Immune checkpoint inhibitors modulate the cytotoxic effect of chemotherapy in lung adenocarcinoma cells.

Immunotherapy using immune checkpoint inhibitors (ICIs) has significantly improved survival in patients with non-small cell lung cancer (NSCLC), and ICIs are increasingly used in combination with cytotoxic treatments, such as chemotherapy. Although combined treatments are more effective, not all patients respond to the therapy; therefore, a detailed understanding of the effect of treatment combinations at the tumour level is needed. The present study aimed to explore whether ICIs could affect the cytotoxic effects of chemotherapy on lung adenocarcinoma cell lines with different PD-L1 expression levels (high, HCC-44; low, A-549). Using the resazurin-based assay, the efficacy of seven chemotherapeutic agents (cisplatin, etoposide, gemcitabine, pemetrexed, vinorelbine, docetaxel and paclitaxel) was compared in the presence or absence of the individually chosen single doses of four ICIs (nivolumab, pembrolizumab, atezolizumab and durvalumab). The results revealed that different ICIs can exhibit either potentiating or depotentiating effects, depending on the chemotherapy agent or lung adenocarcinoma cell line used. Durvalumab was the most promising ICI, which potentiated most chemotherapy agents in both cell lines, especially in the case of high PD-L1 expression. By contrast, nivolumab, exhibited depotentiating trends in several combinations. The immunostaining of γH2AX in treated cells confirmed that the potentiation of the chemotherapeutic cytotoxicity by durvalumab was at least partially mediated via increased DNA damage; however, this effect was strongly dependent on the chemotherapy agent and cell line used. Our future studies aim to address the specific mechanisms underlying the observed ICI-induced potentiation or depotentiation.

Expression of immune checkpoint PD-1 in non-small cell lung cancer is associated with tumor cell DNA-dependent protein kinase.

Immunotherapy using immune checkpoint inhibitors has demonstrated durable responses and has significantly improved survival in patients with non-small cell lung cancer (NSCLC). Moreover, immunotherapy is increasingly used in combination with cytotoxic treatments such as chemotherapy and radiotherapy. Although the combined treatments are more effective, the underling mechanisms that lead to higher antitumor activity are not fully understood. Therefore, the aim of the current retrospective study was to determine the relationship between expression of immune checkpoints [programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1)] and the enzyme DNA-dependent protein kinase (DNA-PK), which is part of a key pathway involved in the repair of cytotoxic cancer therapy induced damage. Surgically excised NSCLC tissues (n=121) were histologically examined for overall extent of inflammation (score 0-3). Expression levels of PD-1 (number of PD-1 positive cells), PD-L1 [tumor proportion score (TPS); %] and DNA-PK (proportion of DNA-PK positive tumor cells; %) were determined using immunohistochemistry. Expressions of these markers were compared in different clinicopathological subgroups and later used for nonparametric Spearman correlation analysis to determine associations. In patients with NSCLC, PD-1 was significantly expressed in males (P=0.030) and in patients with no or trivial inflammation scores (P=0.030). PD-L1 expression was also significantly higher in current smokers (P=0.025). Correlation analysis was based on the individual values of patients and revealed a significant association between one of the targets of immune checkpoint inhibitors and tumor cell DNA-PK. Tumors with higher numbers of PD-1 positive cells also demonstrated higher tumor cell DNA-PK expressions (P=0.027). The results demonstrated a significant positive correlation between the PD-1/PD-L1 axis and tumor cell DNA-PK expression in patients with NSCLC. Further studies are required to clarify the significance of this correlation and its effect on the efficacy of immunotherapy and cytotoxic cancer therapy combinations.

PD-L1 induction in tumor tissue after hypofractionated thoracic radiotherapy for non-small cell lung cancer.

We report on a 67-year old male with advanced stage lung adenocarcinoma (initially PD-L1 negative, EGFR and ALK negative) diagnosed in 2014. The patient received 4 lines of palliative chemotherapy from 2014 to 2017, however the disease progressed. In 2015, he also received palliative hypofractionated radiotherapy to a mediastinal mass, which was causing discomfort and pain. Since there was some data, that radiotherapy could induce PD-L1 expression, a new biopsy was taken in 2017 from the irradiated mediastinal mass. Subsequent pathologic report revealed that PD-L1 status was turned to be highly positive, with tumor proportion score of 100%. Similar high expression of PD-L1 was detected in a new metastasis in the duodenum, which was excised due to a duodenal perforation in 2017. From October 2017 to October 2019, the patient had 2-years of treatment (32 courses) with pembrolizumab and has had a positive effect (partial response) on all the lesions and following stabilization of the disease. Currently, this patient is under follow up and he is in a good condition without any complaints. Last CT-scan in March 2020 showed persisting partial response.

An anaplastic lymphoma kinase (ALK) fusion oncogene positive metastatic sarcomatoid carcinoma of the lung with good response to crizotinib.

