Association of PD-L1 expression with driver gene mutations and clinicopathological characteristics in non-small cell lung cancer: A real-world study of 10 441 patients

BACKGROUND

Programmed death ligand-1 (PD-L1) expression is a well-known predictive biomarker of response to immune checkpoint blockade in non-small cell lung cancer (NSCLC). However, there is limited evidence of the relationship between PD-L1 expression, clinicopathological features, and their association with major driver mutations in NSCLC patients in Latin America.

METHODS

This retrospective study included patients from Argentina with advanced NSCLC, and centralized evaluation of PD-L1 expression concurrently with genomic alterations in the driver genes EGFR, ALK, ROS1, BRAF, and/or KRAS G12C in FFPE tissue samples.

RESULTS

A total of 10 441 patients with advanced NSCLC were analyzed. Adenocarcinoma was the most frequent histological subtype (71.1%). PD-L1 expression was categorized as PD-L1 negative (45.1%), PD-L1 positive low-expression 1%-49% (32.3%), and PD-L1 positive high-expression ≥50% (22.6%). Notably, current smokers and males were more likely to have tumors with PD-L1 tumor proportion score (TPS) ≥50% and ≥ 80% expression, respectively (p < 0.001 and p = 0.013). Tumors with non-adenocarcinoma histology had a significantly higher median PD-L1 expression (p < 0.001). Additionally, PD-L1 in distant nodes was more likely ≥50% (OR 1.60 [95% CI: 1.14-2.25, p < 0.01]). In the multivariate analysis, EGFR-positive tumors were more commonly associated with PD-L1 low expression (OR 0.62 [95% CI: 0.51-0.75], p < 0.01), while ALK-positive tumors had a significant risk of being PD-L1 positive (OR 1.81 [95% CI: 1.30-2.52], p < 0.01).

CONCLUSIONS

PD-L1 expression was associated with well-defined clinicopathological and genomic features. These findings provide a comprehensive view of the expression of PD-L1 in patients with advanced NSCLC in a large Latin American cohort.

Recommendations for detection, prioritization, and treatment of thoracic oncology patients during the COVID-19 pandemic: the THOCOoP cooperative group

The world currently faces a pandemic due to SARS-CoV-2. Relevant information has emerged regarding the higher risk of poor outcomes in lung cancer patients. As such, lung cancer patients must be prioritized in terms of prevention, detection and treatment. On May 7th, 45 experts in thoracic cancers from 11 different countries were invited to participate. A core panel of experts regarding thoracic oncology care amidst the pandemic gathered virtually, and a total of 60 initial recommendations were drafted based on available evidence, 2 questions were deleted due to conflicting evidence. By May 16th, 44 experts had agreed to participate, and voted on each of the 58 recommendation using a Delphi panel on a live voting event. Consensus was reached regarding the recommendations (>66 % strongly agree/agree) for 56 questions. Strong consensus (>80 % strongly agree/agree) was reached for 44 questions. Patients with lung cancer represent a particularly vulnerable population during this time. Special care must be taken to maintain treatment while avoiding exposure.

Combined intensive chemoradiotherapy for organ preservation in patients with resectable and non-resectable oesophageal cancer

From January 1990 to April 1993, 60 oesophageal cancer patients were enrolled in a protocol of non-surgical treatment that consisted of induction chemotherapy followed by concurrent chemoradiotherapy. Induction chemotherapy consisted of cisplatin 40 mg/m2 intravenous bolus days 1, 2, 14, 15; 24 h continuous infusion of 5-fluorouracil (5-FU) 1000 mg/m2 days 1 and 14; leucovorin 20 mg/m2 days 1 and 14 given before and with 5-FU; bleomycin 30 UI days 1 and 14; mitomycin C 10 mg/m2 day 14. Concurrent chemoradiotherapy consisted of 60 Gy (6 weeks) from day 21 and cisplatin 70 mg/m2 days 28, 42 and 56; leucovorin 20 mg/m2 followed by 5-FU 425 mg/m2 days 28, 35, 42, 49 and 56. Complete response occurred in 44 of 55 evaluable patients (80%). The median survival is 32 months; the actuarial survival at 40 months is 35% (CI 18-53). These results appear improved over those reported with surgery or radiation alone, and suggest that organ preservation as a secondary treatment goal should be vigorously investigated.

