Re-biopsy after first line treatment in advanced NSCLC can reveal changes in PD-L1 expression.

OBJECTIVES: Re-biopsy in progressive advanced Non-Small-Cell Lung Cancer (NSCLC) after first line treatment may reveal information about evolving tumor biology during treatment. Our study aims to investigate the feasibility, risk of complications, and clinical relevance of performing re-biopsy systematically. MATERIALS AND METHODS: NSCLC patients with advanced, non-targetable disease, receiving first line systemic treatment, were included in a prospective single-centre study (NCT03512847). A diagnostic biopsy was performed at baseline and repeated at time of progression, preferentially from the progressive lesions as determined by CT or PET/CT. The primary endpoint was feasibility, including complication rate to re-biopsy. Secondary endpoints were clinical relevance, defined as a potential of changing treatment or follow-up, due to new histological evidence, specifically a change in PD-L1 Tumor Proportion Score (TPS). RESULTS: Fifty-one patients with progressive advanced NSCLC had re-biopsy performed. Median time from patients' acceptance to biopsy was seven days (range: 0-31). Complication rate was 6% (n = 3) represented by pneumothorax, hydro-pneumothorax and pneumonia, respectively. No severe or chronic complications occurred. Sufficient material for PD-L1 analyses was obtained in 46 of 51 patients: the remaining five cases had insufficient tissue for analyses, no malignant cells/only suspected malignant cells, questioning whether progression was real. PD-L1 TPS change was observed in 33% of patients (n = 15) and 17% (n = 8) had potentially clinically relevant changes. A significantly higher chance of PD-L1 TPS change was observed in chemotherapy-treated patients. CONCLUSION: Our study showed that re-biopsy is feasible, with low risk of complications, and can be clinically relevant in patients with suspected progression in advanced NSCLC.

Pleural epithelioid hemangioendothelioma mimicking pleural empyema: A case report.

Malignant pleural effusion is an important and difficult differential diagnosis to pleural empyema. Epithelioid hemangioendothelioma is an uncommon vascular tumor, which typically occurs in liver, lung or bone. We present an extremely rare case of primary pleural epithelioid hemangioendothelioma mimicking pleural empyema. We conclude, that pleural epithelioid hemangioendothelioma should be kept in mind as a differential diagnosis in patients suspected of empyema.

A 7-Gene Signature Depicts the Biochemical Profile of Early Prefibrotic Myelofibrosis.

Recent studies have shown that a large proportion of patients classified as essential thrombocythemia (ET) actually have early primary prefibrotic myelofibrosis (prePMF), which implies an inferior prognosis as compared to patients being diagnosed with so-called genuine or true ET. According to the World Health Organization (WHO) 2008 classification, bone marrow histology is a major component in the distinction between these disease entities. However, the differential diagnosis between them may be challenging and several studies have not been able to distinguish between them. Most lately, it has been argued that simple blood tests, including the leukocyte count and plasma lactate dehydrogenase (LDH) may be useful tools to separate genuine ET from prePMF, the latter disease entity more often being featured by anemia, leukocytosis and elevated LDH. Whole blood gene expression profiling was performed in 17 and 9 patients diagnosed with ET and PMF, respectively. Using elevated LDH obtained at the time of diagnosis as a marker of prePMF, a 7-gene signature was identified which correctly predicted the prePMF group with a sensitivity of 100% and a specificity of 89%. The 7 genes included MPO, CEACAM8, CRISP3, MS4A3, CEACAM6, HEMGN, and MMP8, which are genes known to be involved in inflammation, cell adhesion, differentiation and proliferation. Evaluation of bone marrow biopsies and the 7-gene signature showed a concordance rate of 71%, 79%, 62%, and 38%. Our 7-gene signature may be a useful tool to differentiate between genuine ET and prePMF but needs to be validated in a larger cohort of "ET" patients.

Disseminated lung cancer presenting as a rectal mass.

Primary lung cancer is the leading cause of cancer-related deaths globally, and approximately 50% had metastatic disease at the time of diagnosis. A rectal mass and unintended weight loss are common manifestations of rectal cancer. Our case presented with a rectal mass, but workup revealed a metastatic lesion from lung cancer. Lung cancer metastases to the lower gastrointestinal tract imply reduced survival compared with the already poor mean survival of stage IV lung cancer. Despite relevant therapy, the patient died 5 months after referral.

WHO classification 2008 of myeloproliferative neoplasms: a workshop learning effect--the Danish experience.

