Platelet Parameters as Biomarkers for Thrombosis Risk in Cancer: A Systematic Review and Meta-analysis.

Cancer-associated thrombosis (CAT) is a major cause of both morbidity and mortality in cancer patients. Platelet count has been investigated as a predictor of CAT in various settings while knowledge on platelet activation parameters is sparse. This report provides a systematic review and meta-analysis on available literature on associations between platelet count and/or function and arterial and venous thrombosis in adult cancer patients. The review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. PubMed and Embase were searched up to March 2022. The National Heart, Lung, and Blood Institute's tools were used for quality assessment. In total, 100 studies were included which investigated the association between CAT and platelet count (n = 90), platelet indices (n = 19), and platelet function/activation markers (n = 13) in patients with solid cancers (n = 61), hematological cancers (n = 17), or mixed cancer types (n = 22). Eighty-one studies had venous thrombosis as their outcome measure, while 4 had arterial thrombosis and 15 studies had both. We found significantly elevated odds ratio of 1.50 (95% confidence interval: 1.19-1.88) for thrombosis with higher platelet counts. We saw a tendency toward an association between markers of platelet activation in forms of mean platelet volume and soluble P selectin and both arterial and venous thrombosis. Only one study investigated dynamic platelet function using flow cytometry. In conclusion, platelet count is associated with CAT across different cancer types and settings. Platelet function or activation marker analysis may be valuable in assisting thrombosis risk assessment in cancer patients but is sparsely investigated so far.

Clinical Implications of Discrepancy between One-Stage Clotting and Chromogenic Factor IX Activity in Hemophilia B.

BACKGROUND: Discrepancy in factor IX activity (FIX:C) between one-stage assay (OSA) and chromogenic substrate assay (CSA) in patients with hemophilia B (PwHB) introduces challenges for clinical management. AIM: To study the differences in FIX:C using OSA and CSA in moderate and mild hemophilia B (HB), their impact on classification of severity, and correlation with genotype. METHODS: Single-center study including 21 genotyped and clinically characterized PwHB. FIX:C by OSA was measured using ActinFSL (Siemens) and CSA by Biophen (Hyphen). In addition, in vitro experiments with wild-type FIX were performed. Reproducibility of CSA was assessed between three European coagulation laboratories. RESULTS: FIX:C by CSA was consistently lower than by OSA, with 10/17 PwHB having a more severe hemophilia type by CSA. OSA displayed a more accurate description of the clinical bleeding severity, compared with CSA. A twofold difference between OSA:CSA FIX:C was present in 12/17 PwHB; all patients had genetic missense variants in the FIX serine protease domain. Discrepancy was also observed with diluted normal plasma, most significant for values below 0.10 IU/mL. Assessment of samples with low FIX:C showed excellent reproducibility of the CSA results between the laboratories. CONCLUSION: FIX:C was consistently higher by OSA compared with the CSA. Assessing FIX:C by CSA alone would have led to diagnosis of a more severe hemophilia type in a significant proportion of patients. Our study suggests using both OSA and CSA FIX:C together with genotyping to classify HB severity and provide essential information for clinical management.

Impact of Stereotactic Body Radiotherapy on Thrombin Generation and Platelet Aggregation in Patients with Non-Small Cell Lung Cancer.

Patients with localized non-small cell lung cancer (NSCLC) considered unfit for surgery are at substantially increased risk of venous thromboembolism. Radiotherapy may further increase this risk. We aim to investigate the impact of stereotactic body radiotherapy (SBRT) on thrombin generation and platelet aggregation. We included 110 patients with localized NSCLC treated with SBRT. Blood samples were obtained prior to SBRT, immediately after SBRT completion, and 4-6 weeks following SBRT. Ex vivo and in vivo thrombin generations were analyzed using a calibrated automated thrombogram and commercial enzyme-linked immunosorbent assays. Platelet aggregation was evaluated using multiple electrode aggregometry. No significant differences were found in ex vivo or in vivo thrombin generation between blood samples before and immediately after SBRT treatment. Platelet aggregation was lower immediately after SBRT than before SBRT (TRAP: P = 0.04 and ASPI: P = 0.02) but remained within the reference interval. SBRT did not affect in vivo and ex vivo thrombin generation or platelet aggregation. SBRT did not cause prothrombotic changes in the coagulation in this study population of SBRT-treated patients with localized NSCLC.

Increased In Vivo Thrombin Generation in Patients with Localized Non-Small Cell Lung Cancer Unfit for Surgery.

