Elevated platelet count is a strong predictor of poor prognosis in stage I non-small cell lung cancer patients

Cancer progression and tumor hypercoagulability: a platelet perspective

Venous thromboembolism, which is common in cancer patients and accompanies or even precedes malignant tumors, is known as cancer-related thrombosis and is an important cause of cancer- associated death. At present, the exact etiology of the elevated incidence of venous thrombosis in cancer patients remains elusive. Platelets play a crucial role in blood coagulation, which is intimately linked to the development of arterial thrombosis. Additionally, platelets contribute to tumor progression and facilitate immune evasion by tumors. Tumor cells can interact with the coagulation system through various mechanisms, such as producing hemostatic proteins, activating platelets, and directly adhering to normal cells. The relationship between platelets and malignant tumors is also significant. In this review article, we will explore these connections.

The use of platelets as a clinical tool in oncology: opportunities and challenges

Platelets are small circulating anucleated cells mainly involved in thrombosis and hemostasis processes. Moreover, platelets play an active role in tumorigenesis and cancer progression, stimulating angiogenesis and vascular remodelling, and protecting circulating cancer cells from shear forces and immune surveillance. Several reports indicate that platelet number in the blood circulation of cancer patients is associated with prognosis and response to treatment. However, the mechanisms of platelets "education" by cancer cells and the crosstalk between platelets and tumor are still unclear, and the role of "tumor educated platelets" (TEPs) is achieving growing interest in cancer research. TEPs are a biological source of cancer-derived biomarkers, especially RNAs that are protected by platelets membrane from circulating RNases, and could serve as a non-invasive tool for tumor detection, molecular profiling and evolution during therapy in clinical practice. Moreover, short platelet lifespan offers the possibility to get a snapshot assessment of cancer molecular profile, providing a real-time tool. We review and discuss the potential and the clinical utility, in terms of cancer diagnosis and monitoring, of platelet count together with other morphological parameters and of the more recent and innovative TEP profiling.

Pro-Tumorigenic and Thrombotic Activities of Platelets in Lung Cancer

Aside from their key protective roles in hemostasis and innate immunity, platelets are now recognized as having multifaceted, adverse roles in the pathogenesis, progression and outcome of many types of human malignancy. The most consistent and compelling evidence in this context has been derived from the notable association of elevated circulating platelet counts with the onset and prognosis of various human malignancies, particularly lung cancer, which represents the primary focus of the current review. Key topics include an overview of the association of lung cancer with the circulating platelet count, as well as the mechanisms of platelet-mediated, pro-tumorigenic immunosuppression, particularly the role of transforming growth factor beta 1. These issues are followed by a discussion regarding the pro-tumorigenic role of platelet-derived microparticles (PMPs), the most abundant type of microparticles (MPs) in human blood. In this context, the presence of increased levels of PMPs in the blood of lung cancer patients has been associated with tumor growth, invasion, angiogenesis and metastasis, which correlate with disease progression and decreased survival times. The final section of the review addresses, firstly, the role of cancer-related platelet activation and thrombosis in the pathogenesis of secondary cardiovascular disorders and the associated mortality, particularly in lung cancer, which is second only to disease progression; secondly, the review addresses the potential role of antiplatelet agents in the adjunctive therapy of cancer.

Pretreatment Platelet Count is a Prognostic Marker in Lung Cancer: A Danish Registry-based Cohort Study

BACKGROUND

Thrombocytosis has been associated with a poor prognosis in a wide range of malignancies. However, the results have been conflicting for lung cancer. Therefore, we evaluated the prognostic value of platelet count in a large cohort of lung cancer patients.

PATIENTS AND METHODS

All lung cancer patients diagnosed in The Central Denmark Region from 2009 to 2018 were included in the study. Data from the Danish Lung Cancer Registry were combined with data from the clinical laboratory information system on pretreatment platelet count. Platelet count was defined as low, normal, or high based on being below, within, or above the reference intervals. The prognostic value of platelet count was assessed by the Cox proportional hazard model. C-statistics were conducted to investigate if the platelet count added additional prognostic value to existing prognostic markers.

RESULTS

Totally, 6,758 patients with non-small-cell lung cancer (NSCLC) and 1150 patients with small-cell lung cancer (SCLC) were included. Low and high platelet count were significantly associated with decreased overall survival (OS) in NSCLC patients (low: adjusted hazard ratio (HR)=1.75 (95% confidence interval [CI]: 1.49-2.06); high: adjusted HR=1.24 (95% CI: 1.16-1.33)). In SCLC patients, only low platelet count was significantly associated with decreased OS (adjusted HR = 2.71 [95% CI: 2.02-3.65]). C-statistics showed that the prognostic models were significantly improved by the addition of platelet count for both NSCLC and SCLC patients (P < .0001).

CONCLUSION

Low and high platelet count were adverse prognostic factors in NSCLC patients, while only low platelet count was a prognostic marker in SCLC patients.

Plasma Extracellular Vesicle Long RNA in Diagnosis and Prediction in Small Cell Lung Cancer

(1) Introduction: The aim of this study was to identify the plasma extracellular vesicle (EV)-specific transcriptional profile in small-cell lung cancer (SCLC) and to explore the application value of plasma EV long RNA (exLR) in SCLC treatment prediction and diagnosis. (2) Methods: Plasma samples were collected from 57 SCLC treatment-naive patients, 104 non-small-cell lung cancer (NSCLC) patients and 59 healthy participants. The SCLC patients were divided into chemo-sensitive and chemo-refractory groups based on the therapeutic effects. The exLR profiles of the plasma samples were analyzed by high-throughput sequencing. Bioinformatics approaches were used to investigate the differentially expressed exLRs and their biofunctions. Finally, a t-signature was constructed using logistic regression for SCLC treatment prediction and diagnosis. (3) Results: We obtained 220 plasma exLRs profiles in all the participants. Totals of 5787 and 1207 differentially expressed exLRs were identified between SCLC/healthy controls, between the chemo-sensitive/chemo-refractory groups, respectively. Furthermore, we constructed a t-signature that comprised ten exLRs, including EPCAM, CCNE2, CDC6, KRT8, LAMB1, CALB2, STMN1, UCHL1, HOXB7 and CDCA7, for SCLC treatment prediction and diagnosis. The exLR t-score effectively distinguished the chemo-sensitive from the chemo-refractory group (p = 9.268 × 10^-9) with an area under the receiver operating characteristic curve (AUC) of 0.9091 (95% CI: 0.837 to 0.9811) and distinguished SCLC from healthy controls (AUC: 0.9643; 95% CI: 0.9256-1) and NSCLC (AUC: 0.721; 95% CI: 0.6384-0.8036). (4) Conclusions: This study firstly characterized the plasma exLR profiles of SCLC patients and verified the feasibility and value of identifying biomarkers based on exLR profiles in SCLC diagnosis and treatment prediction.

