Cancer in adolescents and young adults (AYA) in North Netherlands (1989–2003): Increased incidence, stable survival and high incidence of secondary tumors

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Background: Lack of improvement in survival in AYA cancer patients as compared to children has led to increased awareness of this young population. We performed a population-based study of the incidence and survival of primary tumors and incidence of second tumors in patients 12–24 years, diagnosed in North Netherlands. Methods: Patients, diagnosed 1989–2003, classified according to Birch, were retrieved from the regional cancer registry and were divided into age groups (12–15, 16–19, 20–24). Age-specific incidence rates per 100,000 were calculated using population data from Statistics Netherlands. Three-year moving means of incidence were calculated for the three age groups. 5-years survival over time for males (M) and females (F) was calculated; difference in survival was assessed with log-rank test. Results: From 1989–2003 1,118 patients were diagnosed: lymphoma 22.9%, germ-cell malignancies 14.5%, melanoma 13.7%, carcinoma 12.7%, sarcoma 11.7%, CNS tumors 11.5%, leukaemia 10%. The total age-specific incidence rates per 100,000 were: M:13.4 (12–15 yrs), 26.9 (16–19 yrs), and 27.5 (20–24 yrs) and F:13.9, 20.7, 20.7. M/F ratio was 1.32. Between 1999–2003 a remarkable high incidence of Hodgkin's lymphoma in 16–19 yrs (M 9.4, F 7.6), germ cell malignancies 14.1 (M, 20–24), and melanoma 7.0 (F, 20–24) was found. The estimated annual percent change in incidence was 2.15% (p=0.001) overall. Multivariate analysis of the incidence showed a significant increase by age and year of diagnosis. The 5 years-survival was 0.80, 0.80 and 0.82 for the three age groups. Survival did not change significantly during the study period, except for a better survival for leukemias (p=0.04). With a follow-up of 8.7 years the relative risk of secondary tumors was 34.98 (23.06- 50.89; p<0.05). Conclusions: Between 1989 and 2003 the total incidence of cancer in AYA increased. Except for leukaemia survival was stable over time. No difference in survival between the age groups (12–15;16–19; 20–24) was found. From 1999–2003 a remarkable high incidence of Hodgkin's lymphomas (M, 16–19), germ cell malignancies (M, 20–24) and melanomas (F, 20–24) was observed. The relative risk of a secondary tumor in this young cohort was 35-fold increased.

No significant financial relationships to disclose.

A possible role for spontaneous interleukin-8 production by acute myeloid leukemic cells in angiogenesis related processes: work in progress

BACKGROUND

Recently, the role of inter-leukin-8 (IL-8) in angiogenesis was reported. We consequently addressed here the question whether IL-8 produced by acute myeloid leukemia (AML) blasts might have a comparable function.

PROCEDURE

In 21 pediatric patients with AML the role of AML derived IL-8 in angiogenesis related processes were investigated. Therefore, IL-8 protein and mRNA expression were measured and endothelial cell (EC) migration and proliferation assays were performed. In addition, bFGF and VEGF mRNA expression were measured by RT-PCR.

RESULTS

In the supernatant of the AML blasts, IL-8 protein was present in a varying amount (median 0.86 microg/L, range: 0.1-320 microg/L) and confirmed by RT-PCR. Normal bone marrow mononuclear cells secreted a significant lower amount of IL-8 protein (median: 0.053 microg/L, range: 0.023-0.055 microg/L, P = 0.007). Seven of the 17 tested AML supernatants induced a varying low amount of EC proliferation compared to control media, which was not inhibited by anti-IL-8 antibodies. In contrast, in the EC migration assay, 15 out of the 17 AML supernatants tested, showed an increased EC migration (median fold increase: 1.97, range: 0.66-6.36, P = 0.002) compared to control medium. The increase in EC migration could partially be blocked by anti-IL-8 in 59% of the cases (18% decrease, range 0-62%, P = 0.003). Other contributors for the increase in EC migration were also determined. Vascular endothelial growth factor (VEGF) transcripts by RT-PCR were demonstrated in six out of the nine tested AML cases, while no transcripts for basic fibroblast growth factor (VEGF) could be shown.

CONCLUSIONS

Neutralizing anti IL-8 antibodies inhibit EC migration when stimulated with AML supernatant. This suggests a facilitating role for AML-derived IL-8 in an important step in angiogenesis.