Patients with lung cancer face a substantially increased risk of thromboembolic disease. Patients with localized non-small cell lung cancer (NSCLC) who are unfit for surgery due to age or comorbidity have additional thrombotic risk factors. Thus, we aimed to investigate markers of primary and secondary hemostasis, since this could assist in treatment decisions. We included 105 patients with localized NSCLC. Ex vivo thrombin generation was determined by calibrated automated thrombogram and in vivo thrombin generation was determined by measurement of thrombin-antithrombin complex (TAT) levels and prothrombin fragment F1 + 2 concentrations (F1 + 2). Platelet aggregation was investigated by impedance aggregometry. Healthy controls were used for comparison. TAT and F1 + 2 concentrations were significantly higher in NSCLC patients than in healthy controls (P < .001). The levels of ex vivo thrombin generation and platelet aggregation were not increased in the NSCLC patients. Patients with localized NSCLC considered unfit for surgery had significantly increased in vivo thrombin generation. This finding should be further investigated as it could be relevant for the choice of thromboprophylaxis in these patients.

Platelet Function Testing: Update and Future Directions.

Platelets play a key role in maintaining normal hemostasis and are also recognized as partners in the development of arterial thrombosis. Today, platelet function testing is used for very different clinical purposes; first, for investigation of platelet dysfunction in acute bleeding and diagnosis of platelet disorders in patients with long-lasting bleeding tendency, and second, for testing the efficacy of antiplatelet therapy in patients with increased thromboembolic risk. Moreover, it has been discussed whether platelet function testing can be used for prediction of bleeding risk (e.g., prior to major surgery). Ever since light transmission aggregometry was introduced, laboratories around the world have worked on testing platelet function, and during the last decades a wide range of new methods has emerged. Besides the clinical utility of platelet function testing, the present review summarizes the test principles and advantages and disadvantages of the different methods, depending on the purpose for which it is to be used. A critical step in investigation of platelet function is the preanalytical factors that can substantially affect test results. Therefore, this review also provides an overview of preanalytical variables that range from patient-related factors such as smoking, coffee, and exercise prior to blood sampling to selection of anticoagulant, needle gauge, and time from blood sampling to analyses. Finally, this review outlines further perspectives on platelet function testing for clinical practice and for research purposes.

Impact of centrifugation time and pneumatic tube transport on plasma concentrations of direct oral anticoagulants.

INTRODUCTION: Rapid results are needed when plasma concentrations of direct oral anticoagulants (DOACs) are required in acute clinical settings. We evaluated the impact of centrifugation time and pneumatic tube transport on DOAC plasma concentrations with the overall aim of reducing turnaround time. METHODS: Blood samples were spiked with rivaroxaban, apixaban or dabigatran in a low and a high concentration prior to centrifugation for 25 minutes (3163 g) or 5 minutes (3000 g) (n = 20 for each DOAC). Both samples spiked with DOACs (n = 20 for each DOAC) and patient samples (n = 25 in total) were transported manually or by pneumatic tube system samples. RESULTS: For samples spiked with DOAC, statistically significant differences in DOAC plasma concentrations were found between centrifugation times for rivaroxaban in low (P < .05) and high (P < .05) concentrations. Relative bias was below 9% for all DOACs. Statistically significant differences were found between modes of transportation for rivaroxaban (P < .01) and dabigatran (P < .01) in high concentrations. Relative bias was 4%-23% for all DOACs. For patient samples, no statistically significant differences were found between modes of transportation, and relative bias was below 12% for all DOACs. CONCLUSION: Minor, clinically insignificant, differences regarding centrifugation times were found in DOAC plasma concentrations. Importantly, no significant differences were found according to transportation modes for samples collected from patients. Although statistically significant differences were found depending on mode of transportation of spiked samples, relative bias was clinically acceptable. Thus, reduced centrifugation time and pneumatic tube transport should be considered to reduce turnaround time for rapid measurement of DOAC plasma concentrations.

Biochemical Changes During the First Year of Feminizing Hormone Therapy in Transfeminine Individuals.