Coagulation parameters in lung cancer patients: A systematic review and meta-analysis

Background

Hypercoagulability in lung cancer patients is associated with a high incidence of mortality and morbidity in the world. Therefore, this meta‐analysis aimed to explore the correlation of the basic coagulation abnormalities in lung cancer patients compared with the control.

Method

PubMed, Scopus, and other sources were employed to identify eligible studies. The outcome variable was expressed using mean ± standard deviation (SD). Heterogeneity among studies and publication bias were evaluated. The quality of included studies was also assessed based on Newcastle–Ottawa Scale checklist.

Result

Finally, through a total of eight studies, prolonged prothrombin time (PT; standard mean difference [SMD]: 1.29; 95% CI: 0.47–2.11), plasma D‐dimer value (SMD 3.10; 95% CI 2.08–4.12), fibrinogen (SMD 2.18; 95% CI:1.30–3.06), and platelet (PLT) count (SMD 1.00; 95% CI 0.84–1.16) were significantly higher in lung cancer patients when compared with the control group. The single‐arm meta‐analysis also showed that compared with control, lung cancer patients had high pooled PT 13.7 (95% CI:12.2–15.58) versus 11.79 (95% CI = 10.56–13.02), high D‐dimer 275.99 (95% CI:172.9–11735.9) versus 0.2 (95% CI:0.20–0.37), high plasma fibrinogen 5.50 (95% CI:4.21–6.79) versus 2.5 (95% CI:2.04–2.91), and high PLT count 342.3 (95% CI:236.1–448.5) versus 206.6 (95% CI:176.4–236.7).

Conclusion

In conclusion, almost all the coagulation abnormalities were closely associated with lung cancer, and hence coagulation indexes provide an urgent clue for early diagnosis and timely management.

What's the difference between lung adenocarcinoma and lung squamous cell carcinoma? Evidence from a retrospective analysis in a cohort of Chinese patients

BACKGROUND

Lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) are the two most common subtypes of lung cancer. Previously, they were categorized into one histological subtype known as non-small cell lung cancer (NSCLC) and often treated similarly. However, increasing evidence suggested that LUAD and LUSC should be classified and treated as different cancers. But yet, detailed differences in clinical features between LUAD and LUSC have not been well described.

METHODS

A cohort of 142 Chinese patients with 111 LUAD and 31 LUSC cases were consecutively enrolled from April 2019 to October 2020 in Hunan Provincial People's Hospital. The clinical features of the patients were retrospectively analyzed and compared in the terms of general information, clinicopathologic characteristics, imaging findings and laboratory data.

RESULTS

In comparison with LUAD, LUSC patients had a significantly higher proportion of males, smokers, drinkers, higher-stage cases. The mean tumor size in LUSC patients was significantly larger than that in LUAD patients. Compared with LUAD patients, more of patients with LUSC had cough, fever and abundant sputum symptoms. Besides that, more bacterial infections and fungal infections were found in LUSC patients than that in LUAD patients. Imaging data shows that ground-glass opacity and patchy shadows in radiological films were more frequent in LUAD patients than that in LUSC patients. In addition to initial laboratory data, LUSC patients had higher levels of leukocytes, platelets, and creatinine that of LUAD patients.

CONCLUSIONS

Together, these results suggested that there exist distinct differences between LUAD and LUSC subtypes; LUSC may be a more malignant type in comparison with LUAD. Our findings may have potential implications in clinical settings. However, further multicenter studies are needed to validate these findings in a larger sample size.

Prognostic significance of thrombocytosis in lung cancer: a systematic review and meta-analysis

A potential relationship between poor prognosis and thrombocytosis has been suggested by previous studies in lung cancer, but the conclusions continued to be controversial. Here, we performed a meta-analysis to explore the prognostic impact of thrombocytosis in lung cancer. The Cochrane Library, EMBASE and PubMed databases were comprehensively and systematically retrieved from establishment to May 5, 2020. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were applied to evaluate overall effects. Heterogeneity was assessed using I² statistics and Cochran's Q test. Sensitivity and subgroup analyses were performed to analyze the sources of heterogeneity. Publication bias was examined using the Egger's test and pooled HR was regulated using the trim-and-fill approach when publication bias was observed. A total of 37 studies including 14,833 patients were enrolled in the meta-analysis. Thrombocytosis was significantly correlated to poor overall survival (HR 1.033; 95% CI 1.017-1.050), disease-free survival (HR 1.568; 95% CI 1.276-1.928), and progression-free survival (HR 1.653; 95% CI 1.069-2.556). Although publication bias was identified, rectification for this bias using the trim-and-fill approach did not change the combined HR substantially. In conclusion, this meta-analysis result suggested that thrombocytosis is a predictor of poor prognosis in lung cancer.

Systemic immune-inflammation index is a stage-dependent prognostic factor in patients with operable non-small cell lung cancer

Background

Immune function is a key component affecting tumor progression in patients with cancer. The purpose of this study was to identify the prognostic value of systemic immune-inflammation index (SII) in patients with non-small cell lung cancer (NSCLC) and the differences of its prognostic value in patients with distinct characteristics.

Methods

Patients with completely resected NSCLC were reviewed according to the eighth TNM classification of lung cancer. Patients were further categorized into the low- and high-SII groups. Cox proportional hazard analyses were performed to identify the independent prognostic factors.

Results

A total of 3984 patients with NSCLC were enrolled in this study. Kaplan-Meier analyses demonstrated that high SII was associated with worse recurrence-free survival (RFS) (P<0.001) and overall survival (OS) (P<0.001). Cox proportional hazard analyses revealed that SII was an independent risk factor for worse RFS (P=0.038) and OS (P=0.043). Further analyses demonstrated that the prognostic value of SII was observed only in patients with stage I disease (P<0.001), solid nodules (P=0.002), or adenocarcinoma (P<0.001). Sensitivity analyses using multiple imputation and competing risk analyses also confirmed similar results.