Primary sarcomatoid carcinoma (SC) of the lung is a rare tumor that accounts for less than 1% of all lung cancers and compared to other non-small cell lung cancers (NSCLC) they appear more aggressive with poorer prognosis and response to treatment. Carcinosarcoma is one of the subtypes of SC. We report a case of carcinosarcoma with ALK-EML4 fusion gene in a 50-year-old male patient with a good response to therapy with crizotinib. An ALK rearrangement is a rare finding in SC, but as this case demonstrates, it may occur and it is necessary to perform the ALK testing in these tumors to find possible targeted treatments for better outcomes.

Isolated Mediastinal Lymphadenopathy Caused by Rhodococcus equi Infection.

Mediastinal lymphadenopathy is common finding in thoracic surgery, and it often requires morphologic confirmation to establish the definitive diagnosis. The most frequent diagnoses are metastatic lung cancer, sarcoidosis, lymphoma, tuberculosis, and other causes of granulomatous infections. Rhodococcus equi is a rare pathogen in humans that mostly affects immunocompromised patients. This report presents a case with isolated mediastinal lymphadenopathy caused by Rhodococcus equi infection in a 71-year-old immunocompetent patient.

Whole exome sequencing of benign pulmonary metastasizing leiomyoma reveals mutation in the BMP8B gene.

BACKGROUND: Benign metastasizing leiomyoma (BML) is an orphan neoplasm commonly characterized by pulmonary metastases consisting of smooth muscle cells. Patients with BML have usually a current or previous uterine leiomyoma, which is therefore suggested to be the most probable source of this tumour. The purpose of this case report was to determine the possible genetic grounds for pulmonary BML. CASE PRESENTATION: We present a case report in an asymptomatic 44-year-old female patient, who has developed uterine leiomyoma with subsequent pulmonary BML. Whole exome sequencing (WES) was used to detect somatic mutations in BML lesion. Somatic single nucleotide mutations were identified by comparing the WES data between the pulmonary metastasis and blood sample of the same BML patient. One heterozygous somatic mutation was selected for validation by Sanger sequencing. Clonality of the pulmonary metastasis and uterine leiomyoma was assessed by X-chromosome inactivation assay. CONCLUSIONS: We describe a potentially deleterious somatic heterozygous mutation in bone morphogenetic protein 8B (BMP8B) gene (c.1139A > G, Tyr380Cys) that was identified in the pulmonary metastasis and was absent from blood and uterine leiomyoma, and may play a facilitating role in the metastasizing of BML. The clonality assay confirmed a skewed pattern of X-chromosome inactivation, suggesting monoclonal origin of the pulmonary metastases.

Resection of unicentric interlobar Castleman disease with following adjuvant radiotherapy.

A 22-year-old female patient with rare interlobar unicentric Castleman disease is presented. The tumour was discovered incidentally and thoracoscopic biopsy was planned to rule out malignancy. Due to dense adhesions to the adjacent anatomical structures and diffuse bleeding when mobilizing the tumour, a thoracoscopic approach was converted to thoracotomy. The tumour was removed without lung resection. Adjuvant radiotherapy was used to avoid possible recurrence of the disease. During the follow-up of 6 years, the patient remains free of any symptoms and evidence of recurrence.

Evaluation of correlation of articular cartilage staining for DDR2 and proteoglycans with histological tissue damage and the results of radiographic assessment in patients with early stages of knee osteoarthritis.

OBJECTIVE: To determine, if staining of articular cartilage for proteoglycans (natural element of healthy and functioning cartilage) and discoidin domain receptor 2 (DDR2) (a protein associated with articular cartilage degradation) is correlated with histological tissue damage or radiographic assessment score in patients with early stages of knee osteoarthritis (OA). METHOD: 40 patients, with early stage OA were enrolled, from whom the biopsies for histological and immunohistochemical studies were obtained from edge of the femoral condyle during the arthroscopy. Semi-quantitative computer based analysis was used to evaluate the proportion of staining in histological sections. RESULTS: No correlation was shown between the proportion of tissue stained for DDR2 and histological score or the results of radiographic assessment of tibiofemoral (TF) joint. There was a negative correlation between the proportion of tissue stained for DDR2 and radiographic grade of patellofemoral (PF) OA (Spearman r=-0.34; 95% CI -0.60 to -0.02; P=0.03). No correlation was shown between the proportion of tissue stained for proteoglycans and histological score or the results of radiographic assessment of TF and PF joints. A negative correlation was found between proportion of tissue stained for DDR2 and proteoglycans. Spearman r=-0.43; 95% CI=-0.66 to -0.12; P=0.006. CONCLUSION: Production of DDR2 in articular cartilage could be related to early stages of OA, as it is significantly correlated to decrease of staining for cartilage proteoglycans. The role of production of DDR2 in cartilage may be decreased in stages, where higher grades of OA are detected on the radiographs.