We examined the learning effect of a workshop for Danish hematopathologists led by an international expert regarding histological subtyping of myeloproliferative neoplasms (MPN). Six hematopathologists evaluated 43 bone marrow (BM) biopsies according to the WHO description (2008), blinded to clinical data. All panelists then participated in the workshop. The case biopsies - mixed with 251 other MPN BM biopsies - were reviewed again. Consensus regarding the histological subtype was significantly improved; from 49% to 72% (Fleiss kappa value 0.302 pre-workshop, 0.474 post-workshop; p = 0.004). There was no significant effect on the isolated morphological characteristics. Agreement between cases with histological consensus and clinical diagnosis was 86% without significant change during workshop sessions. Our study demonstrates that experienced hematopathologists can significantly improve their diagnostic ability by a workshop led by an international expert; not by improving the evaluation of individual histological parameters but by weighting these in their conclusive diagnosis.

World Health Organization-defined classification of myeloproliferative neoplasms: morphological reproducibility and clinical correlations--the Danish experience.

We examined inter- and intraobserver reproducibility and concordance between histological diagnosis and independently collected clinical findings in a large series of patients with the major subtypes of myeloproliferative neoplasms (MPNs) and controls. Seven hematopathologists reviewed 272 bone marrow biopsies including 43 controls. Diagnoses were determined according to the 2008 criteria of the World Health Organization (WHO). The participants were blinded to all clinical data except patient age. After initial evaluation all hematopathologists participated in a 3-day meeting with a leading clinician chaired by an expert hematopathologists. In cases with lack of consensus on fiber grading (n = 57), a new evaluation was performed. In cases with discordance on morphological diagnosis (n = 129), an additional nonblinded evaluation taking clinical data into consideration was carried out. For remaining cases with a lack of concordance between morphological diagnosis and clinical diagnosis (n = 33), a similar nonblinded evaluation was performed. Consensus on final histological diagnosis and concordance with clinical diagnosis were determined. Blinded histological evaluation resulted in a 53% consensus rate. After re-evaluation of fiber content, consensus was reached in 60% of cases. Adding clinical data increased the histological consensus to 83%. For cases with a histological consensus, we found a concordance of 71% with the clinician's diagnoses. This is the first study to present a larger cohort of MPN patients mimicking the diagnostic challenges that hematopathologists face in their daily practice. The results support the postulates of the WHO that both morphological and clinical findings are essential for a valid diagnosis

The JAK2V617F allele burden and STAT3- and STAT5 phosphorylation in myeloproliferative neoplasms: early prefibrotic myelofibrosis compared with essential thrombocythemia, polycythemia vera and myelofibrosis.

Early prefibrotic myelofibrosis (early PMF) is a diagnosis that clinically and histologically mimic essential thrombocythemia (ET), but is important to distinguish from ET, polycythemia vera (PV) and primary myelofibrosis (PMF) due to its different prognosis and clinical evolution. In this study, we assessed the allele burden of JAK2V617F in bone marrow biopsies from patients with these chronic myeloproliferative neoplasms. We correlated our findings with the amount of phosphorylated STAT3 (P-STAT3) and STAT5 (P-STAT5) in megakaryocyte nuclei in the bone marrow. The JAK2V617F allele burden was significantly higher in patients with PV (median: 50.99, range: 23.08-97.29, p < 0.01 and p < 0.01) and PMF (median: 44.13, range: 33.61-92.17, p < 0.05 and p < 0.01) compared with a low allele burden in ET (median: 23.465, range: 8.67-47.92) and early PMF (median: 25.68, range: 0.61-49.13) respectively. In addition, we found a significantly higher phosphorylation of STAT5 and STAT3 in the JAK2V617F positive group than in the negative group. There was no positive correlation between increasing JAK2V617F allele burden and the amount of P-STAT3 and P-STAT5. However, we found low values of P-STAT5 in bone marrow biopsies from patients with ETJAK2V617F+ as compared with patients with early PMFJAK2V617F+. Although this difference was statistically significant, larger studies are needed to firmly support this conclusion.

Use of commercially available rabbit monoclonal antibodies for immunofluorescence double staining.

Immunohistochemistry, that is, the use of polyclonal and monoclonal antibodies to detect cell and tissue antigens at a microscopical level is a powerful tool for both research and diagnostic purposes. Especially in the field of hematologic disease, there is often a need to detect several antigens synchronously, and we report here a fast and easy technique for demonstrating more than 1 antigen in 1 slide using immunofluorescence. We have used commercially available rabbit monoclonal antibodies (Cyclin D1, CD3, CD5, CD23, etc.) paired with mouse monoclonal antibodies (CD7, CD20, CD79a, Pax-5, etc.) for double immunofluorescence labeling on paraffin-embedded tissue sections. Commercially available rabbit monoclonal antibodies in combination with mouse monoclonal antibodies proved useful in double immunofluorescence labeling on paraffin-embedded tissue, and all combinations used yielded excellent results.