Conclusions

SII was associated with worse survival independently, and its prognostic role was exhibited solely in NSCLC patients with stage I disease, solid nodules, and adenocarcinoma. This study helped us specify the target population for clinical use of SII.

Red blood cell distribution width to platelet ratio substantiates preoperative survival prediction in patients with newly-diagnosed glioblastoma

Object

The conception of individual patient-adjusted treatment strategies is constantly emerging in the field of neuro-oncology. Systemic laboratory markers may allow insights into individual needs and estimated treatment benefit at an earliest possible stage. Therefore, the present study was aimed at analyzing the prognostic significance of preoperative routine laboratory values in patients with newly-diagnosed glioblastoma.

Methods

Between 2014 and 2019, 257 patients were surgically treated for newly-diagnosed glioblastoma at the Neuro-Oncology Center of the University Hospital Bonn. Preoperative routine laboratory values including red blood cell distribution width (RDW) and platelet count were reviewed. RDW to platelet count ratio (RPR) was calculated and correlated to overall survival (OS) rates.

Results

Median preoperative RPR was 0.053 (IQR 0.044–0.062). The receiver operating characteristic (ROC) curve indicated an optimal cut-off value for RPR to be 0.05 (AUC 0.62; p = 0.002, 95% CI 0.544–0.685). 101 patients (39%) presented with a preoperative RPR < 0.05, whereas 156 patients (61%) had a RPR ≥ 0.05. Patients with preoperative RPR < 0.05 exhibited a median OS of 20 months (95% CI 17.9–22.1), which was significantly higher compared to a median OS of 13 months (95% CI 10.9–15.1) in patients with preoperative RPR ≥ 0.05 (p < 0.001).

Conclusions

The present study suggests the RPR to constitute a novel prognostic inflammatory marker for glioblastoma patients in the course of preoperative routine laboratory examinations and might contribute to a personalized medicine approach.

Low platelet/platelet distribution width and high platelet/lymphocyte ratio are adverse prognostic factors in patients with newly diagnosed advanced Hodgkin lymphoma

We conducted a retrospective study in 274 previously untreated advanced Hodgkin lymphoma (HL) patients to investigate the prognostic value of baseline platelet (PLT) count, platelet distribution width (PDW), mean platelet volume (MPV), and platelet/lymphocyte ratio (PLR). The median follow-up time was 89 (range 0.3-240) months. By univariate analysis, PLT/PDW <24.5, PLR ≥245, and MPV <8fl were all associated with worse freedom from progression (FFP), progression-free survival (PFS), and overall survival (OS). By multivariate analysis, PLT/PDW <24.5 was a risk factor for FFP (HR 2.02, p = 0.002) and PFS (HR 2.36, p < 0.001). PLR ≥245 was independently associated with inferior FFP (HR 2.04, p = 0.003) and PFS (HR 1.93, p = 0.002). Due to the limited number of death events, multivariate analysis was not conducted for OS. Propensity score matching analysis and subgroup analysis further validated the prognostic value for PLT/PDW and PLR. In conclusion, PLT/PDW and PLR are promising prognostic indicators for newly diagnosed advanced HL.

Pre-surgical level of von Willebrand factor as an evident indicator of breast cancer recurrence

BACKGROUND

Endothelial and platelet activation as well as a disruption of haemostatic balance are crucial in cancer-dependent venous thromboembolism development.

OBJECTIVE

The aim of this study was to investigate the influence of von Willebrand factor (VWF), sE-selectin, sP-selectin as well as VWF/sE-selectin and sP-selectin/sE-selectin ratios on the probability of disease relapse in invasive breast carcinoma (IBrC) cases.

METHODS

Eighty-four patients with IA-IIB stage of IBrC who passed a comprehensive clinicopathologic evaluation were included in the study. Follow-up was completed in all patients with a 15.48 % recurrence rate. An immunoassay of VWF antigen, sE-selectin, sP-selectin, as well as an immunohistochemistry of oestrogen and progesterone receptors, human epidermal growth factor receptor 2 (HER2) and Ki67 was performed in all cases.

RESULTS

The VWF/sE-selectin ratio was significantly higher in patients with poorly differentiated tumours than in those with high-differentiated tumours. A positive correlation between VWF concentration and tumour grade was noted. Eleven of 13 events happened in patients with VWF value below 600 mU/mL with recurrence rate of 25%, but only two events occurred in subject with VWF values above the 600 mU/mL (5%; P= 0.0028).

CONCLUSIONS

Our study show that VWF could be considered as a suitable biomarker of breast cancer relapse.

Quantitative proteomics of hamster lung tissues infected with SARS-CoV-2 reveal host factors having implication in the disease pathogenesis and severity

Syrian golden hamsters (Mesocricetus auratus) infected by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) manifests lung pathology. In this study, efforts were made to check the infectivity of a local SARS‐CoV‐2 isolate in a self‐limiting and non‐lethal hamster model and evaluate the differential expression of lung proteins during acute infection and convalescence. The findings of this study confirm the infectivity of this isolate in vivo. Analysis of clinical parameters and tissue samples show the pathophysiological manifestation of SARS‐CoV‐2 infection similar to that reported earlier in COVID‐19 patients and hamsters infected with other isolates. However, diffuse alveolar damage (DAD), a common histopathological feature of human COVID‐19 was only occasionally noticed. The lung‐associated pathological changes were very prominent on the 4th day post‐infection (dpi), mostly resolved by 14 dpi. Here, we carried out the quantitative proteomic analysis of the lung tissues from SARS‐CoV‐2‐infected hamsters on day 4 and day 14 post‐infection. This resulted in the identification of 1585 proteins of which 68 proteins were significantly altered between both the infected groups. Pathway analysis revealed complement and coagulation cascade, platelet activation, ferroptosis, and focal adhesion as the top enriched pathways. In addition, we also identified altered expression of two pulmonary surfactant‐associated proteins (Sftpd and Sftpb), known for their protective role in lung function. Together, these findings will aid in understanding the mechanism(s) involved in SARS‐CoV‐2 pathogenesis and progression of the disease.

