Serum adiponectin as a predictor of childhood non-Hodgkin's lymphoma: a nationwide case-control study

Attenuated adiponectin, omentin, increased interleukin-6 and tumor necrosis factor-alpha levels with altered cognition and depression in non-Hodgkin lymphoma patients: A case-control study

BACKGROUND AND PURPOSE

Immune dysfunction is one of the risk factors which plays an important role in the development of non-Hodgkin lymphoma (NHL), and inflammation may be involved in its etiology. Minimal data is available on the effect of cytokine levels on neurobehavioral function in lymphoma before the initiation of chemotherapy. Therefore, we aimed to explore the risk of NHL by assessment of cytokine and adipokine levels and their correlation with neurobehavioral changes.

METHODS

This case-control study enrolled 62 subjects (age-sex matched: 31 cases and 31 controls). Neurobehavioral assessment was done using Montreal Cognitive Assessment questionnaire (MoCA) and Patient Health Questionnaire (PHQ-9). EORTC Core Quality of Life questionnaire (EORTC QLQ-C30) was used to assess quality of life. Questionnaire assessment and sample collection were done after the patient enrolment and before first cycle of chemotherapy.

RESULTS

Mean age of NHL patients and healthy controls was 51.9 ± 11.8 and 50 ± 10.9 years, respectively. NHL patients showed significantly higher levels of IL-6 (0.77 ± 0.11) and TNF- α (1.47 ± 1.31) than controls (0.55 ± 0.4 and 0.66 ± 0.89, respectively) with p-value<0.005. Also, NHL patients showed significantly lower levels of adiponectin (0.31 ± 0.24) and omentin (0.46 ± 0.1) than controls (0.42 ± 0.13 and 0.53 ± 0.11, respectively) with p-value<0.005. Lower MoCA and EORTC QLQ C-30 scores and higher PHQ-9 scores were observed in NHL patients in comparison to healthy control.

CONCLUSION

Our results showed that adiponectin, omentin IL-6 and TNF-α may be used as pre-diagnostic markers of NHL risk. Neurobehavioral changes observed in NHL patients may alter the quality of life.

Obesity and Risk for Lymphoma: Possible Role of Leptin

Obesity, which is considered a pandemic due to its high prevalence, is a risk factor for many types of cancers, including lymphoma, through a variety of mechanisms by promoting an inflammatory state. Specifically, over the last few decades, obesity has been suggested not only to increase the risk of lymphoma but also to be associated with poor clinical outcomes and worse responses to different treatments for those diseases. Within the extensive range of proinflammatory mediators that adipose tissue releases, leptin has been demonstrated to be a key adipokine due to its pleotropic effects in many physiological systems and diseases. In this sense, different studies have analyzed leptin levels and leptin/leptin receptor expressions as a probable bridge between obesity and lymphomas. Since both obesity and lymphomas are prevalent pathophysiological conditions worldwide and their incidences have increased over the last few years, here we review the possible role of leptin as a promising proinflammatory mediator promoting lymphomas.

The Association of Pre-diagnostic Inflammatory Markers and Adipokines and the Risk of Non-Hodgkin Lymphoma Development in Egypt

Non-Hodgkin lymphoma (NHL) is an etiologically, clinically, and histologically heterogeneous group of lymphoproliferative disorders. Immune dysfunction is a well-known risk factor and dysregulation of cytokines may mediate disease progression. Obesity is one of the important relations connecting immune system abnormalities and lymphomagenesis. We conducted a study to find out the association between obesity as measured by body mass index (BMI), and risk of non-Hodgkin lymphoma (NHL) development by assessment the of inflammatory cytokines levels, (IL-6, IL-10, IFN-gamma and CRP) and adipokines levels (leptin and adiponectin). Also, to predict the effect of higher BMI on the incidence of NHL. The study included 180 NHL patients and 172 healthy controls. The inflammatory markers (IL-6, IL-10, IFN-γ & CRP) together with adiponectin were assessed by ELISA technique. IL-6, IL-10, CRP, IFN-γ and Adiponectin were statistically higher in cases than control. A positive significant difference of Leptin (p-value 0.001) was found with higher levels in patients with BMI (≥ 25 kg/m²) than in patients with < 25 kg/m². IL-6, IL-10, CRP, IFN-γ and Adiponectin could be implicated in lymphomagenesis in Egyptian NHL. The study results support the hypothesis that obesity has a major role in the development of NHL. An association between Leptin and NHL risk with higher levels in patients with BMI (≥ 25 kg/m²) was proved.

