lung cancer (NSCLC). The current diagnostic test for ALK rearrangement is breakapart fluorescence in situ hybridization (FISH), but FISH has low throughput and is not always reflective of protein concentrations. The emergence of multiple clinically relevant biomarkers in NSCLC necessitates efficient testing of scarce tissue samples. We developed an anaplastic lymphoma kinase (ALK) protein assay that uses multiplexed selected reaction monitoring (SRM) to quantify absolute amounts of ALK in formalin-fixed paraffin-embedded (FFPE) tumor tissue. METHODS:After validation in formalin-fixed cell lines, the SRM assay was used to quantify concentrations of ALK in 18 FFPE NSCLC samples that had been tested for ALK by FISH and immunohistochemistry. Results were correlated with patient response to crizotinib. RESULTS:We detected ALK in 11 of 14 NSCLC samples with known ALK rearrangements by FISH. Absolute ALK concentrations correlated with clinical response in 5 of 8 patients treated with crizotinib. The SRM assay did not detect ALK in 3 FISH-positive patients who had not responded to crizotinib. In 1 of these cases, DNA sequencing revealed a point mutation that predicts a nonfunctional ALK fusion protein. The SRM assay did not detect ALK in any tumor tissue with a negative ALK status by FISH or immunohistochemistry. CONCLUSIONS:ALK concentrations measured by SRM correlate with crizotinib response in NSCLC patients. The ALK SRM proteomic assay, which may be multiplexed with other clinically relevant proteins, allows for rapid identification of patients potentially eligible for targeted therapies.

A 58-year-old woman with stage 4 adenocarcinoma of the lung being treated with pembrolizumab developed dyspnea, non-productive cough, and a right middle lobe infiltrate. Complete resolution of the infiltrate with cessation of pembrolizumab, initiation of prednisone and no antibiotic therapy suggested drug-associated lung toxicity as the cause. While the programmed death-1 (PD-1) inhibitors -pembrolizumab and nivolumab - have been implicated as a cause of diffuse or multifocal pulmonary infiltrates, the current case represents, to our knowledge, the first instance of a unilobar, focal infiltrate associated with their use. We speculate that the blockade of immune tolerance that is the hallmark of PD-1 inhibitors might cause atypical inflammatory reactions such as the focal lobar infiltrate seen in the current patient. Awareness of this novel radiographic pattern of drug-associated lung toxicity may enhance clinicians' management of patients receiving.

Recent success of immunotherapy strategies such as immune checkpoint blockade in several malignancies has established the role of immunotherapy in the treatment of cancer. Cancers use multiple mechanisms to co-opt the host-tumor immune interactions, leading to immune evasion. Our understanding of the host-tumor interactions has evolved over the past few years and led to various promising new therapeutic strategies. This article will focus on the basic principles of immunotherapy, novel pathways/agents, and combinatorial immunotherapies.

BACKGROUND:Tumor-infiltrating lymphocytes (TILs) are usually measured using subjective methods. Studies suggest that TIL subtypes have independent roles in cancer and that they could support the use of novel immunostimulatory therapies. We simultaneously measured TIL subtypes in non-small cell lung cancer (NSCLC) samples using objective methods and determined their relationship with clinico-pathologic characteristics and survival. METHODS:Using multiplexed quantitative fluorescence (QIF), we measured the levels of CD3, CD8, and CD20 in 552 NSCLC from two independent collections represented in tissue microarrays (YTMA79, n = 202 and YTMA140, n = 350). The level of TILs was obtained in different tumor compartments using cytokeratin stain to define tumor cells and 4',6-Diamidino-2-Phenylindole. Association of TILs with clinical parameters was determined using univariate and multivariable analyses. All statistical tests were two-sided. RESULTS:In both NSCLC collections there was a low correlation between the three TIL markers (linear regression coefficients (R(2)) = 0.19-0.22, P < .001 for YTMA79 and R(2) = 0.23-0.32, P < .001 for YTMA140). No consistent association between the level of TIL subtypes and age, sex, smoking history, tumor size, stage, and histology type was found. In univariate analysis, an elevated CD3 or CD8 signal was statistically significantly associated with longer survival in both collections. However, only CD8 was independent from age, tumor size, histology, and stage in multivariable analysis. High CD20 was associated with longer survival in the YTMA79 cohort. CONCLUSIONS:Increased levels of CD3 and CD8 + TILs are associated with better outcome in NSCLC, but only CD8 is independent from other prognostic variables. Objective measurement of TIL subpopulations could be useful to predict response or evaluate the local immune effect of anticancer immune checkpoint inhibitors.

