Positive association of farm or rural residence with acute myeloid leukemia incidence in a cohort of older women

Clinico-Hematological Profile of Acute Leukemia Cases in Bihar: A Multiparameter Study in a Tertiary-Care Hospital

Objective The actual incidence and demographic profile of hematological malignancies are unknown in Bihar because of lack of population-based cancer registry (PBCR) data and specialized tertiary cancer center facilities. The objective of this study was to estimate the prevalence, clinico-hematological profile and subtyping of acute leukemia cases by retrospective medical records.

Materials and Methods A retrospective study was conducted in the Department of Hematology, Indira Gandhi Institute of Medical Sciences, Patna, Bihar, India, over 2 years from July 2019 to June 2021. A total of 176 cases with relevant clinical features and hematological findings were involved in the study. Medical records were studied and data were retrieved.

Statistical Analysis Data were recorded and analyzed using SPSS version 25.

Results A total of 176 cases with relevant clinical features and hematological findings were involved in the study. Acute myeloid leukemia (AML) was most prevalent (52.8%), followed by acute lymphoblastic leukemia (ALL) (34.1%) and unclassified acute leukemia cases (13.1%). Flow cytometry correlation was available in 150 cases. The ratio of males (62.5%) to females (37.5%) is 1.6:1. There was statistically significant difference in physical examination findings between AML and ALL patients. Splenomegaly, lymphadenopathy, and sternal tenderness were more often seen in ALL than in AML patients (p < 0.05). Pallor was more significantly associated with AML than with ALL patients (p < 0.05). Anemia and leucocytosis were found to be significantly associated with acute leukemia patients (p < 0.000).

Conclusion AML M2 was the most common subtype of AML, and B-ALL was the most common subtype of ALL cases.

Maternal ancestry and hematological cancer risk: case-control study in an Argentinean population

Aim: We investigated the role of maternal ancestry in neoplastic hematological malignancies (HMs) risk in a population from Central Argentina. Materials & methods: We analyzed 125 cases with HMs and 310 controls from a public hospital, and a set of 202 colorectal, breast, lung, and hematologic cancer patients from a private hospital. Results: A decreased risk for HMs was associated with the Native American haplogroup B2 (odds ratio = 0.49; 95% CI: 0.25-0.92; p = 0.02). The sub-Saharan African parahaplogroup L was associated with higher susceptibility for disease (odds ratio = 3.10; 95% CI: 1.04-9.31; p = 0.043). Although the mean ancestral proportions in the total studied population was as published (61.7% Native American, 34.6% European and 3.7% African), an unequal distribution was observed between hospitals. Conclusion: We confirmed the tri-hybrid nature of the Argentinean population, with proportions varying within the country. Our finding supports the notion that associated haplogroup is population and cancer specific.

Epidemiology of acute myeloid leukemia in Virginia: Excellent survival outcomes for patients in rural Appalachia

Background

Acute myeloid leukemia, the most common acute leukemia in adults, has a poor overall survival. Studies have suggested that certain socioeconomic factors such as living in a rural or farming area are associated with worse outcomes. Since 42% of acute myeloid leukemia patients seen in our academic center reside in a rural area, we have a unique opportunity to study outcomes of patients in rural versus urban settings.

Aim

This analysis evaluates the effect of geography and socioeconomic factors on the biology, treatment, and overall survival of patients with acute myeloid leukemia, with the goal of understanding health care disparities.

Methods and results

Patient characteristics, cytogenetic data, treatment history, and overall survival were collected and analyzed to identify differences between urban and rural residency. This cohort included 42% of patients who resided in a rural area at the time of acute myeloid leukemia diagnosis. There was no difference in overall survival between the cohorts. The 1 year overall survival for the entire cohort was 47.9%. There was no difference detected in rates of adverse cytogenetics between the rural and urban cohorts. Similar numbers of patients received induction chemotherapy or proceeded to allogeneic stem cell transplant between the cohorts.

Conclusions

This study highlights that similar outcomes can be achieved in rural and urban patients, suggesting that intensive efforts at telehealth, education, and collaboration with local oncology practices may be beneficial.

Prevalence of Leukemia and Associated Factors among Patients with Abnormal Hematological Parameters in Jimma Medical Center, Southwest Ethiopia: A Cross-Sectional Study

Introduction. Leukemia is a heterogeneous group of hematological disorder which comprise several diverse and biologically distinct subgroups. Leukemia represents the 11th and 10th most frequent cause of cancer morbidity and mortality worldwide, respectively. Adequate data regarding the prevalence of leukemia are lacking in Ethiopia, particularly in the study area. This study is aimed to determine the prevalence of leukemia and associated factors among patients who have abnormal hematological parameters in Jimma Medical Center. Methodology. A facility-based cross-sectional study was conducted involving 332 patients who have abnormal hematological parameters. Complete blood count from venous blood was made with Sysmex autohematology analyzer (Sysmex XS-500i and XT-1800; Kobe, Japan). Peripheral blood morphology and bone marrow aspirate examination were done for each patient. Descriptive statistics for the prevalence of leukemia and multinomial logistic regression analysis to assess associated factors were executed with IBM SPSS version 25. Results. The prevalence of leukemia was 9.3%, while acute myeloid leukemia, Acute Lymphoid Leukemia, Chronic Myeloid Leukemia, Chronic Lymphoid Leukemia, Myelodysplastic Syndrome, and undifferentiated leukemia comprises 3.6%, 2.7%, 1.8%, 0.6%, and 0.3%, respectively. Older Age ( $p=0.019$ ), being male ( $p=0.047$ ), being anemic ( $p=0.03$ ), and rural residency of a patient ( $p=0.044$ ) were significantly associated with having acute myeloid leukemia. Conclusion. The prevalence of leukemia among patients who have abnormal hematological parameters in Jimma Medical Center is significant which needs further comprehensive investigations of the associated factors and predictors with more up to date diagnostic methods.