Circulating adiponectin levels in various malignancies: an updated meta-analysis of 107 studies

Early detection of cancers is challenging for lack of specific biomarkers. Adiponectin is an adipokine predominantly derived from adipocytes and hypoadiponectinemia has been reported to associate with risk of many types of cancers. However, available evidence is controversial. Some studies show that increased adiponectin levels correlate with cancer risk. Therefore, we performed a meta-analysis of the association between circulating adiponectin levels and cancer development. A systematic search of PubMed, EMBASE, Wiley Online Library and Cochrane Library was conducted for eligible studies involving circulating adiponectin and malignancies from inception to August 8, 2015. Standard mean differences (SMDs) with 95% confidence intervals (95% CIs) were calculated by use of a random-effect model. Funnel plot and Egger's linear regression test were conducted to examine the risk of publication bias. 107 studies were included with 19,319 cases and 25,675 controls. The pooled analysis indicated that circulating adiponectin levels were lower in patients with various cancers than in controls, with a pooled SMD of −0.334 μg/ml (95% CI, −0.465 to −0.203, P = 0.000). No evidence of publication bias was observed. Circulating high molecular weight adiponectin levels were also lower in cancer patients than in controls, with a pooled SMD of −0.502 μg/ml (95% CI, −0.957 to −0.047, P = 0.000). This meta-analysis provides further evidence that decreased adiponectin levels is associated with risk of various cancers. Hypoadiponectinemia may represent a useful biomarker for early detection of cancers.

The prognostic value of serum and bronchoalveolar lavage levels of adiponectin in advanced non-small-cell lung cancer

Aim

We aimed to explore the prognostic implications of adiponectin (APN) levels in the serum and bronchoalveolar lavage (BAL) of patients with advanced NSCLC.

Materials & methods

29 newly diagnosed patients with stage IV NSCLC were prospectively enrolled. Baseline serum and BAL levels of APN were assayed by ELISA and correlated with various clinicopathological parameters, including overall survival.

Results

No statistically significant correlations were observed between the serum or BAL levels of APN and the clinicopathological parameters evaluated. The only prognostic factor identified, both by univariate and multivariate survival analyses, was performance status.

Conclusion

The results of our cohort failed to reveal any prognostic significance of serum and BAL levels of APN in stage IV NSCLC.

Different molecular signaling sustaining adiponectin action in breast cancer

Obesity is defined as a chronic and excessive growth of adipose tissue. It is increasingly recognized as an oncogenic factor. Adipose tissue, originally thought as a passive depot for fat metabolism, is now identified as an endocrine organ, secreting a wide array of bioactive molecules known as adipocytokines, which act as key mediators in several obesity-associated diseases. Among these adipocytokines, adiponectin has been proposed as having a key role in the pathogenesis of cardiovascular disease and type 2 diabetes along with other diseases such as obesity-associated malignancies, including breast cancer. New insights into the molecular mechanisms linking adiponectin and mammary tumorigenesis could be useful to identify novel therapeutic approaches to be exploited, particularly in obese women.

Adipokines and Insulin Resistance in Young Adult Survivors of Childhood Cancer

We examined the association between adipokines (leptin, adiponectin, and resistin), radiotherapy, measurement of body fat, and insulin resistance among young adult survivors of childhood cancer (CCS). Materials and Methods. Seventy-six survivors were included (mean age 24.1 ± 3.5 years). Insulin resistance (IR) was calculated using the homeostasis model assessment (HOMA-IR). The serum levels of adipokines were assayed by immunoassays. Fat mass was evaluated by DXA. Results. Mean adiponectin level and mean body FAT were higher in the examined females than in males (10009 ± 6367 ng/mL versus 6433 ± 4136 ng/mL, p < 0.01; 35.98 ± 9.61% versus 22.7 ± 7.46%, p < 0.001). Among CCS, one of 75 patients met the criteria of insulin resistance, and in 14 patients there was impaired fasting glucose. The multiple regression model for females showed that leptin/adiponectin ratio (LA ratio) significantly affected HOMA-IR (increase of 0.024 per each unit of LA ratio; p < 0.05). Radiotherapy had no effect on serum adipokines and IR. Conclusion. The observed results support the hypothesis that adiponectin might be associated with insulin resistance and it can not be ruled out that changes in the mean level of adiponectin per FAT mass or leptin/adiponectin ratio may precede the occurrence of insulin resistance in the future.

