The increasing burden of testicular seminomas and non-seminomas in adolescents and young adults (AYAs): incidence, treatment, disease-specific survival and mortality trends in the Netherlands between 1989 and 2019

BACKGROUND

Testicular cancer incidence among adolescents and young adults (AYAs, aged 18-39 years at diagnosis) is increasing worldwide and most patients will survive the initial disease. Still, detailed epidemiological information about testicular cancer among AYAs is scarce. This study aimed to provide a detailed overview of testicular cancer trends in incidence, treatment, long-term relative survival and mortality by histological subtype among AYAs diagnosed in the Netherlands between 1989 and 2019.

MATERIALS AND METHODS

Data of all malignant testicular cancers (ICD-code C62) were extracted from the Netherlands Cancer Registry. Mortality data were retrieved from Statistics Netherlands. European age-standardized incidence and mortality rates with average annual percentage change statistics and relative survival estimates up to 20 years of follow-up were calculated.

RESULTS

A total of 12 528 testicular cancers were diagnosed between 1989 and 2019. Comparing 1989-1999 to 2010-2019, the incidence increased from 4.4 to 11.4 for seminomas and from 5.7 to 11.1 per 100 000 person-years for non-seminomas. Rising trends were most prominent for localized disease. Radiotherapy use in localized testicular seminomas declined from 78% in 1989-1993 to 5% in 2015-2019. Meanwhile, there was a slight increase in chemotherapy use. Most AYAs with localized seminomas and non-seminomas received active surveillance only (>80%). Overall, relative survival estimates remained well above 90% even at 20 years of follow-up for both seminomas and non-seminomas. Mortality rates declined from 0.5 to 0.4 per 100 000 person-years between 1989-1999 and 2010-2019.

CONCLUSIONS

The incidence of seminoma and non-seminoma testicular cancers significantly increased in AYAs in the Netherlands between 1989 and 2019. There was a shift towards less-aggressive treatment regimens without negative survival effects. Relative survival estimates remained well above 90% at 20 years of follow-up in most cases. Testicular cancer mortality was already low, but has improved further over time, which makes survivorship care an important issue for these young adults.

Sexual quality of life of adolescents and young adult breast cancer survivors

BACKGROUND

With increasing survival rates of adolescents and young adults (AYAs) with breast cancer, health-related quality of life (HRQoL) becomes more important. An important aspect of HRQoL is sexual QoL. This study examined long-term sexual QoL of AYA breast cancer survivors, compared sexual QoL scores with that of other AYA cancer survivors, and identified factors associated with long-term sexual QoL of AYA breast cancer survivors.

MATERIALS AND METHODS

Data of the SURVAYA study were utilized for secondary analyses. Sexual QoL was assessed using the European Organization for Research and Treatment of Cancer Quality of Life cancer survivorship core questionnaire (EORTC QLQ-SURV100). Descriptive statistics were used to describe sexual QoL of AYA cancer survivors. Linear regression models were constructed to examine the effect of cancer type on sexual QoL and to identify factors associated with sexual QoL.

RESULTS

Of the 4010 AYA cancer survivors, 944 had breast cancer. Mean sexual QoL scores of AYA breast cancer survivors ranged from 34.5 to 60.0 for functional domains and from 25.2 to 41.5 for symptom-orientated domains. AYA breast cancer survivors reported significantly lower sexual QoL compared to AYA survivors of other cancer types on all domains. Age, time since diagnosis, relationship status, educational level, chemotherapy, hormonal therapy, breast surgery, body image, and coping were associated with sexual QoL of AYA breast cancer survivors.

CONCLUSIONS

AYA breast cancer survivors experience decreased sexual QoL in the long term (5-20 years) after diagnosis and worse score compared to AYA survivors of other cancer types, indicating a clear need to invest in supportive care interventions for those at risk, to enhance sexual well-being.

ESMO - Magnitude of Clinical Benefit Scale V.1.0 questions and answers

The ESMO Magnitude of Clinical Benefit Scale (ESMO-MCBS) is a standardised, generic, validated tool to stratify the magnitude of clinical benefit that can be anticipated from anticancer therapies. The ESMO-MCBS is intended to both assist oncologists in explaining the likely benefits of a particular treatment to their patients as well as to aid public health decision makers' prioritise therapies for reimbursement. From its inception the ESMO-MCBS Working Group has invited questions and critiques to promote understanding and to address misunderstandings regarding the nuanced use of the scale, and to identify shortcomings in the scale to be addressed in future planned revisions and updates. The ESMO-MCBS V.1.0 has attracted many questions regarding its development, structure and potential applications. These questions, together with responses from the ESMO-MCBS Working Group, have been edited and collated, and are herein presented as a supplementary resource.

[Network of specialized sarcoma centres]

Non-specialized centres see relatively few patients with rare cancers like soft tissue sarcoma. This leads to inappropriate diagnostic work-up and treatment resulting in a worse oncological outcome. We believe that modern tailor-made therapy for rare cancers requires not only the multidisciplinary expertise of specialized cancer centres but also, occasionally, the expert knowledge of an international network of specialist centres. Here, we emphasize the importance of national and international networks for the treatment of patients with rare tumours. The importance is placed in perspective using the treatment of sarcoma patients as an example.