Inflammatory cell-associated tumors. Not only macrophages (TAMs), fibroblasts (TAFs) and neutrophils (TANs) can infiltrate the tumor microenvironment. The unique role of tumor associated platelets (TAPs)

It is well known that various inflammatory cells infiltrate cancer cells. Next to TAMs (tumor-associated macrophages), TAFs (tumor-associated fibroblasts) and TANs (tumor-associated neutrophils) also platelets form the tumor microenvironment. Taking into account the role of platelets in the development of cancer, we have decided to introduce a new term: tumor associated platelets-TAPs. To the best of our knowledge, thus far this terminology has not been employed by anyone. Platelets are the first to appear at the site of the inflammatory process that accompanies cancer development. Within the first few hours from the start of the colonization of cancer cells platelet-tumor aggregates are responsible for neutrophils recruitment, and further release a number of factors associated with tumor growth, metastasis and neoangiogenesis. On the other hand, it also has been indicated that factors delivered from platelets can induce a cytotoxic effect on the proliferating neoplastic cells, and even enhance apoptosis. Undoubtedly, TAPs' role seems to be more complex when compared to tumor associated neutrophils and macrophages, which do not allow for their division into TAP P1 and TAP P2, as in the case of TANs and TAMs. In this review we discuss the role of TAPs as an important element of tumor invasiveness and as a potentially new therapeutic target to prevent cancer development. Nevertheless, better exploring the interactions between platelets and tumor cells could help in the formulation of new therapeutic goals that support or improve the effectiveness of cancer treatment.

The association between thrombocytosis and subtype of lung cancer: a systematic review and meta-analysis

Background

Thrombocytosis is associated with poor lung cancer prognosis and has recently been identified as having a high positive predictive value in lung cancer detection. Lung cancer has multiple histological and genetic subtypes and it is not known whether platelet levels differ across these subtypes, or whether thrombocytosis is predictive of a particular subtype.

Methods

PubMed and Embase were systematically searched for studies that reported pre-treatment platelet count, as either averages or proportion of patients with thrombocytosis, by subtype of lung cancer using a pre-specified search strategy. The Newcastle-Ottowa scale was used to assess study quality and risk of bias. Suitable studies were synthesised in meta-analyses and subgroup analyses examined for differences across subtypes.

Results

The prevalence of pre-treatment thrombocytosis across all lung cancer patients was 27% (95% CI: 17% to 37%). By subtype, this was 22% (95% CI: 7% to 41%) for adenocarcinoma, 28% (95% CI: 15% to 43%) for squamous cell carcinoma (SCC), 36% (95% CI: 13% to 62%) for large cell carcinoma (LCC), and 30% (95% CI: 8% to 58%) for small cell lung cancer (SCLC). The pooled mean platelet count for lung cancer patients was 289×10⁹/L (95% CI: 268 to 311). By subtype, this was 282×10⁹/L (95% CI: 259 to 306) for adenocarcinoma, 297×10⁹/L (95% CI: 238 to 356) for SCC, 290×10⁹/L (95% CI: 176 to 404) for LCC, and 293×10⁹/L (95% CI: 244 to 342) for SCLC. There was no difference in thrombocytosis prevalence (P=0.76) or mean platelet count (P=0.96) across the subtypes.

Conclusions

These findings suggest thrombocytosis is no more indicative of one lung cancer subtype over another. We therefore conclude a high platelet count is likely to be generic across all lung cancer subtypes.

Longitudinal analysis of complete blood count parameters in advanced-stage lung cancer patients

BACKGROUND

Metastatic lung cancer is a debilitating disease, but with the advances in immunotherapy, therapeutic options have vastly increased. Numerous complete blood count parameters (CBC) have been described as easily accessible biomarkers that might predict response to immunotherapy. However, to date, no comprehensive study has been performed on the longitudinal changes of these parameters during cancer progression.

METHODS

The clinicopathological variables and CBC parameters of 986 advanced stage lung cancer patients were retrospectively analyzed. Blood tests were performed as part of the routine checkup and the results were recorded at the time of the diagnosis of the primary tumor, the diagnosis of brain or bone metastases, and also during the last available follow-up.

RESULTS

In the experimental subcohort, 352 and 466 patients were diagnosed with brain and bone metastases, respectively. The control group consisted of 168 patients without clinically detectable or other distant organ metastases. In our longitudinal analyses, we found significantly decreasing absolute lymphocyte count (ALC: P < 0.001), and significantly increasing absolute neutrophil count (ANC: P < 0.001) levels in all patient subgroups, irrespective of histopathological type and metastatic site. Interestingly, patients with brain metastases had significantly descending-ascending platelet count (PLT) trendlines (P < 0.001), while the bone metastatic subgroup exhibited significantly ascending-descending trendlines (P = 0.043).

CONCLUSIONS

Significantly decreasing ALC, significantly increasing ANC and fluctuating PLT levels may be found in brain and bone metastatic lung cancer patients during disease progression. Our findings might contribute to improve personalized healthcare in this devastating malignancy.

KEY POINTS

SIGNIFICANT FINDINGS OF THE STUDY: Significantly decreasing ALC, and significantly increasing ANC levels can be found in advanced-stage lung cancer patients during disease progression Patients with brain metastases have descending-ascending PLT trendlines, while patients with bone metastases exhibit ascending-descending trendlines during disease progression WHAT THIS STUDY ADDS: The descending values for ALC, and the ascending mean values for PLT and ANC, might be suggestive of poor response to second- or third-line immunotherapy in advanced-stage lung cancer patients. The current study might help to improve patient selection and treatment strategies for brain and/or bone metastatic lung cancer patients.