Thyroglobulin autoantibodies in endocrine diseases

A simple, rapid haemagglutination laboratory kit was developed for the measurement of the thyroglobulin autoantibodies (Tgl-AAb). The Tgl-AAb kit was applied to the measurement of the AAbs titres in the sera collected from 2861 endocrine patients either hospitalized in the Institute of Endocrinology (about 75%) or endocrine outpatients--the great part of patients (over 90%) being however diagnosed as thyroid disorders. The sex classification showed the F/M ratio 6.61/1 for the whole group and 7.4/1 for the positive cases. The prevalence of the Tgl-AAbs positive sera at low titre (under 1:200) is 11.6% about twofold higher than in a population of 700 blood donors (6.4%), previously reported. Among the significant Tgl-AAbs titres, chosen more or less arbitrarily over 1:200, 30.47% of the patients have titres in the range 1:200-1:5000. The Tgl-AAbs positive and negative sera are classified and analysed according to the endocrine pathology but especially thyroid disorders and the positive thyroid disease are grouped by low, high and very high Tgl-AAbs titres and by Tgl-precipitin positive. Our results are rather similar to those reported for endocrine collectivities in other countries. The technical and methodological sources of some discrepancies between the laboratory Tgl-AAbs results and the clinical symptoms and/or anatomo-pathologic results are commented as well as some of the future perspectives of the laboratory investigation of the thyroid autoimmune diseases. Concluding, a strategy schema for a possible immunogram is presented.

Peptide hormones in saliva. I. Insulin in saliva during the oral glucose tolerance test in female patients

The radioimmunoassay (RIA) of insulin was performed in the serum and saliva of 27 female patients during the oral glucose tolerance test (OGTT). The patients were divided into two groups: 19 non-diabetic patients and 8 patients diagnosed as impaired glucose tolerance (IGT) disease. In one patient in each group, the OGTT was performed twice at intervals of 3-5 days. The results show that immunoreactive insulin (IRI) is present in saliva and its concentration increases during the glucose stimulation test from 6.48 +/- 1.13 microU/ml (means +/- SEM) in basal conditions at peak values of 45.46 +/- 10.14 microU/ml at 2 hrs after glucose intake. In patients with IGT salivary IRI increases from 5.18 +/- 1.39 microU/ml in basal conditions to peak values of 83.34 +/- 25.85 microU/ml at 3 hrs after glucose administration. Great response variations were observed either inter-individual or intraindividual in both groups of patients. Some patients had unusual high salivary IRI concentration especially in those with gastrointestinal troubles. Further, some hypotheses and experimental models, are advanced, considered useful for the explanation of the physiologic significance of the salivary IRI or of the IRI-like material.

Radioreceptorassay of insulin using human erythrocytes. I. Methodological aspects

It is known that human erythrocytes have specific receptors for insulin. This works describes a radioreceptor assay (RRA) suitable for the determination of the insulin binding to the surface receptors of erythrocytes. The erythrocytes were isolated from heparinated blood collected in the morning after overnight fasting. In the incubation mixture are 4-5 X 10(9) cells/ml, labelled porcine insulin and nonlabeled (cold) insulin in serial concentrations, range 10-10(5) ng/ml. Incubation (150 min. at +15 degrees C) is ended by suspending the incubation mixture in cold buffer. After washing, the tracer insulin bound to erythrocytes is measured on a gamma counter and the percentage of the specific binding is calculated against the total radioactivity determined prior to the washing steps. By this procedure, the maximal binding of 125I-Insulin was 10.55 +/- 0.78% (mean +/- SD) in five normal volunteers and 6.79 +/- 1.77 (mean +/- SD) in five obese nondiabetic patients, having an enhanced insulin response in the oral glucose tolerance test. The slight hemolysis that happened accidentally in some tubes after incubation caused rude degradation of the tracer, the binding being decreased at last by 25%. The method described (according to Gambhir K. K. et al 1977 slightly modified) is specific and thus suitable for estimating the prognosis of obese children, patients with acute and chronic hepatitis and also for the study of the role of erythrocytes in insulin metabolism and possibly in the metabolism of other hormones.

The entrapment of biological active substances into liposomes. II. Effects of oral administration of liposomally entrapped insulin in normal and alloxanized rats

Insulin (I) was entrapped into liposomes of various lipid compositions. After oral administration, some of the normal rats treated with neutral liposomes (c) and (d) having egg yolk lecithin, prepared with 2 or 4 mg I/ml respectively, showed a decrease in blood glucose at 2 and 4 hrs. In alloxanized rats (75 mg alloxan/kg body weight) the positive liposomes (f) have induced in some animals a decrease in blood glucose at both time intervals after oral treatment. When neutral liposomes (c) were administered to diabetic rats (125 mg alloxan/kg body) the blood glucose decreased in 9 of 12 animals from 391 to 125 mg/100 ml blood, at 3 hrs after oral treatment. At 1 h, the effect had appeared in 3 of 14 animals. The neutral liposomes (g) having synthetic lecithin, induced a decrease in blood glucose in 5 of 10 animals. A good correlation was observed between decreased glucose and increased insulin levels with the same variability throughout the treated group. No increased insulin levels were observed in diabetic control and normal rats. By the RIA method, the insulin entrapment was 8%. Histological studies have shown that at 35 min after oral administration, neutral liposomes (c) penetrate deeply into the intestinal wall of alloxanized rats as compared both to the neutral liposomes with synthetic lecithin (g) or to the positive ones (f).

