Deciphering the variability in air-sea gas transfer due to sea state and wind history.

Understanding processes driving air-sea gas transfer and being able to model both its mean and variability are critical for studies of climate and carbon cycle. The air-sea gas transfer velocity (K 660) is almost universally parameterized as a function of wind speed in large scale models-an oversimplification that buries the mechanisms controlling K 660 and neglects much natural variability. Sea state has long been speculated to affect gas transfer, but consistent relationships from in situ observations have been elusive. Here, applying a machine learning technique to an updated compilation of shipboard direct observations of the CO2 transfer velocity (K CO2,660), we show that the inclusion of significant wave height improves the model simulation of K CO2,660, while parameters such as wave age, wave steepness, and swell-wind directional difference have little influence on K CO2,660. Wind history is found to be important, as in high seas K CO2,660 during periods of falling winds exceed periods of rising winds by ∼20% in the mean. This hysteresis in K CO2,660 is consistent with the development of waves and increase in whitecap coverage as the seas mature. A similar hysteresis is absent from the transfer of a more soluble gas, confirming that the sea state dependence in K CO2,660 is primarily due to bubble-mediated gas transfer upon wave breaking. We propose a new parameterization of K CO2,660 as a function of wind stress and significant wave height, which resemble observed K CO2,660 both in the mean and on short timescales.

Nonmesothelial Spindle Cell Tumors of Pleura and Pericardium.

Spindle cell lesions of the pleura and pericardium are rare. Distinction from sarcomatoid mesothelioma, which has a range of morphologic patterns, can be difficult, but accurate diagnosis matters. This article provides practical guidance for the diagnosis of pleural spindle cell neoplasms, focusing on primary lesions.

Changes in audiovestibular handicap following treatment of vestibular schwannomas.

OBJECTIVE: This study aimed to assess degree of audiovestibular handicap in patients with vestibular schwannoma. METHODS: Audiovestibular handicap was assessed using the Hearing Handicap Inventory, Tinnitus Handicap Inventory and Dizziness Handicap Inventory. Patients completed questionnaires at presentation and at least one year following treatment with microsurgery, stereotactic radiosurgery or observation. Changes in audiovestibular handicap and factors affecting audiovestibular handicap were assessed. RESULTS: All handicap scores increased at follow up, but not significantly. The Tinnitus Handicap Inventory and Dizziness Handicap Inventory scores predicted tinnitus and dizziness respectively. The Hearing Handicap Inventory was not predictive of hearing loss. Age predicted Tinnitus Handicap Inventory score and microsurgery was associated with a deterioration in Dizziness Handicap Inventory score. CONCLUSION: Audiovestibular handicap is common in patients with vestibular schwannoma, with 75 per cent having some degree of handicap in at least one inventory. The overall burden of handicap was, however, low. The increased audiovestibular handicap over time was not statistically significant, irrespective of treatment modality.

Real-world prevalence of PD-L1 expression in non-small cell lung cancer: an Australia-wide multi-centre retrospective observational study.

An investigator-initiated, Australia-wide multi-centre retrospective observational study was undertaken to investigate the real-world prevalence of programmed death ligand-1 (PD-L1) expression in non-small cell lung carcinoma (NSCLC). Multiple centres around Australia performing PD-L1 immunohistochemistry (IHC) were invited to participate. Histologically confirmed NSCLC of any stage with a PD-L1 IHC test performed for persons aged ≥18 years between 1 January 2018 and 1 January 2020, and eligible for review, were identified at each centre, followed by data extraction and de-identification, after which data were submitted to a central site for collation and analysis. In total data from 6690 eligible PD-L1 IHC tests from histologically (75%) or cytologically (24%) confirmed NSCLC of any stage were reviewed from persons with a median age of 70 years, 43% of which were female. The majority (81%) of tests were performed using the PD-L1 IHC SP263 antibody with the Ventana BenchMark Ultra platform and 19% were performed using Dako PD-L1 IHC 22C3 pharmDx assay. Reported PD-L1 tumour proportion score (TPS) was ≥50% for 30% of all tests, with 62% and 38% scoring PD-L1 ≥1% and <1%, respectively. Relative prevalence of clinicopathological features with PD-L1 scores dichotomised to <50% and ≥50%, or to <1% and ≥1%, were examined. Females scored ≥1% slightly more often than males (64% vs 61%, respectively, p=0.013). However, there was no difference between sexes or age groups (<70 or ≥70 years) where PD-L1 scored ≥50%. Specimens from patients with higher stage (III/IV) scored ≥1% or ≥50% marginally more often compared to specimens from patients with lower stage (I/II) (p≤0.002). Proportions of primary and metastatic specimens did not differ where PD-L1 TPS was ≥1%, however more metastatic samples scored TPS ≥50% than primary samples (metastatic vs primary; 34% vs 27%, p<0.001). Cytology and biopsy specimens were equally reported, at 63% of specimens, to score TPS ≥1%, whereas cytology samples scored TPS ≥50% slightly more often than biopsy samples (34% vs 30%, respectively, p=0.004). Resection specimens (16% of samples tested) were reported to score TPS ≥50% or ≥1% less often than either biopsy or cytology samples (p<0.001). There was no difference in the proportion of tests with TPS ≥1% between PD-L1 IHC assays used, however the proportion of tests scored at TPS ≥50% was marginally higher for 22C3 compared to SP263 (34% vs 29%, respectively, p<0.001). These real-world Australian data are comparable to some previously published global real-world data, with some differences noted.