Oncogenic rearrangements of the RET gene have recently been described in 1% to 2% of lung adenocarcinomas. We report five cases of RET-rearranged lung adenocarcinoma with an unusual constellation of clinical and histologic features that has not previously been described in tumors with this genomic alteration. The age at diagnosis of the five patients (4F, 1M) ranged from 44 to 77 years. All were never-smokers. Radiologically, four tumors showed lymphangitic spread within the lungs at presentation; three of these had multiple bilateral lung nodules. Histology showed psammoma bodies within the tumor in four of five cases. Molecular testing for activating EGFR mutations by standard genotyping and ALK expression by immunohistochemistry was negative in all cases. Additional molecular analysis was prompted by the clinical profile in that all five patients were never-smokers with metastatic, relapsed, and/or refractory disease; and also by unusual histologic findings in two cases. Comprehensive genomic profiling performed by means of a clinical grade cancer gene panel next-generation sequencing assay demonstrated a KIF5B-RET fusion in three; and fluorescence in-situ hybridization documented a RET rearrangement in two. Three of the patients were treated with the RET inhibitor cabozantinib. By Response Evaluation Criteria In Solid Tumors (RECIST) criteria, two had a confirmed partial response (at 6 weeks and 4 weeks) and one had stable disease. Our findings suggest that the combination of lymphangitic spread and psammoma bodies may be characteristic of a subset of advanced stage RET-rearranged lung adenocarcinomas. These findings should prompt additional molecular testing for RET translocations, particularly in never-smokers with EGFR- and ALK-negative lung adenocarcinoma.

We report a case of granular cell tumor (GCT) of the lung with coexistent invasive adenocarcinoma. GCTs are rare tumors and often benign and amenable to local bronchoscopic excision. However, occasionally they are more aggressive and locally infiltrative requiring definitive surgical resection. Our patient had a central and infiltrative GCT, in addition a very small (6 mm) peripheral nodule in the same lobe as the GCT, which after careful examination of the surgical specimen during grossing was found to be an invasive adenocarcinoma. There are a few reports in the literature of GCTs with coexistent bronchogenic cancer. Our case highlights the importance of careful evaluation and exploration of the surgical specimens during grossing of patients with GCTs. In GCT patients presenting with additional pulmonary nodules, a more definitive surgical approach should be considered.

PURPOSE/OBJECTIVE:Blockade of the PD-1/PD-L1 axis emerged as a promising new therapeutic option for cancer that has resulted in lasting responses in metastatic renal, lung carcinomas, and melanomas. Tumor PD-L1 protein expression may predict response to drugs targeting this pathway. Measurement of PD-L1 protein is limited by the lack of standardized immunohistochemical methods and variable performance of antibodies. Our goal was to correlate PD-L1 mRNA expression with clinical variables in primary breast carcinomas. EXPERIMENTAL DESIGN/METHODS:The fluorescent RNAscope paired-primer assay was used to quantify in situ PD-L1 mRNA levels in 636 stage I-III breast carcinomas on two sets of tissue microarrays [YTMA128 (n = 238) and YTMA201 (n = 398)]. Tumor-infiltrating lymphocytes (TIL) were assessed by hematoxylin/eosin stain and quantitative fluorescence. RESULTS:On YTMA128 and YTMA201, 55.7% and 59.5% of cases showed PD-L1 mRNA expression, respectively. Higher PD-L1 mRNA expression was significantly associated with increased TILs (P = 0.04) but not with other clinical variables. Elevated TILs (scores 2 and 3+) occurred in 16.5% on YTMA128 and 14.8% on YTMA201 and was associated with estrogen receptor-negative status (P = 0.01 on YTMA128 and 0.0001 on YTMA201). PD-L1 mRNA expression was associated with longer recurrence-free survival (log-rank P = 0.01), which remained significant in multivariate analysis including age, tumor size, histologic grade, nodal metastasis, hormone receptor, HER2 status, and the extent of TILs (HR, 0.268; CI, 0.099-0.721; P = 0.009). CONCLUSIONS:PD-L1 mRNA expression is identified in nearly 60% of breast tumors and it is associated with increased TILs and improved recurrence-free survival. These observations support the evaluation of PD-1/PD-L1-targeted therapies in breast cancer.