A radioimmunoassay system for human myoglobin: method development and applications

double antibody radioimmunoassay (RIA) system for human myoglobin (hMb) was developed using our own reagents. The antigen (hMb) was isolated from human muscle, purified and stored frozen until needed for immunization, radiolabeling or reference preparation. The anti-hMb serum raised in rabbits was used at 1:2.10(4) dilution (initial). The Chloramine-T method was used for the hMb labeling obtaining at 10-15 muCi/micrograms (370-550 KBq/micrograms) specific activity. Working standards were prepared having concentrations in the range of 2.0 to 500 ng/ml. The reagents were incubated at +4 degrees C for 48 plus 24 hrs. The specificity and accuracy of our hMb-RIA system were validated using for parallel assays an already validated immunochemical system, the hemagglutination inhibition (HI) technique and the parallelism test using serum dilutions from patients with acute myocardial infarction (AMI). The serum hMb concentration in normal subjects (no = 23) was 54.14 +/- 15.08 ng/ml (X +/- SD), being higher in short-term hypothyroidism (no = 13), 87.95 +/- 20.90 ng/ml (p less than 0.0005) or in treated hyperthyroidism (no = 5), 80.03 +/- 21.81 ng/ml. In AMI (no = 6) the serum hMb concentration varied in the range of 123 to 1510 ng/ml. The sensitivity of our hMb-RIA system is 2 ng/ml and the intraassay average error (coefficient of variability % in %B) is 2.26%. Trials to shorten the incubation time showed that adequate binding of labelled Mb may be obtained with 2 plus 4 hr intervals at room temperature. It is necessary to establish, in our conditions, the variation limits for serum hMb in normal subjects according to sex and age as a comparison basis for the study of its physiological and pathological variations.

Immunohistochemical demonstration of thyroglobulin in thyroid pathology

Thyroglobulin (Tg) was detected by the immunoperoxidase method in the following thyroid diseases: euthyroid goiter, Graves' disease, Hashimoto's thyroiditis, folliculo-papillary carcinoma, follicular carcinoma, anaplastic carcinoma and medullary carcinoma. Thyroglobulin was present in all benign lesions. The highest immunohistochemical staining reaction was found in Graves' disease. In euthyroid goiter, some colloid-distended macrofollicles did not show any Tg staining. A heterogeneous pattern of Tg staining was displayed especially by thyroid carcinomas. In most cases of papillary and follicular carcinomas Tg was detected in some neoplastic cells and sometimes in the colloid. There were differences in Tg content between different fields of the same tumor. In all anaplastic carcinomas a negative Tg staining was found. Vizualization of Tg in thyroid carcinomas is important for estimating the degree of differentiation and for indicating the thyroidal origin of metastases of adenocarcinomas.

The simultaneous isolation of the human pituitary hormones. II. The luteinizing hormone

The main purpose of the work is the isolation of luteinizing hormone (LH) from frozen human pituitaries. The procedure for the processing of the glands included the steps described by P. Roos [22] for the preparation of the follicle stimulating hormone (FSH) slightly modified and adapted to our conditions. After thawing, the pituitaries were homogenized in 0.03 N Naphosphate buffer, pH 5.7. The protein bulk containing growth hormone (GH) was separated by precipitation with saturated ammonium sulfate (v/v). The supernatant containing gonadotrophins, obtained by centrifugation, was fractionated by chromatography on DEAE cellulose, the first peak being further fractionated by column gel-filtration on Sephadex G-100 after a previous concentration by dialysis against polyvinylpyrolidone 10%. The first peak obtained by this last fractionation was considered for the time being, as pure LH. The extraction and fractionation steps were followed by disc polyacrylamide gel electrophoresis and by radioimmunoassay measurement of the LH concentration. Studies concerning the homogeneity and the biological activity of our LH preparation by comparison to the LH preparations recommended by WHO, are in progress in our laboratory.

An improved procedure for the preparation of the human thyroglobulin and the development of a thyroglobulin autoantibody kit