Platelet Induced Functional Alteration of CD4+ and CD8+ T Cells in HNSCC

Platelets (PLT) are the second most abundant cell type in human blood and exert various immune-regulatory functions under both physiological and pathological conditions. In fact, immune cell regulation via platelets has been demonstrated in several studies within the past decade. However, the exact mechanisms behind T cell regulation remain poorly understood. We questioned whether the formation of aggregates of platelets and T cells has an impact on T-cell functions. In the present study, we stimulated PBMC cultures with anti-CD3 and anti-CD28 mABs and cultured them at a PLT: PBMC ratio of 1:1 or 100:1. After 24, 48, and 72 h, PD-1, PD-L1 expression, and proliferation were analyzed on T cells using flow cytometry. Cytokine production was measured in PHA stimulated CD4 cells after 6 h. We found a significant platelet-mediated decrease in PD-1 and PD-L1 expression, proliferation, as well as IFN-γ and TNF-α production. Perturbations also at least partially remained after spatial separation of PLTs from PBMCs in Transwell-assays. T cell-platelet aggregates showed similar levels of activation markers, proliferation, and secreted cytokines as their non-complexed counterparts. Results indicate a platelet mediated regulation of T cells via direct and indirect contact, but only mediocre effects of the complex formation itself.

Prognostic value of pretreatment platelet counts in lung cancer: a systematic review and meta-analysis

Background

The prognostic value of elevated pretreatment platelet counts remains controversial in lung cancer patients. We performed the present meta-analysis to determine its precise role in these patients.

Methods

We employed a multiple search strategy in the PubMed, EMBASE and Cochrane Library databases to identify eligible studies. Disease-free survival (DFS)/progression-free survival (PFS)/time to progression (TTP) and overall survival (OS) were used as outcomes with hazard ratios (HRs) and 95% confidence intervals (CIs). Heterogeneity among the studies and publication bias were also evaluated.

Results

A total of 40 studies including 16,696 lung cancer patients were eligible for the analysis. Overall, the pooled analysis showed that compared with normal platelet counts, elevated pretreatment platelet counts were associated with poorer OS (HR = 1.54, 95% CI: 1.37–1.72, P < 0.001) and poorer DFS/PFS/TTP (HR = 1.62, 95% CI: 1.33–1.98, P < 0.001) in patients with lung cancer. In subgroup analyses, elevated pretreatment platelet counts were also associated with poorer OS and DFS/PFS/TTP in most subgroups. There was no evidence of publication bias.

Conclusions

This meta-analysis revealed that elevated pretreatment platelet counts were an independent predictor of OS and DFS/PFS/TTP in lung cancer patients. Large-scale prospective studies and a validation study are warranted.

The "Janus Face" of Platelets in Cancer

Besides their vital role in hemostasis and thrombosis, platelets are also recognized to be involved in cancer, where they play an unexpected central role: They actively influence cancer cell behavior, but, on the other hand, platelet physiology and phenotype are impacted by tumor cells. The existence of this platelet-cancer loop is supported by a large number of experimental and human studies reporting an association between alterations in platelet number and functions and cancer, often in a way dependent on patient, cancer type and treatment. Herein, we shall report on an update on platelet-cancer relationships, with a particular emphasis on how platelets might exert either a protective or a deleterious action in all steps of cancer progression. To this end, we will describe the impact of (i) platelet count, (ii) bioactive molecules secreted upon platelet activation, and (iii) microvesicle-derived miRNAs on cancer behavior. Potential explanations of conflicting results are also reported: Both intrinsic (heterogeneity in platelet-derived bioactive molecules with either inhibitory or stimulatory properties; features of cancer cell types, such as aggressiveness and/or tumour stage) and extrinsic (heterogeneous characteristics of cancer patients, study design and sample preparation) factors, together with other confounding elements, contribute to “the Janus face” of platelets in cancer. Given the difficulty to establish the univocal role of platelets in a tumor, a better understanding of their exact contribution is warranted, in order to identify an efficient therapeutic strategy for cancer management, as well as for better prevention, screening and risk assessment protocols.

Elevated preoperative platelet distribution width predicts poor prognosis in Esophageal Squamous Cell Carcinoma

Activated platelets play a multifaceted role in tumorigenesis and progression. Platelet distribution width (PDW) is generally applied platelet parameters from routine blood test. Preoperative PDW has been considered a prognostic factor in many cancers. Nevertheless, the prognostic value of PDW in esophageal squamous cell carcinoma (ESCC) remains unknown. The study aimed to investigate whether preoperative PDW could serve as a prognostic factor in patients with ESCC. A total of 495 patients with ESCC undergoing curative surgery were enrolled. The relationship between PDW and clinical features in ESCC was analyzed using chi-square tests. Receiver operating characteristic (ROC) curve was used to determine the optimal cut-off value. Overall survival (OS) and disease-free survival (DFS) stratified by PDW were evaluated by Kaplan-Meier method and log-rank test. Univariate and multivariate Cox regression were used to evaluate the prognostic effect of PDW. Of the 495 patients, elevated PDW was observed in 241(48.7%) of the patients, respectively. An elevated PDW was correlated with depth of tumor (T stage, P = 0.031), nerve infiltration (P = 0.016), hospital time after operation (P = 0.020), platelet (P < 0.001), red cell distribution width (P < 0.001), and aspartate transaminase (P = 0.001). Moreover, elevated PDW (PDW ≥ 13.4 fL) predicted a worse OS and DFS in patients with ESCC (both P < 0.001). Multivariate analyses revealed that PDW was independently associated with OS (hazard ratios 1.194; 95% confidence interval 1.120-1.273; P < 0.001) and DFS (hazard ratios 2.562; 95% confidence interval 1.733-3.786; P < 0.001). Our findings indicated that elevated PDW could serve as an independent worse survival in ESCC.

Motivation for Launching a Cancer Metastasis Inhibition (CMI) Program

Metastatic cancers impose significant burdens on patients, affecting quality of life, morbidity, and mortality. Even during remission, microscopic metastases can lurk, but few therapies directly target tumor cell metastasis. Agents that interfere with this process would represent a new paradigm in cancer management, changing the 'waiting game' into a time of active prevention. These therapies could take multiple forms based on the pathways involved in the metastatic process. For example, a phenome-wide association study showed that a single nucleotide polymorphism in the gene TBXA2R is associated with increased metastasis in multiple primary cancers (P = 0.003), suggesting clinical applicability of TBXA2R antagonists. Emerging data related to the role of platelets in metastasis are concordant with our sense that these pathways present significant opportunities for therapeutic development. However, before real progress can be made toward clinical targeting of the metastatic process, foundational work is needed to define informative measures of critical elements such as circulating tumor cells and tumor DNA, and circulatory vs. lymphatic spread. These challenges require an expansion of team science and composition to obtain competitive funding. At our academic medical center, we have implemented a Cancer Metastasis Inhibition (CMI) program investigating this approach across multiple cancers.

