Checkpoint inhibitors targeting the PD-1/PD-L1 axis are a promising treatment option in several tumor types. PD-L1 expression detected by immunohistochemistry is the first clinically validated ...predictive biomarker for response to PD-1/PD-L1 inhibitors, though its predictive value varies significantly between tumor types. With the approval of pembrolizumab monotherapy for treatment-naïve, advanced non-small cell lung cancer, PD-L1 testing has to become broadly available in pathology laboratories. When PD-L1 testing started to be introduced in routine pathology practice, there were several open issues, which needed to be addressed in order to provide accurate results. This review will discuss the complex biological background of PD-L1 as predictive biomarker, summarize relevant clinical trials in NSCLC illustrating the origin of different PD-L1 expression cutoffs and scorings, and address issues important for PD-L1 testing including the analytical comparability of the different clinical trial-validated PD-L1 immunohistochemistry assays, the potential of laboratory-developed tests, and an overview of the different scoring algorithms.
Urinary cytology has a well-established role in the detection and monitoring of urothelial carcinoma. The main strength of cytology is the high specificity for high-grade urothelial carcinoma and ...carcinoma in situ, but it has a low sensitivity for low-grade, non-invasive tumors. There are several other limitations of cytology. Cytology of the upper urinary tract and after intravesical therapy with bacillus Calmette-Guerin is notoriously difficult to interpret. In addition, there is a poorly defined but commonly used category of atypical cytology of uncertain significance. The UroVysion multiprobe fluorescence in situ hybridization has emerged as a helpful tool to address these limitations. It consists of fluorescently labeled DNA probes to detect increased copy numbers (polysomy) of the chromosomes 3, 7 and 17 and deletion of 9p21, the site of the P16 tumor suppressor gene. Multiple studies have shown that fluorescence in situ hybridization in voided urine and washing specimens can help in patient management due to its superior sensitivity over cytology in different situations. It can be particularly useful to clarify equivocal cytological findings. However, some aspects remain to be further addressed including cost efficiency, optimal cut-off values and the true performance under real-life conditions.
The Blueprint (BP) Programmed Death Ligand 1 (PD-L1) Immunohistochemistry Comparability Project is a pivotal academic/professional society and industrial collaboration to assess the feasibility of ...harmonizing the clinical use of five independently developed commercial PD-L1 immunohistochemistry assays. The goal of BP phase 2 (BP2) was to validate the results obtained in BP phase 1 by using real-world clinical lung cancer samples.
BP2 were conducted using 81 lung cancer specimens of various histological and sample types, stained with all five trial-validated PD-L1 assays (22C3, 28-8, SP142, SP263, and 73-10); the slides were evaluated by an international panel of pathologists. BP2 also assessed the reliability of PD-L1 scoring by using digital images, and samples prepared for cytological examination. PD-L1 expression was assessed for percentage (tumor proportional score) of tumor cell (TC) and immune cell areas showing PD-L1 staining, with TCs scored continuously or categorically with the cutoffs used in checkpoint inhibitor trials.
The BP2 results showed highly comparable staining by the 22C3, 28-8 and SP263 assays; less sensitivity with the SP142 assay; and higher sensitivity with the 73-10 assay to detect PD-L1 expression on TCs. Glass slide and digital image scorings were highly concordant (Pearson correlation >0.96). There was very strong reliability among pathologists in TC PD-L1 scoring with all assays (overall intraclass correlation coefficient ICC = 0.86–0.93), poor reliability in IC PD-L1 scoring (overall ICC = 0.18–0.19), and good agreement in assessing PD-L1 status on cytological cell block materials (ICC = 0.78–0.85).
BP2 consolidates the analytical evidence for interchangeability of the 22C3, 28-8, and SP263 assays and lower sensitivity of the SP142 assay for determining tumor proportion score on TCs and demonstrates greater sensitivity of the 73-10 assay compared with that of the other assays.