Adiponectin is associated with poor prognosis in carcinoma patients: evidence from a meta-analysis

Background

Studies have come to conflicting conclusions about whether adiponectin (APN) expression is associated with cancer prognosis. To help resolve this question, we meta-analyzed the available evidence.

Methods

PubMed, EMBASE, the Cochrane Library, the Chinese Biological Medical Database and the Chinese National Knowledge Infrastructure Database were systematically searched to identify all eligible studies examining APN expression and prognosis for patients with any type of cancer. Pooled hazard ratios (HRs) and corresponding 95 % confidence intervals (CIs) related to overall survival (OS) or disease-free survival (DFS) were calculated.

Results

Ten studies involving 999 patients were meta-analyzed. Analysis across all patients revealed no significant association between high/positive APN expression and DFS, but they did show a significant association between high/positive APN expression and OS (HR 1.51, 95 %CI 1.21 to 1.89). Subgroup analysis showed that high/positive APN expression in non-Asians was significantly associated with both DFS (HR 1.36, 95 % CI 1.03 to 1.80) and OS (HR 1.53, 95 %CI 1.20 to 1.96), but no such associations were observed in Asians. In addition, high/positive APN expression was significantly associated with OS across all patients with hepatocellular carcinoma (HR 1.89, 95 %CI 1.20 to 2.98).

Conclusions

The available evidence suggests that high/positive APN expression is associated with poor prognosis for patients with various carcinomas, especially for non-Asian cancer patients and for all patients with hepatocellular carcinoma. These findings should be confirmed and extended in large, well-designed studies.

Leptin and its receptor in hematologic malignancies

Leptin is an adipocyte-derived cytokine coded by the obese gene, not only regulates metabolism, but also participates in hematopoiesis. Aberrant leptin levels in patients with hematologic malignancies were observed and associates with clinical characters, such as body mass index (BMI), gender, blast cell percentage. Leptin concentrations alter while diseases progress or remission. Leptin receptor is expressed in hematopoietic CD34+ stem cells, erythrocytes, lymphocytes, blast cells and samples in leukemia and lymphoma patients. The adipokine stimulates cell proliferation, cytokine secretion and protects malignant cells from apoptosis through Janus kinase-signal transducer and activator of transcription (JAK-STAT), mitogen-activated protein kinase and extracellular signal activated kinase 1/2 (MAPK/ERK1/2), or 3 kinase (PI3K) signaling pathways. These findings indicate leptin signaling possibility take part in occurrence, progression and prognosis of hematologic malignancies. This article reviews leptin/leptin receptor expression and the correlations with clinical characters, treatment and prognosis in myeloid and lymphoid neoplasms.

The diverse roles of adiponectin in non-small-cell lung cancer: current data and future perspectives

In recent years, there is growing research interest for the biological role of adipose tissue-derived bioactive factors, mainly including adipokines, in various forms of cancer. Adiponectin (APN) is the most abundant circulating adipokine, and a key mediator of several cancer-related processes, such as cell proliferation, apoptosis, regulation of tumor cell invasion and angiogenesis. In this review we summarize and critically discuss the published literature on the diverse roles of APN in non-small-cell lung cancer, including its implication in lung cancer development, its use as a diagnostic and prognostic biomarker, and its correlation with cancer-related cachexia. The main challenges and future perspectives, mainly with regard to the potential development of APN-targeted therapeutic agents in cancer therapeutics, are also briefly presented and discussed.

Adiponectin as a biomarker linking obesity and adiposopathy to hematologic malignancies