Prognostic role of pretreatment thrombocytosis on survival in patients with cervical cancer: a systematic review and meta-analysis

BACKGROUND

This meta-analysis summarized the prognostic role of an elevated platelet count before treatment on survival outcomes in patients with cervical cancer.

METHODS

The PubMed, Embase, and Cochrane library electronic databases were systematically searched for studies reporting the effect estimates with 95% confidence intervals (CIs) of pretreatment thrombocytosis on survival from the database inceptions to December 2018. The pooled hazard ratios (HRs) with 95% CIs for overall survival (OS), progression-free survival (PFS), and recurrence-free survival (RFS) were calculated using random-effects models.

RESULTS

Nineteen retrospective studies that recruited 6521 patients with cervical cancer were eligible for this study. The summary results indicated that an elevated platelet count was significantly associated with a poor OS (HR 1.50; 95% CI 1.19-1.88; P = 0.001), PFS (HR 1.33; 95% CI 1.07-1.64; P = 0.010), and RFS (HR 1.66; 95% CI 1.20-2.28; P = 0.002). Sensitivity analysis indicated that the pooled PFS was variable after sequential exclusion of individual studies. The predictive value of pretreatment thrombocytosis on OS differed according to the publication year (P = 0.039), country (P = 0.013), and sample size (P = 0.029), and the role of pretreatment thrombocytosis on PFS could be affected by the study quality (P = 0.046).

CONCLUSION

The findings of this study indicated that an elevated platelet count before treatment was associated with poor OS, PFS, and RFS. These results require further verification in large-scale prospective studies.

Platelet-secreted CCL3 and its receptor CCR5 promote invasive and migratory abilities of anaplastic thyroid carcinoma cells via MMP-1

Platelet counts have been reported to be closely related to distant metastasis of many malignant tumors. Our previous study showed that elevated peripheral blood platelet counts may be an adverse prognostic factor of anaplastic thyroid carcinoma (ATC) patients, indicating that platelets may promote ATC progression. In the present study, we aimed to identify the role of platelets in ATC cell invasion and migration and to explore the underlying mechanisms. We found that platelets can promote the invasive and migratory of ATC cells, which may be related to the interaction between activated platelet-secreted chemokine (C-C motif) ligand 3 (CCL3) and its receptor CCR5. The interaction was shown to induce the upregulation of matrix metalloproteinase (MMP)-1 via NF-κB pathway. These findings could provide a new idea for the research of targeted platelets to inhibit tumor metastasis.

Novel Aspects of Extracellular Vesicles as Mediators of Cancer-Associated Thrombosis

The establishment of prothrombotic states during cancer progression is well reported but the precise mechanisms underlying this process remain elusive. A number of studies have implicated the presence of the clotting initiator protein, tissue factor (TF), in circulating tumor-derived extracellular vesicles (EVs) with thrombotic manifestations in certain cancer types. Tumor cells, as well as tumor-derived EVs, may activate and promote platelet aggregation by TF-dependent and independent pathways. Cancer cells and their secreted EVs may also facilitate the formation of neutrophil extracellular traps (NETs), which may contribute to thrombus development. Alternatively, the presence of polyphosphate (polyP) in tumor-derived EVs may promote thrombosis through a TF-independent route. We conclude that the contribution of EVs to cancer coagulopathy is quite complex, in which one or more mechanisms may take place in a certain cancer type. In this context, strategies that could attenuate the crosstalk between the proposed pro-hemostatic routes could potentially reduce cancer-associated thrombosis.

Elevated Platelet Count Appears to Be Causally Associated with Increased Risk of Lung Cancer: A Mendelian Randomization Analysis

BACKGROUND

Platelets are a critical element in coagulation and inflammation, and activated platelets are linked to cancer risk through diverse mechanisms. However, a causal relationship between platelets and risk of lung cancer remains unclear.

METHODS

We performed single and combined multiple instrumental variable Mendelian randomization analysis by an inverse-weighted method, in addition to a series of sensitivity analyses. Summary data for associations between SNPs and platelet count are from a recent publication that included 48,666 Caucasian Europeans, and the International Lung Cancer Consortium and Transdisciplinary Research in Cancer of the Lung data consisting of 29,266 cases and 56,450 controls to analyze associations between candidate SNPs and lung cancer risk.

RESULTS

Multiple instrumental variable analysis incorporating six SNPs showed a 62% increased risk of overall non-small cell lung cancer [NSCLC; OR, 1.62; 95% confidence interval (CI), 1.15-2.27; P = 0.005] and a 200% increased risk for small-cell lung cancer (OR, 3.00; 95% CI, 1.27-7.06; P = 0.01). Results showed only a trending association with NSCLC histologic subtypes, which may be due to insufficient sample size and/or weak effect size. A series of sensitivity analysis retained these findings.

CONCLUSIONS

Our findings suggest a causal relationship between elevated platelet count and increased risk of lung cancer and provide evidence of possible antiplatelet interventions for lung cancer prevention.

IMPACT

These findings provide a better understanding of lung cancer etiology and potential evidence for antiplatelet interventions for lung cancer prevention.

Activated platelets in the tumor microenvironment for targeting of antibody-drug conjugates to tumors and metastases