A grading system for pulmonary adenocarcinoma has not been established. The International Association for the Study of Lung Cancer pathology panel evaluated a set of histologic criteria associated ...with prognosis aimed at establishing a grading system for invasive pulmonary adenocarcinoma.
A multi-institutional study involving multiple cohorts of invasive pulmonary adenocarcinomas was conducted. A cohort of 284 stage I pulmonary adenocarcinomas was used as a training set to identify histologic features associated with patient outcomes (recurrence-free survival RFS and overall survival OS). Receiver operating characteristic curve analysis was used to select the best model, which was validated (n = 212) and tested (n = 300, including stage I–III) in independent cohorts. Reproducibility of the model was assessed using kappa statistics.
The best model (area under the receiver operating characteristic curve AUC = 0.749 for RFS and 0.787 for OS) was composed of a combination of predominant plus high-grade histologic pattern with a cutoff of 20% for the latter. The model consists of the following: grade 1, lepidic predominant tumor; grade 2, acinar or papillary predominant tumor, both with no or less than 20% of high-grade patterns; and grade 3, any tumor with 20% or more of high-grade patterns (solid, micropapillary, or complex gland). Similar results were seen in the validation (AUC = 0.732 for RFS and 0.787 for OS) and test cohorts (AUC = 0.690 for RFS and 0.743 for OS), confirming the predictive value of the model. Interobserver reproducibility revealed good agreement (k = 0.617).
A grading system based on the predominant and high-grade patterns is practical and prognostic for invasive pulmonary adenocarcinoma.
Comprehensive genomic studies have delineated key driver mutations linked to disease progression for most cancers. However, corresponding transcriptional changes remain largely elusive because of the ...bias associated with cross-study analysis. Here, we overcome these hurdles and generate a comprehensive prostate cancer transcriptome atlas that describes the roadmap to tumor progression in a qualitative and quantitative manner. Most cancers follow a uniform trajectory characterized by upregulation of polycomb-repressive-complex-2, G2-M checkpoints, and M2 macrophage polarization. Using patient-derived xenograft models, we functionally validate our observations and add single-cell resolution. Thereby, we show that tumor progression occurs through transcriptional adaption rather than a selection of pre-existing cancer cell clusters. Moreover, we determine at the single-cell level how inhibition of EZH2 - the top upregulated gene along the trajectory - reverts tumor progression and macrophage polarization. Finally, a user-friendly web-resource is provided enabling the investigation of dynamic transcriptional perturbations linked to disease progression.
The pathological and molecular classification of lung cancer has become substantially more complex over the past decade. For diagnostic purposes on small samples, additional stains are frequently ...required to distinguish between squamous cell carcinoma and adenocarcinoma. Subsequently, for advanced nonsquamous cell nonsmall cell lung carcinoma (NSCLC) patients, predictive analyses on epidermal growth factor receptor, anaplastic lymphoma kinase and ROS1 are required. In NSCLCs negative for these biomarkers, programmed death ligand-1 immunohistochemistry is performed. Small samples (biopsy and cytology) require “tissue” management, which is best achieved by the interaction of all physicians involved.