A standardised, generic, validated approach to stratify the magnitude of clinical benefit that can be anticipated from anti-cancer therapies: the European Society for Medical Oncology Magnitude of Clinical Benefit Scale (ESMO-MCBS)

The value of any new therapeutic strategy or treatment is determined by the magnitude of its clinical benefit balanced against its cost. Evidence for clinical benefit from new treatment options is derived from clinical research, in particular phase III randomised trials, which generate unbiased data regarding the efficacy, benefit and safety of new therapeutic approaches. To date, there is no standard tool for grading the magnitude of clinical benefit of cancer therapies, which may range from trivial (median progression-free survival advantage of only a few weeks) to substantial (improved long-term survival). Indeed, in the absence of a standardised approach for grading the magnitude of clinical benefit, conclusions and recommendations derived from studies are often hotly disputed and very modest incremental advances have often been presented, discussed and promoted as major advances or 'breakthroughs'. Recognising the importance of presenting clear and unbiased statements regarding the magnitude of the clinical benefit from new therapeutic approaches derived from high-quality clinical trials, the European Society for Medical Oncology (ESMO) has developed a validated and reproducible tool to assess the magnitude of clinical benefit for cancer medicines, the ESMO Magnitude of Clinical Benefit Scale (ESMO-MCBS). This tool uses a rational, structured and consistent approach to derive a relative ranking of the magnitude of clinically meaningful benefit that can be expected from a new anti-cancer treatment. The ESMO-MCBS is an important first step to the critical public policy issue of value in cancer care, helping to frame the appropriate use of limited public and personal resources to deliver cost-effective and affordable cancer care. The ESMO-MCBS will be a dynamic tool and its criteria will be revised on a regular basis.

A phase IIb multicentre study comparing the efficacy of trabectedin to doxorubicin in patients with advanced or metastatic untreated soft tissue sarcoma: the TRUSTS trial

PURPOSE

To evaluate whether trabectedin as first-line chemotherapy for advanced/metastatic soft tissue sarcoma prolongs progression-free survival (PFS), compared to doxorubicin and, in the phase IIb part here, to select the most appropriate trabectedin treatment schedule (3-hour or 24-hour infusion) in terms of safety, convenience and efficacy.

PATIENTS AND METHODS

In this randomised multicentre prospective dose-selection phase IIb superiority trial, 133 patients were randomised between doxorubicin (n=43), trabectedin (3-hour infusion, T3h) (n=47) and trabectedin (24-hour infusion, T24h) (n=43). PFS was defined as time from random assignment until objective progression by response evaluation criteria in solid tumours (RECIST 1.1), a global deterioration of the health status requiring discontinuation of the treatment, or death from any cause.

RESULTS

The study was terminated due to lack of superiority in both trabectedin treatment arms as compared to the doxorubicin control arm. Median PFS was 2.8months in the T3h arm, 3.1months in the T24h arm and 5.5months in the doxorubicin arm. No significant improvements in PFS were observed in the trabectedin arms as compared to the doxorubicin arm (T24h versus doxorubicin: hazard ratio (HR) 1.13, 95% confidence interval (CI) 0.67-1.90, P=.675; T3h versus doxorubicin: HR 1.50, 95% CI 0.91-2.48, P=.944). Only one toxic death occurred in the T3h arm, but treatment had to be stopped due to toxicity in 7 (15.2%) (T3h), 8 (19.5%) (T24h) and 1 (2.5%) doxorubicin patients.

CONCLUSION

Doxorubicin continues to be the standard treatment in eligible patients with advanced/metastatic soft-tissue sarcoma (STS). Trabectedin 1.5mg/m(2)/24-hour infusion is the overall proven approach to delivering this agent in the second-line setting for patients with advanced or metastatic STS.

Long-term responders and survivors on pazopanib for advanced soft tissue sarcomas: subanalysis of two European Organisation for Research and Treatment of Cancer (EORTC) clinical trials 62043 and 62072

BACKGROUND

Pazopanib recently received approval for the treatment of certain soft tissue sarcoma (STS) subtypes. We conducted a retrospective analysis on pooled data from two EORTC trials on pazopanib in STS in order to characterize long-term responders and survivors.

PATIENTS AND METHODS

Selected patients were treated with pazopanib in phase II (n = 118) and phase III study (PALETTE) (n = 226). Combined median progression-free survival (PFS) was 4.4 months; the median overall survival (OS) was 11.7 months. Thirty-six percent of patients had a PFS ≥ 6 months and were defined as long-term responders; 34% of patients survived ≥18 months, defined as long-term survivors. Patient characteristics were studied for their association with long-term outcomes.