Higher body mass index and adiposopathy have been associated with increased risk of hematologic malignancies such as leukemia, multiple myeloma, myeloproliferative disorders, Hodgkin’s and non-Hodgkin’s lymphoma, and myelodysplastic syndromes. Adiponectin is a multimeric protein of the white adipose tissue presenting anti-inflammatory, insulin-sensitizing, anti-atherogenic, cardioprotective, and anti-neoplastic properties. Its anti-neoplastic actions are manifested via two mechanisms: (i) direct action on tumor cells by enhancing receptor-mediated signaling pathways and (ii) indirect action by regulating inflammatory responses, influencing cancer angiogenesis, and modulating insulin sensitivity at the target tissue site. In the bone marrow milieu, adiponectin and its main receptors are expressed by the majority of bone marrow stromal cell populations influencing hematopoietic stem cells function. Adiponectin may represent a molecular mediator relating adiposopathy with leukemogenesis and myelomagenesis. Several epidemiological studies conducted to date relate hypoadiponectinemia to the risk of myeloid-derived hematopoietic cancer and multiple myeloma. Adiponectin may be a promising biomarker with potential diagnostic and prognostic utility in determining the likelihood of myeloma and leukemia progression in certain cohorts of monoclonal gammopathy of undetermined significance patients and in myeloid hematologic malignancies, respectively. This review summarizes experimental and epidemiologic data regarding the role of adiponectin in hematologic malignancies in the context of adiposopathy. Enhancement of endogenous adiponectin, adiponectin replacement, or manipulation of adiponectin receptor sensitivity may be an attractive goal for prevention and an effective therapeutic strategy against hematopoietic cancer, specifically in overweight/obese individuals. Further studies are required to elucidate the role of the bone marrow microenvironment adiponectin in complex interactions involved in preleukemic and leukemic states.

From leptin to other adipokines in health and disease: facts and expectations at the beginning of the 21st century

This year marks the 20th anniversary of the discovery of leptin, which has tremendously stimulated translational obesity research. The discovery of leptin has led to realizations that have established adipose tissue as an endocrine organ, secreting bioactive molecules including hormones now termed adipokines. Through adipokines, the adipose tissue influences the regulation of several important physiological functions including but not limited to appetite, satiety, energy expenditure, activity, insulin sensitivity and secretion, glucose and lipid metabolism, fat distribution, endothelial function, hemostasis, blood pressure, neuroendocrine regulation, and function of the immune system. Adipokines have a great potential for clinical use as potential therapeutics for obesity, obesity related metabolic, cardiovascular and other diseases. After 20 years of intense research efforts, recombinant leptin and the leptin analog metreleptin are already available for the treatment of congenital leptin deficiency and lipodystrophy. Other adipokines are also emerging as promising candidates for urgently needed novel pharmacological treatment strategies not only in obesity but also other disease states associated with and influenced by adipose tissue size and activity. In addition, prediction of reduced type 2 diabetes risk by high circulating adiponectin concentrations suggests that adipokines have the potential to be used as biomarkers for individual treatment success and disease progression, to monitor clinical responses and to identify non-responders to anti-obesity interventions. With the growing number of adipokines there is an increasing need to define their function, molecular targets and translational potential for the treatment of obesity and other diseases. In this review we present research data on adipose tissue secreted hormones, the discovery of which followed the discovery of leptin 20 years ago pointing to future research directions to unravel mechanisms of action for adipokines.

Serum adiponectin relates to shortened overall survival in men with squamous cell esophageal cancer treated with preoperative concurrent chemoradiotherapy: a pilot study

BACKGROUND

The convergence of nutritional, genetic, and inflammatory factors plays a significant role in the pathophysiology of squamous cell esophageal cancer (SCEC). The parameters of inflammation, indices of nutritional status, and adipocyte-derived hormones such as leptin, adiponectin, and resistin have been shown to be prognostic factors in some gastrointestinal and pancreatic cancers.

MATERIAL/METHODS

Forty-two patients with SCEC were subjected to a multimodal regimen of concurrent neoadjuvant chemoradiotherapy (CRT) followed by surgery. We retrospectively analyzed the impact of pretreatment values of serum leptin, adiponectin, resistin, soluble leptin receptor, C-reactive protein, TNF alpha, leukocytes, and indices of nutritional status (BMI, plasma total protein, albumin, cholesterol, and triacylglycerols) on overall survival (OS).

RESULTS

Univariate analysis revealed significant a negative correlation between OS and serum adiponectin (p=0.027), and a positive relationship was found between serum albumin (p=0.002), cholesterol (p=0.049) level, and OS. In multivariate analysis, only the trend (p=0.086) for negative serum adiponectin association with the OS was observed.

CONCLUSIONS

In men with SCEC treated by neoadjuvant concurrent CRT and esophagectomy, high pretreatment level of serum adiponectin was associated with shorter OS while the serum albumin and cholesterol were associated with longer OS.