Facial Nerve Function Outcome and Risk Factors in Resection of Large Cystic Vestibular Schwannomas.

Objective Cystic vestibular schwannomas (VS) in contrast to solid VS tend to have accelerated growth, larger volume, rapid/atypical presentation, lobulated/adherent surface, and unpredictable course of the cranial nerves. Cystic VS are surgically challenging, with worse clinical outcomes and higher rate of subtotal resection (STR). Methods We retrospectively analyzed postoperative outcomes of 125 patients with cystic VS, operated between years 2005 and 2019 in our center. We confronted the extent of the resection and House-Brackmann (HB) grade of facial palsy with the results of comparable cohort of patients with solid VS operated in our center and literature review by Thakur et al. 1 Results Translabyrinthine approach was preferred for resection of large, cystic VS (97.6%). Gross-total resection (GTR) was achieved in 78 patients (62.4%), near-total resection (NTR) with remnant (<4 × 4 × 2 mm) in 43 patients (34.4%), and STR in 4 patients (3.2%). NTR/STR were significantly associated with higher age, tumor volume >5 cm 3 , retrosigmoid approach, high-riding jugular bulb, tumor adherence to the brain stem, and facial nerve ( p = 0.016; 0.003; 0.005; 0.025; 0.001; and <0.00001, respectively). One year after the surgery, 76% of patients had HB grades 1 to 2, 16% had HB grades 3 to 4, and 8% had HB grades 5 to 6 palsy. Worse outcome (HB grades 3 to 6) was associated with preoperative facial palsy, tumor volume >25 cm 3 , and cyst over the brain stem ( p = 0.045; 0.014; and 0.05, respectively). Comparable solid VS operated in our center had significantly higher HB grades 1 to 2 rate than our cystic VS (94% versus 76%; p = 0.03). Comparing our results with literature review, our HB grades 1 to 2 rate was significantly higher (76% versus 39%; p = 0.0001). Tumor control rate 5 years after surgery was 95.8%. Conclusion Our study confirmed that microsurgery of cystic VS has worse outcomes of facial nerve preservation and extent of resection compared with solid VS. Greater attention should be paid to the above-mentioned risk factors.

Signet-ring cell appearance of atrophic fat cells.

Cells with 'signet-ring' appearance were found at post-mortem examination of a man with a history of chronic illness, weight loss and multiple regions of 'bowel thickening' during life. Due to the decedent's history, the finding raised the possibility of disseminated signet-ring adenocarcinoma. However, the vacuoles did not stain for mucin and the cells did not stain for keratin. The cells did stain for calretinin and so a diagnosis of signet ring mesothelioma was considered. However, it was suggested that the cells with a cytoplasmic vacuole displacing the nucleus to one side producing the signet-ring appearance were instead atrophic fat cells. This was subsequently proven by Oil Red O staining.

The Incidence of Labelling of Non-Lung Adenocarcinomas With Antibodies Against TTF-1 and Diagnostic Implications.

