Hepatitis B relapse after entecavir or tenofovir alafenamide cessation under anti-viral prophylaxis for cancer chemotherapy

BACKGROUND

No study has comparing hepatitis B virus (HBV) relapse rates among patients with both cancer and hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) who completed anti-viral prophylaxis for chemotherapy and then stopped taking entecavir or tenofovir alafenamide (TAF).

METHODS

A total of 227 HBeAg-negative cancer patients without cirrhosis who previously took entecavir (n = 144) or TAF (n = 83) for antiviral prophylaxis were enrolled.

RESULTS

The cumulative incidence of virological and clinical relapse at 2 years was 37% and 10.4%, respectively, in the entecavir group, and 46.7% and 19.5%, respectively, in the TAF group. The multivariate analysis revealed that the use of hematologic malignancy, TAF use, and high-viremia group at baseline were independent risk factors for virological relapse, and use of rituximab, TAF use, higher FIB-4 index and high-viremia group at baseline were independent risk factors for clinical relapse. After propensity score-matching, the patients who discontinued TAF therapy still exhibited higher virological (P = 0.031) and clinical relapse rates (P = 0.012) than did those who discontinued entecavir therapy. The patients were allocated to high- (> 2000 IU/mL), moderate- (between 20 and 2000 IU/mL) and low- (< 20 IU/mL) viremia groups. In the high-viremia group, those who had taken TAF for antiviral prophylaxis had higher rates of virological and clinical relapse than did those who had taken entecavir; in the moderate- and low-viremia groups, no significant difference in virological and clinical relapse rates was detected between the entecavir and TAF groups. Three patients experienced hepatic decompensation upon clinical relapse. All three patients were lymphoma and underwent rituximab therapy. One patient developed acute on chronic liver failure and died even though timely retreatment.

CONCLUSIONS

In patients with both cancer and CHB who underwent antiviral prophylaxis, TAF use was associated with a higher chance of HBV relapse than entecavir use after nucleos(t)ide analogue cessation, particularly in the high-viremia group. Patients who are hematologic malignancy and undergo a rituximab-containing cytotoxic therapy should be monitored closely after withdrawal from prophylactic NA treatment.

Bone morphogenetic protein and cancer in spinal fusion: a propensity score-matched analysis

OBJECTIVE

Bone morphogenetic protein (BMP) has been increasingly used in spinal surgery to promote arthrodesis. Because BMP stimulates cellular proliferation, its association with tumorigenesis is a concern. Previous research has generated conflicting conclusions on the risk of cancer in patients receiving BMP. The authors aimed to compare the incidence of solid organ and hematopoietic malignancies in patients undergoing spinal arthrodesis with or without BMP.

METHODS

The PearlDiver Mariner Patient Claims Database was queried for patients undergoing thoracolumbar fusion between 2015 and 2021. Patients with preexisting malignancy were excluded. Data were analyzed for incidence of solid organ malignancy and hematopoietic malignancy diagnosed after spinal surgery. Propensity score matching using age, sex, tobacco usage, and year of surgery was performed between patients who did and those who did not receive BMP.

RESULTS

Among patients without prior solid organ malignancy, BMP was used in 22,139 patients and not used in 306,249. In the propensity score-matched group, 3.1% of the BMP group developed solid organ malignancy following surgery compared with 3.5% in the non-BMP group. The relative risk (RR) of developing solid organ malignancy after BMP exposure was 0.89 (95% CI 0.81-0.98, p = 0.02). Among patients without prior hematopoietic malignancy, BMP was used in 23,505 patients and not used in 328,796 patients. In the propensity score-matched group, 0.4% of the BMP group developed hematopoietic malignancy compared with 0.6% of the non-BMP group. The RR of developing hematopoietic malignancy after BMP exposure was 0.71 (95% CI 0.55-0.93, p = 0.015).

CONCLUSIONS

BMP use in thoracolumbar fusion was not associated with an increased risk of new malignancy, which further supports emerging data on the lack of an association between BMP use and increased malignancy.

Common Cancer Types and Risk of Stroke and Bleeding in Patients With Nonvalvular Atrial Fibrillation: A Population-Based Study in England

BACKGROUND

The association between cancer and stroke or bleeding outcomes in atrial fibrillation is unclear. We sought to examine how certain types of cancer influence the balance between stroke and bleeding risk in patients with nonvalvular atrial fibrillation (NVAF).

METHODS AND RESULTS

We estimated stroke and bleeding risk among adult patients with NVAF and certain types of cancer (breast, prostate, colorectal, lung, and hematological cancer) from 2009 to 2019 based on data from the UK Clinical Practice Research Datalink GOLD and Aurum databases. The control group included patients with NVAF only. Of 177 065 patients with NVAF, 11379 (6.4%) had cancer (1691 breast, 3955 prostate, 1666 colorectal, 2491 hematological, and 1576 lung). Compared with patients without cancer, stroke risk was higher in patients with breast cancer (adjusted hazard ratio [aHR], 1.20 [95% CI, 1.07-1.35) and with prostate cancer (aHR, 1.11 [95% CI, 1.01-1.12) if diagnosed within 6 months before NVAF. The risk of bleeding was increased in subjects with hematological cancer (aHR, 1.55 [95% CI, 1.40-1.71]), lung cancer (aHR, 1.49 [95% CI, 1.25, 1.77]), prostate cancer (aHR, 1.38 [95% CI, 1.28-1.49]), and colorectal cancer (aHR, 1.36 [95% CI, 1.21-1.53]), but not for subjects with breast cancer. The more recent the cancer diagnosis before NVAF diagnosis (within 6 months), the higher the risk of bleeding.

CONCLUSIONS

Breast and prostate cancer are associated with increased stroke risk, whereas in some cancer types, the risk of bleeding seemed to exceed stroke risk. In these patients, prescribing of oral anticoagulant should be carefully evaluated to balance bleeding and stroke risk.

Survey on the Knowledge and Management of Cancer-Associated Thrombosis (CAT) in Haemato-Oncology Patients with Thrombocytopenia among Haematologists and Haematology Residents in Nigeria

BACKGROUND

Arterial or venous thrombosis can complicate cancer, and 20% of cancer patients may develop venous thromboembolic disorders. Venous thromboembolism (VTE) is common in some haematologic malignancies and may coexist with thrombocytopenia in those haematologic malignancies. We carried out this survey to assess the knowledge and practice of haematologists and resident doctors in haematology in Nigeria regarding the management of thrombocytopenia and cancer-associated thrombosis.

METHODS

This was a survey that was shared electronically with participants who were consultant haematologists and resident doctors in haematology in Nigeria..

RESULTS

There were 106 respondents, 70 (66%) of which were consultant haematologists. About a third (30.2%) of the respondents saw 6-10 patients with blood malignancies monthly. Fifty-seven (53.8%) of the respondents carried out risk assessment in their patients for cancer-associated thrombosis (CAT); 63 (59.4%) of the respondents saw 1-2 cancer patients with thrombosis in 3 months. The most common mode of treatment was pharmacological - 94 (88%) respondents used low molecular weight heparin. The most common haematologic malignancies associated with thrombocytopenia were acute leukaemias (69; 67%). The most common decision taken by respondents was to stop anticoagulants and transfuse platelets because the most frequent concern was the risk of bleeding in this group of patients.

CONCLUSION

Many haematologists and haematology residents had a high level of awareness, knowledge and good practice regarding thrombocytopenia with CAT in haematooncology patients; however, there is a need for improved knowledge and unified protocols for treatment in line with newer management guidelines.