Rationale: Platelets are increasingly recognized as mediators of tumor growth and metastasis. Hypothesizing that activated platelets in the tumor microenvironment provide a targeting epitope for tumor-directed chemotherapy, we developed an antibody-drug conjugate (ADC), comprised of a single-chain antibody (scFv) against the platelet integrin GPIIb/IIIa (scFvGPIIb/IIIa) linked to the potent chemotherapeutic microtubule inhibitor, monomethyl auristatin E (MMAE). Methods: We developed an ADC comprised of three components: 1) A scFv which specifically binds to the high affinity, activated integrin GPIIb/IIIa on activated platelets. 2) A highly potent microtubule inhibitor, monomethyl auristatin E. 3) A drug activation/release mechanism using a linker cleavable by cathepsin B, which we demonstrate to be abundant in the tumor microenvironment. The scFvGPIIb/IIIa-MMAE was first conjugated with Cyanine7 for in vivo imaging. The therapeutic efficacy of the scFvGPIIb/IIIa-MMAE was then tested in a mouse metastasis model of triple negative breast cancer. Results: In vitro studies confirmed that this ADC specifically binds to activated GPIIb/IIIa, and cathepsin B-mediated drug release/activation resulted in tumor cytotoxicity. In vivo fluorescence imaging demonstrated that the newly generated ADC localized to primary tumors and metastases in a mouse xenograft model of triple negative breast cancer, a difficult to treat tumor for which a selective tumor-targeting therapy remains to be clinically established. Importantly, we demonstrated that the scFvGPIIb/IIIa-MMAE displays marked efficacy as an anti-cancer agent, reducing tumor growth and preventing metastatic disease, without any discernible toxic effects. Conclusion: Here, we demonstrate the utility of a novel ADC that targets a potent cytotoxic drug to activated platelets and specifically releases the cytotoxic agent within the confines of the tumor. This unique targeting mechanism, specific to the tumor microenvironment, holds promise as a novel therapeutic approach for the treatment of a broad range of primary tumors and metastatic disease, particularly for tumors that lack specific molecular epitopes for drug targeting.

Impacts of Cancer on Platelet Production, Activation and Education and Mechanisms of Cancer-Associated Thrombosis

Platelets are small anucleate cells that are traditionally described as the major effectors of hemostasis and thrombosis. However, increasing evidence indicates that platelets play several roles in the progression of malignancies and in cancer-associated thrombosis. A notable cross-communication exists between platelets and cancer cells. On one hand, cancer can “educate” platelets, influencing their RNA profiles, the numbers of circulating platelets and their activation states. On the other hand, tumor-educated platelets contain a plethora of active biomolecules, including platelet-specific and circulating ingested biomolecules, that are released upon platelet activation and participate in the progression of malignancy. The numerous mechanisms by which the primary tumor induces the production, activation and aggregation of platelets (also known as tumor cell induced platelet aggregation, or TCIPA) are directly related to the pro-thrombotic state of cancer patients. Moreover, the activation of platelets is critical for tumor growth and successful metastatic outbreak. The development or use of existing drugs targeting the activation of platelets, adhesive proteins responsible for cancer cell-platelet interactions and platelet agonists should be used to reduce cancer-associated thrombosis and tumor progression.

Cervical cancer systemic inflammation score: a novel predictor of prognosis

Inflammation contributes to development and progression in a variety of cancers, including cervical cancer. We developed a novel cervical cancer systemic inflammation score (CCSIS) based on the preoperative platelet-to-lymphocyte ratio (PLR) and serum albumin levels. A retrospective analysis of clinical data from 795 patients with operable cervical cancer was then conducted to investigate the prognostic value of CCSIS and its association with the patients' clinicopathological features, overall survival (OS), and disease-free survival (DFS). CCSIS was predictive of OS and DFS. High CCSIS was correlated with more advanced FIGO stages, poor tumor differentiation, and the presence of PLN and LVSI. Both albumin levels and the PLR were independent prognostic indicators for operable cervical cancer. The use of the CCSIS could improve risk stratification and traditional clinicopathological analysis in cervical cancer.

Prognostic value of combined platelet, fibrinogen, neutrophil to lymphocyte ratio and platelet to lymphocyte ratio in patients with lung adenosquamous cancer

The aim of the present study was to investigate the prognostic value of the combined platelet (PLT), fibrinogen (FBG), neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) (CO-NPF) for postoperative outcomes in patients with lung adenosquamous cancer (ASC). Test results from patients who presented at The Cancer Institute and Hospital of Tianjin Medical University between January 2005 and December 2013 were retrospectively reviewed. CO-NPF was scored between 0 and 4 according to increased PLT, FBG, NLR and PLR prior to being split into two groups based on the presence (≥2) or absence (<2) of the combination of increased inflammatory indexes. In total, data from 134 patients with ASC were reviewed for the present study. Multivariate analysis identified that increased CO-NPF (P=0.001 and P<0.001, respectively), PLR (P=0.011 and P=0.001, respectively) and FBG (P=0.001 and P<0.001, respectively) were independently associated with shorter disease-free survival (DFS) and overall survival (OS). NLR (P=0.006) and PLT (P=0.001) were independent prognostic factors for OS. The area under the receiver operating characteristic curves of CO-NPF (area under the curve, 0.652, P=0.008, 95% confidence interval, 0.551-0.752) was increased compared with NLR, PLR, PLT and FBG individually, suggesting that CO-NPF has greater predictive value. CO-NPF was significantly and independently associated with shorter DFS and OS, and had greater predictive value compared with NLR, PLR, PLT and FBG in patients with ASC who underwent surgery.

Decreased lung function with mediation of blood parameters linked to e-waste lead and cadmium exposure in preschool children

Blood lead (Pb) and cadmium (Cd) levels have been associated with lower lung function in adults and smokers, but whether this also holds for children from electronic waste (e-waste) recycling areas is still unknown. To investigate the contribution of blood heavy metals and lung function levels, and the relationship among living area, the blood parameter levels, and the lung function levels, a total of 206 preschool children from Guiyu (exposed area), and Haojiang and Xiashan (reference areas) were recruited and required to undergo blood tests and lung function tests during the study period. Preschool children living in e-waste exposed areas were found to have a 1.37 μg/dL increase in blood Pb, 1.18 μg/L increase in blood Cd, and a 41.00 × 10⁹/L increase in platelet counts, while having a 2.82 g/L decrease in hemoglobin, 92 mL decrease in FVC and 86 mL decrease in FEV₁. Each unit of hemoglobin (1 g/L) decline was associated with 5 mL decrease in FVC and 4 mL decrease in FEV₁. We conclude that children living in e-waste exposed area have higher levels of blood Pb, Cd and platelets, and lower levels of hemoglobin and lung function. Hemoglobin can be a good predictor for lung function levels.