Mobilized human CD34+ hematopoietic stem cells enhance tumor growth in a nonobese diabetic/severe combined immunodeficient mouse model of human non-Hodgkin's lymphoma

Autologous peripheral blood stem cell mobilization is increasingly applied in the treatment of hematological malignancies. Despite the frequent clinical use in a setting of residual disease, it is not known whether mobilization of hematopoietic stem cells might facilitate tumor outgrowth in vivo. In the bone marrow, a bipotential precursor for hematopoietic and endothelial cells called hemangioblast exists. This hemangioblast, characterized by the expression of CD34 and vascular endothelial growth factor receptor (VEGFR)-2, is released from the bone marrow by mobilization and might be able to result in not only the generation of peripheral blood cells but vasculogenesis due to differentiation of the hemangioblast along the endothelial lineage [in addition to VEGFR-2 expression, angiopoietin-2 (ANG-2) expression can also be found in this stage]. New vessel formation in the tumor is critical for tumor growth. A xenotransplant model was established with 10 x 10(6) Daudi cells (non-Hodgkin's lymphoma) s.c. injected in the neck region of nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice, who were sublethally irradiated with 2 Gy. At day 10 after tumor inoculation, half of the mice were given 0.5 x 10(6) human CD34+ cells i.v., whereas the other half were given PBS i.v. The human CD34+ cells were obtained from leukapheresis samples of myeloma patients undergoing autologous peripheral blood stem cell mobilization. We compared tumor growth and human-specific VEGFR-2 and ANG-2 expression in the two groups. Tumor growth is enhanced 2-fold when mobilized hematopoietic human CD34+ cells are given compared with PBS controls (P = 0.004). In addition, the human-specific VEGFR-2 and ANG-2 reverse transcription-PCR was only positive in the tumors of mice i.v. injected with human CD34+ cells. This indicates that the injected human CD34+ cells home to the tumors and differentiate along the endothelial lineage. In the present study, we demonstrate that mobilized human CD34+ hematopoietic cells injected i.v. might facilitate the outgrowth of tumors in the setting of minimal residual disease. Malignant tumors are capable of incorporating human CD34+ hematopoietic cells. This study questions the safety of leukapheresis in patients with (residual) tumor and has important implications for further development of intensive chemotherapy protocols with autologous stem cell rescue.

Increased bone marrow vascularization in patients with acute myeloid leukaemia: a possible role for vascular endothelial growth factor

The present study demonstrated that the vessel number in bone marrow biopsies from acute myeloid leukaemia (AML) patients (n = 23) was significantly increased at diagnosis compared with normal bone marrow (P = 0.019) and was restored to normal levels after achieving complete remission (P = 0.03). The in vitro angiogenic potential of culture supernatant of AML cells was assessed using endothelial cell (EC) migration and proliferation assays. Increased EC migration and EC proliferation was induced in 7/20 and 19/20 AML supernatents respectively. The degree of in vivo neovascularization did not correlate with the ability of AML cells to stimulate in vitro endothelial cell migration and/or proliferation. This might be in part a result of the heterogeneous pattern of angiogenic factors produced by AML cells. The expression of different angiogenic factors was studied using reverse transcription polymerase chain reaction. Cells from 17/20 AML patients showed wide variation in spontaneous vascular endothelial growth factor (VEGF) expression, 4/19 expressed varied spontaneous blastic fibroblast growth factor mRNA levels and all patient samples showed spontaneous interleukin 8 mRNA expression. All AML samples expressed matrix metalloproteinase (MMP)-2 and/or MMP-9. VEGF mRNA expression correlated well with protein level (P = 0.006). A correlation was found between the degree of VEGF expression and neoangiogenesis (correlation coefficient = 0.448, P = 0.05). These results suggest that malignant cell proliferation, angiogenesis and VEGF expression are linked in AML and might contribute to the growth advantage of the malignant counterpart as a result of the paracrine production of growth factors produced by the surrounding endothelial cells.

Intrinsic capacity of monocytes to produce cytokines ex vivo in patients with acute lymphoblastic leukaemia

Monocytic cytokine profiles of fifteen children with acute lymphoblastic leukaemia (ALL) were included to determine whether malignancy per se contributes to impaired cytokine profiles in vivo and ex vivo. The ex vivo tumour necrosis factor-alpha (TNF-alpha) and interleukin 1beta (IL-1beta) production was positively correlated with the monocyte number and with the number of intracellular TNF-alpha or IL-1beta positive cells in lipopolysaccharide (LPS)-stimulated MNC cultures. The mean ex vivo TNF-alpha and IL-1beta production per 1x10(4)monocytes in these cultures was not significantly different in children at diagnosis of ALL, at remission or in controls. High IL-10 plasma levels at diagnosis of ALL had no effect on the ex vivo TNF-alpha and IL-1beta production of monocytes in LPS stimulated MNC cultures. These results show that monocytes of ALL patients have a normal intrinsic capacity to produce cytokines ex vivo. However, the decreased monocyte number is responsible for the lower TNF-alpha and IL-1beta concentrations ex vivo upon LPS stimulation.