Human thyroglobulin has various applications as a diagnosis reagent or for studying the physiopathology of the protein and hormonal biosynthesis in the thyroid gland. The previous preparation procedure for isolating the human thyroglobulin currently used in our laboratory, has some inconveniences as regards the low yield and the noxious influence of the ammonium sulfate precipitation upon its molecular integrity. Therefore, we describe an improved fractionation and purification procedure whose main steps are extraction of the thyroid tissue homogenate in 0.15 M NaCl followed by a double gel filtration on Sephadex G-200 column. In this way are obtained thyroglobulins A and B grade using the two chromatographic steps, respectively. Thyroglobulin B grade is further submitted to preparative polyacrylamide gel electrophoresis for separating some thyroglobulin isomers as recognized by other groups using the analytical ultracentrifugation procedure. The different fractionation and purification steps were checked by double diffusion in gel using rabbit anti-thyroglobulin serum and horse antihuman serum protein. The homogeneity and the molecular weight of the different fractions we evidenced were analyzed by the aid of disc and plate electrophoresis in polyacrylamide gel. The authors developed the technique for thyroglobulin autoantibody detection by the passive haemaglutination method using stabilized erythrocytes coated with thyroglobulin A-grade. Thyroglobulin B-grade used as a tracer and a reference preparation in a RIA system offered a sensitivity of 1.5 micrograms/liter for thyroglobulin detection in biological fluids.

The simultaneous isolation of human pituitary hormones. I. Human growth hormone

The main purposes of the present work are: a. the preparation of "clinical grade" human growth hormone (hGH), its physico-chemical analysis and the improvement of its solubility for clinical purposes; b. the development of a method for the isolation of high-purity hGH using frozen pituitaries. Nine batches of 20 g acetone powder were processed resulting in 4940 mg of "clinical grade" hGH. Samples of these batches randomly selected were analysed by Sephadex G-100 chromatography and by disc and preparative polyacrylamide gel electrophoresis (PAGE). Lyophilised hGH, soluble in NaCl 0.15 M was prepared and called "Hormcresc" and directions for use were elaborated. One hundred frozen glands were processed and the "crude" hGH was purified by gel filtration on Sephadex G-100 and tested using double diffusion in agar gel, radioimmunoassay (RIA), rechromatography on Sephadex G-100 and disc PAGE. The experiments led to an extraction yield of 550 +/- 165 (means +/- SD) mg "clinical grade" hGH per 20 g of acetone powder. The elution pattern of Sephadex G-100 chromatography and of preparative PAGE as well as the pattern of disc PAGE showed that the "clinical grade" hGH is similar to the already known GH hormones: Raben Somatrotropin, Crescormon (Sweden) and hGH (FRG) but different from Sotropin-H (DDR). The "clinical grade" hGH in lyophilised form is similar to the GH preparations accepted by the European pharmacopoea; it is soluble in NaCl 0.15 M and painless on injection by comparison to hGH in powder form. A method was worked out for the extraction, isolation and purification of "highly pure" hGH using frozen pituitaries, which made it possible to isolate from the same batch of glands not only hGH but also luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin and thyroid stimulating hormone (TSH). During the purification of "crude" hGH on Sephadex G-100 a rather abundant fraction of MW of about 5000-15000 daltons was observed; this fraction, codified provisionally the "X" fraction does not contain hGH, as results from the RIA measurements. On disc electrophoresis, the purified hGH is not homogeneous: behind the main fast band three slower bands are observed. Studies concerning the comparison of our "highly pure" hGH with the hGH preparations recommended by WHO, are in progress in our laboratory.

Insulin radioimmunoassay measurement by the polyethyleneglycol separation technique using the ROTOP kit reagents. Some clinical applications

The technique described in the instructions booklet of the radioimmunoassay Insulin kit commercially known as the ROTOP-Insulin kit (CCR) tested both in our and in other laboratories did not show the desired reproducibility. Using the main ROTOP reagents (anti-insulin serum and 125I-Insulin) in radioimmunoassay (RIA) systems with other separation techniques (double antibody, dextran-charcoal and polyethyleneglycol) we observed that these reagents are suitable for a sensitive and precise RIA system. The intra-assay variations observed were caused by the separation technique with 86% ethanol as proposed by the procedure. This work describes an insulin-RIA system modified in order to be able to use the ROTOP reagents with the polyethyleneglycol (PEG) separation technique. This variant is used for more than three years in our laboratory but was adopted also in other RIA laboratories in Romania.

A radioimmunoassay system for human thyroglobulin

A radioimmunoassay (RIA) system for thyroglobulin (Tgl) was developed. The crude Tgl was prepared from thyroid glands surgically removed for colloid goiter by ammonium sulphate fractionation. Two purified Tgls were obtained by gel filtration on Sephadex G-200 (Tgl-200) and by preparative polyacrylamide gel electrophoresis (Tgl-PAGE). Both Tgl-200 and Tgl-PAGE were used for immunization of the animals for radioiodination and as reference preparations. The double antibody RIA system using Tgl-200 may detect 1.5 microgram/l, the technique being suitable for Tgl quantification in human biological fluids. The results of the measurement in 54 children without apparent thyroid enlargement showed a rather wide range of variability of the Tgl values in basal conditions, for example 4.67-37.05 micrograms/l in a group of 29 boys aged 6 to 16 years and 4.06-31.90 micrograms/l in a group of 25 girls aged 5 to 16 years.