Summary Background Results of preclinical studies have shown that EGFR immunoliposomes have substantial antitumour effects. We aimed to assess the tolerability, safety, pharmokinetics, and efficacy ...of anti-EGFR immunoliposomes loaded with doxorubicin (anti-EGFR ILs-dox) in patients with solid tumours. Methods In this first-in-man, open-label, phase 1 clinical study, we enrolled patients at University Hospital of Basel, Switzerland, who had EGFR-overexpressing advanced solid tumours no longer amenable to standard treatment. Anti-EGFR ILs-dox nanoparticles were constructed by covalently linking pegylated liposomes containing doxorubicin to antigen-binding fragments (Fab′) of cetuximab. We intravenously infused the nanoparticle at escalating doses (doxorubicin 5 mg/m2 , 10 mg/m2 , 20 mg/m2 , 30 mg/m2 , 40 mg/m2 , 50 mg/m2 , and 60 mg/m2 ) once every 4 weeks for a maximum of six cycles. The primary endpoint was to establish the maximum tolerated dose. We analysed patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov , number NCT01702129. Findings Between Jan 30, 2007, and March 4, 2010, we gave the drug to 29 patients, three of whom were withdrawn from the study because we could not complete a safety assessment. Of the 26 patients assessed for the primary endpoint, two who received a dose of 60 mg/m2 had dose-limiting toxicities (one had neutropenia and the other had anaemia); therefore, the maximum tolerated dose was defined as 50 mg/m2 . At all lower doses, anti-EGFR ILs-dox was well tolerated; grade 1 skin toxicity occurred in two patients only. We recorded 22 serious adverse events (SAEs) in 17 patients, mostly due to tumour progression. Three SAEs were fatal. Only three SAEs (febrile neutropenia, septicaemia, and a fatal massive oral bleed) were probably or possibly related to study drug. No patients had palmar-plantar erythrodysaesthesia, alopecia, cardiotoxicity, or cumulative toxicity. Best response to treatment included one complete response, one partial response, and ten stable disease lasting 2–12 months (median 5·75 months). Interpretation Because anti-EGFR ILs-dox was well tolerated up to 50 mg doxorubicin per m2 , and we recorded clinical activity, further assessment of this nanoparticle at this dose in phase 2 trials is warranted. Funding Cancer League Basel, Swiss Cancer League, Schoenmakers-Müller Foundation, and Werner Geissberger Foundation.
Improved survival rates for prostate cancer through more effective therapies have also led to an increase in the diagnosis of metastases to infrequent locations such as the brain. Here we investigate ...the repertoire of somatic genetic alterations present in brain metastases from 51 patients with prostate cancer brain metastases (PCBM). We highlight the clonal evolution occurring in PCBM and demonstrate an increased mutational burden, concomitant with an enrichment of the homologous recombination deficiency mutational signature in PCBM compared to non-brain metastases. Focusing on known pathogenic alterations within homologous recombination repair genes, we find 10 patients (19.6%) fulfilling the inclusion criteria used in the PROfound clinical trial, which assessed the efficacy of PARP inhibitors (PARPi) in homologous recombination deficient prostate cancer. Eight (15.7%) patients show biallelic loss of one of the 15 genes included in the trial, while 5 patients (9.8%) harbor pathogenic alterations in BRCA1/2 specifically. Uncovering these molecular features of PCBM may have therapeutic implications, suggesting the need of clinical trial enrollment of PCBM patients when evaluating potential benefit from PARPi.
Pre-symptomatic screening of genetic alterations might help identify subpopulations of individuals that could enter into early access prevention programs. Since liquid biopsy is minimally invasive it ...can be used for longitudinal studies in healthy volunteers to monitor events of progression from normal tissue to pre-cancerous and cancerous condition. Yet, cell-free DNA (cfDNA) analysis in healthy individuals comes with substantial challenges such as the lack of large cohort studies addressing the impact of mutations in healthy individuals or the low abundance of cfDNA in plasma. In this study, we aimed to investigate the technical feasibility of cfDNA analysis in a collection of 114 clinically healthy individuals. We first addressed the impact of pre-analytical factors such as cfDNA yield and quality on sequencing performance and compared healthy to cancer donor samples. We then confirmed the validity of our testing strategy by evaluating the mutational status concordance in matched tissue and plasma specimens collected from cancer patients. Finally, we screened our group of healthy donors for genetic alterations, comparing individuals who did not develop any tumor to patients who developed either a benign neoplasm or cancer during 1-10 years of follow-up time. To conclude, we have established a rapid and reliable liquid biopsy workflow that allowed us to study genomic alterations with a limit of detection as low as 0.08% of variant allelic frequency in healthy individuals. We detected pathogenic cancer mutations in four healthy donors that later developed a benign neoplasm or invasive breast cancer up to 10 years after blood collection. Even though larger prospective studies are needed to address the specificity and sensitivity of liquid biopsy as a clinical tool for early cancer detection, systematic screening of healthy individuals will help understanding early events of tumor formation.
PDF