Plasma IL-8 and IL-6 levels can be used to define a group with low risk of septicaemia among cancer patients with fever and neutropenia

The standard therapy for patients with fever and chemotherapy-related neutropenia is hospitalization and infusion of broad-spectrum antibiotics. Early discharge of a defined group of patients at low risk for septicaemia would be of great advantage for these patients. In this study plasma interleukin-8 (IL-8) and interleukin-6 (IL-6) levels measured at start of fever (n = 72) could define a low-risk group of febrile patients with neutropenia due to chemotherapy. For this purpose we collected and analysed data on 72 fever episodes from 53 patients with chemotherapy-related neutropenia, aged between 1 and 66 years. Of the 72 episodes, 18 were classified as bacteraemia and/or clinical sepsis (sepsis group). The IL-6 and IL-8 plasma concentration were significantly increased in patients with chemotherapy-related neutropenia and fever due to bacteraemia versus fever of non-bacterial origin (P = 0.043 and P = 0.022 respectively). Logistic regression analysis, with sepsis as the outcome variable, revealed significant effects of age combined with either IL-6 or IL-8. Sepsis occurrence was lowest for patients <16 years and highest in patients between 16 and 50 years, and was higher in patients with increased IL-6 (P = 0.032) or IL-8 (P = 0.049). No significant effect of leucocyte count, C-reactive protein, sex or underlying malignancy at presentation was detected. The plasma IL-6 and IL-8 levels were fairly strongly correlated (Pearson r = 0.62). Using a cut-off value with 100% sensitivity, both IL-8 and IL-6 could define a low-risk group of neutropenic patients of 28% (CI 15-40%) at the start of the febrile period. Intervention studies are warranted to confirm this result and to investigate whether an early discharge based on IL-8 or IL-6 measurement is safe, increases the quality of life, and results in cost savings.

A minimal level of MHC class II expression is sufficient to abrogate autoreactivity

The establishment of CD4(+) T cell tolerance requires that self-reactive thymocytes are negatively selected during thymic development. A threshold of antigen concentration appears to exist for both MHC class I- and class II-mediated negative selection, below which clonal deletion of a self-reactive transgenic TCR does not occur. Similarly, both the specificity and thymic concentration of MHC molecules affect the efficiency with which autoreactive thymocytes are deleted. However, this threshold for MHC class II concentration has not been well established. Here, we show that this threshold must be extraordinarily low. We have used the human lysozyme promoter to re-express an A(beta)(b) cDNA on macrophages and other phagocytic myelomonocytic cells of class II-deficient A(beta)(b) -/- mice. Surface expression of I-A(b) could be detected on mature peritoneal macrophages and, minimally, on thymic dendritic cells; however, this level of expression was not sufficient for antigen-specific T cell activation. Nevertheless, when backcrossed onto an autoreactive K14 background, this minimal level of class II was sufficient to induce negative selection of a polyclonal self-reactive population. We conclude that provision of extremely low levels of class II to thymic dendritic cells confers on them the ability to mediate clonal deletion of autoreactive T cells.

Lipopolysaccharide-induced cytokine production in peripheral blood mononuclear cells: intracellular localization of tumor necrosis factor alpha and interleukin 1 beta detected with a three-color immunofluorescence technique

Lipopolysaccharide (LPS) can induce monocytes to produce various cytokines such as tumor necrosis factor alpha (TNF alpha) and interleukin 1 beta (IL-1 beta). In the present study, the kinetics of both intracellular and extracellular accumulation of TNF alpha and IL-1 beta in LPS stimulated mononuclear cell (MNC) cultures has been determined. A three-color-immunofluorescence technique was used to detect intracellular accumulation of cytokines. Intracellular accumulation of TNF alpha in monocytes starts shortly after initiation of the culture; i.e., TNF alpha is detectable after 1 h, reaching a peak level after 3-4 hours with 50-65% of monocytes staining positive. In parallel with its increased intracellular presence, TNF alpha was also found in the culture supernatant. The intracellular accumulation of IL-1 beta in monocytes became detectable after 2 h of culture in the presence of LPS. After 4 h, a plateau was reached, with 90% of the monocytes being positive. In parallel, but with a little delay, IL-1 beta could be detected in the culture supernatant. TNF alpha and IL-1 beta can be produced simultaneously in the same monocytes as was shown by a three-color-immunofluorescence technique. It is concluded that TNF alpha and IL-1 beta are good parameters for the early measurement of monocyte activation and that both the intracellular accumulation in monocytes and the amount of secreted cytokines can be used for such a purpose. The intracellular accumulation in monocytes can be measured by the three-color-immunofluorescence technique described.