RESULTS

The median follow-up was 2.3 years. Patient characteristics were compared among four subgroups based on short-/long-term PFS and OS, respectively. Seventy-six patients (22.1%) were both long-term responders and long-term survivors. The analysis confirmed the importance of known prognostic factors in metastatic STS patients treated with systemic treatment, such as performance status and tumor grading, and additionally hemoglobin at baseline as new prognostic factor. We identified 12 patients (3.5%) remaining on pazopanib for more than 2 years: nine aged younger than 50 years, nine females, four with smooth muscle tumors and nine with low or intermediate grade tumors at initial diagnosis. The median time on pazopanib in these patients was 2.4 years with the longest duration of 3.7 years.

CONCLUSIONS

Thirty-six percent and 34% of all STS patients who received pazopanib in these studies had a long PFS and/or OS, respectively. For more than 2 years, 3.5% of patients remained progression free under pazopanib. Good performance status, low/intermediate grade of the primary tumor and a normal hemoglobin level at baseline were advantageous for long-term outcome. NCT00297258 (phase II) and NCT00753688 (phase III, PALETTE).

Randomized phase II/III trial comparing gemcitabine/carboplatin (GC) and methotrexate/carboplatin/vinblastine (M-CAVI) in patients (pts) with advanced urothelial cancer (UC) unfit for cisplatin-based chemotherapy (CHT): Phase III results of EORTC study 30986

LBA4519

Background: About 50% of pts with advanced UC are not eligible for cisplatin based CHT (“unfit”) due to impaired renal function, performance status (PS) or comorbidity. This is the first randomized phase II/III trial comparing two chemotherapy regimens in this pts group.

Methods: The primary objective of the phase III part of this study was to compare the overall survival (OS) of CHT naïve pts with measurable disease and an impaired renal function (GFR<60 but >30 ml/min) and/or PS 2 who were randomized to receive either GC (G 1000 mg/m2 d1 and 8 and C AUC 4.5) q21 days or M-CAVI (M 30 mg/m2 d1 and 15 and 22, C AUC 4.5 d1 and VI 3 mg/m2 d1 and 15 and 22) q28 days. In order to detect an increase of 50% in median survival on GC compared to M-CAVI (13.5 versus 9 months) based on a two sided logrank test at error rates alpha=0.05 and beta=0.20, 225 pts were required. Secondary endpoints were overall response rate (ORR) and progression free survival (PFS).

Results: 238 pts, 119 in each arm, were randomized between January 2001 and March 2008 by 29 institutions. The median follow-up is 4.5 years. Two pts were ineligible and two other pts never started treatment. Best ORRs (CR + PR) were 41.2% (36.1% confirmed response) on GC versus 30.3% (21.0% confirmed response) on M-CAVI (p = 0.08). Median OS was 9.3 months on GC and 8.1 months on M-CAVI (p = 0.64). There was no difference in PFS between the two arms (p = 0.78). OS, PFS and ORR were similar in each of the risk groups (reason unfit for cisplatin and Bajorin risk group). Severe acute toxicity (SAT) (death, grade 4 thrombocytopenia with bleeding, or grade 3/4 renal toxicity, neutropenic fever or mucositis) was observed in 9.3% of pts on GC (2 toxic deaths) and 21.2% on M-CAVI (4 toxic deaths). The most common grade 3/4 toxicities were leucopenia (44.9%, 46.6%), neutropenia (52.5%, 63.5%), febrile neutropenia (4.2%, 14.4%), thrombocytopenia (48.3%, 19.4%), and infection (11.8%, 12.7%) on GC and M-CAVI, respectively.

Conclusions: There were no significant differences in efficacy between the two treatment groups. The incidence of SATs was slightly higher on M-CAVI.

[Table: see text]

Symptomatic brain metastases from small-cell carcinoma of the urinary bladder: The Netherlands Cancer Institute experience and literature review

BACKGROUND

The incidence of symptomatic brain metastases in small-cell carcinoma of the urinary bladder (SCBC) is unknown. This precludes advice about prophylactic cranial irradiation (PCI).

PATIENTS AND METHODS

The medical records of all patients with SCBC seen at The Netherlands Cancer Institute from 1993 to 2009 (n = 51) were reviewed. Limited disease (LD) was defined as any pT, cN₀₋₁, and cM₁. Patients with LD were offered bladder-preserving treatment involving combined chemoradiotherapy. Patients with extensive disease (ED) were treated with palliative chemotherapy. PCI was not applied in any patient.

RESULTS

Among 39 patients with LD, median disease-specific survival was 35 months. Four developed symptomatic brain metastases after a median follow-up of 15 months (range 3-24) and were treated with whole-brain radiotherapy. No patient with ED developed symptomatic brain metastases during a median follow-up of 6 months. The reported incidence of brain metastases in SCBC in the literature ranges between 0% and 40%. On the basis of all reported series, the pooled estimate of the cumulative incidence of brain metastases is 10.5% (95% confidence interval 7.5% to 14.1%).

CONCLUSIONS

The incidence of symptomatic brain metastases from SCBC is significantly lower than that from small-cell lung cancer. Therefore, we do not routinely advise PCI in patients with SCBC.