Combination of platelet count and lymphocyte to monocyte ratio is a prognostic factor in patients undergoing surgery for non-small cell lung cancer

The aim of this study was to investigate the usefulness of a novel inflammation-based prognostic system, called COP-LMR (combination of platelet count and lymphocyte to monocyte ratio), for predicting postoperative survival of patients with non-small cell lung cancer (NSCLC). COP-LMR was calculated on the basis of the obtained data. Patients with both an elevated platelet count (PLT) (>30 × 104mm-3) and a low LMR (<3.6) were assigned a score of 2, and patients with one or none of the parameters were assigned a score of 1 or 0, respectively. A total of 1120 patients who underwent complete resection were enrolled in this study. Multivariate analysis revealed that COP-LMR is an independent prognostic factor for disease-free survival (DFS) (P<0.001) and overall survival (OS) (P<0.001). Kaplan-Meier analysis and the log-rank test revealed that COP-LMR stratified the patients into 3 independent groups (P<0.001). In conclusion, COP-LMR is a potential prognostic biomarker in patients undergoing surgery for NSCLC.

Pre-treatment platelet counts as a prognostic and predictive factor in stage II and III rectal adenocarcinoma

AIM

To investigate if pre-treatment platelet counts could provide prognostic information in patients with rectal adenocarcinoma that received neo-adjuvant treatment.

METHODS

Platelet number on diagnosis of stage II and III rectal cancer was evaluated in 51 patients receiving neo-adjuvant treatment and for whom there were complete follow-up data on progression and survival, as well as pathologic outcome at the time of surgery. Pathologic responses on the surgical specimen of patients with lower platelet counts (150-300 × 10⁹/L) were compared with these of patients with higher platelet counts (> 300 × 10⁹/L) by the χ² test. Overall and progression free survival Kaplan-Meier curves of the two groups were constructed and compared with the Log-Rank test.

RESULTS

A significant difference was present between the two groups in regards to pathologic response with patients with lower platelet counts being more likely to exhibit a good or complete response to neo-adjuvant treatment than patients with higher platelet counts (P = 0.015). Among other factors evaluated, there was also a significant difference between the carcinoembryonic antigen (CEA) at presentation of patients that exhibited a good or complete response and those that had no response or a minimal to moderate response. Patients with a good or complete response were more likely to present with a CEA of less than 5 μg/L (P = 0.00066). There was no significant difference in overall and progression free survival between the two platelet count groups (Log-Rank tests P = 0.42 and P = 0.35, respectively).

CONCLUSION

In this retrospective analysis of stage II and III rectal cancer patients, platelet counts at the time of diagnosis had prognostic value for neo-adjuvant treatment pathologic response. Pre-treatment CEA also held prognostic value in regards to treatment effect.

Cancer and Thrombosis: The Platelet Perspective

Platelets are critical to hemostatic and immunological function, and are key players in cancer progression, metastasis, and cancer-related thrombosis. Platelets interact with immune cells to stimulate anti-tumor responses and can be activated by immune cells and tumor cells. Platelet activation can lead to complex interactions between platelets and tumor cells. Platelets facilitate cancer progression and metastasis by: (1) forming aggregates with tumor cells; (2) inducing tumor growth, epithelial-mesenchymal transition, and invasion; (3) shielding circulating tumor cells from immune surveillance and killing; (4) facilitating tethering and arrest of circulating tumor cells; and (5) promoting angiogenesis and tumor cell establishment at distant sites. Tumor cell-activated platelets also predispose cancer patients to thrombotic events. Tumor cells and tumor-derived microparticles lead to thrombosis by secreting procoagulant factors, resulting in platelet activation and clotting. Platelets play a critical role in cancer progression and thrombosis, and markers of platelet-tumor cell interaction are candidates as biomarkers for cancer progression and thrombosis risk.

Preoperative platelet count improves the prognostic prediction of the FIGO staging system for operable cervical cancer patients

BACKGROUND

Increased platelet has been identified as an independent and unfavorable prognostic indicator in various cancers including cervical cancer. In our study, the prognostic value of preoperative platelet count combining with FIGO (International Federation of Gynecology and Obstetrics) stage in patients with operable cervical cancer was investigated.

METHODS

A large cohort study including 800 operable cervical cancer patients was conducted from May 2005 to December 2012. Cancer-related biomarkers such as platelet count, hematocrit, hemoglobin, RDW was evaluated together with FIGO staging system in stage IA1-IIA2 cervical cancer patients. The prediction validity of platelet together with FIGO stage was then evaluated by receiver operating characteristic (ROC) curve, and the areas under the curve (AUCs) were compared by Z test.

RESULTS

Univariate cox proportional hazard analysis demonstrated that hematocrit, platelet count, hemoglobin, FIGO stage, tumor differentiation, PLN (pelvic lymph node metastasis), LVSI (vascular lymph node invasion) were associated with overall survival (OS) and disease free survival (DFS), instead of RDW (red cell distribution width), age and histological subtype. Multivariate analysis demonstrated that preoperative platelet and FIGO stage were independent predictors for OS and DFS in cervical cancer. Furthermore, significant improvements were found after the combination of platelet count and FIGO stage in predicting OS and DFS for cervical cancer patients (P=0.0128 and P=0.0385, respectively).

CONCLUSIONS

Combination of platelet count and FIGO stage improved the prediction performance of FIGO staging and provide additional risk stratification for operable cervical cancer patients.

Kinetics of postdiagnosis platelet count with overall survival of pancreatic cancer: a counting process approach

The association between long‐term variation of postdiagnosis platelets and survival of pancreatic cancer (PC) has never been discussed by using dynamic survival analysis method. In this retrospective study, we analyzed 311 histologically confirmed PC patients identified from a mega population‐based electronic inpatients database from 2012 to 2013 in China. Counting process approach was applied to restructure the original survival data, the association between post‐diagnosis platelet count and overall survival (OS) of PC was evaluated by multiple failure‐time Cox proportional hazards model. After counting process adjustment, multiple failure‐time Cox proportional hazards model revealed that, regardless of the treatment modalities PC patients received, postdiagnosis thrombocytopenia was prominently associated with OS, compared with PC patients with normally ranged platelet count, the HRs ranged from 2.04 (95% CI: 1.14–3.67) to 10.82 (95% CI: 2.63–44.54), and this inverse association was robust based on further sensitivity analysis. On the contrary, the association between thrombocytosis and OS of PC tended to be inconclusive. Our findings suggested that postdiagnosis thrombocytopenia was associated with significantly compromised survival among PC patients from this large retrospective cohort. Underlying mechanisms behind this association should be further investigated.