Mobile Source Benzene Regulations and Risk of Childhood and Young Adult Hematologic Cancers in Alaska: A Quasi-experimental Study

BACKGROUND

We aimed to evaluate the impact of the EPA's Mobile Source Air Toxics rules (MSAT), which targeted benzene emissions, on childhood and young adult leukemia and lymphoma incidence in Alaska.

METHODS

MSAT was implemented in 2011 and produced a dramatic decline in ambient benzene in Alaska. Due to previous benzene-related regulations enacted in the continental United States, MSAT had relatively modest impacts in other states. This created quasi-experimental conditions leveraged in this study. Using 2-year state-level incidence rates of childhood and young adult leukemia and lymphoma for each US state 2001-2018, we examined MSAT-attributable changes in incidence by applying a difference-in-differences approach.

RESULTS

We found evidence of a substantial reduction associated with MSAT in incidence of childhood and young adult lymphoma (-1.23 [-1.84, -0.62] cases per 100,000), but not in leukemia (-0.13 [-0.77, 0.51] cases per 100,000).

CONCLUSIONS

Our findings are consistent with the hypothesis that MSAT, which reduced benzene levels in Alaska, led to a decline in lymphoma incidence in children and young adults.

Acute myeloid leukaemia following direct acting antiviral drugs in HCV-infected patients: A 10 years' retrospective single-center study

BACKGROUND

After several cases of peculiar hematological malignancies following introduction of new oral anti-hepatitis C virus (HCV) treatments in our recent practice, we aimed to systematically identify all cases of hematological malignancies (HM) in patients with chronic HCV infection and to compare them according to the prescription of oral anti-HCV Direct Acting Antivirals (DAA) treatment or not.

MATERIAL/METHODS

In this single-center retrospective observational study, we included all patients with confirmed HM and chronic HCV infection managed between 2010 and 2019 in the Pitié-Salpêtrière hospital, Paris. Non-inclusion criteria were a benign hematological disorder, an HM preceding chronic HCV infection and HCV acute infection. We compared characteristics of patients who received DAA before HM diagnosis to those with no DAA before HM.

RESULTS

Over the 10 years, 61 cases of HM among HCV infected patients were identified (female 29%, median age of 58.0 years [IQR 17]). Twenty-one received DAA before the onset of HM (Group DAA+) and 40 did not (Group DAA-) including 22 having received DAA after HM. In the DAA+ group, oral NS5B, NS5A and NS3A inhibitors were used in 90, 76 and 29% respectively. HM developed in the two years following DAA initiation in 76%. Eight (38%) had Non-Hodgkin Lymphoma, 5 (24%) had an Acute Myeloid Leukaemia (AML) including two with a mixed phenotype, 2 each had Hodgkin Lymphoma, Multiple Myeloma or a myeloproliferative disorder and one each had a chronic Lymphocytic Leukaemia or AL Amyloidosis. In the Group DAA-, HM were NHL in 20(50%) patients, Myeloproliferative neoplasms in 7 (17%), Multiple Myeloma in 5, Hodgkin Lymphoma in 3, Myelodysplastic syndrome and AML in 2 (5%) each and Acute Lymphoblastic Leukaemia in one. No significant difference between the groups DAA + and - was found according to age, sex, HCV genotype, viral load, co-infection or type and exposition of previous HCV treatments. AML, liver transplantation and cirrhosis were significantly more frequent in the DAA+ group (p = 0.020, 0.045 and 0.032, respectively).

CONCLUSION

AML seemed more frequent after using DAA treatments, notably in severe HCV patients including cirrhotic and/or liver transplanted patients. A multicentric observational study is ongoing to confirm and explore the results.

Delayed Adverse Events after Procedural Sedation in Pediatric Patients with Hematologic Malignancies

Background and objectives: Procedural sedation for bone marrow examination (BME) and intrathecal chemotherapy (ITC) is necessary for pediatric patients with hematological malignancies. There has been no report on adverse events after discharge from the recovery room. This retrospective study evaluated the types and incidences of delayed adverse events among pediatric patients scheduled for BME or ITC under deep sedation in a single center for 3 years. Materials and Methods: The patients were divided into two groups: inpatients (group I) and outpatients (group O). All patients were managed during the procedures and the recovery period. In total, 10 adverse events were assessed; these occurred 2 h (T1, acute), 12 h (T2, early), and 24 h (T3, delayed) after the procedure. The duration of each adverse event was also recorded and was classified as 2 h (D1), 12 h (D2), or 24 h (D3). The data of 263 patients (147 inpatients and 116 outpatients) who met the inclusion criteria were analyzed. Results: The overall incidence of adverse events was statistically significant difference: 48.3% in group I and 33.6% in group O (p = 0.011). The rates of adverse events at T1 and T2 were significantly different between groups I and O (42.8% vs. 11.2% and 7.5% vs. 20.7%, respectively) (p < 0.001). The adverse events were mostly of D1 or D2 duration in both groups. Patients with a higher proportion of ketamine in a propofol−ketamine mixture had a significantly higher proportion of adverse events at T1 (34.6%), as compared with those with a mixture with a lower proportion of ketamine (21.1%) or propofol alone (17.9%) (p = 0.012). Conclusions: The most common adverse events were dizziness or headache; typically, they did not last longer than 12 h. The propofol-ketamine combination with a higher proportion of ketamine seems to produce more adverse events within 2 h after the procedure. Nevertheless, all sedative types appear safe to use without additional management.

Temozolomide duration and secondary hematological neoplasms: A literature review and implications for patients with neuroendocrine neoplasms

Evidence-based recommendations for the optimal duration and sequencing of temozolomide-based treatments in advanced neuroendocrine neoplasms are lacking. Here, we conducted a systematic review of the literature for a descriptive analysis of temozolomide-associated myelodysplasias and leukemias to guide treatment planning. A database search of PubMed and Embase was conducted to identify case reports and/or case series reporting secondary myelodysplasias or leukemias in the setting of temozolomide therapy. Key data items extracted from the studies were the temozolomide dose and duration, latency to hematological disorder, type of secondary malignancy and cytogenetics. Reported cases were summarized graphically. A total of 16 studies with 27 patient cases of therapy-related hematologic neoplasms were identified, all of which were case reports or case series. The median treatment duration and cumulative dose were 19 months and 18,000 mg/m² , respectively. Most patients (21/27) were diagnosed on, or after, 12 months, while only one patient was diagnosed before 6 months of treatment. Most of the patients were diagnosed, while still on treatment with temozolomide. Graphically, cases clustered around a cumulative dose of 10,000 to 30,000 mg/m² and a latency period of 10 to 40 months which translates to an approximate treatment duration of 12.5 to 37.5 months. Taken together, most reported treatment-related hematological neoplasms appear to develop on or beyond the 12-month mark, while patients are still on treatment with temozolomide. For patients with neuroendocrine neoplasms, where sequencing of multiple therapies is important, we suggest an approach to optimizing treatment duration by establishing disease response at 6 months before continuing further treatment and restricting treatment to or establishing closer vigilance beyond 12 months.

Ledipasvir-sofosbuvir in Adolescents With Chronic Hepatitis C and Hematological Malignancies Undergoing Chemotherapy

OBJECTIVES

In children with hematological malignancies, chronic hepatitis C virus (HCV) infection has been associated with more rapid liver disease progression and higher risk of malignancy relapse due to chemotherapy interruption. We evaluated the safety and efficacy of ledipasvir-sofosbuvir for 12weeks in these patients.

METHODS

In a phase 2, open-label study, at one site in Egypt, patients ages 12-<18years with chronic HCV genotype 1 or 4 infection undergoing maintenance chemotherapy for hematological malignancies received ledipasvir-sofosbuvir (90 mg/400 mg) once daily for 12weeks. The efficacy endpoint was sustained virologic response 12 weeks after treatment (SVR12). Safety was assessed by the incidence of adverse events and clinical and laboratory data, including HCV flares defined as alanine aminotransferase >3-fold increase from Day 1 and HCV RNA elevation >1 × log10 from Day 1.