BACKGROUND: Persons with assigned male sex at birth (AMAB) might wish to obtain feminization and/or demasculinization according to the person's gender identity and are therefore treated with estradiol and/or antiandrogens. AIM: The aim was to evaluate biochemical changes and side effects in AMAB individuals treated with guideline-based feminizing hormone treatment (FHT). METHODS: Medical charts of 99 AMAB individuals ≥ 18 years referred to the Center for Gender Identity; Aalborg University hospital, Denmark, between January 2017 and July 2019 were reviewed to identify adverse side effects. Furthermore, data from the laboratory information system (Labka II) were retrieved to obtain biochemical parameters. Biochemical plasma concentrations after initiation of FHT were compared to concentrations prior to FHT and to existing guidelines. OUTCOMES: After 11-19 months, 29% of the trans feminine individuals had plasma estradiol concentrations within the treatment target. RESULTS: The plasma concentration of estradiol varies greatly during FHT. Plasma levels of estrogen were within the treatment target after 11-19 months of treatment, whereas 100% had concentrations within the reference range for premenopausal cis-women. Furthermore, plasma concentrations of lipids and hematological parameters approached female reference ranges after 11 months of FHT. CLINICAL IMPLICATIONS: The target levels of plasma estradiol concentrations during FHT could be expanded, making the wanted physiological changes easier to obtain. STRENGTHS & LIMITATION: This cohort study included 99 AMAB individuals and biochemical evaluation was possible in 67 individuals. Only one individual was lost during follow-up. However, the follow-up period was limited making evaluation of long-term side effects impossible. CONCLUSION: Plasma concentration of estradiol varies greatly during guideline based FHT, making plasma estradiol levels within the target level difficult to attain. JA Hojbjerg, AD Højgaard, A-M Hvas. Biochemical Changes During the First Year of Feminizing Hormone Therapy in Transfeminine Individuals. Sex Med 2021;10:100472.

Current Treatment Regimens for Transfeminine Individuals in the Nordic Countries.

BACKGROUND: The demand for gender-affirming hormone therapy is increasing worldwide prompting a growing requirement for solid evidence for efficacy and safety. AIM: We aimed to report on the organization of transgender care and the current clinical practice of feminizing hormone therapy in specialized clinics in the Nordic countries. METHODS: This study was a cross-sectional study performed as a questionnaire survey. A quantitative questionnaire was sent to 15 specialized clinics prescribing feminizing hormone therapy in the Nordic countries. OUTCOMES: Twelve clinics responded to the inquiry. RESULTS: The answers showed great variance in both number of clinics in each country as well as number of doctors responsible for prescribing gender-affirming hormone therapy. There was great difference in the width of the target ranges for estrogen plasma concentrations and in preferred route of administration for estrogens. Likewise, the risk assessment and monitoring of side effects were diverse. CLINICAL IMPLICATIONS: To gather solid data on efficacy and safety of feminizing hormone therapy, the treatment regimens and the recording of side effects need to be consistent across the clinics responsible for the treatment of transfeminine patients. Strenghts & Limitations: This is to our knowledge the first report on treatment regimens for feminizing hormone treatment in the Nordic countries. The response rate was 80%; however, the included clinics only cover approximately 30% of the expected numbers of transfeminine individuals. CONCLUSION: Despite the great diversity across clinics as regard to organization of clinics and to treatment regimens, the vast majority of clinics operated within the guidelines defined by The Endocrine Society. Hojbjerg JA, Saini SL, Hvas A-M, et al. Current Treatment Regimens for Transfeminine Individuals in the Nordic Countries. J Sex Med 2021;18:656-663.

The Role of Platelets in Cancer-Related Bleeding Risk: A Systematic Review.

Cancer patients face an elevated risk of bleeding, and here platelets play a pivotal role. The association between platelet count and bleeding, as well as safe thresholds for prophylactic platelet transfusion, is described mainly in hematological malignancies, and knowledge is sparse for patients with solid tumors. Platelet function tests may further improve bleeding risk assessment in cancer patients. This study provides a systematic review of the available literature on associations between platelet count and/or function and bleeding in adult cancer patients. The review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. PubMed, Embase, and Web of Science were searched up to August 2019. The National Heart, Lung, and Blood Institute's tools were used for quality assessment. In total, 52 studies investigated associations between bleeding and platelet count (n = 40) or function (n = 12) in patients with hematological malignancy (n = 31), solid tumors (n = 11), or both (n = 10). The majority of included studies rated good (n = 23) or fair (n = 25). The association between platelet count and bleeding was most pronounced at platelet counts ≤ 10 × 109/L but was less evident for solid tumors. Overall, reduced platelet function was significantly associated with bleeding risk. Thus, the available evidence supports current guidelines for prophylactic platelet transfusions at platelet count ≤ 10 × 109/L in hematological cancer patients, whereas more evidence is needed in patients with solid tumors. Platelet function analysis may be valuable in assisting bleeding risk assessment in cancer patients but is sparsely investigated so far.

Day-to-day and within-day biological variation of cell-free DNA.