[New developments in the treatment of muscle-invasive bladder cancer]

Muscle-invasive bladder cancer is an important oncological problem. When no distant metastases are detected, a radical cystectomy is the standard treatment. In recent years new developments in the treatment of the disease have been explored. These developments comprise new surgical techniques such as neobladder construction using the patient's intestinal tissue, sexuality-preserving surgery and robot-assisted surgery. Furthermore, indications for perioperative chemotherapy are discussed. Finally, bladder-sparing approaches are described: brachytherapy and chemo-radiation.

Successful classification of metastatic carcinoma of known primary using the CUPPRINT

20028

Background: It is critical for treatment decisions of metastatic disease to identify the primary tumor of the metastases, since the choice of optimal therapy depends on the correct diagnosis of the primary. Routine diagnostic evaluation is not sufficient to detect the primary site in 2–4% of all patients with pathology proven malignancy who present with metastatic disease. Currently the diagnostic yield is approximately between 20% and 30% for these patients. Microarray-based gene expression profiling has shown great promise to improve this. Methods: A microarray database was constructed of 497 frozen and 127 paraffin embedded (FFPE) samples representing 51 tumor types of both primary and metastatic tumors. The microarray database contained 22,000 gene-expression measurements for each sample. From the microarray database, we used an algorithm to search for gene combinations optimal for multi-tumor classification. This optimal gene-set was printed on 8-pack slides. These “1 × 3” glass slides contain eight mini-arrays with 1900 probes allowing for 8 simultaneous hybridizations, CUPPRINT. A k-nearest-neighbor-algorithm using this optimal gene-set was developed to discriminate between the 51 tumor types. We have independently verified the accuracy of this classification algorithm using FFPE samples from patients with metastases from 90 known and 50 unknown primary carcinomas. The expression data will be compared with clinicopathological data and an additional immunological panel of cytokeratin 7, cytokeratin 20, carcinogen embryonic antigen, CD 10, thyroid transcription factor 1, renal cell carcinoma, thyrogobulin, calcitonin, estrogen, progesterone, prostate specific antigen and CA 125. Results: The microarray based assay was able to classify correctly the primary site in 36 of 41 samples done so far (88% accuracy). The immunological panel showed a discriminative immunophenotype in 73% of these cases. For 49 known and 50 unknown primary tumors comparison between gene expression and clinicopathological investigations is currently pending. Conclusion: CUPPRINT, a microarrays based assay, is capable to accurately determine the tumor site of origin for a metastatic lesion.

[Table: see text]

Prolonged low dose IL-2 and thalidomide in progressive metastatic renal cell carcinoma with concurrent radiotherapy to bone and/or soft tissue metastasis: a phase II study

Metastatic renal cell cancer is one of the immuno-sensitive tumors. Apart from the immuno-modulating agents IFNalpha and IL-2, thalidomide has been reported to be effective in this type of cancer. However, bone metastases and bulky metastases, show limited response to immunotherapy, are often site of recurrent disease and are therefore often treated later with radiotherapy. In this phase II study, we evaluated toxicity and efficacy of the combination of continuous low dose (1 mIU/m2) s.c. IL-2 and thalidomide (200 mg once daily) in 22 patients with progressive metastatic renal cell cancer. In addition, 13 soft tissue lesions and two bone metastases in 13 patients were concurrently treated with fractionated radiotherapy. T cell number and activation in blood was measured by immunoflowcytometry. Nearly all patients developed grade 1-2 toxicity consisting of fatigue, sensory neuropathy, constipation and dizziness. Five patients had a grade 3-4 toxic event: four patients with deep venous thrombosis requiring anticoagulant therapy, and one patient who developed radiation myelopathy. On systemic response evaluation ten patients showed ongoing SD with a mean progression free survival of 9 months. One patient showed a PR (at an irradiated site). Regarding local response to irradiation, seven lesions showed a PR for a mean time period of 8.7 months, whereas seven were stable for 6 months. The radiation response of one lesion was not evaluable. Immunoflowcytometry showed an increase in number and activation of lymphocytes (mainly Natural Killer--NK-cells), which was absent or even decreased in irradiated patients. The combination of sc. low dose IL-2, thalidomide and radiotherapy is feasible, but relatively toxic and does not lead to higher responses at non-irradiated sites. The combination of immunotherapy and concurrent radiotherapy is effective at 60% of the relatively large evaluable sites. Progressive myelopathy developed in one patient, possibly due to radiotherapy in combination with thalidomide.

NEOADJUVANT METHOTREXATE, VINBLASTINE, DOXORUBICIN AND CISPLATIN FOR HISTOLOGICALLY PROVEN LYMPH NODE POSITIVE BLADDER CANCER

PURPOSE

We gained insight into the effect of neoadjuvant chemotherapy and subsequent surgery in patients with bladder cancer with tumor positive lymph nodes.

MATERIALS AND METHODS

A total of 52 patients with histologically proven positive lymph nodes (by lymph node dissection or aspiration cytology) were treated with chemotherapy and post-chemotherapy surgery in case of partial or complete response. We evaluated response in the primary tumor and lymph nodes, long-term clinical outcome, and clinicopathological features potentially predictive of survival.