Increased plasma concentrations of interleukin-1 receptor antagonist in neonatal sepsis

Newborns are prone to severe infections and sepsis. Cytokines such as tumor necrosis factor-alpha and IL-1 beta play a major role in the initiation of the host response to infections. IL-1 receptor antagonist (IL-1ra) is a naturally occurring antagonist of IL-1 beta. We hypothesized that low IL-1ra plasma concentrations might contribute to the high morbidity and mortality of neonatal sepsis. We studied IL-1ra plasma concentrations during neonatal sepsis. Eleven newborns with severe infection or sepsis, 28 newborns suspected as having sepsis, and eight healthy newborns were enrolled in the study. IL-1ra plasma concentrations proved to be increased in the newborns with severe infections or sepsis (5635 +/- 411 ng/L) versus the concentrations in the suspected group (2597 +/- 433 ng/L) and the control group (273 +/- 88 ng/L) (p < 0.001). After the start of antibiotic therapy, the IL-1ra plasma concentrations remained high during the first 16 h. The IL-1 beta plasma concentrations were increased in the group with a proven infection (78 +/- 27 ng/L) versus the suspected group (37 +/- 7 ng/L) (p < 0.05). Interestingly, the mean Il-1RA plasma concentration is a factor 50-100 higher than the IL-1 beta plasma concentrations. We conclude that IL-1ra in newborns is produced in an amount equal to that in adults. An inadequate IL-1ra response does not seem to contribute to the increased morbidity and mortality of neonatal sepsis.

Diagnostic value of plasma levels of tumor necrosis factor alpha (TNF alpha) and interleukin-6 (IL-6) in newborns with sepsis

The aim of this study was to examine if TNF alpha and IL-6 plasma levels could be of value in diagnosing neonatal sepsis. Tumor necrosis factor alpha (TNF alpha) and interleukin-6 (IL-6) plasma levels were determined in 15 newborn infants with confirmed sepsis (group I), 18 with suspected sepsis (group II) and 22 control infants (group III). In 33 newborns, initially suspected of having sepsis (groups I and II), a positive test result for plasma concentration of TNF alpha (> 70 pg/ml) had a sensitivity of 73% and a specificity of 94%. A positive test result for IL-6 (> 500 pg/ml) had a sensitivity of 80% and a specificity of 78%. When plasma levels of TNF alpha and IL-6 were combined for the diagnosis of neonatal sepsis, a positive test result for both tests had a sensitivity of 60% and a specificity of 100%. When both tests are positive the diagnosis of neonatal sepsis is almost certain (likelihood ratio = infinity). The combination of TNF alpha and IL-6 determinations appears to be a good predictor of neonatal sepsis.

Tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6 plasma levels in neonatal sepsis

Tumor necrosis factor-alpha, IL-1 beta, and IL-6 are thought to be involved in the pathogenesis of sepsis with gram-negative bacteria. We studied these cytokines during neonatal sepsis with mainly gram-positive bacteria. Ten newborns with clinical sepsis and 22 healthy controls were enrolled in the study. TNF alpha plasma levels proved to be increased in the newborns with sepsis up to 560 +/- 234 pg/mL (ng/L) versus 36 +/- 4 pg/mL (ng/L) in the control group (p < 0.005), whereas IL-6 plasma levels in newborns with sepsis were 79.700 +/- 37.500 pg/mL (ng/L) versus 55 +/- 28 pg/mL (ng/L) in the control group (p < 0.01). The IL-1 beta plasma levels were only slightly elevated in the group newborns with sepsis [up to 18 +/- 5 pg/mL (ng/L) versus 7 +/- 1 pg/mL (ng/L) in the control group (p < 0.01)]. After the start of therapy with antibiotics, both TNF alpha and IL-6 plasma levels decreased concomitantly with the improvement of the clinical situation within 2 d. These data confirm the abundant presence of TNF alpha and IL-6 during neonatal sepsis, whereas IL-1 beta appeared to be present in small amounts only. Nevertheless, the IL-1 beta but not the TNF alpha plasma level appeared to correlate inversely with the decrease in diastolic tension as standardized according to birth weight (R = 0.66, p = 0.04). TNF alpha, IL-1 beta, and IL-6 were not correlated with any febrile response in the group with sepsis.(ABSTRACT TRUNCATED AT 250 WORDS)