RESULTS

Of the 19 adolescents enrolled and treated, median age was 14 years (range 12-17), 84% (16/19) were male, and all had HCV genotype 4 and were HCV treatment naive. All patients completed treatment and achieved SVR12 (19/19, 100%, 95% confidence interval, 82-100). Common adverse events were pyrexia (5/19, 26%), diarrhea (4/19, 21%), and headache (4/19, 21%). Three patients experienced serious adverse events of pneumonia (two patients), and osteoarthritis and diarrhea (one patient); none were considered related to study drug. No patient experienced HCV flares.

CONCLUSIONS

Ledipasvir-sofosbuvir was well-tolerated and efficacious in adolescents with chronic HCV genotype 4 and leukemia undergoing maintenance chemotherapy. These data support the use of this interferon and ribavirin-free regimen in adolescents with hematological malignancies.

Passive environmental residential exposure to agricultural pesticides and hematological malignancies in the general population: a systematic review

Incidence rates of hematological malignancies have been constantly increasing over the past 40 years. In parallel, an expanding use of agricultural pesticides has been observed. Only a limited number of studies investigated the link between hematological malignancies risk and passive environmental residential exposure to agricultural pesticides in the general population. The purpose of our review was to summarize the current state of knowledge on that question. A systematic literature search was conducted using PubMed and Scopus databases. We built a scoring scale to appraise relevance of each selected articles. We included 23 publications: 13 ecological studies, 9 case-control studies and a cohort study. Positive associations were reported between hematological malignancies and individual pesticides, pesticide groups, all pesticides without distinction, or some crop types. Relevance score was highly various across studies regardless of their design. Children studies were the majority and had overall higher relevance scores. The effect of passive environmental residential exposure to agricultural pesticides on hematological malignancies risk is suggested by the literature. The main limitation of the literature available is the high heterogeneity across studies, especially in terms of exposure assessment approach. Further studies with high methodological relevance should be conducted.

Haematologic malignancies associated with clozapine v. all other antipsychotic agents: a pharmacovigilance study in VigiBase®

BACKGROUND

Clozapine is mainly used in patients with treatment-resistant schizophrenia and may lead to potentially severe haematologic adverse events, such as agranulocytosis. Whether clozapine might be associated with haematologic malignancies is unknown. We aimed to assess the association between haematologic malignancies and clozapine using Vigibase®, the WHO pharmacovigilance database.

METHODS

We performed a disproportionality analysis to compute reporting odds-ratio adjusted for age, sex and concurrent reporting of antineoplastic/immunomodulating agents (aROR) for clozapine and structurally related drugs (loxapine, olanzapine and quetiapine) compared with other antipsychotic drugs. Cases were malignant lymphoma and leukaemia reports. Non-cases were all other reports including at least one antipsychotic report.

RESULTS

Of the 140 226 clozapine-associated reports, 493 were malignant lymphoma cases, and 275 were leukaemia cases. Clozapine was significantly associated with malignant lymphoma (aROR 9.14, 95% CI 7.75-10.77) and leukaemia (aROR 3.54, 95% CI 2.97-4.22). Patients suffering from those haematologic malignancies were significantly younger in the clozapine treatment group than patients treated with other medicines (p < 0.001). The median time to onset (available for 212 cases) was 5.1 years (IQR 2.2-9.9) for malignant lymphoma and 2.5 years (IQR 0.6-7.4) for leukaemia. The aROR by quartile of dose of clozapine in patients with haematologic malignancies suggested a dose-dependent association.

CONCLUSIONS

Clozapine was significantly associated with a pharmacovigilance signal of haematologic malignancies. The risk-benefit balance of clozapine should be carefully assessed in patients with risk factors of haematologic malignancies. Clozapine should be used at the lowest effective posology.

Dietary Acrylamide Intake and the Risk of Hematological Malignancies: The Japan Public Health Center-Based Prospective Study

Acrylamide, which is present in many daily foods, is a probable human carcinogen. In 2002, it was identified in several common foods. Subsequently, western epidemiologists began to explore the relationship between dietary acrylamide exposure and cancer risk; however, limited suggestive associations were found. This prospective study aimed to examine the association between dietary acrylamide intake and the risk of hematological malignancies, including malignant lymphoma (ML), multiple myeloma (MM), and leukemia. We enrolled 85,303 participants in the Japan Public Health Center-based Prospective study on diet and cancer as from 1995. A food frequency questionnaire that included data on acrylamide in all Japanese foods was used to assess dietary acrylamide intake. We applied multivariable adjusted Cox proportional hazards models to reckon hazard ratios (HRs) for acrylamide intake for both categorical variables (tertiles) and continuous variables. After 16.0 median years of follow-up, 326 confirmed cases of ML, 126 cases of MM, and 224 cases of leukemia were available for final multivariable-adjusted analysis. HRs were 0.87 (95% confidence interval [CI]: 0.64–1.18) for ML, 0.64 (95% CI: 0.38–1.05) for MM, and 1.01 (95% CI: 0.71–1.45) for leukemia. Our results implied that acrylamide may not be related to the risk of hematological malignancies.

Bayesian modeling of hematologic cancer and vehicular air pollution among young people in the city of São Paulo, Brazil

Traffic-related air pollution is being associated with hematologic cancer in young individuals. This study performed a spatial analysis of the hematologic cancer incidence and mortality among younger people, using a Bayesian approach, to associate with traffic density in the city of São Paulo, Brazil. Two databases were employed: incidence (2002-2011) and mortality (2002-2013). The relationships between the cases of hematologic cancer and the covariates - traffic density, the Municipal Human Development Index (MHDI), and population density - were evaluated using a Besag-York-Mollié ecological model with relative risks (RRs) estimates. Per 1-unit standard-deviation increase in traffic density, in the MHDI, and in population density, the RR for the incidence was 1.06 (95% CI: 0.97-1.14), 1.28 (95% CI: 1.16-1.42), and 1.01 (95% CI: 0.94-1.08), respectively. For mortality, no covariates were considered risk factors. Our findings suggest significant association between living in regions with better socioeconomic conditions, where traffic density is usually higher, and risk of hematologic cancer in younger people.

Gamma heavy chain disease (γ-HCD) as iatrogenic immunodeficiency- associated lymphoproliferative disorder: Possible emergent subtype of rheumatoid arthritis-associated γ-HCD

Gamma heavy chain disease (γ-HCD) is a rare B-cell neoplasm that produces a truncated immunoglobulin γ-heavy chain lacking the light chain. The clinical features of γ-HCD are heterogeneous, resembling different types of B-cell lymphomas. Although rheumatoid arthritis (RA) is one of the common underlying diseases of γ-HCD, the therapeutic modality for RA has changed greatly in recent years; therefore, γ-HCD as iatrogenic immunodeficiency-associated lymphoproliferative disorder (LPD) should be taken into consideration. Here, we report such a γ-HCD case. A 69-year-old female was admitted because of fever, multiple lymph node swelling in the abdominal cavity, and peritoneal effusion. She had been treated using methotrexate for RA for 14 years, and using infliximab and adalimumab for Crohn’s disease for one year. The serum concentration of IgG was 3,525 mg/dL, which was revealed to be monoclonal IgG lacking the light chain by rocket immunoselection assay. CD19⁺/CD20^-/smκ⁻/smλ⁻ large abnormal lymphocytes were observed in the peritoneal fluid, which were demonstrated to be clonal B-cells by PCR examination. Discontinuation of methotrexate did not improve her condition and she died of pneumonia. Many abnormal lymphocytes positive for IgG and EBER but negative for the light chain were found on immunohistological examination of necropsy specimens from the spleen and bone marrow.