Thyroid transcription factor 1 (TTF-1) is an immunohistochemical marker in the identification of lung and thyroid tumors. However, positive labelling for TTF-1 can occur in tumors from other sites, and this can result in misdiagnosis if only a limited panel of antibodies is used. We assessed the frequency of expression of 3 TTF-1 antibody clones, namely, 8G7G3/1, SPT24, and SP141 on a tissue microarray of 104 colorectal cancer (CRC), and whole-tumor sections of 165 CRC with known microsatellite instability (MSI) status. We also analyzed the expression of TTF-1 in a tissue microarray of 112 prostatic adenocarcinomas. The association of TTF-1 expression with clinicopathologic parameters and patient survival was analyzed. Six of 104 (5.7%) primary colorectal carcinomas expressed TTF-1 with SPT24 and SP141 clones, whereas only 2 (2%) of these tumors labeled positive for TTF-1 with clone 8G7G3/1. A significant association of TTF-1 expression with younger age at diagnosis (P=0.001) was found, but not with stage, or survival. The SP141 clone also labelled 24/165 (14.5%) of 165 CRC with known MSI status. There was an association with younger age (P<0.001), but not with MSI status or survival. TTF-1 expression was found in 39/112 (34%) prostate adenocarcinomas with 6/112 (5.3%) labelling with clone 8G7G3/1, 26/112 (23%) with clone SP141, and 31/112 (28%) with clone SPT24. TTF-1 expression appeared to be associated with extracapsular extension (P=0.022) and with higher stage (P=0.039). Here too TTF-1 expression was not associated with survival. The mRNA expression of TTF-1 in these tumors was confirmed by RTPCR, indicating that this is not false-positive labelling. Depending on the clone used, TTF-1 expression can vary with the SP141 and SPT24 clones exhibiting higher incidence of labelling. Pathologists should be aware of the differences in performance profiles of the different TTF-1 clones in diagnostic practice.

Headache, Cerebrospinal Fluid Leaks, and Pseudomeningoceles after Resection of Vestibular Schwannomas: Efficacy of Venous Sinus Stenting Suggests Cranial Venous Outflow Compromise as a Unifying Pathophysiological Mechanism.

Background Regardless of the operative approach, headache, cerebrospinal fluid (CSF) leaks, and pseudomeningoceles remain disproportionately common problems after surgery for vestibular schwannomas and have a significant negative impact on quality of life and potential to return to full employment. Recent work has raised the possibility that these problems may, in part, be related to acquired obstruction of cranial venous outflow. This article explores this idea further with respect to a group of patients with severe and intractable symptoms. Objective The main objective of this article is to describe our experience diagnosing, investigating, and treating cranial venous outflow obstruction following translabyrinthine resection of vestibular schwannomas. Methods Retrospective review of all patients ( n = 9) at our institution referred for sigmoid sinus stenting following translabyrinthine surgery. Results Headache resolved or improved after sigmoid stenting in all five patients in whom it was the primary symptom. CSF leak was the primary problem in two patients. In one, the leak was unchanged, but headache improved. In the other, the leak resolved, and headache improved. Two patients had symptomatic pseudomeningoceles and both resolved Conclusion Assuming a meticulous approach to wound closure, a CSF leak following surgery for vestibular schwannoma can be viewed as a pathological, but essentially homeostatic, response to raised intracranial pressure caused by acquired obstruction to cranial venous outflow. Postoperative headache (from high or low intracranial pressure) and CSF leaks, therefore, may all respond to measures aimed at eliminating the obstructing lesion.

Accuracy of rapid on-site evaluation of endobronchial ultrasound guided transbronchial needle aspirates by respiratory registrars in training and medical scientists compared to specialist pathologists-an initial pilot study.