Epidemiology of acute myeloid leukemia: Recent progress and enduring challenges

Acute myeloid leukemia (AML) is a malignant disorder of the bone marrow which is characterized by the clonal expansion and differentiation arrest of myeloid progenitor cells. The age-adjusted incidence of AML is 4.3 per 100,000 annually in the United States (US). Incidence increases with age with a median age at diagnosis of 68 years in the US. The etiology of AML is heterogeneous. In some patients, prior exposure to therapeutic, occupational or environmental DNA-damaging agents is implicated, but most cases of AML remain without a clear etiology. AML is the most common form of acute leukemia in adults and has the shortest survival (5-year survival = 24%). Curative therapies, including intensive chemotherapy and allogeneic stem cell transplantation, are generally applicable to a minority of patients who are younger and fit, while most older individuals exhibit poor prognosis and survival. Differences in patient outcomes are influenced by disease characteristics, access to care including active therapies and supportive care, and other factors. After many years without therapeutic advances, several new therapies have been approved and are expected to impact patient outcomes, especially for older patients and those with refractory disease.

George DM, Loffredo CA, Amr S. Nonoccupational exposure to agricultural work and risk of urinary bladder cancer among Egyptian women

This study examined the associations between nonoccupational exposure to agricultural work, through husband or head of household (H/HH) occupation, and urinary bladder cancer risk among Egyptian women. A total of 1,167 women (388 bladder cases and 779 age- and residence-matched, population-based controls) from a multicenter case-control study were included in the analysis. Adjusted odds ratios (AORs) and 95% confidence intervals (CIs) were estimated using logistic regression. Among married women, those who reported H/HH to be an agricultural worker were at increased risk for bladder cancer as compared to those with H/HH in other occupations, AOR = 1.54, 95% CI [1.09, 2.18]; among unmarried women the risk was not increased, AOR = 0.77, 95% CI [0.45, 1.32]. Nonoccupational exposure to agricultural work, defined as living with an agricultural worker, increased the risk for bladder cancer among married Egyptian women.

Leukemia-Related Mortality in Inner Mongolia, 2008-2012

In this study, we aimed to determine the leukemia-related mortality rates and associated sociodemographic characteristics in the Inner Mongolia region of China. We obtained data for the period 2008-2012 from the Death Registry System maintained by the Inner Mongolia Centers for Disease Control and Prevention. We computed the percentages of leukemia-related deaths and controls diagnosed by various methods and at different levels of hospitals. The χ(2) test was used to examine differences in leukemia-related mortality according to sex. We also calculated potential years of life lost (PYLL) and average years of life lost. Unconditional logistic regression models were used to analyze the effect of sociodemographic characteristics. The sex-adjusted leukemia-related mortality rate was 3.74/100 000. The mortality rate in men (4.27/100 000) was significantly higher than that in women (3.17/100 000), as was the respective PYLL (8040.5 vs. 6000.5 person-years). Mortality increased with increasing age in both men and women. The highest mortality rate was observed in those over 70 years of age for both men (18.36/100 000) and women (7.68/100 000). Men with a higher education level showed an increased risk of leukemia (odds ratio [OR] = 1.45, 95% confidence interval [CI] = 1.02-2.07, P = 0.04). In men, unemployment was associated with leukemia-related death (OR = 0.63, 95% CI = 0.42-0.95, P = 0.03). The leukemia-related mortality rate in Inner Mongolia was higher than that worldwide and that in China. A higher level of education and unemployment were associated with leukemia-related mortality in Inner Mongolia.

Farm residence and lymphohematopoietic cancers in the Iowa Women's Health Study

BACKGROUND

Cancer incidence in male farmers has been studied extensively; however, less is known about risk among women residing on farms or in agricultural areas, who may be exposed to pesticides by their proximity to crop fields. We extended a previous follow-up of the Iowa Women's Health Study cohort to examine farm residence and the incidence of lymphohematopoietic cancers. Further, we investigated crop acreage within 750 m of residences, which has been associated with higher herbicide levels in Iowa homes.

METHODS

We analyzed data for a cohort of 37,099 Iowa women aged 55-69 years who reported their residence location (farm, rural (not a farm), town size based on population) at enrollment in 1986. We identified incident lymphohematopoietic cancers (1986-2009) by linkage with the Iowa Cancer Registry. Using a geographic information system, we geocoded addresses and calculated acreage of pasture and row crops within 750 m of homes using the 1992 National Land Cover Database. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) in multivariate analyses of cancer risk in relation to both residence location and crop acreage.