Formaldehyde Exposure and Acute Myeloid Leukemia: A Review of the Literature

Background and objective: The aim of the present study was to evaluate associations between cumulative and peak formaldehyde exposure and occurrence of acute myeloid leukemia. Material and Methods: A comprehensive search was performed using the PubMed and Embase databases. We included studies presenting information about the role of formaldehyde in leukemic occurrence and mortality risk. Then, full texts of the selected references were assessed, and references of included studies were checked to identify additional articles. Result: The information was then summarized and organized in the present review. A total of 81 articles were obtained from the search. Conclusion: Findings from the review of the literature do not support the hypothesis that formaldehyde is a cause of acute myeloid leukemia.

Pyrethroid pesticide exposure and hematological cancer: epidemiological, biological and molecular evidence

Pyrethroid insecticides are commonly used worldwide. The chronic effects of these compounds are of concern given that epidemiological studies have suggested an association with hematological cancer, particularly in children. However, the biological evidence at molecular and cellular levels is limited. A review on the molecular and cellular effects of pyrethroids is helpful to guide the study of the biological plausibility of the association of pyrethroids with hematological cancer. We reviewed studies suggesting that pyrethroids are genotoxic, induce genetic rearrangements, alter gene expression and modify DNA. All of these biological modifications could potentially contribute to the carcinogenic process in hematopoietic cells.

Formaldehyde Exposure and Mortality Risks From Acute Myeloid Leukemia and Other Lymphohematopoietic Malignancies in the US National Cancer Institute Cohort Study of Workers in Formaldehyde Industries

OBJECTIVES

To evaluate associations between cumulative and peak formaldehyde exposure and mortality from acute myeloid leukemia (AML) and other lymphohematopoietic malignancies.

METHODS

Cox proportional hazards analyses.

RESULTS

Acute myeloid leukemia was unrelated to cumulative exposure. Hodgkin lymphoma relative risk estimates in the highest exposure categories of cumulative and peak exposures were, respectively, 3.76 (Ptrend = 0.05) and 5.13 (Ptrend = 0.003). There were suggestive associations with peak exposure observed for chronic myeloid leukemia, albeit based on very small numbers. No other lymphohematopoietic malignancy was associated with either chronic or peak exposure.

CONCLUSIONS

Insofar as there is no prior epidemiologic evidence supporting associations between formaldehyde and either Hodgkin leukemia or chronic myeloid leukemia, any causal interpretations of the observed risk patterns are at most tentative. Findings from this re-analysis do not support the hypothesis that formaldehyde is a cause of AML.

Is exposure to formaldehyde in air causally associated with leukemia?--A hypothesis-based weight-of-evidence analysis

Recent scientific debate has focused on the potential for inhaled formaldehyde to cause lymphohematopoietic cancers, particularly leukemias, in humans. The concern stems from certain epidemiology studies reporting an association, although particulars of endpoints and dosimetry are inconsistent across studies and several other studies show no such effects. Animal studies generally report neither hematotoxicity nor leukemia associated with formaldehyde inhalation, and hematotoxicity studies in humans are inconsistent. Formaldehyde's reactivity has been thought to preclude systemic exposure following inhalation, and its apparent inability to reach and affect the target tissues attacked by known leukemogens has, heretofore, led to skepticism regarding its potential to cause human lymphohematopoietic cancers. Recently, however, potential modes of action for formaldehyde leukemogenesis have been hypothesized, and it has been suggested that formaldehyde be identified as a known human leukemogen. In this article, we apply our hypothesis-based weight-of-evidence (HBWoE) approach to evaluate the large body of evidence regarding formaldehyde and leukemogenesis, attending to how human, animal, and mode-of-action results inform one another. We trace the logic of inference within and across all studies, and articulate how one could account for the suite of available observations under the various proposed hypotheses. Upon comparison of alternative proposals regarding what causal processes may have led to the array of observations as we see them, we conclude that the case for a causal association is weak and strains biological plausibility. Instead, apparent association between formaldehyde inhalation and leukemia in some human studies is better interpreted as due to chance or confounding.

Advances in understanding benzene health effects and susceptibility

Benzene is a ubiquitous chemical in our environment that causes acute leukemia and probably other hematological cancers. Evidence for an association with childhood leukemia is growing. Exposure to benzene can lead to multiple alterations that contribute to the leukemogenic process, indicating a multimodal mechanism of action. Research is needed to elucidate the different roles of multiple metabolites in benzene toxicity and the pathways that lead to their formation. Studies to date have identified a number of polymorphisms in candidate genes that confer susceptibility to benzene hematotoxicity. However, a genome-wide study is needed to truly assess the role of genetic variation in susceptibility. Benzene affects the blood-forming system at low levels of occupational exposure, and there is no evidence of a threshold. There is probably no safe level of exposure to benzene, and all exposures constitute some risk in a linear, if not supralinear, and additive fashion.

Secondary hematological malignancies after breast cancer chemotherapy

According to several reports, the 10 year incidence of secondary acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS) after systemic chemotherapy is approximately 1.5%. The cumulative risk increases by 0.25--1% for the first 8 years after treatment. We have reported only 6 cases of hematological malignancies (0.3%) after breast cancer chemotherapy in our institute. We detected 2 cases of secondary AML and 1 case of MDS, 19, 52 and 12 months, respectively, after systemic chemotherapy for breast cancer. Published data on the occurrence of secondary hematological malignancies other than AML or MDS in this setting are scarce. We encountered diffuse large B-cell lymphoma, angioimmunoblastic lymphoma and mantle cell lymphoma as secondary hematological malignancies after systemic chemotherapy for breast cancer.

Pentachlorophenol and cancer risk: focusing the lens on specific chlorophenols and contaminants

OBJECTIVE

Pentachlorophenol, a fungicide widely used as a wood preservative, was classified in 1999 by the International Agency for Research on Cancer as a possible human carcinogen. We reviewed currently available data to determine the extent to which recent studies assist in distinguishing the effect of pentachlorophenol from that of its contaminants (e.g., dioxins and other chlorophenols).

DATA SOURCES AND EXTRACTION

We performed a systematic review of published studies pertaining to cancer risk in relation to pentachlorophenol exposure, focusing on results pertaining specifically to all cancer sites and specific hematopoietic cancers, and data pertaining to risks associated with other types of chlorophenols, dioxins, or furans.

SYNTHESIS

The pentachlorophenol studies presented considerable evidence pertaining to hematopoietic cancers, with strong associations seen in multiple studies, in different locations, and using different designs. There is little evidence of an association between these cancers and chlorophenols that contain fewer than four chlorines. The extension of a large cohort study of sawmill workers, with follow-up to 1995, provided information about risks of relatively rare cancers (e.g., non-Hodgkin lymphoma, multiple myeloma), using a validated exposure assessment procedure that distinguishes between exposures to pentachlorophenol and tetrachlorophenol. In contrast with dioxin, pentachlorophenol exposure has not been associated with total cancer incidence or mortality.

CONCLUSIONS

The updated cohort study focusing on pentachlorophenol provides increased statistical power and precision, and demonstrates associations between hematopoietic cancer and pentachlorophenol exposure not observed in earlier evaluations of this cohort. Contaminant confounding is an unlikely explanation for the risks seen with pentachlorophenol exposure.

Household exposure to pesticides and risk of childhood hematopoietic malignancies: The ESCALE study (SFCE)

OBJECTIVES

We investigated the role of household exposure to pesticides in the etiology of childhood hematopoietic malignancies.