BACKGROUND: Numerous studies have shown that cell-free DNA (cfDNA) levels may serve as a non-invasive biomarker of a broad spectrum of acute and chronic pathologies. However, in order to make clinical decisions based on cfDNA measurements, it is essential to understand the magnitude of biological variation so this variation is not confused with a variation that actually represent a clinically relevant change. The present study was designed to evaluate the biological variation of cfDNA in healthy subjects and lung cancer patients. METHODS: Plasma samples were collected from 33 healthy subjects and ten lung cancer patients over three days, as well as during the same day. CfDNA was quantified using droplet digital PCR. Biological variation data was estimated using mixed models. FINDINGS: The within-subject variation was 25% and the between-subject variation was 30%. The reference change value for the healthy subjects was 70%. There was no systematic difference in cfDNA levels from day-to-day (p = 0⋅61), but there was a significant decline during the day (p<0⋅01). The within-subject variation in cancer patients was comparable to healthy subjects, whereas the between-subject variation was much larger (139%). No systematic differences from day-to-day were observed for the cancer patients (p>0⋅3). INTERPRETATION: Our findings show that cfDNA levels fluctuate significantly during the day and exhibit considerable within-subject variation. Thus, the data presented offer a substantial contribution to the interpretation of the clinical significance of cfDNA. FUNDING: Læge Sofus Carl Emil Friis og hustru Olga Doris Friis' Legat, Harboefonden, and Dagmar Marshalls Fond.

Circulating miR-30b and miR-30c predict erlotinib response in EGFR-mutated non-small cell lung cancer patients.

OBJECTIVES: MiR-30b, miR-30c, miR-221 and miR-222 are known to induce gefitinib resistance in lung cancer cell lines with activation of mutations in the epidermal growth factor receptor (EGFR). However, the role of these four microRNAs in tyrosine kinase inhibitor (TKI)-resistance in non-small cell lung cancer (NSCLC) patients is unknown. Thus, the aim of this study was to investigate the predictive value of miR-30b, miR-30c, miR-221 and miR-222 in plasma from EGFR-mutated lung cancer patients receiving erlotinib. MATERIALS AND METHODS: The cohort consisted of 29 EGFR-mutated lung cancer patients receiving erlotinib. Plasma levels of miR-30b, miR-30c, miR-221 and miR-222 were analyzed by qPCR from blood samples collected before treatment start. Plasma concentration of each microRNA was correlated to clinical outcome. RESULTS: Plasma concentrations of miR-30b and miR-30c could be determined in all 29 patients. Low plasma concentrations of miR-30b and miR-30c showed significant correlation with superior progression-free survival (PFS) (miR-30b: HR = 0.303 [0.123-0.747], p < 0.05; miR-30c: HR = 0.264 [0.103-0.674], p < 0.05). Low plasma concentrations of miR-30c were also significantly correlated with superior overall survival (OS) (HR = 0.30 [0.094-0.954], p < 0.041). CONCLUSION: High plasma concentrations of miR-30b and miR-30c predicted shorter PFS and OS. This implies that miR-30b and miR-30c could have clinical potential as biomarkers in EGFR-mutated lung cancer patients.

Adjuvant radiotherapy does not affect hemostasis.

Cancer is associated with increased risk of venous thromboembolic disease. Venous thromboembolic disease accounts for a substantial addition to morbidity and mortality rates in cancer patients and is the second leading cause of death in cancer patients, exceeded only by the underlying cancer. Only few previous studies have investigated the influence of radiotherapy on hemostasis and whether radiotherapy in itself causes an increased risk of venous thromboembolic disease. The aim was to investigate if adjuvant radiotherapy affects hemostasis after surgery and chemotherapy in patients with breast cancer. Radiotherapy consisted of either 40 Gy/15 fractions or 50 Gy/25 fractions. Blood samples were obtained from 39 consecutive women before and immediately after the first, the intermediate, and the final radiation fraction. Platelet function was measured using impedance aggregometry, and thrombin generation was determined in platelet-poor plasma using calibrated automated thrombogram. Furthermore, P-selectin, international normalized ratio, fibrinogen, activated partial thromboplastin time, coagulation factor VIII, von Willebrand factor, C-reactive protein (CRP), and soluble thrombomodulin were measured before and after radiation treatment. Platelet aggregation was within reference interval before initiation of radiotherapy, and remained unaffected during the radiation course. Neither serum P-selectin, thrombin generation, fibrinogen, coagulation factor VIII, von Willebrand factor, CRP nor thrombomodulin were substantially influenced by radiation treatment. The present study showed that radiotherapy did not affect hemostasis, neither by a single radiation dose nor during the radiation course, in early breast cancer patients receiving adjuvant radiotherapy.