RESULTS

Complete response, partial response and stable/progressive disease were attained in 29%, 57% and 14%, and resulted in a 5-year survival of 42%, 19% and 0%, respectively. Objective response (HR 4.1), especially complete response (HR 8.0), was independently associated with survival. The prognostic values of lymph node status and bladder tumor status after methotrexate, vinblastine, doxorubicin and cisplatin were evaluated separately. A tumor negative bladder combined with tumor negative nodes were associated with improved survival (HR 4.4) as was a tumor negative lymph node region in the presence of residual bladder disease (HR 2.8). All patients with post-chemotherapy tumor positive nodes died within 2 years. In resected specimens residual disease was found in 4 of 15 clinically complete responders while no tumor could be detected in 3 of 29 clinically assessed as partial responders.

CONCLUSIONS

Response to chemotherapy is associated with improved survival, and our data suggest that lymph node status after methotrexate, vinblastine, doxorubicin and cisplatin is more important than local tumor status in this aspect. In the absence of reliable noninvasive methods, post-chemotherapy surgery in this series was the most adequate method of response evaluation and in limited partial responders led to long-term progression-free survival.

[Young adults with Ewing's sarcoma]

Ewing's sarcoma was diagnosed in three men, one aged 22 and two aged 30. The disease was diagnosed by biopsy and chromosome investigations (t(11;22)-translocation). In the youngest patient with localised disease, supplementary radiotherapy was withheld in view of the good results of induction chemotherapy, surgery and consolidation chemotherapy. However, four months later, there was a localised recurrence, again followed by induction chemotherapy, chemotherapy at high dosage, stem cell transplantation, radiotherapy and finally surgical intervention, after which a complete remission was achieved. The 30-year-old man with localised disease was given induction chemotherapy, surgery, consolidation chemotherapy and radiotherapy; 14 months after the diagnosis he was in good condition. The other 30-year-old man had metastases in TXII and both lungs. Despite intensive therapy he died 8 months after diagnosis. Ewing's sarcoma is a musculoskeletal malignancy that occurs in children and adolescents but also in young adults. It generally manifests itself as a painful swelling originating in bone or soft tissue. There are often accompanying symptoms such as weight loss and fever. In 20-25% of cases there are already metastases (to the lungs, bone and bone marrow) by the time of diagnosis. The diagnosis and treatment of this rare, therapy-sensitive disease should take place in a study setting and in co-operation with a multidisciplinary sarcoma working group.

[Diarrhea due to Clostridium difficile toxin in hemato-oncological patients]

In two patients with multiple myeloma, men aged 72 and 54 years, diarrhoea developed upon chemotherapy with vincristin, doxorubicin and dexamethasone (VAD). In the second patient, diarrhoea developed after subsequent peripheral stem cell mobilisation. Pseudomembranous colitis was seen in the first patient during endoscopy but an enzyme immunoassay of the faeces was false negative for Clostridium difficile enterotoxin. The bacterium was later cultured from stool samples and toxins were detected in a repeated immunoassay. Stool samples of the second patient were positive for C. difficile enterotoxin. For both patients an antibiotic treatment resulted in a rapid recovery. In haemato-oncological patients, diarrhoea is often caused by oncolytic therapy. However, consideration should also be given to C. difficile infection as an alternative cause which is easily treatable.

[Migrating swellings from Asia: gnathostomiasis]

Two patients suffered from intermittent subcutaneous swellings of the face. A 41-year-old man recalled a recent episode with severe thoracic pain and at that time pleurisy was documented. In this patient there was pronounced eosinophilia. The other was a 32-year-old woman. Both patients had traveled to southeast Asia. Antibodies against Gnathostoma spinigerum were detectable in both patients. The first patient was treated with albendazole 200 b.i.d. for three weeks, but because of recurrent facial swelling, he was treated again with albendazole at a higher dose: 400 b.i.d. for eight weeks, which the swellings did not recur. The second patient was not treated because the frequency of the swellings had already decreased spontaneously. Gnathostomiasis is an infection by the nematode G. spinigerum. The main route of human infection is by eating insufficiently not well-cooked fish or frog. The initial infection is often not recognised, but severe symptoms can occur. In humans, the larva of the nematode does not develop further but may wander through the subcutaneous tissues. Untreated, the infection usually runs a mild, self limiting course, but complications such as invasion of the central nervous system or of the eye have been described. Treatment with albendazole reduces recurrence of swellings.

E-selectin and very late activation antigen-4 mediate adhesion of hematopoietic progenitor cells to bone marrow endothelium