BACKGROUND: Rapid on-site evaluation (ROSE) of endobronchial ultrasound guided transbronchial needle aspirates (EBUS-TBNA) increases diagnostic accuracy but in many institutions requires a specialist pathologist. This study aimed to determine if medical scientists or respiratory registrars could adequately perform ROSE to determine sufficiency of EBUS samples. METHODS: ROSE was performed on the first two EBUS-TBNA passes per patient by a pathologist, a medical scientist and two respiratory registrars. The medical scientists involved had all previously performed ROSE on over 50 procedures. The two respiratory registrars received cytology education from a pathologist in four separate hour-long training sessions. Each ROSE reviewer recorded whether each sample was sufficient or insufficient. Pathologist interpretation was taken as gold standard. Specific diagnosis was not required. Final diagnosis and the total number of passes were also recorded. This study recruited 25 patients (50 passes) for statistical evaluation. RESULTS: Assessment by specialist pathologists deemed 16/50 (32%) to be sufficient and 34/50 (68%) insufficient respectively. Medical scientists were 90% concordant with the pathologist (K =0.774; 95% CI, 0.587-0.961). The two respiratory registrars were 78% (K =0.568; 95% CI, 0.338-0.798) and 72% (K =0.448; 95% CI, 0.222-0.674) concordant, respectively. The mean number of passes per patient was 4.9 (range, 3-7). A diagnosis was established in 21/25 (82%) patients from the first EBUS-TBNA procedures with the remaining four patients requiring a further procedure or monitoring with serial CT scans to establish the diagnosis. Malignancy was found in 14/25 (56%) patients and a benign process in 11/25 (44%) patients. CONCLUSIONS: Medical scientist review of ROSE samples is not significantly different to a specialist pathologist and is an acceptable alternative. Respiratory registrars are not a realistic alternative for ROSE without more intensive training, which may be difficult to facilitate in addition to existing respiratory training commitments.

Review of diagnostic error in anatomical pathology and the role and value of second opinions in error prevention.

AIMS: Diagnostic/interpretative accuracy can be challenging in anatomical pathology due to the subjective element of the diagnostic process. This can lead to false-negative or false-positive diagnoses of malignancy, variations in grading and diagnostic misclassification of a condition.It is imperative that an accurate diagnosis is achieved so that an appropriate and timely treatment is administered to the patient, for example, the success of targeted molecular therapeutic options for treatment of cancer is dependent on accurate anatomical pathology diagnoses being issued. METHODS: A literature review of diagnostic accuracy in selected specimen categories was undertaken and was compared with data on metropolitan and regional pathologist diagnostic proficiency performance in an external quality assurance programme from surveys provided 2015-2017. For each specimen category, cases having attracted a diagnostic inaccuracy (ie, major discordance) of ≥20% and cases attracting a combined error rate (ie, major and minor discordance) of ≥30% are reviewed and discussed. RESULTS: The rate of inaccurate diagnoses (assessed as a major discordance) ranged from 3% to 9% among the different specimen groups, with highest mean percentage of inaccurate diagnoses in gynaecology, dermatopathology and gastrointestinal specimens. CONCLUSIONS: It was possible to ascertain that gynaecology, dermatopathology and gastrointestinal specimens had presented the greatest diagnostic challenge to the participant pathologists, determined as highest rate of diagnostic inaccuracy, that is, major discordance with respective case target diagnoses.Through a combination of routine second opinions, directed retrospective peer review and participation in appropriate external quality assurance schemes, the risk associated with these diagnoses can be minimised.

Malignant Mesothelioma, BAP1 Immunohistochemistry, and VEGFA: Does BAP1 Have Potential for Early Diagnosis and Assessment of Prognosis?

Malignant mesothelioma (MM) is an aggressive malignancy of the serosal membranes. Early diagnosis and accurate prognostication remain problematic. BAP1 is a tumour suppressor gene commonly mutated in MM. Germline BAP1 mutation has been associated with early onset and less aggressive disease compared with sporadic MM. Sporadic BAP1 mutations are common and are associated with improved survival in MM, contrary to other malignancies. This study investigated the prognostic role of BAP1 in matched cytology and surgical specimens and aimed to investigate the association between BAP1 and the established prognostic marker VEGFA from a cohort of 81 patients. BAP1 mutation was found in 58% of histology and 59% of cytology specimens. Loss of BAP1 expression in both surgical and cytology specimens was significantly associated with poorer survival in a multivariate analysis when controlling for known prognostic indicators. Increased levels of VEGFA in pleural effusions were associated with poor survival. We conclude that the prognostic significance of BAP1 mutations in MM cannot be determined in isolation of other prognostic factors, which may vary between patients. Pathologists should employ caution when commenting on prognostic implications of BAP1 status of MM patients in diagnostic pathology reports, but it may be useful for early diagnosis.

Intra- and Interobserver Reproducibility Assessment of PD-L1 Biomarker in Non-Small Cell Lung Cancer.