Biomarkers in childhood non-Hodgkin's lymphomas

Pediatric non-Hodgkin's lymphomas (NHLs) are a heterogeneous group of malignancies with distinct clinical, pathological, immunological and genetic characteristics. More than 90% of pediatric NHLs belong to one of three major histological subtypes: mature B-cell neoplasms, lymphoblastic lymphomas and anaplastic large-cell lymphomas. The recognition that different subtypes require different treatment regimens resulted in therapeutic strategies leading to over 80% of patients being cured. On the other hand, patients with resistant or relapsed disease have a poor prognosis. Prognostic biomarkers have not yet been identified for all pediatric NHLs and, although some are very important for diagnosis and prognosis, others may be of questionable value. Discovery of new biomarkers suitable for clinical application may aid the diagnosis and classification of lymphomas, which should, in turn, lead to better patient stratification. Consequent development of new treatment and follow-up approaches should lead to more efficient and less toxic treatment in children with NHL.

Role of adiponectin and its receptors in cancer

Adiponectin (APN), a novel hormone/cytokine derived from adipocyte tissue, is involved in various physiological functions. Genetics, nutrition, and adiposity are factors contributing to circulating plasma concentrations of APN. Clinical correlation studies have shown that lower levels of serum APN are associated with increased malignancy of various cancers, such as breast and colon cancers, suggesting that APN has a role in tumorigenesis. APN affects insulin resistance, thus further influencing cancer development. Tumor cells may express receptors for APN. Cellular signaling is the mechanism by which APN exerts its host-protective responses. These factors suggest that serum APN levels and downstream signaling targets of APN may serve as potential diagnostic markers for malignancies. Further research is necessary to clarify the exact role of APN in cancer diagnosis and therapy.

Adiponectin, driver or passenger on the road to insulin sensitivity?

Almost 20 years have passed since the first laboratory evidence emerged that an abundant message encoding a protein with homology to the C1q superfamily is highly specifically expressed in adipocytes. At this stage, we refer to this protein as adiponectin. Despite more than 10,000 reports in the literature since its initial description, we seem to have written only the first chapter in the textbook on adiponectin physiology. With every new aspect we learn about adiponectin, a host of new questions arise with respect to the underlying molecular mechanisms. Here, we aim to summarize recent findings in the field and bring the rodent studies that suggest a causal relationship between adiponectin levels in plasma and systemic insulin sensitivity in perspective with the currently available data on the clinical side.

Adiponectin deficiency suppresses lymphoma growth in mice by modulating NK cells, CD8 T cells, and myeloid-derived suppressor cells

Previously, we found that adiponectin (APN) suppresses IL-2-induced NK cell activation by downregulating the expression of the IFN-γ-inducible TNF-related apoptosis-inducing ligand and Fas ligand. Although the antitumor function of APN has been reported in several types of solid tumors, with few controversial results, no lymphoma studies have been conducted. In this study, we assessed the role of APN in immune cell function, including NK cells, CTLs, and myeloid-derived suppressor cells, in EL4 and B16F10 tumor-bearing APN knockout (KO) mice. We observed attenuated EL4 growth in the APNKO mice. Increased numbers of splenic NK cells and splenic CTLs were identified under naive conditions and EL4-challenged conditions, respectively. In APNKO mice, splenic NK cells showed enhanced cytotoxicity with and without IL-2 stimulation. Additionally, there were decreased levels of myeloid-derived suppressor cell accumulation in the EL4-bearing APNKO mice. Enforced MHC class I expression on B16F10 cells led to attenuated growth of these tumors in APNKO mice. Thus, our results suggest that EL4 regression in APNKO mice is not only due to an enhanced antitumor immune response but also to a high level of MHC class I expression.

Non-hodgkin lymphoma and circulating markers of inflammation and adiposity in a nested case-control study: the multiethnic cohort

BACKGROUND

Because immune dysfunction is thought to underlie the development of non-Hodgkin lymphoma (NHL), obesity and chronic inflammation may be involved in its etiology. We examined the association of prediagnostic inflammatory markers and adipokines with NHL risk.

METHODS

We conducted a nested case-control analysis (272 cases and 541 matched controls) within the Multiethnic Cohort. Luminex technology was used to measure a 10-plex panel of cytokines, ELISA assays for adipokines, and an autoanalyzer for C-reactive protein (CRP). ORs and 95% confidence intervals (CI) for tertiles of analytes were estimated by conditional logistic regression.