METHODS

The national registry-based case-control study ESCALE (Etude sur les cancers de l'enfant) was carried out in France over the period 2003-2004. Population controls were frequency matched with the cases on age and sex. Maternal household use of pesticides during pregnancy and paternal use during pregnancy or childhood were reported by the mothers in a structured telephone questionnaire. Insecticides (used at home, on pets, or for garden crops), herbicides, and fungicides were distinguished. We estimated odds ratios (ORs) using unconditional regression models closely adjusting for age, sex, degree of urbanization, and type of housing (flat or house).

RESULTS

We included a total of 764 cases of acute leukemia (AL), 130 of Hodgkin lymphoma (HL), 166 of non-Hodgkin lymphoma (NHL), and 1,681 controls. Insecticide use during pregnancy was significantly associated with childhood AL [OR = 2.1; 95% confidence interval (CI), 1.7-2.5], both lymphoblastic and myeloblastic, NHL (OR = 1.8; 95% CI, 1.3-2.6), mainly for Burkitt lymphoma (OR = 2.7; 95% CI, 1.6-4.5), and mixed-cell HL (OR = 4.1; 95% CI, 1.4-11.8), but not nodular sclerosis HL (OR = 1.1; 95% CI, 0.6-1.9). Paternal household use of pesticides was also related to AL (OR = 1.5; 95% CI, 1.2-1.8) and NHL (OR = 1.7; 95% CI, 1.2-2.6); but for AL the relationships did not remain after adjustment for maternal pesticide use during pregnancy.

CONCLUSION

The study findings strengthen the hypothesis that domestic use of pesticides may play a role in the etiology of childhood hematopoietic malignancies. The consistency of the findings with those of previous studies on AL raises the question of the advisability of preventing pesticide use by pregnant women.

Formaldehyde and cancer risk: a quantitative review of cohort studies through 2006

BACKGROUND

Occupational exposure to formaldehyde has been associated with excess risk of nasopharyngeal and selected other cancers.

PATIENTS AND METHODS

We reviewed and pooled the results of cohort studies published through February 2007.

RESULTS

There were 5651 deaths from all cancers observed in six cohorts of industry workers and six of professionals, with a pooled relative risk (RR) of 0.95 for industry workers and of 0.87 for professionals. Nine deaths from nasopharyngeal cancer in three cohorts of industry workers yielded a pooled RR of 1.33, which declined to 0.49 after excluding six cases from one US plant. The pooled RR for lung cancer was 1.06 in industry workers and 0.63 in professionals. Corresponding values were 1.09 and 0.96 for oral and pharyngeal, 0.92 and 1.56 for brain, 0.85 and 1.31 for all lymphatic and hematopoietic cancers, and 0.90 and 1.39 for leukemia.

CONCLUSIONS

Comprehensive review of cancer in industry workers and professionals exposed to formaldehyde shows no appreciable excess risk for oral and pharyngeal, sinonasal or lung cancers. A non-significantly increased RR for nasopharyngeal cancer among industry workers is attributable to a cluster of deaths in a single plant. For brain cancer and lymphohematopoietic neoplasms there were modestly elevated risks in professionals, but not industry workers.

Occupational exposure to pesticides and risk of hematopoietic cancers: meta-analysis of case–control studies

OBJECTIVE

In this study we conducted a meta-analysis of 13 case-control studies that examined the occurrence of hematopoietic cancers in pesticide related occupations in order to undertake a qualitative and quantitative evaluation of a possible relationship.

METHODS

Pubmed databases were searched for case-control studies published between 1990 and 2005 investigating the relation between hematopoietic cancers and occupational exposure to pesticides. Fixed and random effect meta-analysis models were used depending on the presence of heterogeneity between studies.

RESULTS

The overall meta-odds ratio obtained after pooling 44 ORs from 13 studies was 1.3 (95% CI: 1.3-1.5). We realized stratified analysis on three different types of hematopoietic cancers (non-Hodgkin lymphoma (NHL), leukemia and multiple myeloma). A significant increased risk of NHL was found (OR = 1.35; 95% CI = 1.2-1.5). Moreover, increased risks of Leukemia (OR = 1.35; 95% CI = 0.9-2) and multiple myeloma (OR = 1.16; 95% CI = 0.99-1.36) were also detected but these results were not statistically significant. Significant heterogeneity existed among the different studies and a publication bias was detected. Therefore, a meta-regression was carried out. Our results showed that a long period of exposure (more than 10 years) provided an increase in the risk of all hematopoietic cancers and for NHL by fractions of 2.18 (95% CI = 1.43-3.35) and 1.65 (95% CI = 1.08-2.51), respectively.

CONCLUSIONS

The overall meta-odds ratio suggests that there is a significantly positive association between occupational exposure to pesticides and all hematopoietic cancers as well as NHL. A major limitation of our meta-analysis is the lack of sufficient data about exposure information and other risk factors for hematopoietic cancer (genetic predisposition, ethnic origin, immunodepression...). In addition, data concerning specific subtypes of hematopoietic cancers are often confusing. Thus, future epidemiological studies should undertake a major effort to assess the identity and the level of pesticides exposure and should control for the most likely potential confounders.

Comparison of genotoxic potency of styrene 7,8-oxide with gamma radiation and human cancer risk estimation of styrene using the rad-equivalence approach

Styrene is suspected to cause lympho-hematopoietic malignancies through the formation of styrene 7,8-oxide. However, we are still unable to calculate the cancer risk for workers exposed to styrene using epidemiological data. The aims of this study were to determine the blood dose after styrene exposure and to compare the genotoxic potency of styrene 7,8-oxide and gamma radiation in order to calculate the cancer risk by means of the rad-equivalence approach. Leucocytes of 20 individuals were exposed to 0, 0.1, 0.2 or 0.3 mM styrene 7,8-oxide (1 h) or 1, 2 or 3 gray (=100, 200, 300 rad) gamma radiation. Genotoxicity was evaluated with the cytokinesis-block micronucleus assay. Comparison of the two slopes of the regression lines between micronuclei and dose revealed a genotoxic potency for styrene 7,8-oxide of 37 rad/mMh, corresponding with a median value derived from mutagenicity studies (1, 37, 208 rad/mMh). At exposure levels of 1 ppm styrene, a blood styrene 7,8-oxide concentration between 0.03 x 10(-)(6) and 0.42 x 10(-)(6) mM is to be expected using data of toxicokinetic models and human exposure studies. With the cancer risk per unit dose of gamma radiation as benchmark, we calculated a lifetime risk of acquiring a fatal lympho-hematopoietic cancer of 0.17 in 10(3) workers (between 0.037 x 10(-)(3) and 5.0 x 10(-)(3)) exposed to 20 ppm styrene during 40 years.

Consumption of Aspartame-Containing Beverages and Incidence of Hematopoietic and Brain Malignancies

BACKGROUND

In a few animal experiments, aspartame has been linked to hematopoietic and brain cancers. Most animal studies have found no increase in the risk of these or other cancers. Data on humans are sparse for either cancer. Concern lingers regarding this widely used artificial sweetener.

OBJECTIVE

We investigated prospectively whether aspartame consumption is associated with the risk of hematopoietic cancers or gliomas (malignant brain cancer).

METHODS

We examined 285,079 men and 188,905 women ages 50 to 71 years in the NIH-AARP Diet and Health Study cohort. Daily aspartame intake was derived from responses to a baseline self-administered food frequency questionnaire that queried consumption of four aspartame-containing beverages (soda, fruit drinks, sweetened iced tea, and aspartame added to hot coffee and tea) during the past year. Histologically confirmed incident cancers were identified from eight state cancer registries. Multivariable-adjusted relative risks (RR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards regression that adjusted for age, sex, ethnicity, body mass index, and history of diabetes.