Adhesion of CD34+ hematopoietic progenitor cells (HPCs) to sinusoidal endothelium probably plays a key role in homing of transplanted CD34+ HPCs to the bone marrow (BM). We have investigated the role of various adhesion molecules in the interaction of purified CD34+ HPCs derived from BM or peripheral blood (PB) and a human BM-derived endothelial cell line. Adhesion of CD34+ HPCs to endothelial cells was measured with the use of a double-color flow microfluorimetric adhesion assay. In this assay, adhesion is measured under stirring conditions, simulating blood flow in sinusoidal marrow vessels. Adhesion of PB CD34+ cells to human BM endothelial cells (HBMECs) was observed only after interleukin (IL)-1beta prestimulation of the endothelial cells. This adhesion was strongly increased after addition of phorbol-myristate acetate (PMA). Adhesion of PB CD34+ cells to IL-1beta-prestimulated HBMECs was inhibited by blocking monoclonal antibodies (mAbs) against E-selectin and by neuraminidase treatment of the PB CD34+ cells. mAbs against very late activation antigen (VLA)-4 inhibited adhesion only when the E-selectin-mediated interaction was prevented. No clear inhibiting effect was found with blocking mAbs against beta2-integrins. Stimulation with the beta1-integrin-activating mAb, 8A2, induced adhesion of CD34+ cells to endothelial cells. In conclusion, stimulation of both endothelial cells and CD34+ HPCs is necessary for adhesion of CD34+ HPCs to endothelial cells. We furthermore demonstrated that E-selectin and VLA-4 mediated this adhesion.

Hepatocyte growth factor/scatter factor (HGF/SF) is produced by human bone marrow stromal cells and promotes proliferation, adhesion and survival of human hematopoietic progenitor cells (CD34+)

The fate of hematopoietic progenitor cells (HPCs) in the bone marrow (BM) microenvironment is determined by two different interactions: 1) they adhere (via integrins) to both extracellular matrix molecules and BM stromal cells; and 2) stromal cells produce cytokines that influence their survival, proliferation, differentiation, and mobilization. The ligands for the protein tyrosine kinase receptors c-KIT and FLT3/FLK2, stem cell factor (SCF), and FL are produced by BM stromal cells and are known to affect several facets of hematopoiesis. We studied another protein tyrosine kinase receptor, c-MET, and its ligand hepatocyte growth factor (HGF), also known as scatter factor (SF), which play a similar role in hematopoiesis. c-MET mRNA is expressed in immature human BM HPCs (CD34+CD33- or CD34+CD38-), but not in more mature HPCs (CD34+CD33+ or CD34+CD38+). The ligand HGF/SF is predominantly produced by BM stromal cells at both the mRNA and protein levels. We confirmed functionally that HGF/SF alone has no effect on proliferation of HPCs, but that when combined with granulocyte/macrophage colony-stimulating factor (GM-CSF) or interleukin-3 it acts as a synergistic proliferative factor, although not as potently as kit-ligand or FLT-3/FLK-2 ligand. Furthermore, HGF/SF promotes adhesion of HPCs to immobilized fibronectin. HGF/SF-induced adhesion to fibronectin is probably caused by activation of the integrins alpha4beta1 and alpha5beta1, insofar as we were able to block this interaction by using monoclonal blocking antibodies directed against these integrin subunits. Addition of the tyrosine-phosphorylation inhibitor genistein inhibited HGF/SF-induced adhesion, supporting the idea that HGF/SF-induced effects are the result of signaling via the receptor c-MET after ligand binding. The enhanced adhesion of HGF/SF to fibronectin proved to be beneficial for the maintenance of the colony-forming potential of HPCs. HGF/SF alone and especially in combination with fibronectin prolongs survival of GM colony-forming cells in liquid culture. Our data indicate that HGF/SF is a polyfunctional cytokine in the BM microenvironment. It is produced by human BM stromal cells and directly or indirectly promotes proliferation, adhesion, and survival of human HPCs.

Granulocyte colony-stimulating factor administration to healthy volunteers: analysis of the immediate activating effects on circulating neutrophils

In four healthy volunteers, we analyzed in detail the immediate in vivo effects on circulating neutrophils of subcutaneous administration of 300 micrograms of granulocyte colony-stimulating factor (G-CSF). Neutrophil activation was assessed by measurement of degranulation. Mobilization of secretory vesicles was shown by a decrease in leukocyte alkaline phosphatase content of the circulating neutrophils. Furthermore, shortly postinjection, Fc gamma RIII was found to be upregulated from an intracellular pool that we identified by immunoelectron microscopy as secretory vesicles. Intravascular release of specific granules was shown by increased plasma levels of lactoferrin and by upregulation of the expression of CD66b and CD11b on circulating neutrophils. Moreover, measurement of fourfold elevated plasma levels of elastase, bound to its physiologic inhibitor alpha 1-antitrypsin, indicated mobilization of azurophil granules. However, no expression of CD63, a marker of azurophil granules, was observed on circulating neutrophils. G-CSF--induced mobilization of secretory vesicles and specific granules could be mimicked in whole blood cultures in vitro, in contrast to release of azurophil granules. Therefore, we postulate that the most activated neutrophils leave the circulation, as observed shortly postinjection, and undergo subsequent stimulation in the endothelial microenvironment, resulting in mobilization of azurophil granules. Our data demonstrate that G-CSF should be regarded as a potent immediate activator of neutrophils in vivo.