RESULTS

After a median time of 2.7 years from phlebotomy to diagnosis, interleukin (IL)-10 was significantly related to NHL risk (ORT3 vs. T1 = 3.07; 95%CI, 2.02-4.66; Ptrend < 0.001). TNF-α and IL-8 showed borderline elevated risks, whereas IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, and CRP were not associated with NHL. Leptin but not adiponectin was related to NHL risk (ORT3 vs. T1 = 0.48; 95%CI, 0.30-0.76; Ptrend < 0.001). Adjustment for body mass index did not substantially affect the risk estimates. Stratification by subtype indicated significant associations with IL-10 and leptin for follicular but not for diffuse large B-cell lymphoma. Excluding cases diagnosed less than 1 year after phlebotomy attenuated all associations.

CONCLUSIONS

IL-10 was the only cytokine and leptin the only adipokine associated with NHL, but due to the short follow-up time, preclinical effects cannot be excluded.

IMPACT

Although markers of inflammation and adiposity may provide new insights into the etiology of NHL, they need to be assessed many years before clinical diagnosis.

Single-agent lenalidomide in relapsed/refractory mantle cell lymphoma: results from a UK phase II study suggest activity and possible gender differences

We present data from a phase II study investigating a novel treatment strategy for relapsed/refractory mantle cell lymphoma (MCL). Twenty-six patients received lenalidomide 25 mg/d (days 1-21 of a 28-d cycle) for up to 6 cycles followed by low-dose maintenance lenalidomide (15 mg) in responding patients. Eight patients achieved complete or partial response to give an overall response rate of 31% with median response duration of 22·2 months [95% confidence interval (CI) 0·0-53·6] and median progression-free survival (PFS) of 3·9 months (95% CI 0·0-11·1). An additional six patients (23%) achieved stable disease. Eleven patients received maintenance with median PFS of 14·6 months (95% CI 7·3-21·9). Correlative studies showed that peripheral T and Natural Killer (NK) cells increased in responding patients by 40-60% over the first 6 cycles with an initial dip in NK cells suggestive of tumour infiltration. Peripheral regulatory T cells were increased in MCL patients (P = 0·001) and expanded further following lenalidomide. Sequential plasma analysis showed increased IL12 p40 and IL7 alongside decreased MMP9, IL10, and adiponectin. Finally, a significant correlation (P = 0·02) between gender and response suggested that female MCL patients were more sensitive to lenalidomide than males. In summary, we confirm the activity, safety and immunomodulatory properties of lenalidomide in MCL and highlight its potential as a low-dose maintenance agent.

The role of adiponectin in cancer: a review of current evidence

Excess body weight is associated not only with an increased risk of type 2 diabetes and cardiovascular disease (CVD) but also with various types of malignancies. Adiponectin, the most abundant protein secreted by adipose tissue, exhibits insulin-sensitizing, antiinflammatory, antiatherogenic, proapoptotic, and antiproliferative properties. Circulating adiponectin levels, which are determined predominantly by genetic factors, diet, physical activity, and abdominal adiposity, are decreased in patients with diabetes, CVD, and several obesity-associated cancers. Also, adiponectin levels are inversely associated with the risk of developing diabetes, CVD, and several malignancies later in life. Many cancer cell lines express adiponectin receptors, and adiponectin in vitro limits cell proliferation and induces apoptosis. Recent in vitro studies demonstrate the antiangiogenic and tumor growth-limiting properties of adiponectin. Studies in both animals and humans have investigated adiponectin and adiponectin receptor regulation and expression in several cancers. Current evidence supports a role of adiponectin as a novel risk factor and potential diagnostic and prognostic biomarker in cancer. In addition, either adiponectin per se or medications that increase adiponectin levels or up-regulate signaling pathways downstream of adiponectin may prove to be useful anticancer agents. This review presents the role of adiponectin in carcinogenesis and cancer progression and examines the pathophysiological mechanisms that underlie the association between adiponectin and malignancy in the context of a dysfunctional adipose tissue in obesity. Understanding of these mechanisms may be important for the development of preventive and therapeutic strategies against obesity-associated malignancies.

In vitro fertilization and risk of childhood leukemia in Greece and Sweden

BACKGROUND

Cancer risk in children born after in vitro fertilization (IVF) remains largely unknown. We aimed to investigate risk of leukemia and lymphoma following IVF using two nationwide datasets.