Purpose: Reliable and reproducible methods for identifying PD-L1 expression on tumor cells are necessary to identify responders to anti-PD-1 therapy. We tested the reproducibility of the assessment of PD-L1 expression in non-small cell lung cancer (NSCLC) tissue samples by pathologists.Experimental Design: NSCLC samples were stained with PD-L1 22C3 pharmDx kit using the Dako Autostainer Link 48 Platform. Two sample sets of 60 samples each were designed to assess inter- and intraobserver reproducibility considering two cut points for positivity: 1% or 50% of PD-L1 stained tumor cells. A randomization process was used to obtain equal distribution of PD-L1 positive and negative samples within each sample set. Ten pathologists were randomly assigned to two subgroups. Subgroup 1 analyzed all samples on two consecutive days. Subgroup 2 performed the same assessments, except they received a 1-hour training session prior to the second assessment.Results: For intraobserver reproducibility, the overall percent agreement (OPA) was 89.7% [95% confidence interval (CI), 85.7-92.6] for the 1% cut point and 91.3% (95% CI, 87.6-94.0) for the 50% cut point. For interobserver reproducibility, OPA was 84.2% (95% CI, 82.8-85.5) for the 1% cut point and 81.9% (95% CI, 80.4-83.3) for the 50% cut point, and Cohen's κ coefficients were 0.68 (95% CI, 0.65-0.71) and 0.58 (95% CI, 0.55-0.62), respectively. The training was found to have no or very little impact on intra- or interobserver reproducibility.Conclusions: Pathologists reported good reproducibility at both 1% and 50% cut points. More adapted training could potentially increase reliability, in particular for samples with PD-L1 proportion, scores around 50%. Clin Cancer Res; 23(16); 4569-77. ©2017 AACR.

Cell block samples from endobronchial ultrasound transbronchial needle aspiration provide sufficient material for ancillary testing in lung cancer-a quaternary referral centre experience.

BACKGROUND: Rapid on site examination (ROSE) is encouraged at endobronchial ultrasound transbronchial needles aspiration (EBUS-TBNA) to improve diagnostic yield. Due to new therapeutic options in lung cancer, it is not sufficient to merely distinguish between non-small cell lung carcinoma (NSCLC) and small cell lung carcinoma (SCLC). Immunohistochemistry (IHC) distinction is now standard practice, as well as additional molecular testing where clinically indicated. We investigated the diagnostic yield of on-site smears vs. cell block and the provision of cellular material for ancillary testing at our centre. METHODS: A retrospective audit of all EBUS-TBNA procedures performed until July 2012 was undertaken. Diagnostic yield on smears versus cell block was recorded. Cell blocks were reviewed by an experienced pathologist to determine diagnostic accuracy and whether IHC and molecular testing were possible. RESULTS: In total, 234 procedures were recorded with 101 (43.2%) malignant cases, 107 (45.7%) benign cases and an initial 26/234 (11.1%) insufficient for diagnosis of which 11/234 (4.7%) were false negatives for malignancy after further follow up. The average number of passes was 4.5. For malignancies, smear diagnosis was possible in 95% (96/101) of cases and cell block diagnosis in 93.5% (87/93) of cases. There was sufficient material for IHC in 97.7% (85/87) of malignant cases. In 79.3% (69/87) of NSCLCs molecular testing for epidermal growth factor receptor (EGFR) mutation analysis was theoretically possible on samples obtained. CONCLUSIONS: Cell blocks are not inferior to smears for diagnostic accuracy and provide sufficient samples for histology. However, ROSE assists the physician on how best to manage samples for ancillary testing.

Usefulness of Aquaporin 1 as a Prognostic Marker in a Prospective Cohort of Malignant Mesotheliomas.

(1) BACKGROUND: Malignant mesothelioma (MM) is an aggressive tumour of the serosal membranes, associated with exposure to asbestos. Survival is generally poor, but prognostication for individual patients is difficult. We recently described Aquaporin 1 (AQP1) as independent prognostic factor in two separate retrospective cohorts of MM patients. Here we assess the usefulness of AQP1 prospectively, and determine the inter-observer agreement in assessing AQP1 scores; (2) METHODS: A total of 104 consecutive cases of MM were included. Sufficient tissue for immunohistochemistry was available for 100 cases, and these cases were labelled for AQP1. Labelling was assessed by two pathologists. Complete clinical information and follow up was available for 91 cases; (3) RESULTS: Labelling of ≥50% of tumour cells for AQP indicated improved prognosis in a univariate model (median survival 13 versus 8 months, p = 0.008), but the significance was decreased in a multivariate analysis. Scoring for AQP1 was robust, with an inter-observer kappa value of 0.722, indicating substantial agreement between observers; (4) CONCLUSION: AQP1 is a useful prognostic marker that can be easily incorporated in existing diagnostic immunohistochemical panels and which can be reliably interpreted by different pathologists.