Recombinant granulocyte colony-stimulating factor administration to healthy volunteers: induction of immunophenotypically and functionally altered neutrophils via an effect on myeloid progenitor cells

We performed a detailed kinetic study on the in vivo effect of a single subcutaneous dose of granulocyte colony-stimulating factor (G-CSF; 300 micrograms) in four healthy individuals on the expression and function of neutrophil Fc gamma receptors (Fc gamma R). G-CSF did not induce Fc gamma RI (CD64) on circulating neutrophils. However, neutrophils newly formed in response to G-CSF were Fc gamma RI positive and were able to perform antibody-dependent cellular cytotoxicity in an Fc gamma RI-dependent way. Fc gamma RII (CD32) expression was not changed significantly. Fc gamma RIII (CD16, phosphatidylinositol-linked) expression, slightly increased immediately (30 minutes) postinjection, was found to be strongly decreased on the newly formed population. For comparison, we studied the expression of the PI-linked proteins leukocyte alkaline phosphatase (LAP) and CD14. Intracellular levels of LAP mirrored the biphasic expression pattern as membrane-bound Fc gamma RIII. In contrast, CD14 expression on neutrophils was initially constant, followed by high levels on the newly formed neutrophils. Soluble CD14 levels were found to be elevated transiently, whereas peak levels of soluble Fc gamma III were observed as late as 6 days postinjection. In conclusion, we have shown that G-CSF results in an immunophenotypically and functionally altered neutrophil population for an important part as a result of its effect on myeloid precursor cells.

Interleukin-6 is a survival factor for committed myeloid progenitor cells

In this study, we investigated the effect of recombinant human interleukin-6 (IL-6) on colony-forming cells for granulocytes and macrophages (CFU-GM) cultured in suspension. IL-6 when used alone did not induce proliferation of highly purified CD34+ human hematopoietic progenitors. Moreover, no influence of IL-6 was observed on the proliferation induced by granulocyte-macrophage colony-stimulating factor (GM-CSF) or granulocyte (G)-CSF. However, a marked survival enhancement (GM-CSF 228 +/- 42%, p < 0.01, and G-CSF 137 +/- 9%, p < 0.05) was observed when CD34+ cells were preincubated with IL-6 for 6 days. This survival effect became even more pronounced under serum-poor conditions (GM-CSF 380 +/- 80%, p < 0.01, and G-CSF 180 +/- 20%, p < 0.01) and could also be demonstrated at the single cell level in a colony-forming assay. By analysis of subpopulations of CD34+ bone marrow (BM) cells selected on the basis of CD45RO expression, the observed IL-6-mediated survival effect was found to be restricted to the CFU-GM containing CD45RO- subset. Our data show that IL-6 is a survival factor for CFU-GM.

Granulocyte colony-stimulating factor induces hFc gamma RI (CD64 antigen)-positive neutrophils via an effect on myeloid precursor cells

In this study we have examined hFc gamma RI expression during myelopoiesis. Normal bone marrow (BM) cells were found to express hFc gamma RI up to the metamyelocyte stage. A different Fc gamma RI expression pattern was observed in an in vitro model of myelopoiesis. Purified CD34-positive BM cells, cultured for 12 to 14 days with granulocyte colony-stimulating factor (G-CSF), differentiate into a population of mature granulocytic cells. In these cultures, in which hFc gamma RI was virtually absent on the initial CD34-positive BM cells, hFc gamma RI was strongly induced by G-CSF after only 5 days. During final maturation the cells remained hFc gamma RI positive. This expression was confirmed functionally by antibody-sensitized erythrocytes (EA)-rosette assays. Moreover, the mature myeloid cells were found to express mRNA encoding for hFc gamma RI, whereas reverse-transcriptase polymerase chain reaction analysis showed that both hFc gamma RIA and hFc gamma RIB genes were expressed. In contrast, on peripheral blood (PB) polymorphonuclear neutrophil leukocytes (PMN) the in vitro effect of G-CSF as to hFc gamma RI induction was limited. Therefore, we conclude that, with respect to hFc gamma RI expression on PMN, G-CSF acts on myeloid precursor cells rather than on mature cells. This conclusion could be strengthened by in vivo administration of a single dose of G-CSF to a healthy volunteer. After a 12-hour lag time, hFc gamma RI expressing PMNs were detected in the peripheral blood. This study shows that hFc gamma RI is an early myeloid differentiation marker that is lost during normal final maturation. However, committed myeloid progenitor cells can be strongly induced by G-CSF to express hFc gamma RI, ultimately resulting in mature granulocytic cells expressing the high-affinity receptor for IgG. This expression may have important consequences for the functional capacity of these cells.