METHODS

The hospital-based case-control study in Greece derived from the National Registry for Childhood Hematological Malignancies (1996-2008, 814 leukemia and 277 lymphoma incident cases with their 1:1 matched controls). The Swedish case-control study was nested in the Swedish Medical Birth Register (MBR) (1995-2007, 520 leukemia and 71 lymphoma cases with their 5,200 and 710 matched controls) with ascertainment of incident cancer cases in the National Cancer Register. Study-specific and combined odds ratios (OR) were estimated using conditional logistic regression, with adjustment for possible risk factors.

RESULTS

Nationwide studies pointed to similar size excess risk of leukemia following IVF, but to a null association between IVF and lymphoma. The proportion of leukemia cases conceived through IVF was 3% in Greece and 2.7% in Sweden; prevalence of IVF in matched controls was 1.8% and 1.6%, respectively. In combined multivariable analyses, the increased risk of leukemia was confined to age below 3.8 years (OR = 2.21; 95% confidence interval, CI: 1.27-3.85) and to acute lymphoblastic leukemia (ALL) (OR = 1.77; 95% CI: 1.06-2.95) with no sufficient evidence of excess risk for other leukemias (OR = 1.34; 95% CI: 0.38-4.69). Following IVF, OR for ALL was 2.58 (95% CI: 1.37-4.84) before age 3.8 and 4.29 (95% CI: 1.49-12.37) before age 2 years.

CONCLUSIONS

IVF seems to be associated with increased risk of early onset ALL in the offspring.

Adipokines, body fatness, and insulin resistance among survivors of childhood leukemia

BACKGROUND

Following our previous reports of an increased prevalence of insulin resistance and adiposity among acute lymphoblastic leukemia (ALL) survivors, particularly women treated with cranial radiotherapy (CRT), we aimed to (1) assess the relationships between adipokines (leptin and adiponectin), CRT, and measures of body fatness and (2) determine correlates of insulin resistance, by gender.

METHODS

We conducted cross-sectional evaluation of 116 ALL survivors (median age: 23.0 years; range: 18-37; average time from treatment: 17.5 years), including fasting laboratory testing (adiponectin, leptin, insulin, and glucose), anthropometric measurements (weight, height, and waist circumference), DXA (total body fat and truncal-to-lower-body-fat ratio), and abdominal CT (visceral fat). We estimated insulin resistance using the homeostasis model for assessment of insulin resistance (HOMA-IR). Analytic approaches included regression models and Wilcoxon rank sum testing.

RESULTS

Mean leptin per kilogram fat mass was higher for females (0.7 ng/ml/kg) than males (0.4 ng/ml/kg, P < 0.01), and among subjects who had received CRT compared to those who had not received CRT (females CRT =0.9 ng/ml/kg, no CRT = 0.7 ng/ml/kg; P = 0.1; males CRT = 0.5 ng/ml/kg, no CRT = 0.3 ng/ml/kg; P < 0.01). Elevated HOMA-IR was nearly uniformly present, even among subjects with BMI < 25 kg/m(2), and was associated with higher leptin:adiponectin ratio (LA ratio; P < 0.01).

CONCLUSIONS

Among survivors of childhood leukemia, higher leptin levels were associated with measures of body fat and insulin resistance. Anthropomorphic and metabolic changes many years after ALL treatment remain a major health problem facing survivors and may be related to central leptin resistance.

Overweight as a prognostic factor in children with acute lymphoblastic leukemia

Our purpose was to investigate the prognostic impact of overweight/obesity in 5-year event-free survival (EFS) in a cohort of children with acute lymphoblastic leukemia (ALL). We retrospectively analyzed 181 newly diagnosed ALL children enrolled between 1990 and 2009 and treated with Berlin-Frankfurt-Munich (BFM) protocols. The majority of children in our cohort were <10 years-old. Our data clearly indicated that overweight/obesity is an independent predictor of relapse risk, mainly in the intermediate- and high-risk groups (HR) of children. These results could be explained by changes in the chemotherapy pharmacokinetics in overweight/obese patients and by the antiapoptotic effects in leukemic cells caused by adipocytes.