RESULTS

As found in an earlier analysis of residence location, risk of acute myeloid leukemia (AML) was higher among women living on farms (HR=2.23, 95%CI: 1.25-3.99) or rural areas (but not on a farm) (HR=1.95, 95%CI: 0.89-4.29) compared with women living in towns of >10,000 population. We observed no association between farm or rural residence and non-Hodgkin lymphoma (NHL; overall or for major subtypes) or multiple myeloma. In analyses of crop acreage, we observed no association between pasture or row crop acreage within 750 m of homes and risk of leukemia overall or for the AML subtype. Chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) risk was nonsignificantly elevated among women with pasture acreage within 750 m of their home (HRs for increasing tertiles=1.8, 1.8 and 1.5) and with row crop acreage within 750 m (HRs for increasing tertiles of acreage=1.4, 1.5 and 1.6) compared to women with no pasture or row crop acreage, respectively.

CONCLUSIONS

Iowa women living on a farm or in a rural area were at increased risk of developing AML, which was not related to crop acreage near the home. Living near pasture or row crops may confer an increased risk of CLL/SLL regardless of residence location. Further investigation of specific farm-related exposures and these cancers among women living on farms and in agricultural areas is warranted.

Childhood cancer and traffic-related air pollution exposure in pregnancy and early life

BACKGROUND

The literature on traffic-related air pollution and childhood cancers is inconclusive, and little is known on rarer cancer types.

OBJECTIVES

We sought to examine associations between childhood cancers and traffic-related pollution exposure.

METHODS

The present study included children < 6 years of age identified in the California Cancer Registry (born 1998-2007) who could be linked to a California birth certificate (n = 3,590). Controls were selected at random from California birthrolls (n = 80,224). CAlifornia LINE Source Dispersion Modeling, version 4 (CALINE4) was used to generate estimates of local traffic exposures for each trimester of pregnancy and in the first year of life at the address indicated on the birth certificate. We checked our findings by additionally examining associations with particulate matter (≤ 2.5 μm in aerodynamic diameter; PM2.5) pollution measured by community-based air pollution monitors, and with a simple measure of traffic density.

RESULTS

With unconditional logistic regression, a per interquartile range increase in exposure to traffic-related pollution during the first trimester (0.0538 ppm carbon monoxide, estimated using CALINE4) was associated with acute lymphoblastic leukemia [ALL; first trimester odds ratio (OR) = 1.05; 95% CI: 1.01, 1.10]; germ cell tumors (OR = 1.16; 95% CI: 1.04, 1.29), particularly teratomas (OR = 1.26; 95% CI: 1.12, 1.41); and retinoblastoma (OR = 1.11; 95% CI: 1.01, 1.21), particularly bilateral retinoblastoma (OR = 1.16; 95% CI: 1.02, 1.33). Retinoblastoma was also associated with average PM2.5 concentrations during pregnancy, and ALL and teratomas were associated with traffic density near the child's residence at birth.

CONCLUSIONS

We estimated weak associations between early exposure to traffic pollution and several childhood cancers. Because this is the first study to report on traffic pollution in relation to retinoblastoma or germ cell tumors, and both cancers are rare, these findings require replication in other studies.

A systematic review of myeloid leukemias and occupational pesticide exposure

OBJECTIVE

To conduct a systematic review and meta-analyses of published studies examining the association between myeloid leukemias (ML) and occupational pesticide exposure.

METHODS

Studies were identified from a MEDLINE search through 31 May 2006 and from the reference lists of identified publications. Studies were summarized and evaluated for publication bias. Relative risk estimates for ML were extracted from 17 cohort and 16 case-control studies published between 1979 and 2005. Fixed- or random-effect meta-analysis models were used depending on the presence of heterogeneity between studies. Separate analyses were conducted after stratification for study design, occupational group, ML subtype or gender.

RESULTS

The overall meta-rate ratio estimate (meta-RR) for the cohort studies was 1.21 (95% confidence interval [CI] 0.99-1.48). Substantial heterogeneity existed among cohort studies (p=1.064 x 10(-5)), mainly reflecting the varying occupational categories examined. The meta-RR was 6.32 (95% CI: 1.90-21.01) for manufacturing workers and 2.14 (95% CI: 1.39-3.31) for pesticide applicators. After stratification of cohort studies by specific ML subtype, an increased risk of acute myeloid leukemia (AML) was found (meta-RR: 1.55; 95% CI: 1.02-2.34). No significant heterogeneity was detected among case-control studies and an increased risk of chronic myeloid leukemia (CML) was found among men (meta-RR: 1.39; 95% CI: 1.03-1.88) and farmers or agricultural workers (meta-RR: 1.38; 95% CI: 1.06-1.79).

CONCLUSION

The strongest evidence of an increased risk of ML comes from manufacturing workers and pesticide applicators. Further studies will be needed to correlate reliable exposure data within these specific occupational groups with well-defined subtypes of leukemia to refine this assessment.