RESULTS

During over 5 years of follow-up (1995-2000), 1,888 hematopoietic cancers and 315 malignant gliomas were ascertained. Higher levels of aspartame intake were not associated with the risk of overall hematopoietic cancer (RR for >/=600 mg/d, 0.98; 95% CI, 0.76-1.27), glioma (RR for >/=400 mg/d, 0.73; 95% CI, 0.46-1.15; P for inverse linear trend = 0.05), or their subtypes in men and women.

CONCLUSIONS

Our findings do not support the hypothesis that aspartame increases hematopoietic or brain cancer risk.

Cancer and Pesticides: An Overview and Some Results of the Italian Multicenter Case-Control Study on Hematolymphopoietic Malignancies

Exposure to pesticides is recognized as an important environmental risk factor associated with development of cancer. Epidemiological studies, although sometimes contradictory, have linked phenoxy acid herbicides with non-Hodgkin's lymphoma (NHL) and Soft Tissue Sarcoma (STS); organochlorine insecticides with STS, NHL, and leukemia; organophosphorous compounds with NHL and leukemia; and triazine herbicides with ovarian cancer. Exposure assessment is a crucial point in studying the association between cancer and pesticides. In order to investigate the association between hematolymphopoietic malignancies and occupational exposures, including pesticides, a population-based case-control study was carried out in Italy in 11 areas, 9 of which are agricultural or mixed areas. All newly diagnosed cases of hematolymphopoietic malignancies were collected in a 3-year period (1991-1993). The control group consisted of a random sample of the population residing in each area. The approach to infer exposures in agriculture was based on: the use of an agricultural questionnaire with 24 crop-specific questionnaires; expert agronomists who reviewed the collected information for each subject and translated it into pesticides histories. In total, 1925 cases and 1232 controls were interviewed in the nine agricultural areas. Increased risk was observed for some specific classes of pesticides. Furthermore, a nonstatistically significant increased risk of NHL was observed for subjects who were exposed to phenoxy herbicides not using protective equipment and a significant increased risk for exposure to 2, 4-dichlorophenoxy acetic acid (2,4-D).

Biomarkers of exposure, effect, and susceptibility in workers exposed to nitrotoluenes

Nitrotoluenes, such as 2-nitrotoluene, 2,4-dinitrotoluene (24DNT), and 26DNT, are carcinogenic in animal experiments. Humans are exposed to such chemicals in the workplace and in the environment. It is therefore important to develop methods to biomonitor people exposed to nitrotoluenes to prevent the potential harmful effects. For the present study, workers exposed to high levels of these chemicals were investigated. The external dose (air levels), the internal dose (urine metabolites), the biologically effective dose [hemoglobin (Hb) adducts and urine mutagenicity], and biological effects (chromosomal aberrations and health effects) were determined. Individual susceptibility was assessed by determining genetic polymorphisms of enzymes assumed to function in nitrotoluene metabolism, namely glutathione S-transferases (GSTM1, GSTT1, GSTP1), N-acetyltransferases (NAT1, NAT2), and sulfotransferases (SULT1A1, SULT1A2). The levels of urinary metabolites did not correlate with the air levels. The urinary mutagenicity levels determined in a subset of workers correlated with the levels of a benzylalcohol metabolite of DNT. The Hb-adducts correlated with the urine metabolites but not with the air levels. The frequency of chromosomal aberrations (gaps included) was increased (P < 0.05) in the exposed workers in comparison with a group of factory controls and correlated with the level of 24DNT Hb-adducts in young subjects (<31 years). The GSTM1-null genotype was significantly more prevalent in the controls than in the exposed group, which probably reflected an elevated susceptibility of the GSTM1-null genotype to adverse health effects of DNT exposure, such as nausea (odds ratio, 8.8; 95% confidence interval, 2.4-32.2). A statistically significant effect was seen for SULT1A2 genotype on a 24DNT Hb-adduct; GSTP1 genotype on a 2,4,6-trinitrotoluene Hb-adduct; and SULT1A1, SULT1A2, NAT1, GSTT1, and GSTP1 genotypes on chromosomal aberrations in the exposed workers.

Identification of candidate alkylator-induced cancer susceptibility genes by whole genome scanning in mice

Secondary malignancies are a serious adverse consequence of alkylator chemotherapy. The risk of developing an alkylator-associated malignancy is influenced by genetic background, although the relevant genetic factors are poorly understood. To screen for novel susceptibility factors, we established a mouse model of alkylator-induced malignancy. We exposed mice from 20 inbred strains to the prototypical alkylating agent, N-nitroso-N-ethylurea (ENU). ENU was a potent carcinogen in many of the strains tested, inducing 140 tumors in 240 ENU-treated mice (66% incidence of at least one tumor in evaluable mice), compared with a background incidence of 8% spontaneous tumors in 240 strain-, age-, and sex-matched control mice (relative risk, 8.4; P < 0.0001). A wide variety of tumor histologies were noted, including epithelial carcinomas, soft tissue sarcomas, and hematopoietic tumors. Cancer susceptibility was a heritable trait for the most common tumor types, lung adenocarcinoma (H(2) = 0.25), T cell lymphoma (H(2) = 0.19), and myeloid malignancies (H(2) = 0.10). Quantitative trait locus mapping identified regions on chromosomes 3, 6, 9, and 15 containing candidate genes associated with lung adenoma, lung carcinoma, and lymphoma susceptibility. This novel mouse model recapitulates many features of human alkylator-associated cancer and supports the hypothesis that susceptibility to this syndrome is influenced by inherited polymorphisms that could be used to make informed clinical treatment decisions.

Biomarkers of environmental contaminants in field population of green mussel (Perna viridis) from Karnataka-Kerala coast (South West coast of India)

The green mussel Perna viridis was sampled from relatively clean and contaminated sites along the Kartanata-Kerala coast (south west coast of India) to study the tissue concentration of trace metals and biological responses to stress (biomarkers) such as sister chromatid exchange (SCE), chromosomal aberration, micronucleus (MN) test, hemic neoplasia (HN), Chromotest (Ames test) and comet assay. In general, mean tissue concentrations of toxic trace metals collected from 25 sampling sites were found to be below the World Health Organisation (WHO) permissible concentration given for seafood. The digestive gland extract of mussels from all 25 sampling sites showed negative reaction for mutagenic activity (Ames test) in the absence of metabolic activation. Very low levels of chromosomal aberration, SCE, MN, HN and comet cells were observed in mussels collected from both the urban associated and relatively clean sites. This study seems to indicate that that the coastal waters of Karnataka and Kerala are minimally contaminated with genotoxic and carcinogenic chemicals.

Clinical experience with docetaxel for Chinese breast cancer patients: Hematological toxicity profiles

BACKGROUND

Asians are generally regarded to tolerate cytotoxic drugs less well than their Caucasian counterpart. A substantial proportion of patients receive suboptimal doses of chemotherapy for fear of severe toxicity. This retrospective study aims to evaluate the adverse events, especially hematological, of docetaxel in Chinese patients with breast cancer.

PATIENTS AND METHODS

Fifty-nine patients, age ranged from 33 to 70 (median=47) years, were assigned to receive 3 to 6 (median=4) cycles of Docetaxel 100 mg/m2 every 21 days as neoadjuvant (n=3), adjuvant (n=26), neoadjuvant plus adjuvant (n=3), or active therapy for metastatic or relapsed breast cancer (n=27).