National Working Group Meeting on ALK diagnostics in lung cancer.

The global landscape of molecular testing is rapidly changing, with the recent publication of the International Association for the Study of Lung Cancer (IASLC)/College of American Pathologists (CAP) guidelines and the ALK Atlas. The IASLC/CAP guidelines recommend that tumors from patients with non-small cell lung cancer (NSCLC) be tested for ALK rearrangements in addition to epidermal growth factor receptor (EGFR) mutations. The spur for this recommendation is the availability of novel therapies that target these rearrangements. This article is based on coverage of a Pfizer-sponsored National Working Group Meeting on ALK Diagnostics in Lung Cancer, held around the 15th World Lung Cancer Conference, in Sydney on October 31, 2013. It is based on the presentations given by the authors at the meeting and the discussion that ensued. The content for this article was discussed and agreed on by the authors.

Squamous cell carcinoma of the temporal bone: clinical outcomes from radical surgery and postoperative radiotherapy.

OBJECTIVE: To review the treatment of squamous carcinoma of the temporal bone at a regional skull base unit for the period 1982-2012. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Sixty patients with primary squamous carcinoma of the temporal bone. INTERVENTIONS: Multidisciplinary team approach including surgical resection, reconstruction, and postoperative radiotherapy. MAIN OUTCOME MEASURES: Disease-specific survival, overall survival. RESULTS: The 5-year disease-specific survival for the whole cohort was 44% (CI, 37%-51%). Multivariable analysis revealed nodal status, poorly differentiated squamous cell histology, and carotid involvement to be poor prognostic indicators. CONCLUSION: Although the survival figures in this series are comparable with the best outcomes from other units, our experience would suggest improvements can still be achieved by reconsidering the selection of patients for neck dissection and temperomandibular joint excision in early stage disease. We also conclude that postoperative radiotherapy should be delivered to all patients, including surgical salvage cases who may have received previous irradiation. Finally, the minority of patients with poor prognostic features should be offered a more palliative therapeutic approach.

A unique case of pneumatised styloid process with cholesteatoma.

Pneumatisation of styloid process is a very rare finding and has never been reported previously. We present a unique case of a pneumatised styloid process with a cholesteatoma arising within the cavity. We describe the clinical features, associated radiological findings, and management of this lesion.

Defective lung macrophage function in lung cancer ± chronic obstructive pulmonary disease (COPD/emphysema)-mediated by cancer cell production of PGE2?

In chronic obstructive pulmonary disease (COPD/emphysema) we have shown a reduced ability of lung and alveolar (AM) macrophages to phagocytose apoptotic cells (defective 'efferocytosis'), associated with evidence of secondary cellular necrosis and a resultant inflammatory response in the airway. It is unknown whether this defect is present in cancer (no COPD) and if so, whether this results from soluble mediators produced by cancer cells. We investigated efferocytosis in AM (26 controls, 15 healthy smokers, 37 COPD, 20 COPD+ non small cell lung cancer (NSCLC) and 8 patients with NSCLC without COPD) and tumor and tumor-free lung tissue macrophages (21 NSCLC with/13 without COPD). To investigate the effects of soluble mediators produced by lung cancer cells we then treated AM or U937 macrophages with cancer cell line supernatant and assessed their efferocytosis ability. We qualitatively identified Arachidonic Acid (AA) metabolites in cancer cells by LC-ESI-MSMS, and assessed the effects of COX inhibition (using indomethacin) on efferocytosis. Decreased efferocytosis was noted in all cancer/COPD groups in all compartments. Conditioned media from cancer cell cultures decreased the efferocytosis ability of both AM and U937 macrophages with the most pronounced effects occurring with supernatant from SCLC (an aggressive lung cancer type). AA metabolites identified in cancer cells included PGE2. The inhibitory effect of PGE2 on efferocytosis, and the involvement of the COX-2 pathway were shown. Efferocytosis is decreased in COPD/emphysema and lung cancer; the latter at least partially a result of inhibition by soluble mediators produced by cancer cells that include PGE2.