Maternal smoking during pregnancy and childhood lymphoma: a meta-analysis

Results from epidemiological studies exploring the association between childhood lymphoma and maternal smoking during pregnancy have been contradictory. This meta-analysis included all published cohort (n = 2) and case-control (n = 10) articles; among the latter, the data of the Greek Nationwide Registry for Childhood Hematological Malignancies study were updated to include all recently available cases (-2008). Odds ratios (ORs), relative risks and hazard ratios were appropriately pooled in three separate analyses concerning non-Hodgkin lymphoma (NHL, n = 1,072 cases), Hodgkin lymphoma (HL, n = 538 cases) and any lymphoma (n = 1,591 cases), according to data availability in the included studies. An additional metaregression analysis was conducted to explore dose-response relationships. A statistically significant association between maternal smoking (any vs. no) during pregnancy and risk for childhood NHL was observed (OR = 1.22, 95% confidence interval, CI: 1.03-1.45, fixed effects model), whereas the risk for childhood HL was not statistically significant (OR = 0.90, 95% CI: 0.66-1.21, fixed effects model). The analysis on any lymphoma did not reach statistical significance (OR = 1.10, 95% CI = 0.96-1.27, fixed effects model), possibly because of the case-mix of NHL to HL. No dose-response association was revealed in the metaregression analysis. In conclusion, this meta-analysis points to a modest increase in the risk for childhood NHL, but not HL, among children born by mothers smoking during pregnancy. Further investigation of dose-response phenomena in the NHL association, however, warrants accumulation of additional data.

Adipocytokines in relation to Hodgkin lymphoma in children

This case-control study aims to explore the association of serum adiponectin/leptin with childhood Hodgkin lymphoma (HL). Study participants were 75 children with histologically confirmed HL, registered in the Nationwide Registry for Childhood Haematological Malignancies and 75 age- and gender-matched controls. Multiple conditional logistic regression analyses were performed, adjusting for sociodemographic and lifestyle parameters. Adiponectin levels were consistently higher among cases in all models with ORs >1.25; 95% CIs ranging from 0.9 to 1.8 and P-values from 0.09 to 0.20. By contrast, there was no association of serum leptin with HL. In conclusion, elevated serum adiponectin might be a risk factor for childhood HL.

Physical activity and hematologic cancer prevention

This chapter presents the epidemiologic evidence on the association between physical activity and hematologic cancers and related hypothesized biologic mechanisms. Some preliminary indications of a protective role for physical activity for non-Hodgkin's lymphoma, leukemia, multiple myeloma, and Hodgkin's lymphoma exist, but the level of epidemiologic evidence is still insufficient to make any definitive conclusions regarding the nature of these associations. Several plausible biologic mechanisms underlying the possible associations between physical activity and hematologic cancers have been proposed, including enhancement of immune function, reduction in obesity, improvement of antioxidant defense systems, impact on metabolic hormones, and anti-inflammatory effects. Future studies should improve the estimation of physical activity by using more reliable, valid, and comprehensive measurement tools, assessing all components of physical activity (type, intensity, and time period), and conducting intervention studies to evaluate the effect of physical activity on various biomarkers of cancer in order to provide further insight into plausible biologic mechanisms underlying the possible association between physical activity and hematologic cancers.

Leptin and Adiponectin: new players in the field of tumor cell and leukocyte migration

Adipose tissue is no longer considered to be solely an energy storage, but exerts important endocrine functions, which are primarily mediated by a network of various soluble factors derived from fat cells, called adipocytokines. In addition to their responsibility to influence energy homeostasis, new studies have identified important pathways linking metabolism with the immune system, and demonstrating a modulatory role of adipocytokines in immune function. Additionally, epidemiological studies underline that obesity represents a significant risk factor for the development of cancer, although the exact mechanism of this relationship remains to be determined. Whereas a possible influence of adipocytokines on the proliferation of tumor cells is already known, new evidence has come to light elucidating a modulatory role of this signaling substances in the regulation of migration of leukocytes and tumor cells. The migration of leukocytes is a key feature to fight cancer cells, whereas the locomotion of tumor cells is a prerequisite for tumor formation and metastasis. We herein review the latest tumor biological findings on the role of the most prominent adipocytokines leptin and adiponectin, which are secreted by fat cells, and which are involved in leukocyte migration, tumor growth, invasion and metastasis. This review thus accentuates the complex, interactive involvement of adipocytokines in the regulation of migration of both leukocytes and tumor cells, and gives an insight in the underlying molecular mechanisms.