RESULTS

A total of 56 (95%) patients completed the assigned whole regimen and only 3 (5%) patients discontinued due to either poor tolerance to the drug's side effects or worsening of disease leading to death. On average, the received dose intensity (RDI) was 0.86 for docetaxel 100 mg/m2 in this study. Among all the clinical adverse events, hematological toxicities were not excessively higher. Of the total 59 patients, major adverse events of all grades were leukopenia (22%), neutropenia (20%), fever (19%), and febrile neutropenia (14%). Only 12% and 14% of patients experienced grade 3 or 4 leukopenia and neutropenia, respectively.

CONCLUSION

In view of the increasing breast cancer incidence and the acceptable toxicity profile of docetaxel among Chinese patients, a dosage of 100 mg/m2 can be recommended for use among Asians.

Induction of aberrant crypt foci in DNA mismatch repair-deficient mice by the food-borne carcinogen 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP)

Disruption of the DNA mismatch repair (MMR) pathway results in elevated mutation rates, inappropriate survival of cells bearing DNA damage, and increased cancer risk. Relatively little is known about the impact of environmentally relevant carcinogens on cancer risk in individuals with MMR-deficiency. We evaluated the effect of MMR status (Mlh1(+/+) versus Mlh1(-/-)) on the carcinogenic potential of the cooked-meat mutagen, 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) in mice. PhIP exposure did not obviously increase lymphoma or small intestinal tumorigenesis in either Mlh1-deficient or -proficient mice. In contrast, the frequency of aberrant crypt foci (ACF), a preneoplastic biomarker for colon tumorigenesis, was increased by PhIP, and the increase due to PhIP was significantly greater in Mlh1(-/-) versus wild-type littermates. This apparent heightened susceptibility to induction of ACF parallels the previously reported hypermutability of Mlh1-deficient mice to PhIP and is consistent with the hypothesis that MMR-deficiency would increase the likelihood of PhIP-induced carcinogenic mutations. Further evaluation of the risk that consumption of heterocyclic amines may impart to MMR-deficient individuals therefore is warranted.

Occupational exposures and haematological malignancies: overview on human recent data

OBJECTIVE

Occupational causes of haematological malignancies are relatively uncommon, under-studied and under-identified. They are also often unrecognized by clinicians. This review summarizes the principal epidemiologic studies on this topic.

METHODS

We analyzed the recent relevant human data found in the Medline, the Pascal and the BDSP databases.

RESULTS

Benzene and ionizing radiation are the only agents conclusively demonstrated to be carcinogenic to the haematopoietic system. In particular, both exposures are strongly associated with acute myeloid leukaemia. Low doses of both may also be related to myeloid malignancies. Infectious agents and pesticides are also thought to induce lymphoproliferative cancers. Some studies show an association between haematological malignancies and low-frequency electromagnetic fields and organic solvents. All of these suspected occupational causes must be confirmed by further studies.

CONCLUSIONS

Better knowledge and understanding of occupational causes of haematological malignancies are necessary to improve their prevention and compensation.

Epidemiologic studies of chrome and cancer mortality: A series of meta-analyses

We used 49 epidemiologic studies based on 84 papers published since 1950 to develop an array of meta-analyses relating exposure to chrome-six compounds with 10 causes of death. Most exposures occurred in occupational settings. Studies were assessed for quality, and for control of smoking or economic status if they related to lung or stomach cancer. There was no excess mortality from all causes combined among chrome-exposed persons. A minimal excess of cancer (SMR=112), overall, was due primarily to an excess of lung cancer (SMR=141) but the SMR was 112 among the better-quality, smoking-controlled studies. The overall SMR for stomach cancer was 113 but it was 82 among the studies that were controlled for economic status. Findings were unremarkable for the six other cancers evaluated: prostate, kidney, and central nervous system cancer and leukemia, Hodgkin's disease and other lymphatohematopoietic cancer. This series of meta-analyses indicates that chrome-six is a weak cause of lung cancer and is not a cause of any of the other seven forms of cancer evaluated.

Vinyl chloride: a case study of data suppression and misrepresentation

When the U.S. Environmental Protection Agency (EPA) finalized its 2000 update of the toxicological effects of vinyl chloride (VC), it was concerned with two issues: the classification of VC as a carcinogen and the numerical estimate of its potency. In this commentary we describe how the U.S. EPA review of VC toxicology, which was drafted with substantial input from the chemical industry, weakened safeguards on both points. First, the assessment down-plays risks from all cancer sites other than the liver. Second, the estimate of cancer potency was reduced 10-fold from values previously used for environmental decision making, a finding that reduces the cost and extent of pollution reduction and cleanup measures. We suggest that this assessment reflects discredited scientific practices and recommend that the U.S. EPA reverse its trend toward ever-increasing collaborations with the regulated industries when generating scientific reviews and risk assessments.

Personal use of hair dyes and risk of cancer: a meta-analysis

CONTEXT

Use of hair dyes has been suggested recently as a risk factor for several types of cancer in epidemiologic studies. This alarming news and controversial declarations by scientific organizations and general media have made necessary a systematic evaluation of the epidemiologic evidence.

OBJECTIVE

To examine the association between personal use of hair dyes and relative risk of cancer.

DATA SOURCES

We retrieved studies published in any language by systematically searching the MEDLINE (1966-January 2005), EMBASE, LILACS, and ISI Proceedings computerized databases and by manually examining the references of the original articles, reviews, and monographs retrieved.

STUDY SELECTION

We included cohort and case-control studies reporting relative risk estimates and 95% confidence intervals (CIs) (or data to calculate them) of personal hair dye use and cancer. We excluded studies that dealt with occupational exposure. We carried out separate analyses for bladder, breast, and hematopoietic cancers and cancers of other sites. Seventy-nine studies were included of 210 articles identified in the search.

DATA EXTRACTION

Data were extracted independently by 2 investigators. We used a standardized questionnaire to record information on study design, sample size, type of controls, year of publication, adjustment factors, and relative risks of cancer among ever users of hair dyes. When possible, we extracted association measures on use of permanent dyes and extensive use (>200 lifetime episodes of dye use).

DATA SYNTHESIS

Study-specific relative risks were weighted by the inverse of their variance to obtain fixed- and random-effects pooled estimates. The pooled relative risk for ever users of hair dyes was 1.06 (95% CI, 0.95-1.18) for breast cancer (14 studies), 1.01 (95% CI, 0.89-1.14) for bladder cancer (10 studies), and 1.15 (95% CI, 1.05-1.27) for hematopoietic cancers (40 studies). Other cancers were examined by only 1 or 2 studies, of which the pooled or single relative risk was elevated for brain cancer, ovarian cancer, and cancer of the salivary glands. No effect was observed for use of permanent dyes or for extensive use.

CONCLUSIONS

We did not find strong evidence of a marked increase in the risk of cancer among personal hair dye users. Some aspects related to hematopoietic cancer and other cancers that have shown evidence of increased risk in 1 or 2 studies should be investigated further.

Haematopoietic malignancies in rheumatoid arthritis: lymphoma risk and characteristics after exposure to tumour necrosis factor antagonists

BACKGROUND

Patients with rheumatoid arthritis (RA) are at increased risk of malignant lymphomas, and maybe also of leukaemia and multiple myeloma. The effect of tumour necrosis factor (TNF) antagonists on lymphoma risk and characteristics is unclear.

OBJECTIVE

To assess expected rates and relative risks of haematopoietic malignancies, especially those associated with TNF antagonists, in large population based cohorts of patients with RA.

METHODS

A population based cohort study was performed of patients with RA (one prevalent cohort (n = 53,067), one incident cohort (n = 3703), and one TNF antagonist treated cohort 1999 through 2003 (n = 4160)), who were linked with the Swedish Cancer Register. Additionally, the lymphoma specimens for the 12 lymphomas occurring in patients with RA exposed to TNF antagonists in Sweden 1999 through 2004 were reviewed.