Alpha 4 beta 1 and alpha 5 beta 1 are differentially expressed during myelopoiesis and mediate the adherence of human CD34+ cells to fibronectin in an activation-dependent way

To study the receptors involved in the interaction between extracellular matrix proteins and hematopoietic progenitor cells, we analyzed the expression of beta 1 integrins on CD34+ bone marrow cells by means of immunoflowcytometry. Alpha 4 beta 1 and alpha 5 beta 1 were expressed, whereas alpha 1 beta 1, alpha 2 beta 1, alpha 3 beta 1, alpha 6 beta 1, and alpha v beta 1 were virtually absent. Furthermore, we assessed the alpha 4 and alpha 5 expression on committed myeloid progenitor cells. These colony-forming cells were detected in the alpha 4 dull fraction and the alpha 5 dull fraction. During myeloid differentiation, both in vivo and in vitro, a differential expression of alpha 4 beta 1 and alpha 5 beta 1 was observed. alpha 5 beta 1 was found to be lost at the myelocytic-metamyelocytic stage, before the loss of alpha 4 beta 1, at the band stage. Functional studies showed no binding of erythroid progenitor-depleted, CD34+ bone marrow cells to fibronectin. However, protein kinase C activation strongly induced fibronectin binding (68% of the cells). Inhibition experiments with specific antibodies and peptides showed the binding to be mediated by both alpha 4 beta 1 and alpha 5 beta 1. Also, colony-forming cells of granulocytes and macrophages were demonstrated to adhere to fibronectin in an activation-dependent way. During granulocyte colony-stimulating factor-induced in vitro maturation, the activation-dependent fibronectin binding capacity is gradually lost. We conclude that: (1) CD34+ bone marrow cells express alpha 4 beta 1 and alpha 5 beta 1; (2) the expression of alpha 4 beta 1 and alpha 5 beta 1 is differentially expressed during myeloid differentiation; and (3) binding of CD34+ bone marrow cells to fibronectin is activation dependent.

Local production of interleukin-6 during acute rejection in human renal allografts

Interleukin-6 is involved in T-cell activation and possibly plays a role in the pathogenesis of acute rejection of transplanted organs. This is indicated by elevated levels of interleukin-6 in serum and urine of renal allograft recipients, and elevated amounts of mRNA for interleukin-6 in all different cell types of the renal allograft during acute rejection episodes. However, transplant recipients receive immunosuppressive drug therapy which may inhibit production of interleukin-6 at the post-transcriptional level. Therefore, the aim of the present study was to detect interleukin-6 in biopsies taken during acute renal allograft rejection by immunohistochemical staining. In addition, serial sections were stained with cellular markers to identify interleukin-6-producing cells. In biopsies taken during acute rejection (n = 7), interleukin-6 could be detected in tubular cells (7/7) mesangial cells (3/7) and monocytes/macrophages (4/7), but not in vascular endothelium or lymphocytes. In control biopsies weak interleukin-6 staining of tubular cells only was present or there was no staining at all. We conclude that interleukin-6 is actually produced in the renal allograft during acute rejection, and that elevated urinary interleukin-6 levels during acute rejection seem to originate mainly from synthesis of interleukin-6 by renal tubular cells.

Combined measurement of growth and differentiation in suspension cultures of purified human CD34-positive cells enables a detailed analysis of myelopoiesis

In this study we have made a detailed analysis of growth factor (granulocyte-macrophage colony-stimulating factor [GM-CSF], granulocyte colony-stimulating factor [G-CSF], and macrophage colony-stimulating factor [M-CSF])-induced proliferation and differentiation of highly purified CD34+ committed human myeloid progenitor cells in suspension cultures. The results were compared with colony formation in semisolid medium. Proliferation in suspension cultures was determined by means of incorporation of [3H]thymidine, differentiation by flow cytometric immunophenotyping using a panel of monoclonal antibodies against monomyeloid antigens, and by morphology. A good correlation was found between the number of granulocyte-macrophage colony-forming units (CFU-GM) in semisolid medium and [3H]thymidine incorporation in suspension (r = 0.82), both assessed at day 11. Moreover, the frequency of proliferating cells as determined in suspension cultures by limiting dilution analysis was similar to the frequencies of CFU-GM as measured in semisolid medium. Studies on GM-CSF- and G-CSF-induced cell-growth kinetics revealed distinct proliferation patterns. Immunophenotypically the subsequent induction of the mature granulocytic antigens CD15 and CD67 was observed to be accompanied by a gradual loss of the HLA-DR antigen, whereas little monocytic differentiation was observed. M-CSF, although inducing no colony formation of CD34+ cells and minimal proliferation in suspension, induced monocytic differentiation, demonstrated by the expression of HLA-DR, CD14, and CD36 in the absence of CD15 and CD67. The observed immunophenotypical profiles were confirmed by the results of cytological characterization. Thus, the combined measurement of growth factor-induced proliferation and differentiation of progenitor cells in suspension cultures can be a useful alternative for the CFU-GM assay. Moreover, because small numbers of cells are required, it allows for detailed studies on cell-growth kinetics and developmental stages within the granulocytic and monocytic lineages.

Platelet volume analysis in thrombocytopenia in relation to bleeding tendency

It has been shown that large platelets are hemostatically more active than the smaller ones. We therefore studied the relationship between the mean platelet volume and the percentage of micro- and mega-thrombocytes measured by a Coulter counter S plus II, and the bleeding tendency in 57 unselected patients with a platelet count below 50 X 10(9)/l. We found no significant differences for any of these parameters between patients without and those with mild or severe bleeding tendency. This also held true when patients with a possible platelet dysfunction or with coagulation abnormalities were excluded. We conclude that platelet volume analysis in unselected patients with severe thrombocytopenia is not helpful in the prediction of their risk of bleeding.