RESULTS

Study of almost 500 observed haematopoietic malignancies showed that prevalent and incident patients with RA were at increased risk of lymphoma (SIR = 1.9 and 2.0, respectively) and leukaemia (SIR = 2.1 and 2.2, respectively) but not of myeloma. Patients with RA treated with TNF antagonists had a tripled lymphoma risk (SIR = 2.9) compared with the general population. After adjustment for sex, age, and disease duration, the lymphoma risk after exposure to TNF antagonists was no higher than in the other RA cohorts. Lymphomas associated with TNF antagonists had characteristics similar to those of other RA lymphomas.

CONCLUSION

Overall, patients with RA are at equally increased risks for lymphomas and leukaemias. Patients with RA treated with TNF antagonists did not have higher lymphoma risks than other patients with RA. Prolonged observation is needed to determine the long term effects of TNF antagonists on lymphoma risk.

Tumour necrosis factor blockers do not increase overall tumour risk in patients with rheumatoid arthritis, but may be associated with an increased risk of lymphomas

OBJECTIVE

To determine whether TNF blockers increase tumour risk in patients with RA.

MATERIALS AND METHODS

The South Swedish Arthritis Treatment Group register (SSATG) comprises over 90% of anti-TNF treated patients with RA in the area. 757 patients treated with etanercept or infliximab included between 1 February 1999 and 31 December 2002 were identified. 800 patients with conventional antirheumatic treatment in a community based cohort served as a comparison cohort. Tumours and deaths were identified in the cancer registry and population census registers. Patients were followed up from initiation of anti-TNF treatment or 1 July 1997 for the comparison group, until death or 31 December 2002.

RESULTS

In the anti-TNF group, 16 tumours (5 lymphomas) were identified in 1603 person-years at risk, and in the comparison group 69 tumours (2 lymphomas) in 3948 person-years. Standardised incidence ratios (SIRs) for total tumour relative risk for the anti-TNF group and the comparison group were 1.1 (95% confidence interval (CI) 0.6 to 1.8) and 1.4 (95% CI 1.1 to 1.8), respectively. The lymphoma relative risk (RR) was 11.5 (95% CI 3.7 to 26.9) and 1.3 (95% CI 0.2 to 4.5), respectively The total tumour RR excluding lymphoma was 0.79 (95% CI 0.4 to 1.42) and 1.39 (95% CI 1.08 to 1.76), respectively. Proportional hazard analysis for lymphomas yielded RR 4.9 (95% CI 0.9 to 26.2) in anti-TNF treated versus untreated patients.

CONCLUSION

Community based patients with RA treated conventionally had an increased overall tumour risk compared with the background population. A possible additional increased risk for lymphoma associated with TNF blockers was based on few cases and needs confirmation.

Cancer mortality and incidence among a cohort of benzidine and dichlorobenzidine dye manufacturing workers

BACKGROUND

Benzidine is classified as a definite human carcinogen and dichlorobenzidine as a probable human carcinogen.

METHODS

A cohort study of 538 workers potentially exposed to benzidine and/or dichlorobenzidine from a single chemical manufacturing facility was conducted. Social Security records were used to identify all employees who worked at the facility from 1960 to 1977. Vital status was determined through 2001 and cancer incidence through 2002.

RESULTS

A total of 22 bladder cancer cases were identified. For three individuals, bladder cancer was the underlying cause of death. Increased standardized mortality ratios (SMRs) were found for all cancer 1.54 (95% CI 1.04-2.19), bladder cancer 8.34 (95% CI 1.72-24.78), and lymphohematopoietic cancer 2.84 (95% CI 1.04-6.18). The standardized incidence ratio (SIR) for bladder cancer was 6.85 (95% CI 4.30-10.4). Only one case of bladder cancer was identified among the workers who were exposed to dichlorobenzidine only. However, an increased risk for lymphohematopoietic cancer was found among these dichlorobenzidine only workers (SMR 6.62 (95% CI 1.37-19.36)).

CONCLUSIONS

This study confirms the high risk of bladder cancer among benzidine exposed workers even years after exposure has ceased, and raises suggestive evidence of increased risk to lymphohematopoietic cancer from exposure to benzidine or dichlorobenzidine.

What is the calcineurin inhibitor of choice for pediatric renal transplantation?

Cyclosporine microemulsion (CyA) and tacrolimus (Tac) are the principal immunosuppressants prescribed for adult and pediatric renal transplantation. In the majority of patients, these calcineurin inhibitors have been used in combination with other immunosuppressive drugs, such as azathioprine or mycophenolate mofetil (MMF). In this review we will address the question of what calcineurin inhibitor we should use in an individual pediatric renal transplant patient. Well-designed randomized studies in children showed no difference in short-term patient and graft survival with cyclosporine microemulsion and tacrolimus. However Tac is significantly more effective than CyA microemulsion in preventing acute rejection after renal transplantation in a pediatric population when used in conjunction with azathioprine and corticosteroids. This difference disappears when calcineurin inhibitors are used in combination with MMF as both Tac and CyA produce similar rejection rates and graft survival. However, Tac is associated with improved graft function at 1 and 2 yr post-transplant. Adverse events of hypomagnesaemia and diarrhea seem to be higher in Tac group whereas hypertrichosis, flu syndrome and gum hyperplasia occurs more frequently in the CyA group. The incidence of post-transplant diabetes mellitus was almost identical between Tac and CyA treated patients. The recommendation drawn from the available data is that both CyA and Tac can be used safely and effectively in children. However Tac may be preferable to CyA because of steroid sparing effect and less hirsutism. We recommend that cyclosporine should be chosen when patients experience Tac-related adverse events. Nevertheless, the best calcineurin inhibitor should be decided on individual patients according to variable risk factors, such as risk of rejection in sensitized patient or delayed graft function. The possibility of adverse events should also be considered.

Tumor Profile of Novel p53 Heterozygous Tg.AC (v-Ha-ras) Bitransgenic Mice Treated with Benzo(a)pyrene and Fed Dietary N-acetyl-L-cysteine (NAC)

We designed a novel short-term bitransgenic model to better characterize the effects of benzo(a)pyrene (BP) exposure on multi-organ carcinogenesis and to evaluate the effects of a well-recognized antioxidant, N-acetyl-L-cysteine (NAC), on neoplasia. We selected the p53 heterozygous Tg.AC (v-Ha-ras) mouse model for our studies because these mice possess a carcinogen-inducible ras oncogene and one functional p53 tumor suppressor allele. Both mutations occur frequently in human cancers. In a 2 x 2 experimental design, both female and male mice were fed basal diet alone or containing 3% NAC and administered by gavage corn oil vehicle alone or containing 20 mg BP/kg body weight given twice weekly for 10 weeks. Mice (n = 15 for each grouping and sex) were subsequently observed an additional 18 weeks followed by tissue collection for evaluation of multi-organ pathology. Benzo(a)pyrene increased neoplasia in the thymus, spleen, stomach, and hematopoietic system after 28 weeks. We observed modest NAC-associated decreases in BP-induced pathology of the liver, papilloma formation and hyperplasia in the forestomach, and the occurrence of malignant lymphoma. Benzo(a)pyrene exposure reduced survival to approximately 40% in male mice, suggesting toxicity; however, survival in control groups was approximately 60%. Survival decreased to approximately 30% for females in all groups. We noted a clear, but nonsignificant, 15% decline in body weights of male, but not female, mice fed NAC, although food intake did not differ. Collectively, the data suggested carcinogen and antioxidant-associated effects on neoplasia that appeared sex-dependent. Thus, this novel short-term bitransgenic model may potentially be useful for testing dietary modulation of carcinogenesis.